mirrors/linux-stable
1
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git synced 2024-10-30 08:02:30 +00:00
Code Issues Releases Wiki Activity
linux-stable/kernel/sched.c

9628 lines
229 KiB
C
Raw Normal View History

Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
/*
* kernel/sched.c
*
* Kernel scheduler and related syscalls
*
* Copyright (C) 1991-2002 Linus Torvalds
*
* 1996-12-23 Modified by Dave Grothe to fix bugs in semaphores and
* make semaphores SMP safe
* 1998-11-19 Implemented schedule_timeout() and related stuff
* by Andrea Arcangeli
* 2002-01-04 New ultra-scalable O(1) scheduler by Ingo Molnar:
* hybrid priority-list and round-robin design with
* an array-switch method of distributing timeslices
* and per-CPU runqueues. Cleanups and useful suggestions
* by Davide Libenzi, preemptible kernel bits by Robert Love.
* 2003-09-03 Interactivity tuning by Con Kolivas.
* 2004-04-02 Scheduler domains code by Nick Piggin
sched: add CFS credits add credits for recent major scheduler contributions: Con Kolivas, for pioneering the fair-scheduling approach Peter Williams, for smpnice Mike Galbraith, for interactivity tuning of CFS Srivatsa Vaddagiri, for group scheduling enhancements Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-09 16:52:01 +00:00
* 2007-04-15 Work begun on replacing all interactivity tuning with a
* fair scheduling design by Con Kolivas.
* 2007-05-05 Load balancing (smp-nice) and other improvements
* by Peter Williams
* 2007-05-06 Interactivity improvements to CFS by Mike Galbraith
* 2007-07-01 Group scheduling enhancements by Srivatsa Vaddagiri
sched: add credits for RT balancing improvements add credits for RT balancing improvements. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:19 +00:00
* 2007-11-29 RT balancing improvements by Steven Rostedt, Gregory Haskins,
* Thomas Gleixner, Mike Kravetz
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
*/
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/nmi.h>
#include <linux/init.h>
sched: clean up include files in sched.c clean up include files in sched.c, they were still old-style <asm/>. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-09 16:52:00 +00:00
#include <linux/uaccess.h>
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
#include <linux/highmem.h>
#include <asm/mmu_context.h>
#include <linux/interrupt.h>
[PATCH] move capable() to capability.h - Move capable() from sched.h to capability.h; - Use <linux/capability.h> where capable() is used (in include/, block/, ipc/, kernel/, a few drivers/, mm/, security/, & sound/; many more drivers/ to go) Signed-off-by: Randy Dunlap <rdunlap@xenotime.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-11 20:17:46 +00:00
#include <linux/capability.h>
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
#include <linux/completion.h>
#include <linux/kernel_stat.h>
[PATCH] lockdep: better lock debugging Generic lock debugging: - generalized lock debugging framework. For example, a bug in one lock subsystem turns off debugging in all lock subsystems. - got rid of the caller address passing (__IP__/__IP_DECL__/etc.) from the mutex/rtmutex debugging code: it caused way too much prototype hackery, and lockdep will give the same information anyway. - ability to do silent tests - check lock freeing in vfree too. - more finegrained debugging options, to allow distributions to turn off more expensive debugging features. There's no separate 'held mutexes' list anymore - but there's a 'held locks' stack within lockdep, which unifies deadlock detection across all lock classes. (this is independent of the lockdep validation stuff - lockdep first checks whether we are holding a lock already) Here are the current debugging options: CONFIG_DEBUG_MUTEXES=y CONFIG_DEBUG_LOCK_ALLOC=y which do: config DEBUG_MUTEXES bool "Mutex debugging, basic checks" config DEBUG_LOCK_ALLOC bool "Detect incorrect freeing of live mutexes" Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-03 07:24:33 +00:00
#include <linux/debug_locks.h>
perf: Do the big rename: Performance Counters -> Performance Events Bye-bye Performance Counters, welcome Performance Events! In the past few months the perfcounters subsystem has grown out its initial role of counting hardware events, and has become (and is becoming) a much broader generic event enumeration, reporting, logging, monitoring, analysis facility. Naming its core object 'perf_counter' and naming the subsystem 'perfcounters' has become more and more of a misnomer. With pending code like hw-breakpoints support the 'counter' name is less and less appropriate. All in one, we've decided to rename the subsystem to 'performance events' and to propagate this rename through all fields, variables and API names. (in an ABI compatible fashion) The word 'event' is also a bit shorter than 'counter' - which makes it slightly more convenient to write/handle as well. Thanks goes to Stephane Eranian who first observed this misnomer and suggested a rename. User-space tooling and ABI compatibility is not affected - this patch should be function-invariant. (Also, defconfigs were not touched to keep the size down.) This patch has been generated via the following script: FILES=$(find * -type f | grep -vE 'oprofile|[^K]config') sed -i \ -e 's/PERF_EVENT_/PERF_RECORD_/g' \ -e 's/PERF_COUNTER/PERF_EVENT/g' \ -e 's/perf_counter/perf_event/g' \ -e 's/nb_counters/nb_events/g' \ -e 's/swcounter/swevent/g' \ -e 's/tpcounter_event/tp_event/g' \ $FILES for N in $(find . -name perf_counter.[ch]); do M=$(echo $N | sed 's/perf_counter/perf_event/g') mv $N $M done FILES=$(find . -name perf_event.*) sed -i \ -e 's/COUNTER_MASK/REG_MASK/g' \ -e 's/COUNTER/EVENT/g' \ -e 's/\<event\>/event_id/g' \ -e 's/counter/event/g' \ -e 's/Counter/Event/g' \ $FILES ... to keep it as correct as possible. This script can also be used by anyone who has pending perfcounters patches - it converts a Linux kernel tree over to the new naming. We tried to time this change to the point in time where the amount of pending patches is the smallest: the end of the merge window. Namespace clashes were fixed up in a preparatory patch - and some stylistic fallout will be fixed up in a subsequent patch. ( NOTE: 'counters' are still the proper terminology when we deal with hardware registers - and these sed scripts are a bit over-eager in renaming them. I've undone some of that, but in case there's something left where 'counter' would be better than 'event' we can undo that on an individual basis instead of touching an otherwise nicely automated patch. ) Suggested-by: Stephane Eranian <eranian@google.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Paul Mackerras <paulus@samba.org> Reviewed-by: Arjan van de Ven <arjan@linux.intel.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: David Howells <dhowells@redhat.com> Cc: Kyle McMartin <kyle@mcmartin.ca> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: <linux-arch@vger.kernel.org> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-09-21 10:02:48 +00:00
#include <linux/perf_event.h>
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
#include <linux/security.h>
#include <linux/notifier.h>
#include <linux/profile.h>
[PATCH] Add include/linux/freezer.h and move definitions from sched.h Move process freezing functions from include/linux/sched.h to freezer.h, so that modifications to the freezer or the kernel configuration don't require recompiling just about everything. [akpm@osdl.org: fix ueagle driver] Signed-off-by: Nigel Cunningham <nigel@suspend2.net> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Cc: Pavel Machek <pavel@ucw.cz> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-07 04:34:23 +00:00
#include <linux/freezer.h>
[PATCH] scheduler cache-hot-autodetect ) From: Ingo Molnar <mingo@elte.hu> This is the latest version of the scheduler cache-hot-auto-tune patch. The first problem was that detection time scaled with O(N^2), which is unacceptable on larger SMP and NUMA systems. To solve this: - I've added a 'domain distance' function, which is used to cache measurement results. Each distance is only measured once. This means that e.g. on NUMA distances of 0, 1 and 2 might be measured, on HT distances 0 and 1, and on SMP distance 0 is measured. The code walks the domain tree to determine the distance, so it automatically follows whatever hierarchy an architecture sets up. This cuts down on the boot time significantly and removes the O(N^2) limit. The only assumption is that migration costs can be expressed as a function of domain distance - this covers the overwhelming majority of existing systems, and is a good guess even for more assymetric systems. [ People hacking systems that have assymetries that break this assumption (e.g. different CPU speeds) should experiment a bit with the cpu_distance() function. Adding a ->migration_distance factor to the domain structure would be one possible solution - but lets first see the problem systems, if they exist at all. Lets not overdesign. ] Another problem was that only a single cache-size was used for measuring the cost of migration, and most architectures didnt set that variable up. Furthermore, a single cache-size does not fit NUMA hierarchies with L3 caches and does not fit HT setups, where different CPUs will often have different 'effective cache sizes'. To solve this problem: - Instead of relying on a single cache-size provided by the platform and sticking to it, the code now auto-detects the 'effective migration cost' between two measured CPUs, via iterating through a wide range of cachesizes. The code searches for the maximum migration cost, which occurs when the working set of the test-workload falls just below the 'effective cache size'. I.e. real-life optimized search is done for the maximum migration cost, between two real CPUs. This, amongst other things, has the positive effect hat if e.g. two CPUs share a L2/L3 cache, a different (and accurate) migration cost will be found than between two CPUs on the same system that dont share any caches. (The reliable measurement of migration costs is tricky - see the source for details.) Furthermore i've added various boot-time options to override/tune migration behavior. Firstly, there's a blanket override for autodetection: migration_cost=1000,2000,3000 will override the depth 0/1/2 values with 1msec/2msec/3msec values. Secondly, there's a global factor that can be used to increase (or decrease) the autodetected values: migration_factor=120 will increase the autodetected values by 20%. This option is useful to tune things in a workload-dependent way - e.g. if a workload is cache-insensitive then CPU utilization can be maximized by specifying migration_factor=0. I've tested the autodetection code quite extensively on x86, on 3 P3/Xeon/2MB, and the autodetected values look pretty good: Dual Celeron (128K L2 cache): --------------------- migration cost matrix (max_cache_size: 131072, cpu: 467 MHz): --------------------- [00] [01] [00]: - 1.7(1) [01]: 1.7(1) - --------------------- cacheflush times [2]: 0.0 (0) 1.7 (1784008) --------------------- Here the slow memory subsystem dominates system performance, and even though caches are small, the migration cost is 1.7 msecs. Dual HT P4 (512K L2 cache): --------------------- migration cost matrix (max_cache_size: 524288, cpu: 2379 MHz): --------------------- [00] [01] [02] [03] [00]: - 0.4(1) 0.0(0) 0.4(1) [01]: 0.4(1) - 0.4(1) 0.0(0) [02]: 0.0(0) 0.4(1) - 0.4(1) [03]: 0.4(1) 0.0(0) 0.4(1) - --------------------- cacheflush times [2]: 0.0 (33900) 0.4 (448514) --------------------- Here it can be seen that there is no migration cost between two HT siblings (CPU#0/2 and CPU#1/3 are separate physical CPUs). A fast memory system makes inter-physical-CPU migration pretty cheap: 0.4 msecs. 8-way P3/Xeon [2MB L2 cache]: --------------------- migration cost matrix (max_cache_size: 2097152, cpu: 700 MHz): --------------------- [00] [01] [02] [03] [04] [05] [06] [07] [00]: - 19.2(1) 19.2(1) 19.2(1) 19.2(1) 19.2(1) 19.2(1) 19.2(1) [01]: 19.2(1) - 19.2(1) 19.2(1) 19.2(1) 19.2(1) 19.2(1) 19.2(1) [02]: 19.2(1) 19.2(1) - 19.2(1) 19.2(1) 19.2(1) 19.2(1) 19.2(1) [03]: 19.2(1) 19.2(1) 19.2(1) - 19.2(1) 19.2(1) 19.2(1) 19.2(1) [04]: 19.2(1) 19.2(1) 19.2(1) 19.2(1) - 19.2(1) 19.2(1) 19.2(1) [05]: 19.2(1) 19.2(1) 19.2(1) 19.2(1) 19.2(1) - 19.2(1) 19.2(1) [06]: 19.2(1) 19.2(1) 19.2(1) 19.2(1) 19.2(1) 19.2(1) - 19.2(1) [07]: 19.2(1) 19.2(1) 19.2(1) 19.2(1) 19.2(1) 19.2(1) 19.2(1) - --------------------- cacheflush times [2]: 0.0 (0) 19.2 (19281756) --------------------- This one has huge caches and a relatively slow memory subsystem - so the migration cost is 19 msecs. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Ashok Raj <ashok.raj@intel.com> Signed-off-by: Ken Chen <kenneth.w.chen@intel.com> Cc: <wilder@us.ibm.com> Signed-off-by: John Hawkes <hawkes@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-12 09:05:30 +00:00
#include <linux/vmalloc.h>
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
#include <linux/blkdev.h>
#include <linux/delay.h>
pid namespaces: changes to show virtual ids to user This is the largest patch in the set. Make all (I hope) the places where the pid is shown to or get from user operate on the virtual pids. The idea is: - all in-kernel data structures must store either struct pid itself or the pid's global nr, obtained with pid_nr() call; - when seeking the task from kernel code with the stored id one should use find_task_by_pid() call that works with global pids; - when showing pid's numerical value to the user the virtual one should be used, but however when one shows task's pid outside this task's namespace the global one is to be used; - when getting the pid from userspace one need to consider this as the virtual one and use appropriate task/pid-searching functions. [akpm@linux-foundation.org: build fix] [akpm@linux-foundation.org: nuther build fix] [akpm@linux-foundation.org: yet nuther build fix] [akpm@linux-foundation.org: remove unneeded casts] Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Signed-off-by: Alexey Dobriyan <adobriyan@openvz.org> Cc: Sukadev Bhattiprolu <sukadev@us.ibm.com> Cc: Oleg Nesterov <oleg@tv-sign.ru> Cc: Paul Menage <menage@google.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-19 06:40:14 +00:00
#include <linux/pid_namespace.h>
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
#include <linux/smp.h>
#include <linux/threads.h>
#include <linux/timer.h>
#include <linux/rcupdate.h>
#include <linux/cpu.h>
#include <linux/cpuset.h>
#include <linux/percpu.h>
proc: move /proc/schedstat boilerplate to kernel/sched_stats.h Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
2008-10-06 09:23:43 +00:00
#include <linux/proc_fs.h>
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
#include <linux/seq_file.h>
sched: replace migration_thread with cpu_stop Currently migration_thread is serving three purposes - migration pusher, context to execute active_load_balance() and forced context switcher for expedited RCU synchronize_sched. All three roles are hardcoded into migration_thread() and determining which job is scheduled is slightly messy. This patch kills migration_thread and replaces all three uses with cpu_stop. The three different roles of migration_thread() are splitted into three separate cpu_stop callbacks - migration_cpu_stop(), active_load_balance_cpu_stop() and synchronize_sched_expedited_cpu_stop() - and each use case now simply asks cpu_stop to execute the callback as necessary. synchronize_sched_expedited() was implemented with private preallocated resources and custom multi-cpu queueing and waiting logic, both of which are provided by cpu_stop. synchronize_sched_expedited_count is made atomic and all other shared resources along with the mutex are dropped. synchronize_sched_expedited() also implemented a check to detect cases where not all the callback got executed on their assigned cpus and fall back to synchronize_sched(). If called with cpu hotplug blocked, cpu_stop already guarantees that and the condition cannot happen; otherwise, stop_machine() would break. However, this patch preserves the paranoid check using a cpumask to record on which cpus the stopper ran so that it can serve as a bisection point if something actually goes wrong theree. Because the internal execution state is no longer visible, rcu_expedited_torture_stats() is removed. This patch also renames cpu_stop threads to from "stopper/%d" to "migration/%d". The names of these threads ultimately don't matter and there's no reason to make unnecessary userland visible changes. With this patch applied, stop_machine() and sched now share the same resources. stop_machine() is faster without wasting any resources and sched migration users are much cleaner. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Dipankar Sarma <dipankar@in.ibm.com> Cc: Josh Triplett <josh@freedesktop.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Dimitri Sivanich <sivanich@sgi.com>
2010-05-06 16:49:21 +00:00
#include <linux/stop_machine.h>
[PATCH] sched: debug feature - make the sched-domains tree runtime-tweakable debugging feature: make the sched-domains tree runtime-tweakable. Signed-off-by: Andrew Morton <akpm@linux-foundation.org> [ mingo@elte.hu: made it depend on CONFIG_SCHED_DEBUG & small updates ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-26 11:40:43 +00:00
#include <linux/sysctl.h>
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
#include <linux/syscalls.h>
#include <linux/times.h>
[PATCH] csa: convert CONFIG tag for extended accounting routines There were a few accounting data/macros that are used in CSA but are #ifdef'ed inside CONFIG_BSD_PROCESS_ACCT. This patch is to change those ifdef's from CONFIG_BSD_PROCESS_ACCT to CONFIG_TASK_XACCT. A few defines are moved from kernel/acct.c and include/linux/acct.h to kernel/tsacct.c and include/linux/tsacct_kern.h. Signed-off-by: Jay Lan <jlan@sgi.com> Cc: Shailabh Nagar <nagar@watson.ibm.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Jes Sorensen <jes@sgi.com> Cc: Chris Sturtivant <csturtiv@sgi.com> Cc: Tony Ernst <tee@sgi.com> Cc: Guillaume Thouvenin <guillaume.thouvenin@bull.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-01 06:28:59 +00:00
#include <linux/tsacct_kern.h>
[PATCH] kretprobe instance recycled by parent process When kretprobe probes the schedule() function, if the probed process exits then schedule() will never return, so some kretprobe instances will never be recycled. In this patch the parent process will recycle retprobe instances of the probed function and there will be no memory leak of kretprobe instances. Signed-off-by: bibo mao <bibo.mao@intel.com> Cc: Masami Hiramatsu <hiramatu@sdl.hitachi.co.jp> Cc: Prasanna S Panchamukhi <prasanna@in.ibm.com> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-26 09:38:20 +00:00
#include <linux/kprobes.h>
[PATCH] per-task-delay-accounting: sync block I/O and swapin delay collection Unlike earlier iterations of the delay accounting patches, now delays are only collected for the actual I/O waits rather than try and cover the delays seen in I/O submission paths. Account separately for block I/O delays incurred as a result of swapin page faults whose frequency can be affected by the task/process' rss limit. Hence swapin delays can act as feedback for rss limit changes independent of I/O priority changes. Signed-off-by: Shailabh Nagar <nagar@watson.ibm.com> Signed-off-by: Balbir Singh <balbir@in.ibm.com> Cc: Jes Sorensen <jes@sgi.com> Cc: Peter Chubb <peterc@gelato.unsw.edu.au> Cc: Erich Focht <efocht@ess.nec.de> Cc: Levent Serinol <lserinol@gmail.com> Cc: Jay Lan <jlan@engr.sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-14 07:24:37 +00:00
#include <linux/delayacct.h>
sched: clean up include files in sched.c clean up include files in sched.c, they were still old-style <asm/>. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-09 16:52:00 +00:00
#include <linux/unistd.h>
Fix warnings with !CONFIG_BLOCK Hide everything in blkdev.h with CONFIG_BLOCK isn't set, and fixup the (few) files that fail to build because they were relying on blkdev.h pulling in extra includes for them. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2007-09-21 07:19:54 +00:00
#include <linux/pagemap.h>
sched: high-res preemption tick Use HR-timers (when available) to deliver an accurate preemption tick. The regular scheduler tick that runs at 1/HZ can be too coarse when nice level are used. The fairness system will still keep the cpu utilisation 'fair' by then delaying the task that got an excessive amount of CPU time but try to minimize this by delivering preemption points spot-on. The average frequency of this extra interrupt is sched_latency / nr_latency. Which need not be higher than 1/HZ, its just that the distribution within the sched_latency period is important. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:29 +00:00
#include <linux/hrtimer.h>
sched: sched.c needs tick.h kernel/sched.c:506: erreur: implicit declaration of function tick_get_tick_sched kernel/sched.c:506: erreur: invalid type argument of -> kernel/sched.c:506: erreur: NOHZ_MODE_INACTIVE undeclared (first use in this function) kernel/sched.c:506: erreur: (Each undeclared identifier is reported only once kernel/sched.c:506: erreur: for each function it appears in.) Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-03-17 23:19:05 +00:00
#include <linux/tick.h>
sched: /debug/sched_features provide a text based interface to the scheduler features; this saves the 'user' from setting bits using decimal arithmetic. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 17:45:00 +00:00
#include <linux/debugfs.h>
#include <linux/ctype.h>
ftrace: trace preempt off critical timings Add preempt off timings. A lot of kernel core code is taken from the RT patch latency trace that was written by Ingo Molnar. This adds "preemptoff" and "preemptirqsoff" to /debugfs/tracing/available_tracers Now instead of just tracing irqs off, preemption off can be selected to be recorded. When this is selected, it shares the same files as irqs off timings. One can either trace preemption off, irqs off, or one or the other off. By echoing "preemptoff" into /debugfs/tracing/current_tracer, recording of preempt off only is performed. "irqsoff" will only record the time irqs are disabled, but "preemptirqsoff" will take the total time irqs or preemption are disabled. Runtime switching of these options is now supported by simpling echoing in the appropriate trace name into /debugfs/tracing/current_tracer. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-12 19:20:42 +00:00
#include <linux/ftrace.h>
include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-24 08:04:11 +00:00
#include <linux/slab.h>
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
Speed up divides by cpu_power in scheduler I noticed expensive divides done in try_to_wakeup() and find_busiest_group() on a bi dual core Opteron machine (total of 4 cores), moderatly loaded (15.000 context switch per second) oprofile numbers : CPU: AMD64 processors, speed 2600.05 MHz (estimated) Counted CPU_CLK_UNHALTED events (Cycles outside of halt state) with a unit mask of 0x00 (No unit mask) count 50000 samples % symbol name ... 613914 1.0498 try_to_wake_up 834 0.0013 :ffffffff80227ae1: div %rcx 77513 0.1191 :ffffffff80227ae4: mov %rax,%r11 608893 1.0413 find_busiest_group 1841 0.0031 :ffffffff802260bf: div %rdi 140109 0.2394 :ffffffff802260c2: test %sil,%sil Some of these divides can use the reciprocal divides we introduced some time ago (currently used in slab AFAIK) We can assume a load will fit in a 32bits number, because with a SCHED_LOAD_SCALE=128 value, its still a theorical limit of 33554432 When/if we reach this limit one day, probably cpus will have a fast hardware divide and we can zap the reciprocal divide trick. Ingo suggested to rename cpu_power to __cpu_power to make clear it should not be modified without changing its reciprocal value too. I did not convert the divide in cpu_avg_load_per_task(), because tracking nr_running changes may be not worth it ? We could use a static table of 32 reciprocal values but it would add a conditional branch and table lookup. [akpm@linux-foundation.org: !SMP build fix] Signed-off-by: Eric Dumazet <dada1@cosmosbay.com> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-08 07:32:57 +00:00
#include <asm/tlb.h>
sched: use show_regs() to improve __schedule_bug() output A full register dump along with stack backtrace would make the "scheduling while atomic" message more helpful. Use show_regs() instead of dump_stack() for this. We already know we're atomic in here (that is why this function was called) so show_regs()'s atomicity expectations are guaranteed. Also, modify the output of the "BUG: scheduling while atomic:" header a bit to keep task->comm and task->pid together and preempt_count() after them. Signed-off-by: Satyam Sharma <satyam@infradead.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-24 16:23:50 +00:00
#include <asm/irq_regs.h>
mutexes, sched: Introduce arch_mutex_cpu_relax() The spinning mutex implementation uses cpu_relax() in busy loops as a compiler barrier. Depending on the architecture, cpu_relax() may do more than needed in this specific mutex spin loops. On System z we also give up the time slice of the virtual cpu in cpu_relax(), which prevents effective spinning on the mutex. This patch replaces cpu_relax() in the spinning mutex code with arch_mutex_cpu_relax(), which can be defined by each architecture that selects HAVE_ARCH_MUTEX_CPU_RELAX. The default is still cpu_relax(), so this patch should not affect other architectures than System z for now. Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1290437256.7455.4.camel@thinkpad> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-22 14:47:36 +00:00
#include <asm/mutex.h>
KVM guest: Steal time accounting This patch accounts steal time time in account_process_tick. If one or more tick is considered stolen in the current accounting cycle, user/system accounting is skipped. Idle is fine, since the hypervisor does not report steal time if the guest is halted. Accounting steal time from the core scheduler give us the advantage of direct acess to the runqueue data. In a later opportunity, it can be used to tweak cpu power and make the scheduler aware of the time it lost. [avi: <asm/paravirt.h> doesn't exist on many archs] Signed-off-by: Glauber Costa <glommer@redhat.com> Acked-by: Rik van Riel <riel@redhat.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Tested-by: Eric B Munson <emunson@mgebm.net> CC: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> CC: Anthony Liguori <aliguori@us.ibm.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-07-11 19:28:17 +00:00
#ifdef CONFIG_PARAVIRT
#include <asm/paravirt.h>
#endif
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
sched: use a 2-d bitmap for searching lowest-pri CPU The current code use a linear algorithm which causes scaling issues on larger SMP machines. This patch replaces that algorithm with a 2-dimensional bitmap to reduce latencies in the wake-up path. Signed-off-by: Gregory Haskins <ghaskins@novell.com> Acked-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-12 19:21:01 +00:00
#include "sched_cpupri.h"
sched: add hooks for workqueue Concurrency managed workqueue needs to know when workers are going to sleep and waking up. Using these two hooks, cmwq keeps track of the current concurrency level and throttles execution of new works if it's too high and wakes up another worker from the sleep hook if it becomes too low. This patch introduces PF_WQ_WORKER to identify workqueue workers and adds the following two hooks. * wq_worker_waking_up(): called when a worker is woken up. * wq_worker_sleeping(): called when a worker is going to sleep and may return a pointer to a local task which should be woken up. The returned task is woken up using try_to_wake_up_local() which is simplified ttwu which is called under rq lock and can only wake up local tasks. Both hooks are currently defined as noop in kernel/workqueue_sched.h. Later cmwq implementation will replace them with proper implementation. These hooks are hard coded as they'll always be enabled. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Ingo Molnar <mingo@elte.hu>
2010-06-08 19:40:37 +00:00
#include "workqueue_sched.h"
sched: Add 'autogroup' scheduling feature: automated per session task groups A recurring complaint from CFS users is that parallel kbuild has a negative impact on desktop interactivity. This patch implements an idea from Linus, to automatically create task groups. Currently, only per session autogroups are implemented, but the patch leaves the way open for enhancement. Implementation: each task's signal struct contains an inherited pointer to a refcounted autogroup struct containing a task group pointer, the default for all tasks pointing to the init_task_group. When a task calls setsid(), a new task group is created, the process is moved into the new task group, and a reference to the preveious task group is dropped. Child processes inherit this task group thereafter, and increase it's refcount. When the last thread of a process exits, the process's reference is dropped, such that when the last process referencing an autogroup exits, the autogroup is destroyed. At runqueue selection time, IFF a task has no cgroup assignment, its current autogroup is used. Autogroup bandwidth is controllable via setting it's nice level through the proc filesystem: cat /proc/<pid>/autogroup Displays the task's group and the group's nice level. echo <nice level> > /proc/<pid>/autogroup Sets the task group's shares to the weight of nice <level> task. Setting nice level is rate limited for !admin users due to the abuse risk of task group locking. The feature is enabled from boot by default if CONFIG_SCHED_AUTOGROUP=y is selected, but can be disabled via the boot option noautogroup, and can also be turned on/off on the fly via: echo [01] > /proc/sys/kernel/sched_autogroup_enabled ... which will automatically move tasks to/from the root task group. Signed-off-by: Mike Galbraith <efault@gmx.de> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Markus Trippelsdorf <markus@trippelsdorf.de> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Paul Turner <pjt@google.com> Cc: Oleg Nesterov <oleg@redhat.com> [ Removed the task_group_path() debug code, and fixed !EVENTFD build failure. ] Signed-off-by: Ingo Molnar <mingo@elte.hu> LKML-Reference: <1290281700.28711.9.camel@maggy.simson.net> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-30 13:18:03 +00:00
#include "sched_autogroup.h"
sched: use a 2-d bitmap for searching lowest-pri CPU The current code use a linear algorithm which causes scaling issues on larger SMP machines. This patch replaces that algorithm with a 2-dimensional bitmap to reduce latencies in the wake-up path. Signed-off-by: Gregory Haskins <ghaskins@novell.com> Acked-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-12 19:21:01 +00:00
tracing: create automated trace defines This patch lowers the number of places a developer must modify to add new tracepoints. The current method to add a new tracepoint into an existing system is to write the trace point macro in the trace header with one of the macros TRACE_EVENT, TRACE_FORMAT or DECLARE_TRACE, then they must add the same named item into the C file with the macro DEFINE_TRACE(name) and then add the trace point. This change cuts out the needing to add the DEFINE_TRACE(name). Every file that uses the tracepoint must still include the trace/<type>.h file, but the one C file must also add a define before the including of that file. #define CREATE_TRACE_POINTS #include <trace/mytrace.h> This will cause the trace/mytrace.h file to also produce the C code necessary to implement the trace point. Note, if more than one trace/<type>.h is used to create the C code it is best to list them all together. #define CREATE_TRACE_POINTS #include <trace/foo.h> #include <trace/bar.h> #include <trace/fido.h> Thanks to Mathieu Desnoyers and Christoph Hellwig for coming up with the cleaner solution of the define above the includes over my first design to have the C code include a "special" header. This patch converts sched, irq and lockdep and skb to use this new method. Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Neil Horman <nhorman@tuxdriver.com> Cc: Zhao Lei <zhaolei@cn.fujitsu.com> Cc: Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro> Cc: Pekka Enberg <penberg@cs.helsinki.fi> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-04-10 13:36:00 +00:00
#define CREATE_TRACE_POINTS
tracing/events: move trace point headers into include/trace/events Impact: clean up Create a sub directory in include/trace called events to keep the trace point headers in their own separate directory. Only headers that declare trace points should be defined in this directory. Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Neil Horman <nhorman@tuxdriver.com> Cc: Zhao Lei <zhaolei@cn.fujitsu.com> Cc: Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro> Cc: Pekka Enberg <penberg@cs.helsinki.fi> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-04-14 23:39:12 +00:00
#include <trace/events/sched.h>
tracing: create automated trace defines This patch lowers the number of places a developer must modify to add new tracepoints. The current method to add a new tracepoint into an existing system is to write the trace point macro in the trace header with one of the macros TRACE_EVENT, TRACE_FORMAT or DECLARE_TRACE, then they must add the same named item into the C file with the macro DEFINE_TRACE(name) and then add the trace point. This change cuts out the needing to add the DEFINE_TRACE(name). Every file that uses the tracepoint must still include the trace/<type>.h file, but the one C file must also add a define before the including of that file. #define CREATE_TRACE_POINTS #include <trace/mytrace.h> This will cause the trace/mytrace.h file to also produce the C code necessary to implement the trace point. Note, if more than one trace/<type>.h is used to create the C code it is best to list them all together. #define CREATE_TRACE_POINTS #include <trace/foo.h> #include <trace/bar.h> #include <trace/fido.h> Thanks to Mathieu Desnoyers and Christoph Hellwig for coming up with the cleaner solution of the define above the includes over my first design to have the C code include a "special" header. This patch converts sched, irq and lockdep and skb to use this new method. Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Neil Horman <nhorman@tuxdriver.com> Cc: Zhao Lei <zhaolei@cn.fujitsu.com> Cc: Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro> Cc: Pekka Enberg <penberg@cs.helsinki.fi> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-04-10 13:36:00 +00:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
/*
* Convert user-nice values [ -20 ... 0 ... 19 ]
* to static priority [ MAX_RT_PRIO..MAX_PRIO-1 ],
* and back.
*/
#define NICE_TO_PRIO(nice) (MAX_RT_PRIO + (nice) + 20)
#define PRIO_TO_NICE(prio) ((prio) - MAX_RT_PRIO - 20)
#define TASK_NICE(p) PRIO_TO_NICE((p)->static_prio)
/*
* 'User priority' is the nice value converted to something we
* can work with better when scaling various scheduler parameters,
* it's a [ 0 ... 39 ] range.
*/
#define USER_PRIO(p) ((p)-MAX_RT_PRIO)
#define TASK_USER_PRIO(p) USER_PRIO((p)->static_prio)
#define MAX_USER_PRIO (USER_PRIO(MAX_PRIO))
/*
sched: remove unused JIFFIES_TO_NS() macro remove unused JIFFIES_TO_NS() macro. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:19 +00:00
* Helpers for converting nanosecond timing to jiffy resolution
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
*/
sched: cleanup, use NSEC_PER_MSEC and NSEC_PER_SEC 1) hardcoded 1000000000 value is used five times in places where NSEC_PER_SEC might be more readable. 2) A conversion from nsec to msec uses the hardcoded 1000000 value, which is a candidate for NSEC_PER_MSEC. no code changed: text data bss dec hex filename 44359 3326 36 47721 ba69 sched.o.before 44359 3326 36 47721 ba69 sched.o.after Signed-off-by: Eric Dumazet <dada1@cosmosbay.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-11-09 21:39:38 +00:00
#define NS_TO_JIFFIES(TIME) ((unsigned long)(TIME) / (NSEC_PER_SEC / HZ))
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
sched: cfs rq data types add the CFS rq data types to sched.c. (the old scheduler fields are still intact, they are removed by a later patch) Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-09 16:51:58 +00:00
#define NICE_0_LOAD SCHED_LOAD_SCALE
#define NICE_0_SHIFT SCHED_LOAD_SHIFT
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
/*
* These are the 'tuning knobs' of the scheduler:
*
sched: tidy up SCHED_RR - make timeslices of SCHED_RR tasks constant and not dependent on task's static_prio [1] ; - remove obsolete code (timeslice related bits); - make sched_rr_get_interval() return something more meaningful [2] for SCHED_OTHER tasks. [1] according to the following link, it's not compliant with SUSv3 (not sure though, what is the reference for us :-) http://lkml.org/lkml/2007/3/7/656 [2] the interval is dynamic and can be depicted as follows "should a task be one of the runnable tasks at this particular moment, it would expect to run for this interval of time before being re-scheduled by the scheduler tick". (i.e. it's more precise if a task is runnable at the moment) yeah, this seems to require task_rq_lock/unlock() but this is not a hot path. results: (SCHED_FIFO) dimm@earth:~/storage/prog$ sudo chrt -f 10 ./rr_interval time_slice: 0 : 0 (SCHED_RR) dimm@earth:~/storage/prog$ sudo chrt 10 ./rr_interval time_slice: 0 : 99984800 (SCHED_NORMAL) dimm@earth:~/storage/prog$ ./rr_interval time_slice: 0 : 19996960 (SCHED_NORMAL + a cpu_hog of similar 'weight' on the same CPU --- so should be a half of the previous result) dimm@earth:~/storage/prog$ taskset 1 ./rr_interval time_slice: 0 : 9998480 Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 15:00:13 +00:00
* default timeslice is 100 msecs (used only for SCHED_RR tasks).
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
* Timeslices get refilled after they expire.
*/
#define DEF_TIMESLICE (100 * HZ / 1000)
[PATCH] sched: implement smpnice Problem: The introduction of separate run queues per CPU has brought with it "nice" enforcement problems that are best described by a simple example. For the sake of argument suppose that on a single CPU machine with a nice==19 hard spinner and a nice==0 hard spinner running that the nice==0 task gets 95% of the CPU and the nice==19 task gets 5% of the CPU. Now suppose that there is a system with 2 CPUs and 2 nice==19 hard spinners and 2 nice==0 hard spinners running. The user of this system would be entitled to expect that the nice==0 tasks each get 95% of a CPU and the nice==19 tasks only get 5% each. However, whether this expectation is met is pretty much down to luck as there are four equally likely distributions of the tasks to the CPUs that the load balancing code will consider to be balanced with loads of 2.0 for each CPU. Two of these distributions involve one nice==0 and one nice==19 task per CPU and in these circumstances the users expectations will be met. The other two distributions both involve both nice==0 tasks being on one CPU and both nice==19 being on the other CPU and each task will get 50% of a CPU and the user's expectations will not be met. Solution: The solution to this problem that is implemented in the attached patch is to use weighted loads when determining if the system is balanced and, when an imbalance is detected, to move an amount of weighted load between run queues (as opposed to a number of tasks) to restore the balance. Once again, the easiest way to explain why both of these measures are necessary is to use a simple example. Suppose that (in a slight variation of the above example) that we have a two CPU system with 4 nice==0 and 4 nice=19 hard spinning tasks running and that the 4 nice==0 tasks are on one CPU and the 4 nice==19 tasks are on the other CPU. The weighted loads for the two CPUs would be 4.0 and 0.2 respectively and the load balancing code would move 2 tasks resulting in one CPU with a load of 2.0 and the other with load of 2.2. If this was considered to be a big enough imbalance to justify moving a task and that task was moved using the current move_tasks() then it would move the highest priority task that it found and this would result in one CPU with a load of 3.0 and the other with a load of 1.2 which would result in the movement of a task in the opposite direction and so on -- infinite loop. If, on the other hand, an amount of load to be moved is calculated from the imbalance (in this case 0.1) and move_tasks() skips tasks until it find ones whose contributions to the weighted load are less than this amount it would move two of the nice==19 tasks resulting in a system with 2 nice==0 and 2 nice=19 on each CPU with loads of 2.1 for each CPU. One of the advantages of this mechanism is that on a system where all tasks have nice==0 the load balancing calculations would be mathematically identical to the current load balancing code. Notes: struct task_struct: has a new field load_weight which (in a trade off of space for speed) stores the contribution that this task makes to a CPU's weighted load when it is runnable. struct runqueue: has a new field raw_weighted_load which is the sum of the load_weight values for the currently runnable tasks on this run queue. This field always needs to be updated when nr_running is updated so two new inline functions inc_nr_running() and dec_nr_running() have been created to make sure that this happens. This also offers a convenient way to optimize away this part of the smpnice mechanism when CONFIG_SMP is not defined. int try_to_wake_up(): in this function the value SCHED_LOAD_BALANCE is used to represent the load contribution of a single task in various calculations in the code that decides which CPU to put the waking task on. While this would be a valid on a system where the nice values for the runnable tasks were distributed evenly around zero it will lead to anomalous load balancing if the distribution is skewed in either direction. To overcome this problem SCHED_LOAD_SCALE has been replaced by the load_weight for the relevant task or by the average load_weight per task for the queue in question (as appropriate). int move_tasks(): The modifications to this function were complicated by the fact that active_load_balance() uses it to move exactly one task without checking whether an imbalance actually exists. This precluded the simple overloading of max_nr_move with max_load_move and necessitated the addition of the latter as an extra argument to the function. The internal implementation is then modified to move up to max_nr_move tasks and max_load_move of weighted load. This slightly complicates the code where move_tasks() is called and if ever active_load_balance() is changed to not use move_tasks() the implementation of move_tasks() should be simplified accordingly. struct sched_group *find_busiest_group(): Similar to try_to_wake_up(), there are places in this function where SCHED_LOAD_SCALE is used to represent the load contribution of a single task and the same issues are created. A similar solution is adopted except that it is now the average per task contribution to a group's load (as opposed to a run queue) that is required. As this value is not directly available from the group it is calculated on the fly as the queues in the groups are visited when determining the busiest group. A key change to this function is that it is no longer to scale down *imbalance on exit as move_tasks() uses the load in its scaled form. void set_user_nice(): has been modified to update the task's load_weight field when it's nice value and also to ensure that its run queue's raw_weighted_load field is updated if it was runnable. From: "Siddha, Suresh B" <suresh.b.siddha@intel.com> With smpnice, sched groups with highest priority tasks can mask the imbalance between the other sched groups with in the same domain. This patch fixes some of the listed down scenarios by not considering the sched groups which are lightly loaded. a) on a simple 4-way MP system, if we have one high priority and 4 normal priority tasks, with smpnice we would like to see the high priority task scheduled on one cpu, two other cpus getting one normal task each and the fourth cpu getting the remaining two normal tasks. but with current smpnice extra normal priority task keeps jumping from one cpu to another cpu having the normal priority task. This is because of the busiest_has_loaded_cpus, nr_loaded_cpus logic.. We are not including the cpu with high priority task in max_load calculations but including that in total and avg_load calcuations.. leading to max_load < avg_load and load balance between cpus running normal priority tasks(2 Vs 1) will always show imbalanace as one normal priority and the extra normal priority task will keep moving from one cpu to another cpu having normal priority task.. b) 4-way system with HT (8 logical processors). Package-P0 T0 has a highest priority task, T1 is idle. Package-P1 Both T0 and T1 have 1 normal priority task each.. P2 and P3 are idle. With this patch, one of the normal priority tasks on P1 will be moved to P2 or P3.. c) With the current weighted smp nice calculations, it doesn't always make sense to look at the highest weighted runqueue in the busy group.. Consider a load balance scenario on a DP with HT system, with Package-0 containing one high priority and one low priority, Package-1 containing one low priority(with other thread being idle).. Package-1 thinks that it need to take the low priority thread from Package-0. And find_busiest_queue() returns the cpu thread with highest priority task.. And ultimately(with help of active load balance) we move high priority task to Package-1. And same continues with Package-0 now, moving high priority task from package-1 to package-0.. Even without the presence of active load balance, load balance will fail to balance the above scenario.. Fix find_busiest_queue to use "imbalance" when it is lightly loaded. [kernel@kolivas.org: sched: store weighted load on up] [kernel@kolivas.org: sched: add discrete weighted cpu load function] [suresh.b.siddha@intel.com: sched: remove dead code] Signed-off-by: Peter Williams <pwil3058@bigpond.com.au> Cc: "Siddha, Suresh B" <suresh.b.siddha@intel.com> Cc: "Chen, Kenneth W" <kenneth.w.chen@intel.com> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Con Kolivas <kernel@kolivas.org> Cc: John Hawkes <hawkes@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 09:54:34 +00:00
sched: rt-group: synchonised bandwidth period Various SMP balancing algorithms require that the bandwidth period run in sync. Possible improvements are moving the rt_bandwidth thing into root_domain and keeping a span per rt_bandwidth which marks throttled cpus. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 17:44:57 +00:00
/*
* single value that denotes runtime == period, ie unlimited time.
*/
#define RUNTIME_INF ((u64)~0ULL)
sched: clean up the rt priority macros clean up the rt priority macros, pointed out by Andrew Morton. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-09 16:51:59 +00:00
static inline int rt_policy(int policy)
{
sched: Remove unlikely() from rt_policy() in sched.c The rt_policy() has an unlikely() that the policy it is checking is of RT priority (SCHED_FIFO or SCHED_RR). According to the annotate branch profiler it is incorrect most of the time: correct incorrect % Function File Line ------- --------- - -------- ---- ---- 36667 654674 94 rt_policy sched.c 126 This makes sense because the rt_policy() is used by the sched_set_scheduler() and nice(). Although users may use sys_nice a bit, all RT users use the sched_set_scheduler() to set their RT priority, including kernel threads. The above numbers were from a normal desktop computer running firefox, evolution, xchat and was part of a distcc compile farm. Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-12-06 19:48:10 +00:00
if (policy == SCHED_FIFO || policy == SCHED_RR)
sched: clean up the rt priority macros clean up the rt priority macros, pointed out by Andrew Morton. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-09 16:51:59 +00:00
return 1;
return 0;
}
static inline int task_has_rt_policy(struct task_struct *p)
{
return rt_policy(p->policy);
}
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
/*
sched: cfs rq data types add the CFS rq data types to sched.c. (the old scheduler fields are still intact, they are removed by a later patch) Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-09 16:51:58 +00:00
* This is the priority-queue data structure of the RT scheduling class:
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
*/
sched: cfs rq data types add the CFS rq data types to sched.c. (the old scheduler fields are still intact, they are removed by a later patch) Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-09 16:51:58 +00:00
struct rt_prio_array {
DECLARE_BITMAP(bitmap, MAX_RT_PRIO+1); /* include 1 bit for delimiter */
struct list_head queue[MAX_RT_PRIO];
};
sched: rt-group: synchonised bandwidth period Various SMP balancing algorithms require that the bandwidth period run in sync. Possible improvements are moving the rt_bandwidth thing into root_domain and keeping a span per rt_bandwidth which marks throttled cpus. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 17:44:57 +00:00
struct rt_bandwidth {
sched: fix checks Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-03-25 12:51:45 +00:00
/* nests inside the rq lock: */
sched: Convert rt_runtime_lock to raw_spinlock Convert locks which cannot be sleeping locks in preempt-rt to raw_spinlocks. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Ingo Molnar <mingo@elte.hu>
2009-11-17 14:32:06 +00:00
raw_spinlock_t rt_runtime_lock;
sched: fix checks Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-03-25 12:51:45 +00:00
ktime_t rt_period;
u64 rt_runtime;
struct hrtimer rt_period_timer;
sched: rt-group: synchonised bandwidth period Various SMP balancing algorithms require that the bandwidth period run in sync. Possible improvements are moving the rt_bandwidth thing into root_domain and keeping a span per rt_bandwidth which marks throttled cpus. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 17:44:57 +00:00
};
static struct rt_bandwidth def_rt_bandwidth;
static int do_sched_rt_period_timer(struct rt_bandwidth *rt_b, int overrun);
static enum hrtimer_restart sched_rt_period_timer(struct hrtimer *timer)
{
struct rt_bandwidth *rt_b =
container_of(timer, struct rt_bandwidth, rt_period_timer);
ktime_t now;
int overrun;
int idle = 0;
for (;;) {
now = hrtimer_cb_get_time(timer);
overrun = hrtimer_forward(timer, now, rt_b->rt_period);
if (!overrun)
break;
idle = do_sched_rt_period_timer(rt_b, overrun);
}
return idle ? HRTIMER_NORESTART : HRTIMER_RESTART;
}
static
void init_rt_bandwidth(struct rt_bandwidth *rt_b, u64 period, u64 runtime)
{
rt_b->rt_period = ns_to_ktime(period);
rt_b->rt_runtime = runtime;
sched: Convert rt_runtime_lock to raw_spinlock Convert locks which cannot be sleeping locks in preempt-rt to raw_spinlocks. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Ingo Molnar <mingo@elte.hu>
2009-11-17 14:32:06 +00:00
raw_spin_lock_init(&rt_b->rt_runtime_lock);
sched: rt-group: smp balancing Currently the rt group scheduling does a per cpu runtime limit, however the rt load balancer makes no guarantees about an equal spread of real- time tasks, just that at any one time, the highest priority tasks run. Solve this by making the runtime limit a global property by borrowing excessive runtime from the other cpus once the local limit runs out. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 17:44:58 +00:00
sched: rt-group: synchonised bandwidth period Various SMP balancing algorithms require that the bandwidth period run in sync. Possible improvements are moving the rt_bandwidth thing into root_domain and keeping a span per rt_bandwidth which marks throttled cpus. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 17:44:57 +00:00
hrtimer_init(&rt_b->rt_period_timer,
CLOCK_MONOTONIC, HRTIMER_MODE_REL);
rt_b->rt_period_timer.function = sched_rt_period_timer;
}
sched: compilation fix with gcc 3.4.6 I found that 2.6.27-rc5-mm1 does not compile with gcc 3.4.6. The error is: CC kernel/sched.o kernel/sched.c: In function `start_rt_bandwidth': kernel/sched.c:208: sorry, unimplemented: inlining failed in call to 'rt_bandwidth_enabled': function body not available kernel/sched.c:214: sorry, unimplemented: called from here make[1]: *** [kernel/sched.o] Error 1 make: *** [kernel] Error 2 It seems that the gcc 3.4.6 requires full inline definition before first usage. The patch below fixes the compilation problem. Signed-off-by: Krzysztof Helt <krzysztof.h1@wp.pl> (if needed> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-05 21:46:19 +00:00
static inline int rt_bandwidth_enabled(void)
{
return sysctl_sched_rt_runtime >= 0;
sched: rt-group: synchonised bandwidth period Various SMP balancing algorithms require that the bandwidth period run in sync. Possible improvements are moving the rt_bandwidth thing into root_domain and keeping a span per rt_bandwidth which marks throttled cpus. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 17:44:57 +00:00
}
static void start_rt_bandwidth(struct rt_bandwidth *rt_b)
{
ktime_t now;
sched_rt: don't start timer when rt bandwidth disabled Impact: fix incorrect condition check No need to start rt bandwidth timer when rt bandwidth is disabled. If this timer starts, it may stop at sched_rt_period_timer() on the first time. Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-25 17:59:26 +00:00
if (!rt_bandwidth_enabled() || rt_b->rt_runtime == RUNTIME_INF)
sched: rt-group: synchonised bandwidth period Various SMP balancing algorithms require that the bandwidth period run in sync. Possible improvements are moving the rt_bandwidth thing into root_domain and keeping a span per rt_bandwidth which marks throttled cpus. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 17:44:57 +00:00
return;
if (hrtimer_active(&rt_b->rt_period_timer))
return;
sched: Convert rt_runtime_lock to raw_spinlock Convert locks which cannot be sleeping locks in preempt-rt to raw_spinlocks. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Ingo Molnar <mingo@elte.hu>
2009-11-17 14:32:06 +00:00
raw_spin_lock(&rt_b->rt_runtime_lock);
sched: rt-group: synchonised bandwidth period Various SMP balancing algorithms require that the bandwidth period run in sync. Possible improvements are moving the rt_bandwidth thing into root_domain and keeping a span per rt_bandwidth which marks throttled cpus. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 17:44:57 +00:00
for (;;) {
hrtimer: fix rq->lock inversion (again) It appears I inadvertly introduced rq->lock recursion to the hrtimer_start() path when I delegated running already expired timers to softirq context. This patch fixes it by introducing a __hrtimer_start_range_ns() method that will not use raise_softirq_irqoff() but __raise_softirq_irqoff() which avoids the wakeup. It then also changes schedule() to check for pending softirqs and do the wakeup then, I'm not quite sure I like this last bit, nor am I convinced its really needed. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: paulus@samba.org LKML-Reference: <20090313112301.096138802@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-13 11:21:27 +00:00
unsigned long delta;
ktime_t soft, hard;
sched: rt-group: synchonised bandwidth period Various SMP balancing algorithms require that the bandwidth period run in sync. Possible improvements are moving the rt_bandwidth thing into root_domain and keeping a span per rt_bandwidth which marks throttled cpus. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 17:44:57 +00:00
if (hrtimer_active(&rt_b->rt_period_timer))
break;
now = hrtimer_cb_get_time(&rt_b->rt_period_timer);
hrtimer_forward(&rt_b->rt_period_timer, now, rt_b->rt_period);
hrtimer: fix rq->lock inversion (again) It appears I inadvertly introduced rq->lock recursion to the hrtimer_start() path when I delegated running already expired timers to softirq context. This patch fixes it by introducing a __hrtimer_start_range_ns() method that will not use raise_softirq_irqoff() but __raise_softirq_irqoff() which avoids the wakeup. It then also changes schedule() to check for pending softirqs and do the wakeup then, I'm not quite sure I like this last bit, nor am I convinced its really needed. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: paulus@samba.org LKML-Reference: <20090313112301.096138802@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-13 11:21:27 +00:00
soft = hrtimer_get_softexpires(&rt_b->rt_period_timer);
hard = hrtimer_get_expires(&rt_b->rt_period_timer);
delta = ktime_to_ns(ktime_sub(hard, soft));
__hrtimer_start_range_ns(&rt_b->rt_period_timer, soft, delta,
timers: Identifying the existing pinned timers * Arun R Bharadwaj <arun@linux.vnet.ibm.com> [2009-04-16 12:11:36]: The following pinned hrtimers have been identified and marked: 1)sched_rt_period_timer 2)tick_sched_timer 3)stack_trace_timer_fn [ tglx: fixup the hrtimer pinned mode ] Signed-off-by: Arun R Bharadwaj <arun@linux.vnet.ibm.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2009-04-16 06:44:37 +00:00
HRTIMER_MODE_ABS_PINNED, 0);
sched: rt-group: synchonised bandwidth period Various SMP balancing algorithms require that the bandwidth period run in sync. Possible improvements are moving the rt_bandwidth thing into root_domain and keeping a span per rt_bandwidth which marks throttled cpus. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 17:44:57 +00:00
}
sched: Convert rt_runtime_lock to raw_spinlock Convert locks which cannot be sleeping locks in preempt-rt to raw_spinlocks. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Ingo Molnar <mingo@elte.hu>
2009-11-17 14:32:06 +00:00
raw_spin_unlock(&rt_b->rt_runtime_lock);
sched: rt-group: synchonised bandwidth period Various SMP balancing algorithms require that the bandwidth period run in sync. Possible improvements are moving the rt_bandwidth thing into root_domain and keeping a span per rt_bandwidth which marks throttled cpus. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 17:44:57 +00:00
}
#ifdef CONFIG_RT_GROUP_SCHED
static void destroy_rt_bandwidth(struct rt_bandwidth *rt_b)
{
hrtimer_cancel(&rt_b->rt_period_timer);
}
#endif
sched: fix missing locking in sched_domains code Concurrent calls to detach_destroy_domains and arch_init_sched_domains were prevented by the old scheduler subsystem cpu hotplug mutex. When this got converted to get_online_cpus() the locking got broken. Unlike before now several processes can concurrently enter the critical sections that were protected by the old lock. So use the already present doms_cur_mutex to protect these sections again. Cc: Gautham R Shenoy <ego@in.ibm.com> Cc: Paul Jackson <pj@sgi.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-28 09:33:07 +00:00
/*
sched: Remove obsolete arch_ prefixes Non weak static functions clearly are not arch specific, so remove the arch_ prefix. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122941.820460566@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:09:42 +00:00
* sched_domains_mutex serializes calls to init_sched_domains,
sched: fix missing locking in sched_domains code Concurrent calls to detach_destroy_domains and arch_init_sched_domains were prevented by the old scheduler subsystem cpu hotplug mutex. When this got converted to get_online_cpus() the locking got broken. Unlike before now several processes can concurrently enter the critical sections that were protected by the old lock. So use the already present doms_cur_mutex to protect these sections again. Cc: Gautham R Shenoy <ego@in.ibm.com> Cc: Paul Jackson <pj@sgi.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-28 09:33:07 +00:00
* detach_destroy_domains and partition_sched_domains.
*/
static DEFINE_MUTEX(sched_domains_mutex);
sched: Remove USER_SCHED Remove the USER_SCHED feature. It has been scheduled to be removed in 2.6.34 as per http://marc.info/?l=linux-kernel&m=125728479022976&w=2 Signed-off-by: Dhaval Giani <dhaval.giani@gmail.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1263990378.24844.3.camel@localhost> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-01-20 12:26:18 +00:00
#ifdef CONFIG_CGROUP_SCHED
sched: group-scheduler core Add interface to control cpu bandwidth allocation to task-groups. (not yet configurable, due to missing CONFIG_CONTAINERS) Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
2007-10-15 15:00:07 +00:00
Hook up group scheduler with control groups Enable "cgroup" (formerly containers) based fair group scheduling. This will let administrator create arbitrary groups of tasks (using "cgroup" pseudo filesystem) and control their cpu bandwidth usage. [akpm@linux-foundation.org: fix cpp condition] Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Cc: Randy Dunlap <randy.dunlap@oracle.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Paul Menage <menage@google.com> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-19 06:41:03 +00:00
#include <linux/cgroup.h>
sched: group-scheduler core Add interface to control cpu bandwidth allocation to task-groups. (not yet configurable, due to missing CONFIG_CONTAINERS) Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
2007-10-15 15:00:07 +00:00
struct cfs_rq;
sched: rt group scheduling Extend group scheduling to also cover the realtime classes. It uses the time limiting introduced by the previous patch to allow multiple realtime groups. The hard time limit is required to keep behaviour deterministic. The algorithms used make the realtime scheduler O(tg), linear scaling wrt the number of task groups. This is the worst case behaviour I can't seem to get out of, the avg. case of the algorithms can be improved, I focused on correctness and worst case. [ akpm@linux-foundation.org: move side-effects out of BUG_ON(). ] Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:30 +00:00
static LIST_HEAD(task_groups);
sched: Introduce primitives to account for CFS bandwidth tracking In this patch we introduce the notion of CFS bandwidth, partitioned into globally unassigned bandwidth, and locally claimed bandwidth. - The global bandwidth is per task_group, it represents a pool of unclaimed bandwidth that cfs_rqs can allocate from. - The local bandwidth is tracked per-cfs_rq, this represents allotments from the global pool bandwidth assigned to a specific cpu. Bandwidth is managed via cgroupfs, adding two new interfaces to the cpu subsystem: - cpu.cfs_period_us : the bandwidth period in usecs - cpu.cfs_quota_us : the cpu bandwidth (in usecs) that this tg will be allowed to consume over period above. Signed-off-by: Paul Turner <pjt@google.com> Signed-off-by: Nikhil Rao <ncrao@google.com> Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com> Reviewed-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110721184756.972636699@google.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-21 16:43:28 +00:00
struct cfs_bandwidth {
#ifdef CONFIG_CFS_BANDWIDTH
raw_spinlock_t lock;
ktime_t period;
sched: Accumulate per-cfs_rq cpu usage and charge against bandwidth Account bandwidth usage on the cfs_rq level versus the task_groups to which they belong. Whether we are tracking bandwidth on a given cfs_rq is maintained under cfs_rq->runtime_enabled. cfs_rq's which belong to a bandwidth constrained task_group have their runtime accounted via the update_curr() path, which withdraws bandwidth from the global pool as desired. Updates involving the global pool are currently protected under cfs_bandwidth->lock, local runtime is protected by rq->lock. This patch only assigns and tracks quota, no action is taken in the case that cfs_rq->runtime_used exceeds cfs_rq->runtime_assigned. Signed-off-by: Paul Turner <pjt@google.com> Signed-off-by: Nikhil Rao <ncrao@google.com> Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com> Reviewed-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110721184757.179386821@google.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-21 16:43:30 +00:00
u64 quota, runtime;
sched: Validate CFS quota hierarchies Add constraints validation for CFS bandwidth hierarchies. Validate that: max(child bandwidth) <= parent_bandwidth In a quota limited hierarchy, an unconstrained entity (e.g. bandwidth==RUNTIME_INF) inherits the bandwidth of its parent. This constraint is chosen over sum(child_bandwidth) as notion of over-commit is valuable within SCHED_OTHER. Some basic code from the RT case is re-factored for reuse. Signed-off-by: Paul Turner <pjt@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110721184757.083774572@google.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-21 16:43:29 +00:00
s64 hierarchal_quota;
sched: Introduce primitives to account for CFS bandwidth tracking In this patch we introduce the notion of CFS bandwidth, partitioned into globally unassigned bandwidth, and locally claimed bandwidth. - The global bandwidth is per task_group, it represents a pool of unclaimed bandwidth that cfs_rqs can allocate from. - The local bandwidth is tracked per-cfs_rq, this represents allotments from the global pool bandwidth assigned to a specific cpu. Bandwidth is managed via cgroupfs, adding two new interfaces to the cpu subsystem: - cpu.cfs_period_us : the bandwidth period in usecs - cpu.cfs_quota_us : the cpu bandwidth (in usecs) that this tg will be allowed to consume over period above. Signed-off-by: Paul Turner <pjt@google.com> Signed-off-by: Nikhil Rao <ncrao@google.com> Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com> Reviewed-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110721184756.972636699@google.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-21 16:43:28 +00:00
#endif
};
sched: group-scheduler core Add interface to control cpu bandwidth allocation to task-groups. (not yet configurable, due to missing CONFIG_CONTAINERS) Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
2007-10-15 15:00:07 +00:00
/* task group related information */
sched: cleanup: rename task_grp to task_group cleanup: rename task_grp to task_group. No need to save two characters and 'grp' is annoying to read. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 15:00:14 +00:00
struct task_group {
Hook up group scheduler with control groups Enable "cgroup" (formerly containers) based fair group scheduling. This will let administrator create arbitrary groups of tasks (using "cgroup" pseudo filesystem) and control their cpu bandwidth usage. [akpm@linux-foundation.org: fix cpp condition] Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Cc: Randy Dunlap <randy.dunlap@oracle.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Paul Menage <menage@google.com> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-19 06:41:03 +00:00
struct cgroup_subsys_state css;
sched: add uid information to sched_debug for CONFIG_USER_SCHED Impact: extend information in /proc/sched_debug This patch adds uid information in sched_debug for CONFIG_USER_SCHED Signed-off-by: Arun R Bharadwaj <arun@linux.vnet.ibm.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-01 15:19:05 +00:00
sched: rt-group: make rt groups scheduling configurable Make the rt group scheduler compile time configurable. Keep it experimental for now. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-13 14:45:40 +00:00
#ifdef CONFIG_FAIR_GROUP_SCHED
sched: group-scheduler core Add interface to control cpu bandwidth allocation to task-groups. (not yet configurable, due to missing CONFIG_CONTAINERS) Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
2007-10-15 15:00:07 +00:00
/* schedulable entities of this group on each cpu */
struct sched_entity **se;
/* runqueue "owned" by this group on each cpu */
struct cfs_rq **cfs_rq;
unsigned long shares;
sched: Rewrite tg_shares_up) By tracking a per-cpu load-avg for each cfs_rq and folding it into a global task_group load on each tick we can rework tg_shares_up to be strictly per-cpu. This should improve cpu-cgroup performance for smp systems significantly. [ Paul: changed to use queueing cfs_rq + bug fixes ] Signed-off-by: Paul Turner <pjt@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20101115234937.580480400@google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-15 23:47:00 +00:00
atomic_t load_weight;
sched: rt-group: make rt groups scheduling configurable Make the rt group scheduler compile time configurable. Keep it experimental for now. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-13 14:45:40 +00:00
#endif
#ifdef CONFIG_RT_GROUP_SCHED
struct sched_rt_entity **rt_se;
struct rt_rq **rt_rq;
sched: rt-group: synchonised bandwidth period Various SMP balancing algorithms require that the bandwidth period run in sync. Possible improvements are moving the rt_bandwidth thing into root_domain and keeping a span per rt_bandwidth which marks throttled cpus. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 17:44:57 +00:00
struct rt_bandwidth rt_bandwidth;
sched: rt-group: make rt groups scheduling configurable Make the rt group scheduler compile time configurable. Keep it experimental for now. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-13 14:45:40 +00:00
#endif
sched: group scheduler, fix fairness of cpu bandwidth allocation for task groups The current load balancing scheme isn't good enough for precise group fairness. For example: on a 8-cpu system, I created 3 groups as under: a = 8 tasks (cpu.shares = 1024) b = 4 tasks (cpu.shares = 1024) c = 3 tasks (cpu.shares = 1024) a, b and c are task groups that have equal weight. We would expect each of the groups to receive 33.33% of cpu bandwidth under a fair scheduler. This is what I get with the latest scheduler git tree: Signed-off-by: Ingo Molnar <mingo@elte.hu> -------------------------------------------------------------------------------- Col1 | Col2 | Col3 | Col4 ------|---------|-------|------------------------------------------------------- a | 277.676 | 57.8% | 54.1% 54.1% 54.1% 54.2% 56.7% 62.2% 62.8% 64.5% b | 116.108 | 24.2% | 47.4% 48.1% 48.7% 49.3% c | 86.326 | 18.0% | 47.5% 47.9% 48.5% -------------------------------------------------------------------------------- Explanation of o/p: Col1 -> Group name Col2 -> Cumulative execution time (in seconds) received by all tasks of that group in a 60sec window across 8 cpus Col3 -> CPU bandwidth received by the group in the 60sec window, expressed in percentage. Col3 data is derived as: Col3 = 100 * Col2 / (NR_CPUS * 60) Col4 -> CPU bandwidth received by each individual task of the group. Col4 = 100 * cpu_time_recd_by_task / 60 [I can share the test case that produces a similar o/p if reqd] The deviation from desired group fairness is as below: a = +24.47% b = -9.13% c = -15.33% which is quite high. After the patch below is applied, here are the results: -------------------------------------------------------------------------------- Col1 | Col2 | Col3 | Col4 ------|---------|-------|------------------------------------------------------- a | 163.112 | 34.0% | 33.2% 33.4% 33.5% 33.5% 33.7% 34.4% 34.8% 35.3% b | 156.220 | 32.5% | 63.3% 64.5% 66.1% 66.5% c | 160.653 | 33.5% | 85.8% 90.6% 91.4% -------------------------------------------------------------------------------- Deviation from desired group fairness is as below: a = +0.67% b = -0.83% c = +0.17% which is far better IMO. Most of other runs have yielded a deviation within +-2% at the most, which is good. Why do we see bad (group) fairness with current scheuler? ========================================================= Currently cpu's weight is just the summation of individual task weights. This can yield incorrect results. For ex: consider three groups as below on a 2-cpu system: CPU0 CPU1 --------------------------- A (10) B(5) C(5) --------------------------- Group A has 10 tasks, all on CPU0, Group B and C have 5 tasks each all of which are on CPU1. Each task has the same weight (NICE_0_LOAD = 1024). The current scheme would yield a cpu weight of 10240 (10*1024) for each cpu and the load balancer will think both CPUs are perfectly balanced and won't move around any tasks. This, however, would yield this bandwidth: A = 50% B = 25% C = 25% which is not the desired result. What's changing in the patch? ============================= - How cpu weights are calculated when CONFIF_FAIR_GROUP_SCHED is defined (see below) - API Change - Two tunables introduced in sysfs (under SCHED_DEBUG) to control the frequency at which the load balance monitor thread runs. The basic change made in this patch is how cpu weight (rq->load.weight) is calculated. Its now calculated as the summation of group weights on a cpu, rather than summation of task weights. Weight exerted by a group on a cpu is dependent on the shares allocated to it and also the number of tasks the group has on that cpu compared to the total number of (runnable) tasks the group has in the system. Let, W(K,i) = Weight of group K on cpu i T(K,i) = Task load present in group K's cfs_rq on cpu i T(K) = Total task load of group K across various cpus S(K) = Shares allocated to group K NRCPUS = Number of online cpus in the scheduler domain to which group K is assigned. Then, W(K,i) = S(K) * NRCPUS * T(K,i) / T(K) A load balance monitor thread is created at bootup, which periodically runs and adjusts group's weight on each cpu. To avoid its overhead, two min/max tunables are introduced (under SCHED_DEBUG) to control the rate at which it runs. Fixes from: Peter Zijlstra <a.p.zijlstra@chello.nl> - don't start the load_balance_monitor when there is only a single cpu. - rename the kthread because its currently longer than TASK_COMM_LEN Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:00 +00:00
sched: move rcu_head to task_group struct Peter Zijlstra noticed that the rcu_head object need not be present in every cfs_rq of a group. Move it to the task_group structure instead. Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-29 20:18:11 +00:00
struct rcu_head rcu;
sched: rt group scheduling Extend group scheduling to also cover the realtime classes. It uses the time limiting introduced by the previous patch to allow multiple realtime groups. The hard time limit is required to keep behaviour deterministic. The algorithms used make the realtime scheduler O(tg), linear scaling wrt the number of task groups. This is the worst case behaviour I can't seem to get out of, the avg. case of the algorithms can be improved, I focused on correctness and worst case. [ akpm@linux-foundation.org: move side-effects out of BUG_ON(). ] Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:30 +00:00
struct list_head list;
sched: task_group hierarchy Add the full parent<->child relation thing into task_groups as well. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 17:45:00 +00:00
struct task_group *parent;
struct list_head siblings;
struct list_head children;
sched: Add 'autogroup' scheduling feature: automated per session task groups A recurring complaint from CFS users is that parallel kbuild has a negative impact on desktop interactivity. This patch implements an idea from Linus, to automatically create task groups. Currently, only per session autogroups are implemented, but the patch leaves the way open for enhancement. Implementation: each task's signal struct contains an inherited pointer to a refcounted autogroup struct containing a task group pointer, the default for all tasks pointing to the init_task_group. When a task calls setsid(), a new task group is created, the process is moved into the new task group, and a reference to the preveious task group is dropped. Child processes inherit this task group thereafter, and increase it's refcount. When the last thread of a process exits, the process's reference is dropped, such that when the last process referencing an autogroup exits, the autogroup is destroyed. At runqueue selection time, IFF a task has no cgroup assignment, its current autogroup is used. Autogroup bandwidth is controllable via setting it's nice level through the proc filesystem: cat /proc/<pid>/autogroup Displays the task's group and the group's nice level. echo <nice level> > /proc/<pid>/autogroup Sets the task group's shares to the weight of nice <level> task. Setting nice level is rate limited for !admin users due to the abuse risk of task group locking. The feature is enabled from boot by default if CONFIG_SCHED_AUTOGROUP=y is selected, but can be disabled via the boot option noautogroup, and can also be turned on/off on the fly via: echo [01] > /proc/sys/kernel/sched_autogroup_enabled ... which will automatically move tasks to/from the root task group. Signed-off-by: Mike Galbraith <efault@gmx.de> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Markus Trippelsdorf <markus@trippelsdorf.de> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Paul Turner <pjt@google.com> Cc: Oleg Nesterov <oleg@redhat.com> [ Removed the task_group_path() debug code, and fixed !EVENTFD build failure. ] Signed-off-by: Ingo Molnar <mingo@elte.hu> LKML-Reference: <1290281700.28711.9.camel@maggy.simson.net> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-30 13:18:03 +00:00
#ifdef CONFIG_SCHED_AUTOGROUP
struct autogroup *autogroup;
#endif
sched: Introduce primitives to account for CFS bandwidth tracking In this patch we introduce the notion of CFS bandwidth, partitioned into globally unassigned bandwidth, and locally claimed bandwidth. - The global bandwidth is per task_group, it represents a pool of unclaimed bandwidth that cfs_rqs can allocate from. - The local bandwidth is tracked per-cfs_rq, this represents allotments from the global pool bandwidth assigned to a specific cpu. Bandwidth is managed via cgroupfs, adding two new interfaces to the cpu subsystem: - cpu.cfs_period_us : the bandwidth period in usecs - cpu.cfs_quota_us : the cpu bandwidth (in usecs) that this tg will be allowed to consume over period above. Signed-off-by: Paul Turner <pjt@google.com> Signed-off-by: Nikhil Rao <ncrao@google.com> Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com> Reviewed-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110721184756.972636699@google.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-21 16:43:28 +00:00
struct cfs_bandwidth cfs_bandwidth;
sched: group-scheduler core Add interface to control cpu bandwidth allocation to task-groups. (not yet configurable, due to missing CONFIG_CONTAINERS) Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
2007-10-15 15:00:07 +00:00
};
sched: Implement on-demand (active) cfs_rq list Make certain load-balance actions scale per number of active cgroups instead of the number of existing cgroups. This makes wakeup/sleep paths more expensive, but is a win for systems where the vast majority of existing cgroups are idle. Signed-off-by: Paul Turner <pjt@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20101115234937.666535048@google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-15 23:47:01 +00:00
/* task_group_lock serializes the addition/removal of task groups */
sched: fair-group: separate tg->shares from task_group_lock On Mon, 2008-02-11 at 15:09 +0300, Denis V. Lunev wrote: > BUG: sleeping function called from invalid context > at /home/den/src/linux-netns26/kernel/mutex.c:209 > in_atomic():1, irqs_disabled():0 > no locks held by swapper/0. > Pid: 0, comm: swapper Not tainted 2.6.24 #304 > > Call Trace: > <IRQ> [<ffffffff80252d1e>] ? __debug_show_held_locks+0x15/0x27 > [<ffffffff8022c2a8>] __might_sleep+0xc0/0xdf > [<ffffffff8049f1df>] mutex_lock_nested+0x28/0x2a9 > [<ffffffff80231294>] sched_destroy_group+0x18/0xea > [<ffffffff8023e835>] sched_destroy_user+0xd/0xf > [<ffffffff8023e8c1>] free_uid+0x8a/0xab > [<ffffffff80233e24>] __put_task_struct+0x3f/0xd3 > [<ffffffff80236708>] delayed_put_task_struct+0x23/0x25 > [<ffffffff8026fda7>] __rcu_process_callbacks+0x8d/0x215 > [<ffffffff8026ff52>] rcu_process_callbacks+0x23/0x44 > [<ffffffff8023a2ae>] __do_softirq+0x79/0xf8 > [<ffffffff8020f8c3>] ? profile_pc+0x2a/0x67 > [<ffffffff8020d38c>] call_softirq+0x1c/0x30 > [<ffffffff8020f689>] do_softirq+0x61/0x9c > [<ffffffff8023a233>] irq_exit+0x51/0x53 > [<ffffffff8021bd1a>] smp_apic_timer_interrupt+0x77/0xad > [<ffffffff8020ce3b>] apic_timer_interrupt+0x6b/0x70 > <EOI> [<ffffffff8020b0dd>] ? default_idle+0x43/0x76 > [<ffffffff8020b0db>] ? default_idle+0x41/0x76 > [<ffffffff8020b09a>] ? default_idle+0x0/0x76 > [<ffffffff8020b186>] ? cpu_idle+0x76/0x98 separate the tg->shares protection from the task_group lock. Reported-by: Denis V. Lunev <den@openvz.org> Tested-by: Denis V. Lunev <den@openvz.org> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-13 14:45:39 +00:00
static DEFINE_SPINLOCK(task_group_lock);
sched: group scheduling, minor fixes Minor bug fixes for the group scheduler: - Use a mutex to serialize add/remove of task groups and also when changing shares of a task group. Use the same mutex when printing cfs_rq debugging stats for various task groups. - Use list_for_each_entry_rcu in for_each_leaf_cfs_rq macro (when walking task group list) Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:07:59 +00:00
sched: Use root_task_group_empty only with FAIR_GROUP_SCHED root_task_group_empty is used only with FAIR_GROUP_SCHED so if we use other scheduler options we get: kernel/sched.c:314: warning: 'root_task_group_empty' defined but not used So move CONFIG_FAIR_GROUP_SCHED up that it covers root_task_group_empty(). Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <20091026192414.GB5321@lenovo> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-10-26 19:24:14 +00:00
#ifdef CONFIG_FAIR_GROUP_SCHED
sched: Consolidate the name of root_task_group and init_task_group root_task_group is the leftover of USER_SCHED, now it's always same to init_task_group. But as Mike suggested, root_task_group is maybe the suitable name to keep for a tree. So in this patch: init_task_group --> root_task_group init_task_group_load --> root_task_group_load INIT_TASK_GROUP_LOAD --> ROOT_TASK_GROUP_LOAD Suggested-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Yong Zhang <yong.zhang0@gmail.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20110107071736.GA32635@windriver.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-01-07 07:17:36 +00:00
# define ROOT_TASK_GROUP_LOAD NICE_0_LOAD
sched: rt-group: make rt groups scheduling configurable Make the rt group scheduler compile time configurable. Keep it experimental for now. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-13 14:45:40 +00:00
sched: fair-group: fix a Div0 error of the fair group scheduler When I echoed 0 into the "cpu.shares" file, a Div0 error occured. We found it is caused by the following calling. sched_group_set_shares(tg, shares) set_se_shares(tg->se[i], shares/nr_cpu_ids) __set_se_shares(se, shares) div64_64((1ULL<<32), shares) When the echoed value was less than the number of processores, the result of the sentence "shares/nr_cpu_ids" was 0, and then the system called div64() to divide the result, the Div0 error occured. It is unnecessary that the shares value is divided by nr_cpu_ids, I think. Because in the function __update_group_shares_cpu() and init_tg_cfs_entry(), the shares value isn't divided by nr_cpu_ids when setting shares of the sched entity. This patch fixes this bug. And echoing ULONG_MAX value into cpu.shares also causes Div0 error, so we set a macro MAX_SHARES to limit the max value of shares. Signed-off-by: Miao Xie <miaox@cn.fujitsu.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-28 04:54:56 +00:00
/*
sched: fair group: fix overflow(was: fix divide by zero) I found a bug which can be reproduced by this way:(linux-2.6.26-rc5, x86-64) (use 2^32, 2^33, ...., 2^63 as shares value) # mkdir /dev/cpuctl # mount -t cgroup -o cpu cpuctl /dev/cpuctl # cd /dev/cpuctl # mkdir sub # echo 0x8000000000000000 > sub/cpu.shares # echo $$ > sub/tasks oops here! divide by zero. This is because do_div() expects the 2th parameter to be 32 bits, but unsigned long is 64 bits in x86_64. Peter Zijstra pointed it out that the sane thing to do is limit the shares value to something smaller instead of using an even more expensive divide. Also, I found another bug about "the shares value is too large": pid1 and pid2 are set affinity to cpu#0 pid1 is attached to cg1 and pid2 is attached to cg2 if cg1/cpu.shares = 1024 cg2/cpu.shares = 2000000000 then pid2 got 100% usage of cpu, and pid1 0% if cg1/cpu.shares = 1024 cg2/cpu.shares = 20000000000 then pid2 got 0% usage of cpu, and pid1 100% And a weight of a cfs_rq is the sum of weights of which entities are queued on this cfs_rq, so the shares value should be limited to a smaller value. I think that (1UL << 18) is a good limited value: 1) it's not too large, we can create a lot of group before overflow 2) it's several times the weight value for nice=-19 (not too small) Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-12 08:42:58 +00:00
* A weight of 0 or 1 can cause arithmetics problems.
* A weight of a cfs_rq is the sum of weights of which entities
* are queued on this cfs_rq, so a weight of a entity should not be
* too large, so as the shares value of a task group.
sched: fair-group: fix a Div0 error of the fair group scheduler When I echoed 0 into the "cpu.shares" file, a Div0 error occured. We found it is caused by the following calling. sched_group_set_shares(tg, shares) set_se_shares(tg->se[i], shares/nr_cpu_ids) __set_se_shares(se, shares) div64_64((1ULL<<32), shares) When the echoed value was less than the number of processores, the result of the sentence "shares/nr_cpu_ids" was 0, and then the system called div64() to divide the result, the Div0 error occured. It is unnecessary that the shares value is divided by nr_cpu_ids, I think. Because in the function __update_group_shares_cpu() and init_tg_cfs_entry(), the shares value isn't divided by nr_cpu_ids when setting shares of the sched entity. This patch fixes this bug. And echoing ULONG_MAX value into cpu.shares also causes Div0 error, so we set a macro MAX_SHARES to limit the max value of shares. Signed-off-by: Miao Xie <miaox@cn.fujitsu.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-28 04:54:56 +00:00
* (The default weight is 1024 - so there's no practical
* limitation from this.)
*/
sched, cgroups: Fix MIN_SHARES on 64-bit boxen Commit c8b28116 ("sched: Increase SCHED_LOAD_SCALE resolution") intended to have no user-visible effect, but allows setting cpu.shares to < MIN_SHARES, which the user then sees. Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Nikhil Rao <ncrao@google.com> Link: http://lkml.kernel.org/r/1307192600.8618.3.camel@marge.simson.net Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-06-04 13:03:20 +00:00
#define MIN_SHARES (1UL << 1)
#define MAX_SHARES (1UL << 18)
sched: fair-group: SMP-nice for group scheduling Implement SMP nice support for the full group hierarchy. On each load-balance action, compile a sched_domain wide view of the full task_group tree. We compute the domain wide view when walking down the hierarchy, and readjust the weights when walking back up. After collecting and readjusting the domain wide view, we try to balance the tasks within the task_groups. The current approach is a naively balance each task group until we've moved the targeted amount of load. Inspired by Srivatsa Vaddsgiri's previous code and Abhishek Chandra's H-SMP paper. XXX: there will be some numerical issues due to the limited nature of SCHED_LOAD_SCALE wrt to representing a task_groups influence on the total weight. When the tree is deep enough, or the task weight small enough, we'll run out of bits. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> CC: Abhishek Chandra <chandra@cs.umn.edu> CC: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 17:45:00 +00:00
sched: Consolidate the name of root_task_group and init_task_group root_task_group is the leftover of USER_SCHED, now it's always same to init_task_group. But as Mike suggested, root_task_group is maybe the suitable name to keep for a tree. So in this patch: init_task_group --> root_task_group init_task_group_load --> root_task_group_load INIT_TASK_GROUP_LOAD --> ROOT_TASK_GROUP_LOAD Suggested-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Yong Zhang <yong.zhang0@gmail.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20110107071736.GA32635@windriver.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-01-07 07:17:36 +00:00
static int root_task_group_load = ROOT_TASK_GROUP_LOAD;
sched: rt-group: make rt groups scheduling configurable Make the rt group scheduler compile time configurable. Keep it experimental for now. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-13 14:45:40 +00:00
#endif
sched: group-scheduler core Add interface to control cpu bandwidth allocation to task-groups. (not yet configurable, due to missing CONFIG_CONTAINERS) Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
2007-10-15 15:00:07 +00:00
/* Default task group.
sched: whitespace cleanups more whitespace cleanups. No code changed: text data bss dec hex filename 26553 2790 288 29631 73bf sched.o.before 26553 2790 288 29631 73bf sched.o.after Signed-off-by: Ingo Molnar <mingo@elte.hu> Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-15 15:00:12 +00:00
* Every task in system belong to this group at bootup.
sched: group-scheduler core Add interface to control cpu bandwidth allocation to task-groups. (not yet configurable, due to missing CONFIG_CONTAINERS) Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
2007-10-15 15:00:07 +00:00
*/
sched: Consolidate the name of root_task_group and init_task_group root_task_group is the leftover of USER_SCHED, now it's always same to init_task_group. But as Mike suggested, root_task_group is maybe the suitable name to keep for a tree. So in this patch: init_task_group --> root_task_group init_task_group_load --> root_task_group_load INIT_TASK_GROUP_LOAD --> ROOT_TASK_GROUP_LOAD Suggested-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Yong Zhang <yong.zhang0@gmail.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20110107071736.GA32635@windriver.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-01-07 07:17:36 +00:00
struct task_group root_task_group;
sched: group-scheduler core Add interface to control cpu bandwidth allocation to task-groups. (not yet configurable, due to missing CONFIG_CONTAINERS) Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
2007-10-15 15:00:07 +00:00
sched: Remove USER_SCHED Remove the USER_SCHED feature. It has been scheduled to be removed in 2.6.34 as per http://marc.info/?l=linux-kernel&m=125728479022976&w=2 Signed-off-by: Dhaval Giani <dhaval.giani@gmail.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1263990378.24844.3.camel@localhost> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-01-20 12:26:18 +00:00
#endif /* CONFIG_CGROUP_SCHED */
sched: group-scheduler core Add interface to control cpu bandwidth allocation to task-groups. (not yet configurable, due to missing CONFIG_CONTAINERS) Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
2007-10-15 15:00:07 +00:00
sched: cfs rq data types add the CFS rq data types to sched.c. (the old scheduler fields are still intact, they are removed by a later patch) Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-09 16:51:58 +00:00
/* CFS-related fields in a runqueue */
struct cfs_rq {
struct load_weight load;
sched: Implement hierarchical task accounting for SCHED_OTHER Introduce hierarchical task accounting for the group scheduling case in CFS, as well as promoting the responsibility for maintaining rq->nr_running to the scheduling classes. The primary motivation for this is that with scheduling classes supporting bandwidth throttling it is possible for entities participating in throttled sub-trees to not have root visible changes in rq->nr_running across activate and de-activate operations. This in turn leads to incorrect idle and weight-per-task load balance decisions. This also allows us to make a small fixlet to the fastpath in pick_next_task() under group scheduling. Note: this issue also exists with the existing sched_rt throttling mechanism. This patch does not address that. Signed-off-by: Paul Turner <pjt@google.com> Reviewed-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110721184756.878333391@google.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-21 16:43:27 +00:00
unsigned long nr_running, h_nr_running;
sched: cfs rq data types add the CFS rq data types to sched.c. (the old scheduler fields are still intact, they are removed by a later patch) Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-09 16:51:58 +00:00
u64 exec_clock;
sched: introduce se->vruntime introduce se->vruntime as a sum of weighted delta-exec's, and use that as the key into the tree. the idea to use absolute virtual time as the basic metric of scheduling has been first raised by William Lee Irwin, advanced by Tong Li and first prototyped by Roman Zippel in the "Really Fair Scheduler" (RFS) patchset. also see: http://lkml.org/lkml/2007/9/2/76 for a simpler variant of this patch. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Mike Galbraith <efault@gmx.de> Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-15 15:00:04 +00:00
u64 min_vruntime;
sched: Deal with non-atomic min_vruntime reads on 32bits In order to avoid reading partial updated min_vruntime values on 32bit implement a seqcount like solution. Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110405152729.111378493@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-05 15:23:48 +00:00
#ifndef CONFIG_64BIT
u64 min_vruntime_copy;
#endif
sched: cfs rq data types add the CFS rq data types to sched.c. (the old scheduler fields are still intact, they are removed by a later patch) Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-09 16:51:58 +00:00
struct rb_root tasks_timeline;
struct rb_node *rb_leftmost;
sched: fair-group: de-couple load-balancing from the rb-trees De-couple load-balancing from the rb-trees, so that I can change their organization. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 17:45:00 +00:00
struct list_head tasks;
struct list_head *balance_iterator;
/*
* 'curr' points to currently running entity on this cfs_rq.
sched: cfs rq data types add the CFS rq data types to sched.c. (the old scheduler fields are still intact, they are removed by a later patch) Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-09 16:51:58 +00:00
* It is set to NULL otherwise (i.e when none are currently running).
*/
sched: Use a buddy to implement yield_task_fair() Use the buddy mechanism to implement yield_task_fair. This allows us to skip onto the next highest priority se at every level in the CFS tree, unless doing so would introduce gross unfairness in CPU time distribution. We order the buddy selection in pick_next_entity to check yield first, then last, then next. We need next to be able to override yield, because it is possible for the "next" and "yield" task to be different processen in the same sub-tree of the CFS tree. When they are, we need to go into that sub-tree regardless of the "yield" hint, and pick the correct entity once we get to the right level. Signed-off-by: Rik van Riel <riel@redhat.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20110201095103.3a79e92a@annuminas.surriel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-02-01 14:51:03 +00:00
struct sched_entity *curr, *next, *last, *skip;
sched debug: check spread debug feature: check how well we schedule within a reasonable vruntime 'spread' range. (note that CPU overload can increase the spread, so this is not a hard condition, but normal loads should be within the spread.) Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
2007-10-15 15:00:10 +00:00
sched: Wrap the 'cfs_rq->nr_spread_over' field with CONFIG_SCHED_DEBUG cfs_rq->nr_spread_over is only used when CONFIG_SCHED_DEBUG is set. So wrap it with CONFIG_SCHED_DEBUG. Signed-off-by: Rakib Mullick <rakib.mullick@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1304528026.15681.3.camel@localhost.localdomain Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-05-04 16:53:46 +00:00
#ifdef CONFIG_SCHED_DEBUG
sched: clean up debug info Impact: clean up and fix debug info printout While looking over the sched_debug code I noticed that we printed the rq schedstats for every cfs_rq, ammend this. Also change nr_spead_over into an int, and fix a little buglet in min_vruntime printing. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-10 09:46:32 +00:00
unsigned int nr_spread_over;
sched: Wrap the 'cfs_rq->nr_spread_over' field with CONFIG_SCHED_DEBUG cfs_rq->nr_spread_over is only used when CONFIG_SCHED_DEBUG is set. So wrap it with CONFIG_SCHED_DEBUG. Signed-off-by: Rakib Mullick <rakib.mullick@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1304528026.15681.3.camel@localhost.localdomain Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-05-04 16:53:46 +00:00
#endif
sched debug: check spread debug feature: check how well we schedule within a reasonable vruntime 'spread' range. (note that CPU overload can increase the spread, so this is not a hard condition, but normal loads should be within the spread.) Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
2007-10-15 15:00:10 +00:00
sched: track cfs_rq->curr on !group-scheduling too Noticed by Roman Zippel: use cfs_rq->curr in the !group-scheduling case too. Small micro-optimization and cleanup effect: text data bss dec hex filename 36269 3482 24 39775 9b5f sched.o.before 36177 3486 24 39687 9b07 sched.o.after Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Mike Galbraith <efault@gmx.de> Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-15 15:00:03 +00:00
#ifdef CONFIG_FAIR_GROUP_SCHED
sched: cfs rq data types add the CFS rq data types to sched.c. (the old scheduler fields are still intact, they are removed by a later patch) Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-09 16:51:58 +00:00
struct rq *rq; /* cpu runqueue to which this cfs_rq is attached */
sched: style cleanups style cleanup of various changes that were done recently. no code changed: text data bss dec hex filename 23680 2542 28 26250 668a sched.o.before 23680 2542 28 26250 668a sched.o.after Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-12-05 14:46:09 +00:00
/*
* leaf cfs_rqs are those that hold tasks (lowest schedulable entity in
sched: cfs rq data types add the CFS rq data types to sched.c. (the old scheduler fields are still intact, they are removed by a later patch) Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-09 16:51:58 +00:00
* a hierarchy). Non-leaf lrqs hold other higher schedulable entities
* (like users, containers etc.)
*
* leaf_cfs_rq_list ties together list of leaf cfs_rq's in a cpu. This
* list is used during load balance.
*/
sched: Implement on-demand (active) cfs_rq list Make certain load-balance actions scale per number of active cgroups instead of the number of existing cgroups. This makes wakeup/sleep paths more expensive, but is a win for systems where the vast majority of existing cgroups are idle. Signed-off-by: Paul Turner <pjt@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20101115234937.666535048@google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-15 23:47:01 +00:00
int on_list;
sched: style cleanups style cleanup of various changes that were done recently. no code changed: text data bss dec hex filename 23680 2542 28 26250 668a sched.o.before 23680 2542 28 26250 668a sched.o.after Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-12-05 14:46:09 +00:00
struct list_head leaf_cfs_rq_list;
struct task_group *tg; /* group that "owns" this runqueue */
sched: revert revert of: fair-group: SMP-nice for group scheduling Try again.. Initial commit: 18d95a2832c1392a2d63227a7a6d433cb9f2037e Revert: 6363ca57c76b7b83639ca8c83fc285fa26a7880e Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Cc: Mike Galbraith <efault@gmx.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-27 11:41:14 +00:00
#ifdef CONFIG_SMP
/*
sched: simplify the group load balancer While thinking about the previous patch - I realized that using per domain aggregate load values in load_balance_fair() is wrong. We should use the load value for that CPU. By not needing per domain hierarchical load values we don't need to store per domain aggregate shares, which greatly simplifies all the math. It basically falls apart in two separate computations: - per domain update of the shares - per CPU update of the hierarchical load Also get rid of the move_group_shares() stuff - just re-compute the shares again after a successful load balance. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Cc: Mike Galbraith <efault@gmx.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-27 11:41:23 +00:00
* the part of load.weight contributed by tasks
sched: revert revert of: fair-group: SMP-nice for group scheduling Try again.. Initial commit: 18d95a2832c1392a2d63227a7a6d433cb9f2037e Revert: 6363ca57c76b7b83639ca8c83fc285fa26a7880e Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Cc: Mike Galbraith <efault@gmx.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-27 11:41:14 +00:00
*/
sched: simplify the group load balancer While thinking about the previous patch - I realized that using per domain aggregate load values in load_balance_fair() is wrong. We should use the load value for that CPU. By not needing per domain hierarchical load values we don't need to store per domain aggregate shares, which greatly simplifies all the math. It basically falls apart in two separate computations: - per domain update of the shares - per CPU update of the hierarchical load Also get rid of the move_group_shares() stuff - just re-compute the shares again after a successful load balance. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Cc: Mike Galbraith <efault@gmx.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-27 11:41:23 +00:00
unsigned long task_weight;
sched: revert revert of: fair-group: SMP-nice for group scheduling Try again.. Initial commit: 18d95a2832c1392a2d63227a7a6d433cb9f2037e Revert: 6363ca57c76b7b83639ca8c83fc285fa26a7880e Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Cc: Mike Galbraith <efault@gmx.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-27 11:41:14 +00:00
sched: simplify the group load balancer While thinking about the previous patch - I realized that using per domain aggregate load values in load_balance_fair() is wrong. We should use the load value for that CPU. By not needing per domain hierarchical load values we don't need to store per domain aggregate shares, which greatly simplifies all the math. It basically falls apart in two separate computations: - per domain update of the shares - per CPU update of the hierarchical load Also get rid of the move_group_shares() stuff - just re-compute the shares again after a successful load balance. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Cc: Mike Galbraith <efault@gmx.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-27 11:41:23 +00:00
/*
* h_load = weight * f(tg)
*
* Where f(tg) is the recursive weight fraction assigned to
* this group.
*/
unsigned long h_load;
sched: revert revert of: fair-group: SMP-nice for group scheduling Try again.. Initial commit: 18d95a2832c1392a2d63227a7a6d433cb9f2037e Revert: 6363ca57c76b7b83639ca8c83fc285fa26a7880e Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Cc: Mike Galbraith <efault@gmx.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-27 11:41:14 +00:00
sched: simplify the group load balancer While thinking about the previous patch - I realized that using per domain aggregate load values in load_balance_fair() is wrong. We should use the load value for that CPU. By not needing per domain hierarchical load values we don't need to store per domain aggregate shares, which greatly simplifies all the math. It basically falls apart in two separate computations: - per domain update of the shares - per CPU update of the hierarchical load Also get rid of the move_group_shares() stuff - just re-compute the shares again after a successful load balance. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Cc: Mike Galbraith <efault@gmx.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-27 11:41:23 +00:00
/*
sched: Implement demand based update_cfs_load() When the system is busy, dilation of rq->next_balance makes lb->update_shares() insufficiently frequent for threads which don't sleep (no dequeue/enqueue updates). Adjust for this by making demand based updates based on the accumulation of execution time sufficient to wrap our averaging window. Signed-off-by: Paul Turner <pjt@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20101115234938.291159744@google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-15 23:47:08 +00:00
* Maintaining per-cpu shares distribution for group scheduling
*
* load_stamp is the last time we updated the load average
* load_last is the last time we updated the load average and saw load
* load_unacc_exec_time is currently unaccounted execution time
sched: simplify the group load balancer While thinking about the previous patch - I realized that using per domain aggregate load values in load_balance_fair() is wrong. We should use the load value for that CPU. By not needing per domain hierarchical load values we don't need to store per domain aggregate shares, which greatly simplifies all the math. It basically falls apart in two separate computations: - per domain update of the shares - per CPU update of the hierarchical load Also get rid of the move_group_shares() stuff - just re-compute the shares again after a successful load balance. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Cc: Mike Galbraith <efault@gmx.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-27 11:41:23 +00:00
*/
sched: Rewrite tg_shares_up) By tracking a per-cpu load-avg for each cfs_rq and folding it into a global task_group load on each tick we can rework tg_shares_up to be strictly per-cpu. This should improve cpu-cgroup performance for smp systems significantly. [ Paul: changed to use queueing cfs_rq + bug fixes ] Signed-off-by: Paul Turner <pjt@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20101115234937.580480400@google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-15 23:47:00 +00:00
u64 load_avg;
u64 load_period;
sched: Implement demand based update_cfs_load() When the system is busy, dilation of rq->next_balance makes lb->update_shares() insufficiently frequent for threads which don't sleep (no dequeue/enqueue updates). Adjust for this by making demand based updates based on the accumulation of execution time sufficient to wrap our averaging window. Signed-off-by: Paul Turner <pjt@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20101115234938.291159744@google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-15 23:47:08 +00:00
u64 load_stamp, load_last, load_unacc_exec_time;
sched: incremental effective_load() Increase the accuracy of the effective_load values. Not only consider the current increment (as per the attempted wakeup), but also consider the delta between when we last adjusted the shares and the current situation. Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Cc: Mike Galbraith <efault@gmx.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-27 11:41:38 +00:00
sched: Rewrite tg_shares_up) By tracking a per-cpu load-avg for each cfs_rq and folding it into a global task_group load on each tick we can rework tg_shares_up to be strictly per-cpu. This should improve cpu-cgroup performance for smp systems significantly. [ Paul: changed to use queueing cfs_rq + bug fixes ] Signed-off-by: Paul Turner <pjt@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20101115234937.580480400@google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-15 23:47:00 +00:00
unsigned long load_contribution;
sched: revert revert of: fair-group: SMP-nice for group scheduling Try again.. Initial commit: 18d95a2832c1392a2d63227a7a6d433cb9f2037e Revert: 6363ca57c76b7b83639ca8c83fc285fa26a7880e Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Cc: Mike Galbraith <efault@gmx.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-27 11:41:14 +00:00
#endif
sched: Introduce primitives to account for CFS bandwidth tracking In this patch we introduce the notion of CFS bandwidth, partitioned into globally unassigned bandwidth, and locally claimed bandwidth. - The global bandwidth is per task_group, it represents a pool of unclaimed bandwidth that cfs_rqs can allocate from. - The local bandwidth is tracked per-cfs_rq, this represents allotments from the global pool bandwidth assigned to a specific cpu. Bandwidth is managed via cgroupfs, adding two new interfaces to the cpu subsystem: - cpu.cfs_period_us : the bandwidth period in usecs - cpu.cfs_quota_us : the cpu bandwidth (in usecs) that this tg will be allowed to consume over period above. Signed-off-by: Paul Turner <pjt@google.com> Signed-off-by: Nikhil Rao <ncrao@google.com> Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com> Reviewed-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110721184756.972636699@google.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-21 16:43:28 +00:00
#ifdef CONFIG_CFS_BANDWIDTH
int runtime_enabled;
s64 runtime_remaining;
#endif
sched: cfs rq data types add the CFS rq data types to sched.c. (the old scheduler fields are still intact, they are removed by a later patch) Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-09 16:51:58 +00:00
#endif
};
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
sched: Introduce primitives to account for CFS bandwidth tracking In this patch we introduce the notion of CFS bandwidth, partitioned into globally unassigned bandwidth, and locally claimed bandwidth. - The global bandwidth is per task_group, it represents a pool of unclaimed bandwidth that cfs_rqs can allocate from. - The local bandwidth is tracked per-cfs_rq, this represents allotments from the global pool bandwidth assigned to a specific cpu. Bandwidth is managed via cgroupfs, adding two new interfaces to the cpu subsystem: - cpu.cfs_period_us : the bandwidth period in usecs - cpu.cfs_quota_us : the cpu bandwidth (in usecs) that this tg will be allowed to consume over period above. Signed-off-by: Paul Turner <pjt@google.com> Signed-off-by: Nikhil Rao <ncrao@google.com> Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com> Reviewed-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110721184756.972636699@google.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-21 16:43:28 +00:00
#ifdef CONFIG_FAIR_GROUP_SCHED
#ifdef CONFIG_CFS_BANDWIDTH
static inline struct cfs_bandwidth *tg_cfs_bandwidth(struct task_group *tg)
{
return &tg->cfs_bandwidth;
}
static inline u64 default_cfs_period(void);
static void init_cfs_bandwidth(struct cfs_bandwidth *cfs_b)
{
raw_spin_lock_init(&cfs_b->lock);
sched: Accumulate per-cfs_rq cpu usage and charge against bandwidth Account bandwidth usage on the cfs_rq level versus the task_groups to which they belong. Whether we are tracking bandwidth on a given cfs_rq is maintained under cfs_rq->runtime_enabled. cfs_rq's which belong to a bandwidth constrained task_group have their runtime accounted via the update_curr() path, which withdraws bandwidth from the global pool as desired. Updates involving the global pool are currently protected under cfs_bandwidth->lock, local runtime is protected by rq->lock. This patch only assigns and tracks quota, no action is taken in the case that cfs_rq->runtime_used exceeds cfs_rq->runtime_assigned. Signed-off-by: Paul Turner <pjt@google.com> Signed-off-by: Nikhil Rao <ncrao@google.com> Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com> Reviewed-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110721184757.179386821@google.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-21 16:43:30 +00:00
cfs_b->runtime = 0;
sched: Introduce primitives to account for CFS bandwidth tracking In this patch we introduce the notion of CFS bandwidth, partitioned into globally unassigned bandwidth, and locally claimed bandwidth. - The global bandwidth is per task_group, it represents a pool of unclaimed bandwidth that cfs_rqs can allocate from. - The local bandwidth is tracked per-cfs_rq, this represents allotments from the global pool bandwidth assigned to a specific cpu. Bandwidth is managed via cgroupfs, adding two new interfaces to the cpu subsystem: - cpu.cfs_period_us : the bandwidth period in usecs - cpu.cfs_quota_us : the cpu bandwidth (in usecs) that this tg will be allowed to consume over period above. Signed-off-by: Paul Turner <pjt@google.com> Signed-off-by: Nikhil Rao <ncrao@google.com> Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com> Reviewed-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110721184756.972636699@google.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-21 16:43:28 +00:00
cfs_b->quota = RUNTIME_INF;
cfs_b->period = ns_to_ktime(default_cfs_period());
}
static void init_cfs_rq_runtime(struct cfs_rq *cfs_rq)
{
cfs_rq->runtime_enabled = 0;
}
static void destroy_cfs_bandwidth(struct cfs_bandwidth *cfs_b)
{}
#else
static void init_cfs_rq_runtime(struct cfs_rq *cfs_rq) {}
static void init_cfs_bandwidth(struct cfs_bandwidth *cfs_b) {}
static void destroy_cfs_bandwidth(struct cfs_bandwidth *cfs_b) {}
static inline struct cfs_bandwidth *tg_cfs_bandwidth(struct task_group *tg)
{
return NULL;
}
#endif /* CONFIG_CFS_BANDWIDTH */
#endif /* CONFIG_FAIR_GROUP_SCHED */
sched: cfs rq data types add the CFS rq data types to sched.c. (the old scheduler fields are still intact, they are removed by a later patch) Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-09 16:51:58 +00:00
/* Real-Time classes' related field in a runqueue: */
struct rt_rq {
struct rt_prio_array active;
sched: count # of queued RT tasks This patch adds accounting to keep track of the number of RT tasks running on a runqueue. This information will be used in later patches. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:03 +00:00
unsigned long rt_nr_running;
sched: rt-group: make rt groups scheduling configurable Make the rt group scheduler compile time configurable. Keep it experimental for now. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-13 14:45:40 +00:00
#if defined CONFIG_SMP || defined CONFIG_RT_GROUP_SCHED
sched: track the next-highest priority on each runqueue We will use this later in the series to reduce the amount of rq-lock contention during a pull operation Signed-off-by: Gregory Haskins <ghaskins@novell.com>
2008-12-29 14:39:49 +00:00
struct {
int curr; /* highest queued rt task prio */
sched: fix build error in kernel/sched_rt.c when RT_GROUP_SCHED && !SMP Ingo found a build error in the scheduler when RT_GROUP_SCHED was enabled, but SMP was not. This patch rearranges the code such that it is a little more streamlined and compiles under all permutations of SMP, UP and RT_GROUP_SCHED. It was boot tested on my 4-way x86_64 and it still passes preempt-test. Signed-off-by: Gregory Haskins <ghaskins@novell.com>
2009-01-14 14:10:04 +00:00
#ifdef CONFIG_SMP
sched: track the next-highest priority on each runqueue We will use this later in the series to reduce the amount of rq-lock contention during a pull operation Signed-off-by: Gregory Haskins <ghaskins@novell.com>
2008-12-29 14:39:49 +00:00
int next; /* next highest */
sched: fix build error in kernel/sched_rt.c when RT_GROUP_SCHED && !SMP Ingo found a build error in the scheduler when RT_GROUP_SCHED was enabled, but SMP was not. This patch rearranges the code such that it is a little more streamlined and compiles under all permutations of SMP, UP and RT_GROUP_SCHED. It was boot tested on my 4-way x86_64 and it still passes preempt-test. Signed-off-by: Gregory Haskins <ghaskins@novell.com>
2009-01-14 14:10:04 +00:00
#endif
sched: track the next-highest priority on each runqueue We will use this later in the series to reduce the amount of rq-lock contention during a pull operation Signed-off-by: Gregory Haskins <ghaskins@novell.com>
2008-12-29 14:39:49 +00:00
} highest_prio;
sched: rt group scheduling Extend group scheduling to also cover the realtime classes. It uses the time limiting introduced by the previous patch to allow multiple realtime groups. The hard time limit is required to keep behaviour deterministic. The algorithms used make the realtime scheduler O(tg), linear scaling wrt the number of task groups. This is the worst case behaviour I can't seem to get out of, the avg. case of the algorithms can be improved, I focused on correctness and worst case. [ akpm@linux-foundation.org: move side-effects out of BUG_ON(). ] Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:30 +00:00
#endif
sched: rt time limit Very simple time limit on the realtime scheduling classes. Allow the rq's realtime class to consume sched_rt_ratio of every sched_rt_period slice. If the class exceeds this quota the fair class will preempt the realtime class. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:29 +00:00
#ifdef CONFIG_SMP
sched: add RT-balance cpu-weight Some RT tasks (particularly kthreads) are bound to one specific CPU. It is fairly common for two or more bound tasks to get queued up at the same time. Consider, for instance, softirq_timer and softirq_sched. A timer goes off in an ISR which schedules softirq_thread to run at RT50. Then the timer handler determines that it's time to smp-rebalance the system so it schedules softirq_sched to run. So we are in a situation where we have two RT50 tasks queued, and the system will go into rt-overload condition to request other CPUs for help. This causes two problems in the current code: 1) If a high-priority bound task and a low-priority unbounded task queue up behind the running task, we will fail to ever relocate the unbounded task because we terminate the search on the first unmovable task. 2) We spend precious futile cycles in the fast-path trying to pull overloaded tasks over. It is therefore optimial to strive to avoid the overhead all together if we can cheaply detect the condition before overload even occurs. This patch tries to achieve this optimization by utilizing the hamming weight of the task->cpus_allowed mask. A weight of 1 indicates that the task cannot be migrated. We will then utilize this information to skip non-migratable tasks and to eliminate uncessary rebalance attempts. We introduce a per-rq variable to count the number of migratable tasks that are currently running. We only go into overload if we have more than one rt task, AND at least one of them is migratable. In addition, we introduce a per-task variable to cache the cpus_allowed weight, since the hamming calculation is probably relatively expensive. We only update the cached value when the mask is updated which should be relatively infrequent, especially compared to scheduling frequency in the fast path. Signed-off-by: Gregory Haskins <ghaskins@novell.com> Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:07 +00:00
unsigned long rt_nr_migratory;
sched_rt: Fix overload bug on rt group scheduling Fixes an easily triggerable BUG() when setting process affinities. Make sure to count the number of migratable tasks in the same place: the root rt_rq. Otherwise the number doesn't make sense and we'll hit the BUG in set_cpus_allowed_rt(). Also, make sure we only count tasks, not groups (this is probably already taken care of by the fact that rt_se->nr_cpus_allowed will be 0 for groups, but be more explicit) Tested-by: Thomas Gleixner <tglx@linutronix.de> CC: stable@kernel.org Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Gregory Haskins <ghaskins@novell.com> LKML-Reference: <1247067476.9777.57.camel@twins> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-01 16:40:15 +00:00
unsigned long rt_nr_total;
sched: wake-balance fixes We have logic to detect whether the system has migratable tasks, but we are not using it when deciding whether to push tasks away. So we add support for considering this new information. Signed-off-by: Gregory Haskins <ghaskins@novell.com> Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:12 +00:00
int overloaded;
sched: create "pushable_tasks" list to limit pushing to one attempt The RT scheduler employs a "push/pull" design to actively balance tasks within the system (on a per disjoint cpuset basis). When a task is awoken, it is immediately determined if there are any lower priority cpus which should be preempted. This is opposed to the way normal SCHED_OTHER tasks behave, which will wait for a periodic rebalancing operation to occur before spreading out load. When a particular RQ has more than 1 active RT task, it is said to be in an "overloaded" state. Once this occurs, the system enters the active balancing mode, where it will try to push the task away, or persuade a different cpu to pull it over. The system will stay in this state until the system falls back below the <= 1 queued RT task per RQ. However, the current implementation suffers from a limitation in the push logic. Once overloaded, all tasks (other than current) on the RQ are analyzed on every push operation, even if it was previously unpushable (due to affinity, etc). Whats more, the operation stops at the first task that is unpushable and will not look at items lower in the queue. This causes two problems: 1) We can have the same tasks analyzed over and over again during each push, which extends out the fast path in the scheduler for no gain. Consider a RQ that has dozens of tasks that are bound to a core. Each one of those tasks will be encountered and skipped for each push operation while they are queued. 2) There may be lower-priority tasks under the unpushable task that could have been successfully pushed, but will never be considered until either the unpushable task is cleared, or a pull operation succeeds. The net result is a potential latency source for mid priority tasks. This patch aims to rectify these two conditions by introducing a new priority sorted list: "pushable_tasks". A task is added to the list each time a task is activated or preempted. It is removed from the list any time it is deactivated, made current, or fails to push. This works because a task only needs to be attempted to push once. After an initial failure to push, the other cpus will eventually try to pull the task when the conditions are proper. This also solves the problem that we don't completely analyze all tasks due to encountering an unpushable tasks. Now every task will have a push attempted (when appropriate). This reduces latency both by shorting the critical section of the rq->lock for certain workloads, and by making sure the algorithm considers all eligible tasks in the system. [ rostedt: added a couple more BUG_ONs ] Signed-off-by: Gregory Haskins <ghaskins@novell.com> Acked-by: Steven Rostedt <srostedt@redhat.com>
2008-12-29 14:39:53 +00:00
struct plist_head pushable_tasks;
sched: rt time limit Very simple time limit on the realtime scheduling classes. Allow the rq's realtime class to consume sched_rt_ratio of every sched_rt_period slice. If the class exceeds this quota the fair class will preempt the realtime class. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:29 +00:00
#endif
sched: rt group scheduling Extend group scheduling to also cover the realtime classes. It uses the time limiting introduced by the previous patch to allow multiple realtime groups. The hard time limit is required to keep behaviour deterministic. The algorithms used make the realtime scheduler O(tg), linear scaling wrt the number of task groups. This is the worst case behaviour I can't seem to get out of, the avg. case of the algorithms can be improved, I focused on correctness and worst case. [ akpm@linux-foundation.org: move side-effects out of BUG_ON(). ] Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:30 +00:00
int rt_throttled;
sched: rt time limit Very simple time limit on the realtime scheduling classes. Allow the rq's realtime class to consume sched_rt_ratio of every sched_rt_period slice. If the class exceeds this quota the fair class will preempt the realtime class. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:29 +00:00
u64 rt_time;
sched: rt-group: smp balancing Currently the rt group scheduling does a per cpu runtime limit, however the rt load balancer makes no guarantees about an equal spread of real- time tasks, just that at any one time, the highest priority tasks run. Solve this by making the runtime limit a global property by borrowing excessive runtime from the other cpus once the local limit runs out. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 17:44:58 +00:00
u64 rt_runtime;
sched: fix checks Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-03-25 12:51:45 +00:00
/* Nests inside the rq lock: */
sched: Convert rt_runtime_lock to raw_spinlock Convert locks which cannot be sleeping locks in preempt-rt to raw_spinlocks. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Ingo Molnar <mingo@elte.hu>
2009-11-17 14:32:06 +00:00
raw_spinlock_t rt_runtime_lock;
sched: rt group scheduling Extend group scheduling to also cover the realtime classes. It uses the time limiting introduced by the previous patch to allow multiple realtime groups. The hard time limit is required to keep behaviour deterministic. The algorithms used make the realtime scheduler O(tg), linear scaling wrt the number of task groups. This is the worst case behaviour I can't seem to get out of, the avg. case of the algorithms can be improved, I focused on correctness and worst case. [ akpm@linux-foundation.org: move side-effects out of BUG_ON(). ] Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:30 +00:00
sched: rt-group: make rt groups scheduling configurable Make the rt group scheduler compile time configurable. Keep it experimental for now. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-13 14:45:40 +00:00
#ifdef CONFIG_RT_GROUP_SCHED
sched: rt-group: deal with PI Steven mentioned the fun case where a lock holding task will be throttled. Simple fix: allow groups that have boosted tasks to run anyway. If a runnable task in a throttled group gets boosted the dequeue/enqueue done by rt_mutex_setprio() is enough to unthrottle the group. This is ofcourse not quite correct. Two possible ways forward are: - second prio array for boosted tasks - boost to a prio ceiling (this would also work for deadline scheduling) Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-13 14:45:39 +00:00
unsigned long rt_nr_boosted;
sched: rt group scheduling Extend group scheduling to also cover the realtime classes. It uses the time limiting introduced by the previous patch to allow multiple realtime groups. The hard time limit is required to keep behaviour deterministic. The algorithms used make the realtime scheduler O(tg), linear scaling wrt the number of task groups. This is the worst case behaviour I can't seem to get out of, the avg. case of the algorithms can be improved, I focused on correctness and worst case. [ akpm@linux-foundation.org: move side-effects out of BUG_ON(). ] Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:30 +00:00
struct rq *rq;
struct list_head leaf_rt_rq_list;
struct task_group *tg;
#endif
sched: cfs rq data types add the CFS rq data types to sched.c. (the old scheduler fields are still intact, they are removed by a later patch) Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-09 16:51:58 +00:00
};
sched: add sched-domain roots We add the notion of a root-domain which will be used later to rescope global variables to per-domain variables. Each exclusive cpuset essentially defines an island domain by fully partitioning the member cpus from any other cpuset. However, we currently still maintain some policy/state as global variables which transcend all cpusets. Consider, for instance, rt-overload state. Whenever a new exclusive cpuset is created, we also create a new root-domain object and move each cpu member to the root-domain's span. By default the system creates a single root-domain with all cpus as members (mimicking the global state we have today). We add some plumbing for storing class specific data in our root-domain. Whenever a RQ is switching root-domains (because of repartitioning) we give each sched_class the opportunity to remove any state from its old domain and add state to the new one. This logic doesn't have any clients yet but it will later in the series. Signed-off-by: Gregory Haskins <ghaskins@novell.com> CC: Christoph Lameter <clameter@sgi.com> CC: Paul Jackson <pj@sgi.com> CC: Simon Derr <simon.derr@bull.net> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:18 +00:00
#ifdef CONFIG_SMP
/*
* We add the notion of a root-domain which will be used to define per-domain
sched: style cleanup, #2 style cleanup of various changes that were done recently. no code changed: text data bss dec hex filename 26399 2578 48 29025 7161 sched.o.before 26399 2578 48 29025 7161 sched.o.after Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:19 +00:00
* variables. Each exclusive cpuset essentially defines an island domain by
* fully partitioning the member cpus from any other cpuset. Whenever a new
sched: add sched-domain roots We add the notion of a root-domain which will be used later to rescope global variables to per-domain variables. Each exclusive cpuset essentially defines an island domain by fully partitioning the member cpus from any other cpuset. However, we currently still maintain some policy/state as global variables which transcend all cpusets. Consider, for instance, rt-overload state. Whenever a new exclusive cpuset is created, we also create a new root-domain object and move each cpu member to the root-domain's span. By default the system creates a single root-domain with all cpus as members (mimicking the global state we have today). We add some plumbing for storing class specific data in our root-domain. Whenever a RQ is switching root-domains (because of repartitioning) we give each sched_class the opportunity to remove any state from its old domain and add state to the new one. This logic doesn't have any clients yet but it will later in the series. Signed-off-by: Gregory Haskins <ghaskins@novell.com> CC: Christoph Lameter <clameter@sgi.com> CC: Paul Jackson <pj@sgi.com> CC: Simon Derr <simon.derr@bull.net> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:18 +00:00
* exclusive cpuset is created, we also create and attach a new root-domain
* object.
*
*/
struct root_domain {
atomic_t refcount;
sched: Reorder root_domain to remove 64 bit alignment padding Reorder root_domain to remove 8 bytes of alignment padding on 64 bit builds, this shrinks the size from 1736 to 1728 bytes, therefore using one fewer cachelines. Signed-off-by: Richard Kennedy <richard@rsk.demon.co.uk> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1310726492.1977.5.camel@castor.rsk Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-15 10:41:31 +00:00
atomic_t rto_count;
sched: Dynamically allocate sched_domain/sched_group data-structures Instead of relying on static allocations for the sched_domain and sched_group trees, dynamically allocate and RCU free them. Allocating this dynamically also allows for some build_sched_groups() simplification since we can now (like with other simplifications) rely on the sched_domain tree instead of hard-coded knowledge. One tricky to note is that detach_destroy_domains() needs to hold rcu_read_lock() over the entire tear-down, per-cpu is not sufficient since that can lead to partial sched_group existance (could possibly be solved by doing the tear-down backwards but this is much more robust). A concequence of the above is that we can no longer print the sched_domain debug stuff from cpu_attach_domain() since that might now run with preemption disabled (due to classic RCU etc.) and sched_domain_debug() does some GFP_KERNEL allocations. Another thing to note is that we now fully rely on normal RCU and not RCU-sched, this is because with the new and exiting RCU flavours we grew over the years BH doesn't necessarily hold off RCU-sched grace periods (-rt is known to break this). This would in fact already cause us grief since we do sched_domain/sched_group iterations from softirq context. This patch is somewhat larger than I would like it to be, but I didn't find any means of shrinking/splitting this. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.245307941@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:09:50 +00:00
struct rcu_head rcu;
sched: convert struct root_domain to cpumask_var_t. Impact: (future) size reduction for large NR_CPUS. Dynamically allocating cpumasks (when CONFIG_CPUMASK_OFFSTACK) saves space for small nr_cpu_ids but big CONFIG_NR_CPUS. cpumask_var_t is just a struct cpumask for !CONFIG_CPUMASK_OFFSTACK. def_root_domain is static, and so its masks are initialized with alloc_bootmem_cpumask_var. After that, alloc_cpumask_var is used. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-24 16:05:05 +00:00
cpumask_var_t span;
cpumask_var_t online;
sched: only balance our RT tasks within our domain We move the rt-overload data as the first global to per-domain reclassification. This limits the scope of overload related cache-line bouncing to stay with a specified partition instead of affecting all cpus in the system. Finally, we limit the scope of find_lowest_cpu searches to the domain instead of the entire system. Note that we would always respect domain boundaries even without this patch, but we first would scan potentially all cpus before whittling the list down. Now we can avoid looking at RQs that are out of scope, again reducing cache-line hits. Note: In some cases, task->cpus_allowed will effectively reduce our search to within our domain. However, I believe there are cases where the cpus_allowed mask may be all ones and therefore we err on the side of caution. If it can be optimized later, so be it. Signed-off-by: Gregory Haskins <ghaskins@novell.com> CC: Christoph Lameter <clameter@sgi.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:18 +00:00
sched: style cleanup, #2 style cleanup of various changes that were done recently. no code changed: text data bss dec hex filename 26399 2578 48 29025 7161 sched.o.before 26399 2578 48 29025 7161 sched.o.after Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:19 +00:00
/*
sched: only balance our RT tasks within our domain We move the rt-overload data as the first global to per-domain reclassification. This limits the scope of overload related cache-line bouncing to stay with a specified partition instead of affecting all cpus in the system. Finally, we limit the scope of find_lowest_cpu searches to the domain instead of the entire system. Note that we would always respect domain boundaries even without this patch, but we first would scan potentially all cpus before whittling the list down. Now we can avoid looking at RQs that are out of scope, again reducing cache-line hits. Note: In some cases, task->cpus_allowed will effectively reduce our search to within our domain. However, I believe there are cases where the cpus_allowed mask may be all ones and therefore we err on the side of caution. If it can be optimized later, so be it. Signed-off-by: Gregory Haskins <ghaskins@novell.com> CC: Christoph Lameter <clameter@sgi.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:18 +00:00
* The "RT overload" flag: it gets set if a CPU has more than
* one runnable RT task.
*/
sched: convert struct root_domain to cpumask_var_t. Impact: (future) size reduction for large NR_CPUS. Dynamically allocating cpumasks (when CONFIG_CPUMASK_OFFSTACK) saves space for small nr_cpu_ids but big CONFIG_NR_CPUS. cpumask_var_t is just a struct cpumask for !CONFIG_CPUMASK_OFFSTACK. def_root_domain is static, and so its masks are initialized with alloc_bootmem_cpumask_var. After that, alloc_cpumask_var is used. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-24 16:05:05 +00:00
cpumask_var_t rto_mask;
sched: use a 2-d bitmap for searching lowest-pri CPU The current code use a linear algorithm which causes scaling issues on larger SMP machines. This patch replaces that algorithm with a 2-dimensional bitmap to reduce latencies in the wake-up path. Signed-off-by: Gregory Haskins <ghaskins@novell.com> Acked-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-12 19:21:01 +00:00
struct cpupri cpupri;
sched: add sched-domain roots We add the notion of a root-domain which will be used later to rescope global variables to per-domain variables. Each exclusive cpuset essentially defines an island domain by fully partitioning the member cpus from any other cpuset. However, we currently still maintain some policy/state as global variables which transcend all cpusets. Consider, for instance, rt-overload state. Whenever a new exclusive cpuset is created, we also create a new root-domain object and move each cpu member to the root-domain's span. By default the system creates a single root-domain with all cpus as members (mimicking the global state we have today). We add some plumbing for storing class specific data in our root-domain. Whenever a RQ is switching root-domains (because of repartitioning) we give each sched_class the opportunity to remove any state from its old domain and add state to the new one. This logic doesn't have any clients yet but it will later in the series. Signed-off-by: Gregory Haskins <ghaskins@novell.com> CC: Christoph Lameter <clameter@sgi.com> CC: Paul Jackson <pj@sgi.com> CC: Simon Derr <simon.derr@bull.net> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:18 +00:00
};
sched: dynamically update the root-domain span/online maps The baseline code statically builds the span maps when the domain is formed. Previous attempts at dynamically updating the maps caused a suspend-to-ram regression, which should now be fixed. Signed-off-by: Gregory Haskins <ghaskins@novell.com> CC: Gautham R Shenoy <ego@in.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:26 +00:00
/*
* By default the system creates a single root-domain with all cpus as
* members (mimicking the global state we have today).
*/
sched: add sched-domain roots We add the notion of a root-domain which will be used later to rescope global variables to per-domain variables. Each exclusive cpuset essentially defines an island domain by fully partitioning the member cpus from any other cpuset. However, we currently still maintain some policy/state as global variables which transcend all cpusets. Consider, for instance, rt-overload state. Whenever a new exclusive cpuset is created, we also create a new root-domain object and move each cpu member to the root-domain's span. By default the system creates a single root-domain with all cpus as members (mimicking the global state we have today). We add some plumbing for storing class specific data in our root-domain. Whenever a RQ is switching root-domains (because of repartitioning) we give each sched_class the opportunity to remove any state from its old domain and add state to the new one. This logic doesn't have any clients yet but it will later in the series. Signed-off-by: Gregory Haskins <ghaskins@novell.com> CC: Christoph Lameter <clameter@sgi.com> CC: Paul Jackson <pj@sgi.com> CC: Simon Derr <simon.derr@bull.net> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:18 +00:00
static struct root_domain def_root_domain;
sched: Remove unnecessary #ifdef CONFIG_SMP The CONFIG_SMP ifdef isn't necessary at this point, because it is checked in an outer ifdef level already and has no effect here. Cleanup only, no functional effect. Signed-off-by: Christian Dietrich <qy03fugy@stud.informatik.uni-erlangen.de> Cc: vamos-dev@i4.informatik.uni-erlangen.de Cc: Peter Zijlstra <peterz@infradead.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Tejun Heo <tj@kernel.org> LKML-Reference: <7a3a39ef3f765a4473cb026b1f204059568a7098.1283782701.git.qy03fugy@stud.informatik.uni-erlangen.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-09-06 14:37:05 +00:00
#endif /* CONFIG_SMP */
sched: add sched-domain roots We add the notion of a root-domain which will be used later to rescope global variables to per-domain variables. Each exclusive cpuset essentially defines an island domain by fully partitioning the member cpus from any other cpuset. However, we currently still maintain some policy/state as global variables which transcend all cpusets. Consider, for instance, rt-overload state. Whenever a new exclusive cpuset is created, we also create a new root-domain object and move each cpu member to the root-domain's span. By default the system creates a single root-domain with all cpus as members (mimicking the global state we have today). We add some plumbing for storing class specific data in our root-domain. Whenever a RQ is switching root-domains (because of repartitioning) we give each sched_class the opportunity to remove any state from its old domain and add state to the new one. This logic doesn't have any clients yet but it will later in the series. Signed-off-by: Gregory Haskins <ghaskins@novell.com> CC: Christoph Lameter <clameter@sgi.com> CC: Paul Jackson <pj@sgi.com> CC: Simon Derr <simon.derr@bull.net> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:18 +00:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
/*
* This is the main, per-CPU runqueue data structure.
*
* Locking rule: those places that want to lock multiple runqueues
* (such as the load balancing or the thread migration code), lock
* acquire operations must be ordered by ascending &runqueue.
*/
[PATCH] sched: cleanup, convert sched.c-internal typedefs to struct convert: - runqueue_t to 'struct rq' - prio_array_t to 'struct prio_array' - migration_req_t to 'struct migration_req' I was the one who added these but they are both against the kernel coding style and also were used inconsistently at places. So just get rid of them at once, now that we are flushing the scheduler patch-queue anyway. Conversion was mostly scripted, the result was reviewed and all secondary whitespace and style impact (if any) was fixed up by hand. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-03 07:25:42 +00:00
struct rq {
sched: cleanup, make struct rq comments more consistent cleanup, make struct rq comments more consistent. found via scripts/checkpatch.pl. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-18 19:32:55 +00:00
/* runqueue lock: */
sched: Convert rq->lock to raw_spinlock Convert locks which cannot be sleeping locks in preempt-rt to raw_spinlocks. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Ingo Molnar <mingo@elte.hu>
2009-11-17 13:28:38 +00:00
raw_spinlock_t lock;
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
/*
* nr_running and cpu_load should be in the same cacheline because
* remote CPUs use both these fields when doing load calculation.
*/
unsigned long nr_running;
sched: cfs rq data types add the CFS rq data types to sched.c. (the old scheduler fields are still intact, they are removed by a later patch) Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-09 16:51:58 +00:00
#define CPU_LOAD_IDX_MAX 5
unsigned long cpu_load[CPU_LOAD_IDX_MAX];
sched: Avoid side-effect of tickless idle on update_cpu_load tickless idle has a negative side effect on update_cpu_load(), which in turn can affect load balancing behavior. update_cpu_load() is supposed to be called every tick, to keep track of various load indicies. With tickless idle, there are no scheduler ticks called on the idle CPUs. Idle CPUs may still do load balancing (with idle_load_balance CPU) using the stale cpu_load. It will also cause problems when all CPUs go idle for a while and become active again. In this case loads would not degrade as expected. This is how rq->nr_load_updates change looks like under different conditions: <cpu_num> <nr_load_updates change> All CPUS idle for 10 seconds (HZ=1000) 0 1621 10 496 11 139 12 875 13 1672 14 12 15 21 1 1472 2 2426 3 1161 4 2108 5 1525 6 701 7 249 8 766 9 1967 One CPU busy rest idle for 10 seconds 0 10003 10 601 11 95 12 966 13 1597 14 114 15 98 1 3457 2 93 3 6679 4 1425 5 1479 6 595 7 193 8 633 9 1687 All CPUs busy for 10 seconds 0 10026 10 10026 11 10026 12 10026 13 10025 14 10025 15 10025 1 10026 2 10026 3 10026 4 10026 5 10026 6 10026 7 10026 8 10026 9 10026 That is update_cpu_load works properly only when all CPUs are busy. If all are idle, all the CPUs get way lower updates. And when few CPUs are busy and rest are idle, only busy and ilb CPU does proper updates and rest of the idle CPUs will do lower updates. The patch keeps track of when a last update was done and fixes up the load avg based on current time. On one of my test system SPECjbb with warehouse 1..numcpus, patch improves throughput numbers by ~1% (average of 6 runs). On another test system (with different domain hierarchy) there is no noticable change in perf. Signed-off-by: Venkatesh Pallipadi <venki@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Thomas Gleixner <tglx@linutronix.de> LKML-Reference: <AANLkTilLtDWQsAUrIxJ6s04WTgmw9GuOODc5AOrYsaR5@mail.gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-05-18 01:14:43 +00:00
unsigned long last_load_update_tick;
sched: dynticks idle load balancing Fix the process idle load balancing in the presence of dynticks. cpus for which ticks are stopped will sleep till the next event wakes it up. Potentially these sleeps can be for large durations and during which today, there is no periodic idle load balancing being done. This patch nominates an owner among the idle cpus, which does the idle load balancing on behalf of the other idle cpus. And once all the cpus are completely idle, then we can stop this idle load balancing too. Checks added in fast path are minimized. Whenever there are busy cpus in the system, there will be an owner(idle cpu) doing the system wide idle load balancing. Open items: 1. Intelligent owner selection (like an idle core in a busy package). 2. Merge with rcu's nohz_cpu_mask? Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-08 07:32:51 +00:00
#ifdef CONFIG_NO_HZ
sched: Rate-limit nohz Entering nohz code on every micro-idle is costing ~10% throughput for netperf TCP_RR when scheduling cross-cpu. Rate limiting entry fixes this, but raises ticks a bit. On my Q6600, an idle box goes from ~85 interrupts/sec to 128. The higher the context switch rate, the more nohz entry costs. With this patch and some cycle recovery patches in my tree, max cross cpu context switch rate is improved by ~16%, a large portion of which of which is this ratelimiting. Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1268301003.6785.28.camel@marge.simson.net> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-03-11 16:17:13 +00:00
u64 nohz_stamp;
sched: Change nohz idle load balancing logic to push model In the new push model, all idle CPUs indeed go into nohz mode. There is still the concept of idle load balancer (performing the load balancing on behalf of all the idle cpu's in the system). Busy CPU kicks the nohz balancer when any of the nohz CPUs need idle load balancing. The kickee CPU does the idle load balancing on behalf of all idle CPUs instead of the normal idle balance. This addresses the below two problems with the current nohz ilb logic: * the idle load balancer continued to have periodic ticks during idle and wokeup frequently, even though it did not have any rebalancing to do on behalf of any of the idle CPUs. * On x86 and CPUs that have APIC timer stoppage on idle CPUs, this periodic wakeup can result in a periodic additional interrupt on a CPU doing the timer broadcast. Also currently we are migrating the unpinned timers from an idle to the cpu doing idle load balancing (when all the cpus in the system are idle, there is no idle load balancing cpu and timers get added to the same idle cpu where the request was made. So the existing optimization works only on semi idle system). And In semi idle system, we no longer have periodic ticks on the idle load balancer CPU. Using that cpu will add more delays to the timers than intended (as that cpu's timer base may not be uptodate wrt jiffies etc). This was causing mysterious slowdowns during boot etc. For now, in the semi idle case, use the nearest busy cpu for migrating timers from an idle cpu. This is good for power-savings anyway. Signed-off-by: Venkatesh Pallipadi <venki@google.com> Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Thomas Gleixner <tglx@linutronix.de> LKML-Reference: <1274486981.2840.46.camel@sbs-t61.sc.intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-05-22 00:09:41 +00:00
unsigned char nohz_balance_kick;
sched: dynticks idle load balancing Fix the process idle load balancing in the presence of dynticks. cpus for which ticks are stopped will sleep till the next event wakes it up. Potentially these sleeps can be for large durations and during which today, there is no periodic idle load balancing being done. This patch nominates an owner among the idle cpus, which does the idle load balancing on behalf of the other idle cpus. And once all the cpus are completely idle, then we can stop this idle load balancing too. Checks added in fast path are minimized. Whenever there are busy cpus in the system, there will be an owner(idle cpu) doing the system wide idle load balancing. Open items: 1. Intelligent owner selection (like an idle core in a busy package). 2. Merge with rcu's nohz_cpu_mask? Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-08 07:32:51 +00:00
#endif
sched, rt: Update rq clock when unthrottling of an otherwise idle CPU If an RT task is awakened while it's rt_rq is throttled, the time between wakeup/enqueue and unthrottle/selection may be accounted as rt_time if the CPU is idle. Set rq->skip_clock_update negative upon throttle release to tell put_prev_task() that we need a clock update. Reported-by: Thomas Giesel <skoe@directbox.com> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1304059010.7472.1.camel@marge.simson.net Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-29 06:36:50 +00:00
int skip_clock_update;
sched: Cleanup/optimize clock updates Now that we no longer depend on the clock being updated prior to enqueueing on migratory wakeup, we can clean up a bit, placing calls to update_rq_clock() exactly where they are needed, ie on enqueue, dequeue and schedule events. In the case of a freshly enqueued task immediately preempting, we can skip the update during preemption, as the clock was just updated by the enqueue event. We also save an unneeded call during a migratory wakeup by not updating the previous runqueue, where update_curr() won't be invoked. Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1268301199.6785.32.camel@marge.simson.net> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-03-11 16:16:20 +00:00
sched: cleanup, make struct rq comments more consistent cleanup, make struct rq comments more consistent. found via scripts/checkpatch.pl. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-18 19:32:55 +00:00
/* capture load from *all* tasks on this cpu: */
struct load_weight load;
sched: cfs rq data types add the CFS rq data types to sched.c. (the old scheduler fields are still intact, they are removed by a later patch) Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-09 16:51:58 +00:00
unsigned long nr_load_updates;
u64 nr_switches;
struct cfs_rq cfs;
sched: rt group scheduling Extend group scheduling to also cover the realtime classes. It uses the time limiting introduced by the previous patch to allow multiple realtime groups. The hard time limit is required to keep behaviour deterministic. The algorithms used make the realtime scheduler O(tg), linear scaling wrt the number of task groups. This is the worst case behaviour I can't seem to get out of, the avg. case of the algorithms can be improved, I focused on correctness and worst case. [ akpm@linux-foundation.org: move side-effects out of BUG_ON(). ] Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:30 +00:00
struct rt_rq rt;
sched: cfs rq data types add the CFS rq data types to sched.c. (the old scheduler fields are still intact, they are removed by a later patch) Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-09 16:51:58 +00:00
#ifdef CONFIG_FAIR_GROUP_SCHED
sched: cleanup, make struct rq comments more consistent cleanup, make struct rq comments more consistent. found via scripts/checkpatch.pl. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-18 19:32:55 +00:00
/* list of leaf cfs_rq on this cpu: */
struct list_head leaf_cfs_rq_list;
sched: rt-group: make rt groups scheduling configurable Make the rt group scheduler compile time configurable. Keep it experimental for now. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-13 14:45:40 +00:00
#endif
#ifdef CONFIG_RT_GROUP_SCHED
sched: rt group scheduling Extend group scheduling to also cover the realtime classes. It uses the time limiting introduced by the previous patch to allow multiple realtime groups. The hard time limit is required to keep behaviour deterministic. The algorithms used make the realtime scheduler O(tg), linear scaling wrt the number of task groups. This is the worst case behaviour I can't seem to get out of, the avg. case of the algorithms can be improved, I focused on correctness and worst case. [ akpm@linux-foundation.org: move side-effects out of BUG_ON(). ] Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:30 +00:00
struct list_head leaf_rt_rq_list;
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
#endif
/*
* This is part of a global counter where only the total sum
* over all CPUs matters. A task can increase this counter on
* one CPU and if it got migrated afterwards it may decrease
* it on another CPU. Always updated under the runqueue lock:
*/
unsigned long nr_uninterruptible;
sched: Create special class for stop/migrate work In order to separate the stop/migrate work thread from the SCHED_FIFO implementation, create a special class for it that is of higher priority than SCHED_FIFO itself. This currently solves a problem where cpu-hotplug consumes so much cpu-time that the SCHED_FIFO class gets throttled, but has the bandwidth replenishment timer pending on the now dead cpu. It is also required for when we add the planned deadline scheduling class above SCHED_FIFO, as the stop/migrate thread still needs to transcent those tasks. Tested-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1285165776.2275.1022.camel@laptop> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-09-22 11:53:15 +00:00
struct task_struct *curr, *idle, *stop;
[PATCH] sched: use softirq for load balancing Call rebalance_tick (renamed to run_rebalance_domains) from a newly introduced softirq. We calculate the earliest time for each layer of sched domains to be rescanned (this is the rescan time for idle) and use the earliest of those to schedule the softirq via a new field "next_balance" added to struct rq. Signed-off-by: Christoph Lameter <clameter@sgi.com> Cc: Peter Williams <pwil3058@bigpond.net.au> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Christoph Lameter <clameter@sgi.com> Cc: "Siddha, Suresh B" <suresh.b.siddha@intel.com> Cc: "Chen, Kenneth W" <kenneth.w.chen@intel.com> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 10:20:25 +00:00
unsigned long next_balance;
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
struct mm_struct *prev_mm;
sched: cfs rq data types add the CFS rq data types to sched.c. (the old scheduler fields are still intact, they are removed by a later patch) Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-09 16:51:58 +00:00
sched: add optional support for CONFIG_HAVE_UNSTABLE_SCHED_CLOCK this replaces the rq->clock stuff (and possibly cpu_clock()). - architectures that have an 'imperfect' hardware clock can set CONFIG_HAVE_UNSTABLE_SCHED_CLOCK - the 'jiffie' window might be superfulous when we update tick_gtod before the __update_sched_clock() call in sched_clock_tick() - cpu_clock() might be implemented as: sched_clock_cpu(smp_processor_id()) if the accuracy proves good enough - how far can TSC drift in a single jiffie when considering the filtering and idle hooks? [ mingo@elte.hu: various fixes and cleanups ] Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-05-03 16:29:28 +00:00
u64 clock;
sched: Do not account irq time to current task Scheduler accounts both softirq and interrupt processing times to the currently running task. This means, if the interrupt processing was for some other task in the system, then the current task ends up being penalized as it gets shorter runtime than otherwise. Change sched task accounting to acoount only actual task time from currently running task. Now update_curr(), modifies the delta_exec to depend on rq->clock_task. Note that this change only handles CONFIG_IRQ_TIME_ACCOUNTING case. We can extend this to CONFIG_VIRT_CPU_ACCOUNTING with minimal effort. But, thats for later. This change will impact scheduling behavior in interrupt heavy conditions. Tested on a 4-way system with eth0 handled by CPU 2 and a network heavy task (nc) running on CPU 3 (and no RSS/RFS). With that I have CPU 2 spending 75%+ of its time in irq processing. CPU 3 spending around 35% time running nc task. Now, if I run another CPU intensive task on CPU 2, without this change /proc/<pid>/schedstat shows 100% of time accounted to this task. With this change, it rightly shows less than 25% accounted to this task as remaining time is actually spent on irq processing. Signed-off-by: Venkatesh Pallipadi <venki@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1286237003-12406-7-git-send-email-venki@google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-05 00:03:21 +00:00
u64 clock_task;
sched: cfs rq data types add the CFS rq data types to sched.c. (the old scheduler fields are still intact, they are removed by a later patch) Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-09 16:51:58 +00:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
atomic_t nr_iowait;
#ifdef CONFIG_SMP
sched: style cleanup, #2 style cleanup of various changes that were done recently. no code changed: text data bss dec hex filename 26399 2578 48 29025 7161 sched.o.before 26399 2578 48 29025 7161 sched.o.after Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:19 +00:00
struct root_domain *rd;
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
struct sched_domain *sd;
sched: Fix wake_affine() vs RT tasks Mike reports that since e9e9250b (sched: Scale down cpu_power due to RT tasks), wake_affine() goes funny on RT tasks due to them still having a !0 weight and wake_affine() still subtracts that from the rq weight. Since nobody should be using se->weight for RT tasks, set the value to zero. Also, since we now use ->cpu_power to normalize rq weights to account for RT cpu usage, add that factor into the imbalance computation. Reported-by: Mike Galbraith <efault@gmx.de> Tested-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1275316109.27810.22969.camel@twins> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-05-31 10:37:30 +00:00
unsigned long cpu_power;
sched: idle_at_tick is only used when CONFIG_SMP is set Impact: struct rq size optimization The idle_at_tick in struct rq is only used in SMP settings and it does not make sense to have this in the rq in an UP setup. Signed-off-by: Henrik Austad <henrik@austad.us> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-13 19:35:45 +00:00
unsigned char idle_at_tick;
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
/* For active balancing */
sched: Enhance the pre/post scheduling logic We currently have an explicit "needs_post" vtable method which returns a stack variable for whether we should later run post-schedule. This leads to an awkward exchange of the variable as it bubbles back up out of the context switch. Peter Zijlstra observed that this information could be stored in the run-queue itself instead of handled on the stack. Therefore, we revert to the method of having context_switch return void, and update an internal rq->post_schedule variable when we require further processing. In addition, we fix a race condition where we try to access current->sched_class without holding the rq->lock. This is technically racy, as the sched-class could change out from under us. Instead, we reference the per-rq post_schedule variable with the runqueue unlocked, but with preemption disabled to see if we need to reacquire the rq->lock. Finally, we clean the code up slightly by removing the #ifdef CONFIG_SMP conditionals from the schedule() call, and implement some inline helper functions instead. This patch passes checkpatch, and rt-migrate. Signed-off-by: Gregory Haskins <ghaskins@novell.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20090729150422.17691.55590.stgit@dev.haskins.net> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-07-29 15:08:47 +00:00
int post_schedule;
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
int active_balance;
int push_cpu;
sched: replace migration_thread with cpu_stop Currently migration_thread is serving three purposes - migration pusher, context to execute active_load_balance() and forced context switcher for expedited RCU synchronize_sched. All three roles are hardcoded into migration_thread() and determining which job is scheduled is slightly messy. This patch kills migration_thread and replaces all three uses with cpu_stop. The three different roles of migration_thread() are splitted into three separate cpu_stop callbacks - migration_cpu_stop(), active_load_balance_cpu_stop() and synchronize_sched_expedited_cpu_stop() - and each use case now simply asks cpu_stop to execute the callback as necessary. synchronize_sched_expedited() was implemented with private preallocated resources and custom multi-cpu queueing and waiting logic, both of which are provided by cpu_stop. synchronize_sched_expedited_count is made atomic and all other shared resources along with the mutex are dropped. synchronize_sched_expedited() also implemented a check to detect cases where not all the callback got executed on their assigned cpus and fall back to synchronize_sched(). If called with cpu hotplug blocked, cpu_stop already guarantees that and the condition cannot happen; otherwise, stop_machine() would break. However, this patch preserves the paranoid check using a cpumask to record on which cpus the stopper ran so that it can serve as a bisection point if something actually goes wrong theree. Because the internal execution state is no longer visible, rcu_expedited_torture_stats() is removed. This patch also renames cpu_stop threads to from "stopper/%d" to "migration/%d". The names of these threads ultimately don't matter and there's no reason to make unnecessary userland visible changes. With this patch applied, stop_machine() and sched now share the same resources. stop_machine() is faster without wasting any resources and sched migration users are much cleaner. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Dipankar Sarma <dipankar@in.ibm.com> Cc: Josh Triplett <josh@freedesktop.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Dimitri Sivanich <sivanich@sgi.com>
2010-05-06 16:49:21 +00:00
struct cpu_stop_work active_balance_work;
sched: cleanup, make struct rq comments more consistent cleanup, make struct rq comments more consistent. found via scripts/checkpatch.pl. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-18 19:32:55 +00:00
/* cpu of this runqueue: */
int cpu;
sched: fix cpupri hotplug support The RT folks over at RedHat found an issue w.r.t. hotplug support which was traced to problems with the cpupri infrastructure in the scheduler: https://bugzilla.redhat.com/show_bug.cgi?id=449676 This bug affects 23-rt12+, 24-rtX, 25-rtX, and sched-devel. This patch applies to 25.4-rt4, though it should trivially apply to most cpupri enabled kernels mentioned above. It turned out that the issue was that offline cpus could get inadvertently registered with cpupri so that they were erroneously selected during migration decisions. The end result would be an OOPS as the offline cpu had tasks routed to it. This patch generalizes the old join/leave domain interface into an online/offline interface, and adjusts the root-domain/hotplug code to utilize it. I was able to easily reproduce the issue prior to this patch, and am no longer able to reproduce it after this patch. I can offline cpus indefinately and everything seems to be in working order. Thanks to Arnaldo (acme), Thomas, and Peter for doing the legwork to point me in the right direction. Also thank you to Peter for reviewing the early iterations of this patch. Signed-off-by: Gregory Haskins <ghaskins@novell.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-06-04 19:04:05 +00:00
int online;
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
sched: Scale down cpu_power due to RT tasks Keep an average on the amount of time spend on RT tasks and use that fraction to scale down the cpu_power for regular tasks. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Tested-by: Andreas Herrmann <andreas.herrmann3@amd.com> Acked-by: Andreas Herrmann <andreas.herrmann3@amd.com> Acked-by: Gautham R Shenoy <ego@in.ibm.com> Cc: Balbir Singh <balbir@in.ibm.com> LKML-Reference: <20090901083826.287778431@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-09-01 08:34:37 +00:00
u64 rt_avg;
u64 age_stamp;
sched: Rate-limit newidle Rate limit newidle to migration_cost. It's a win for all stages of sysbench oltp tests. Signed-off-by: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-11-04 16:53:50 +00:00
u64 idle_stamp;
u64 avg_idle;
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
#endif
sched: Remove irq time from available CPU power The idea was suggested by Peter Zijlstra here: http://marc.info/?l=linux-kernel&m=127476934517534&w=2 irq time is technically not available to the tasks running on the CPU. This patch removes irq time from CPU power piggybacking on sched_rt_avg_update(). Tested this by keeping CPU X busy with a network intensive task having 75% oa a single CPU irq processing (hard+soft) on a 4-way system. And start seven cycle soakers on the system. Without this change, there will be two tasks on each CPU. With this change, there is a single task on irq busy CPU X and remaining 7 tasks are spread around among other 3 CPUs. Signed-off-by: Venkatesh Pallipadi <venki@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1286237003-12406-8-git-send-email-venki@google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-05 00:03:22 +00:00
#ifdef CONFIG_IRQ_TIME_ACCOUNTING
u64 prev_irq_time;
#endif
KVM guest: Steal time accounting This patch accounts steal time time in account_process_tick. If one or more tick is considered stolen in the current accounting cycle, user/system accounting is skipped. Idle is fine, since the hypervisor does not report steal time if the guest is halted. Accounting steal time from the core scheduler give us the advantage of direct acess to the runqueue data. In a later opportunity, it can be used to tweak cpu power and make the scheduler aware of the time it lost. [avi: <asm/paravirt.h> doesn't exist on many archs] Signed-off-by: Glauber Costa <glommer@redhat.com> Acked-by: Rik van Riel <riel@redhat.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Tested-by: Eric B Munson <emunson@mgebm.net> CC: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> CC: Anthony Liguori <aliguori@us.ibm.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-07-11 19:28:17 +00:00
#ifdef CONFIG_PARAVIRT
u64 prev_steal_time;
#endif
sched: adjust scheduler cpu power for stolen time This patch makes update_rq_clock() aware of steal time. The mechanism of operation is not different from irq_time, and follows the same principles. This lives in a CONFIG option itself, and can be compiled out independently of the rest of steal time reporting. The effect of disabling it is that the scheduler will still report steal time (that cannot be disabled), but won't use this information for cpu power adjustments. Everytime update_rq_clock_task() is invoked, we query information about how much time was stolen since last call, and feed it into sched_rt_avg_update(). Although steal time reporting in account_process_tick() keeps track of the last time we read the steal clock, in prev_steal_time, this patch do it independently using another field, prev_steal_time_rq. This is because otherwise, information about time accounted in update_process_tick() would never reach us in update_rq_clock(). Signed-off-by: Glauber Costa <glommer@redhat.com> Acked-by: Rik van Riel <riel@redhat.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Tested-by: Eric B Munson <emunson@mgebm.net> CC: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> CC: Anthony Liguori <aliguori@us.ibm.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-07-11 19:28:18 +00:00
#ifdef CONFIG_PARAVIRT_TIME_ACCOUNTING
u64 prev_steal_time_rq;
#endif
sched: Remove irq time from available CPU power The idea was suggested by Peter Zijlstra here: http://marc.info/?l=linux-kernel&m=127476934517534&w=2 irq time is technically not available to the tasks running on the CPU. This patch removes irq time from CPU power piggybacking on sched_rt_avg_update(). Tested this by keeping CPU X busy with a network intensive task having 75% oa a single CPU irq processing (hard+soft) on a 4-way system. And start seven cycle soakers on the system. Without this change, there will be two tasks on each CPU. With this change, there is a single task on irq busy CPU X and remaining 7 tasks are spread around among other 3 CPUs. Signed-off-by: Venkatesh Pallipadi <venki@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1286237003-12406-8-git-send-email-venki@google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-05 00:03:22 +00:00
sched, timers: move calc_load() to scheduler Dimitri Sivanich noticed that xtime_lock is held write locked across calc_load() which iterates over all online CPUs. That can cause long latencies for xtime_lock readers on large SMP systems. The load average calculation is an rough estimate anyway so there is no real need to protect the readers vs. the update. It's not a problem when the avenrun array is updated while a reader copies the values. Instead of iterating over all online CPUs let the scheduler_tick code update the number of active tasks shortly before the avenrun update happens. The avenrun update itself is handled by the CPU which calls do_timer(). [ Impact: reduce xtime_lock write locked section ] Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org>
2009-04-11 08:43:41 +00:00
/* calc_load related fields */
unsigned long calc_load_update;
long calc_load_active;
sched: high-res preemption tick Use HR-timers (when available) to deliver an accurate preemption tick. The regular scheduler tick that runs at 1/HZ can be too coarse when nice level are used. The fairness system will still keep the cpu utilisation 'fair' by then delaying the task that got an excessive amount of CPU time but try to minimize this by delivering preemption points spot-on. The average frequency of this extra interrupt is sched_latency / nr_latency. Which need not be higher than 1/HZ, its just that the distribution within the sched_latency period is important. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:29 +00:00
#ifdef CONFIG_SCHED_HRTICK
sched, x86: clean up hrtick implementation random uvesafb failures were reported against Gentoo: http://bugs.gentoo.org/show_bug.cgi?id=222799 and Mihai Moldovan bisected it back to: > 8f4d37ec073c17e2d4aa8851df5837d798606d6f is first bad commit > commit 8f4d37ec073c17e2d4aa8851df5837d798606d6f > Author: Peter Zijlstra <a.p.zijlstra@chello.nl> > Date: Fri Jan 25 21:08:29 2008 +0100 > > sched: high-res preemption tick Linus suspected it to be hrtick + vm86 interaction and observed: > Btw, Peter, Ingo: I think that commit is doing bad things. They aren't > _incorrect_ per se, but they are definitely bad. > > Why? > > Using random _TIF_WORK_MASK flags is really impolite for doing > "scheduling" work. There's a reason that arch/x86/kernel/entry_32.S > special-cases the _TIF_NEED_RESCHED flag: we don't want to exit out of > vm86 mode unnecessarily. > > See the "work_notifysig_v86" label, and how it does that > "save_v86_state()" thing etc etc. Right, I never liked having to fiddle with those TIF flags. Initially I needed it because the hrtimer base lock could not nest in the rq lock. That however is fixed these days. Currently the only reason left to fiddle with the TIF flags is remote wakeups. We cannot program a remote cpu's hrtimer. I've been thinking about using the new and improved IPI function call stuff to implement hrtimer_start_on(). However that does require that smp_call_function_single(.wait=0) works from interrupt context - /me looks at the latest series from Jens - Yes that does seem to be supported, good. Here's a stab at cleaning this stuff up ... Mihai reported test success as well. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Tested-by: Mihai Moldovan <ionic@ionic.de> Cc: Michal Januszewski <spock@gentoo.org> Cc: Antonino Daplas <adaplas@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-18 16:01:23 +00:00
#ifdef CONFIG_SMP
int hrtick_csd_pending;
struct call_single_data hrtick_csd;
#endif
sched: high-res preemption tick Use HR-timers (when available) to deliver an accurate preemption tick. The regular scheduler tick that runs at 1/HZ can be too coarse when nice level are used. The fairness system will still keep the cpu utilisation 'fair' by then delaying the task that got an excessive amount of CPU time but try to minimize this by delivering preemption points spot-on. The average frequency of this extra interrupt is sched_latency / nr_latency. Which need not be higher than 1/HZ, its just that the distribution within the sched_latency period is important. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:29 +00:00
struct hrtimer hrtick_timer;
#endif
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
#ifdef CONFIG_SCHEDSTATS
/* latency stats */
struct sched_info rq_sched_info;
schedstat: consolidate per-task cpu runtime stats Impact: simplify code When we turn on CONFIG_SCHEDSTATS, per-task cpu runtime is accumulated twice. Once in task->se.sum_exec_runtime and once in sched_info.cpu_time. These two stats are exactly the same. Given that task->se.sum_exec_runtime is always accumulated by the core scheduler, sched_info can reuse that data instead of duplicate the accounting. Signed-off-by: Ken Chen <kenchen@google.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-17 07:41:22 +00:00
unsigned long long rq_cpu_time;
/* could above be rq->cfs_rq.exec_clock + rq->rt_rq.rt_runtime ? */
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
/* sys_sched_yield() stats */
sched: reduce schedstat variable overhead a bit schedstat is useful in investigating CPU scheduler behavior. Ideally, I think it is beneficial to have it on all the time. However, the cost of turning it on in production system is quite high, largely due to number of events it collects and also due to its large memory footprint. Most of the fields probably don't need to be full 64-bit on 64-bit arch. Rolling over 4 billion events will most like take a long time and user space tool can be made to accommodate that. I'm proposing kernel to cut back most of variable width on 64-bit system. (note, the following patch doesn't affect 32-bit system). Signed-off-by: Ken Chen <kenchen@google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-18 19:32:56 +00:00
unsigned int yld_count;
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
/* schedule() stats */
sched: reduce schedstat variable overhead a bit schedstat is useful in investigating CPU scheduler behavior. Ideally, I think it is beneficial to have it on all the time. However, the cost of turning it on in production system is quite high, largely due to number of events it collects and also due to its large memory footprint. Most of the fields probably don't need to be full 64-bit on 64-bit arch. Rolling over 4 billion events will most like take a long time and user space tool can be made to accommodate that. I'm proposing kernel to cut back most of variable width on 64-bit system. (note, the following patch doesn't affect 32-bit system). Signed-off-by: Ken Chen <kenchen@google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-18 19:32:56 +00:00
unsigned int sched_switch;
unsigned int sched_count;
unsigned int sched_goidle;
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
/* try_to_wake_up() stats */
sched: reduce schedstat variable overhead a bit schedstat is useful in investigating CPU scheduler behavior. Ideally, I think it is beneficial to have it on all the time. However, the cost of turning it on in production system is quite high, largely due to number of events it collects and also due to its large memory footprint. Most of the fields probably don't need to be full 64-bit on 64-bit arch. Rolling over 4 billion events will most like take a long time and user space tool can be made to accommodate that. I'm proposing kernel to cut back most of variable width on 64-bit system. (note, the following patch doesn't affect 32-bit system). Signed-off-by: Ken Chen <kenchen@google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-18 19:32:56 +00:00
unsigned int ttwu_count;
unsigned int ttwu_local;
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
#endif
sched: Move the second half of ttwu() to the remote cpu Now that we've removed the rq->lock requirement from the first part of ttwu() and can compute placement without holding any rq->lock, ensure we execute the second half of ttwu() on the actual cpu we want the task to run on. This avoids having to take rq->lock and doing the task enqueue remotely, saving lots on cacheline transfers. As measured using: http://oss.oracle.com/~mason/sembench.c $ for i in /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor ; do echo performance > $i; done $ echo 4096 32000 64 128 > /proc/sys/kernel/sem $ ./sembench -t 2048 -w 1900 -o 0 unpatched: run time 30 seconds 647278 worker burns per second patched: run time 30 seconds 816715 worker burns per second Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110405152729.515897185@chello.nl
2011-04-05 15:23:58 +00:00
#ifdef CONFIG_SMP
struct task_struct *wake_list;
#endif
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
};
use the new percpu interface for shared data Currently most of the per cpu data, which is accessed by different cpus, has a ____cacheline_aligned_in_smp attribute. Move all this data to the new per cpu shared data section: .data.percpu.shared_aligned. This will seperate the percpu data which is referenced frequently by other cpus from the local only percpu data. Signed-off-by: Fenghua Yu <fenghua.yu@intel.com> Acked-by: Suresh Siddha <suresh.b.siddha@intel.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Christoph Lameter <clameter@sgi.com> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Andi Kleen <ak@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-19 08:48:13 +00:00
static DEFINE_PER_CPU_SHARED_ALIGNED(struct rq, runqueues);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
sched: Cleanup/optimize clock updates Now that we no longer depend on the clock being updated prior to enqueueing on migratory wakeup, we can clean up a bit, placing calls to update_rq_clock() exactly where they are needed, ie on enqueue, dequeue and schedule events. In the case of a freshly enqueued task immediately preempting, we can skip the update during preemption, as the clock was just updated by the enqueue event. We also save an unneeded call during a migratory wakeup by not updating the previous runqueue, where update_curr() won't be invoked. Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1268301199.6785.32.camel@marge.simson.net> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-03-11 16:16:20 +00:00
sched: Fix cross-sched-class wakeup preemption Instead of dealing with sched classes inside each check_preempt_curr() implementation, pull out this logic into the generic wakeup preemption path. This fixes a hang in KVM (and others) where we are waiting for the stop machine thread to run ... Reported-by: Markus Trippelsdorf <markus@trippelsdorf.de> Tested-by: Marcelo Tosatti <mtosatti@redhat.com> Tested-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1288891946.2039.31.camel@laptop> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-31 11:37:04 +00:00
static void check_preempt_curr(struct rq *rq, struct task_struct *p, int flags);
sched: cfs core code apply the CFS core code. this change switches over the scheduler core to CFS's modular design and makes use of kernel/sched_fair/rt/idletask.c to implement Linux's scheduling policies. thanks to Andrew Morton and Thomas Gleixner for lots of detailed review feedback and for fixlets. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
2007-07-09 16:51:59 +00:00
[PATCH] Fix longstanding load balancing bug in the scheduler The scheduler will stop load balancing if the most busy processor contains processes pinned via processor affinity. The scheduler currently only does one search for busiest cpu. If it cannot pull any tasks away from the busiest cpu because they were pinned then the scheduler goes into a corner and sulks leaving the idle processors idle. F.e. If you have processor 0 busy running four tasks pinned via taskset, there are none on processor 1 and one just started two processes on processor 2 then the scheduler will not move one of the two processes away from processor 2. This patch fixes that issue by forcing the scheduler to come out of its corner and retrying the load balancing by considering other processors for load balancing. This patch was originally developed by John Hawkes and discussed at http://marc.theaimsgroup.com/?l=linux-kernel&m=113901368523205&w=2. I have removed extraneous material and gone back to equipping struct rq with the cpu the queue is associated with since this makes the patch much easier and it is likely that others in the future will have the same difficulty of figuring out which processor owns which runqueue. The overhead added through these patches is a single word on the stack if the kernel is configured to support 32 cpus or less (32 bit). For 32 bit environments the maximum number of cpus that can be configued is 255 which would result in the use of 32 bytes additional on the stack. On IA64 up to 1k cpus can be configured which will result in the use of 128 additional bytes on the stack. The maximum additional cache footprint is one cacheline. Typically memory use will be much less than a cacheline and the additional cpumask will be placed on the stack in a cacheline that already contains other local variable. Signed-off-by: Christoph Lameter <clameter@sgi.com> Cc: John Hawkes <hawkes@sgi.com> Cc: "Siddha, Suresh B" <suresh.b.siddha@intel.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Peter Williams <pwil3058@bigpond.net.au> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-26 06:30:51 +00:00
static inline int cpu_of(struct rq *rq)
{
#ifdef CONFIG_SMP
return rq->cpu;
#else
return 0;
#endif
}
sched: Better name for for_each_domain_rd As suggested by Peter Ziljstra, make better choice of name for for_each_domain_rd(), containing "rcu_dereference", given that it is but a wrapper for rcu_dereference_check(). The name rcu_dereference_check_sched_domain() does that and provides a separate per-subsystem name space. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: laijs@cn.fujitsu.com Cc: dipankar@in.ibm.com Cc: mathieu.desnoyers@polymtl.ca Cc: josh@joshtriplett.org Cc: dvhltc@us.ibm.com Cc: niv@us.ibm.com Cc: peterz@infradead.org Cc: rostedt@goodmis.org Cc: Valdis.Kletnieks@vt.edu Cc: dhowells@redhat.com LKML-Reference: <1266887105-1528-7-git-send-email-paulmck@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-02-23 01:04:51 +00:00
#define rcu_dereference_check_sched_domain(p) \
sched: Use lockdep-based checking on rcu_dereference() Update the rcu_dereference() usages to take advantage of the new lockdep-based checking. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: laijs@cn.fujitsu.com Cc: dipankar@in.ibm.com Cc: mathieu.desnoyers@polymtl.ca Cc: josh@joshtriplett.org Cc: dvhltc@us.ibm.com Cc: niv@us.ibm.com Cc: peterz@infradead.org Cc: rostedt@goodmis.org Cc: Valdis.Kletnieks@vt.edu Cc: dhowells@redhat.com LKML-Reference: <1266887105-1528-6-git-send-email-paulmck@linux.vnet.ibm.com> [ -v2: fix allmodconfig missing symbol export build failure on x86 ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-02-23 01:04:50 +00:00
rcu_dereference_check((p), \
lockdep_is_held(&sched_domains_mutex))
[PATCH] sched: RCU domains One of the problems with the multilevel balance-on-fork/exec is that it needs to jump through hoops to satisfy sched-domain's locking semantics (that is, you may traverse your own domain when not preemptable, and you may traverse others' domains when holding their runqueue lock). balance-on-exec had to potentially migrate between more than one CPU before finding a final CPU to migrate to, and balance-on-fork needed to potentially take multiple runqueue locks. So bite the bullet and make sched-domains go completely RCU. This actually simplifies the code quite a bit. From: Ingo Molnar <mingo@elte.hu> schedstats RCU fix, and a nice comment on for_each_domain, from Ingo. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Nick Piggin <nickpiggin@yahoo.com.au> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-25 21:57:27 +00:00
/*
* The domain tree (rq->sd) is protected by RCU's quiescent state transition.
[PATCH] Dynamic sched domains: sched changes The following patches add dynamic sched domains functionality that was extensively discussed on lkml and lse-tech. I would like to see this added to -mm o The main advantage with this feature is that it ensures that the scheduler load balacing code only balances against the cpus that are in the sched domain as defined by an exclusive cpuset and not all of the cpus in the system. This removes any overhead due to load balancing code trying to pull tasks outside of the cpu exclusive cpuset only to be prevented by the tasks' cpus_allowed mask. o cpu exclusive cpusets are useful for servers running orthogonal workloads such as RT applications requiring low latency and HPC applications that are throughput sensitive o It provides a new API partition_sched_domains in sched.c that makes dynamic sched domains possible. o cpu_exclusive cpusets sets are now associated with a sched domain. Which means that the users can dynamically modify the sched domains through the cpuset file system interface o ia64 sched domain code has been updated to support this feature as well o Currently, this does not support hotplug. (However some of my tests indicate hotplug+preempt is currently broken) o I have tested it extensively on x86. o This should have very minimal impact on performance as none of the fast paths are affected Signed-off-by: Dinakar Guniguntala <dino@in.ibm.com> Acked-by: Paul Jackson <pj@sgi.com> Acked-by: Nick Piggin <nickpiggin@yahoo.com.au> Acked-by: Matthew Dobson <colpatch@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-25 21:57:33 +00:00
* See detach_destroy_domains: synchronize_sched for details.
[PATCH] sched: RCU domains One of the problems with the multilevel balance-on-fork/exec is that it needs to jump through hoops to satisfy sched-domain's locking semantics (that is, you may traverse your own domain when not preemptable, and you may traverse others' domains when holding their runqueue lock). balance-on-exec had to potentially migrate between more than one CPU before finding a final CPU to migrate to, and balance-on-fork needed to potentially take multiple runqueue locks. So bite the bullet and make sched-domains go completely RCU. This actually simplifies the code quite a bit. From: Ingo Molnar <mingo@elte.hu> schedstats RCU fix, and a nice comment on for_each_domain, from Ingo. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Nick Piggin <nickpiggin@yahoo.com.au> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-25 21:57:27 +00:00
*
* The domain tree of any CPU may only be accessed from within
* preempt-disabled sections.
*/
[PATCH] sched: clean up fallout of recent changes Clean up some of the impact of recent (and not so recent) scheduler changes: - turning macros into nice inline functions - sanitizing and unifying variable definitions - whitespace, style consistency, 80-lines, comment correctness, spelling and curly braces police Due to the macro hell and variable placement simplifications there's even 26 bytes of .text saved: text data bss dec hex filename 25510 4153 192 29855 749f sched.o.before 25484 4153 192 29829 7485 sched.o.after [akpm@osdl.org: build fix] Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-03 07:25:40 +00:00
#define for_each_domain(cpu, __sd) \
sched: Better name for for_each_domain_rd As suggested by Peter Ziljstra, make better choice of name for for_each_domain_rd(), containing "rcu_dereference", given that it is but a wrapper for rcu_dereference_check(). The name rcu_dereference_check_sched_domain() does that and provides a separate per-subsystem name space. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: laijs@cn.fujitsu.com Cc: dipankar@in.ibm.com Cc: mathieu.desnoyers@polymtl.ca Cc: josh@joshtriplett.org Cc: dvhltc@us.ibm.com Cc: niv@us.ibm.com Cc: peterz@infradead.org Cc: rostedt@goodmis.org Cc: Valdis.Kletnieks@vt.edu Cc: dhowells@redhat.com LKML-Reference: <1266887105-1528-7-git-send-email-paulmck@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-02-23 01:04:51 +00:00
for (__sd = rcu_dereference_check_sched_domain(cpu_rq(cpu)->sd); __sd; __sd = __sd->parent)
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
#define cpu_rq(cpu) (&per_cpu(runqueues, (cpu)))
#define this_rq() (&__get_cpu_var(runqueues))
#define task_rq(p) cpu_rq(task_cpu(p))
#define cpu_curr(cpu) (cpu_rq(cpu)->curr)
sched: Hide runqueues from direct reference at source code level for __raw_get_cpu_var() Hide __raw_get_cpu_var() as well - thus all the direct references to runqueues will abstracted out. Signed-off-by: Hitoshi Mitake <mitake@dcl.info.waseda.ac.jp> LKML-Reference: <20090629.144457.886429910353660979.mitake@dcl.info.waseda.ac.jp> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-06-29 05:44:57 +00:00
#define raw_rq() (&__raw_get_cpu_var(runqueues))
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
sched: Fix PROVE_RCU vs cpu_cgroup PROVE_RCU has a few issues with the cpu_cgroup because the scheduler typically holds rq->lock around the css rcu derefs but the generic cgroup code doesn't (and can't) know about that lock. Provide means to add extra checks to the css dereference and use that in the scheduler to annotate its users. The addition of rq->lock to these checks is correct because the cgroup_subsys::attach() method takes the rq->lock for each task it moves, therefore by holding that lock, we ensure the task is pinned to the current cgroup and the RCU derefence is valid. That leaves one genuine race in __sched_setscheduler() where we used task_group() without holding any of the required locks and thus raced with the cgroup code. Solve this by moving the check under the appropriate lock. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-06-08 09:40:42 +00:00
#ifdef CONFIG_CGROUP_SCHED
/*
* Return the group to which this tasks belongs.
*
sched: Fix/clarify set_task_cpu() locking rules Sergey reported a CONFIG_PROVE_RCU warning in push_rt_task where set_task_cpu() was called with both relevant rq->locks held, which should be sufficient for running tasks since holding its rq->lock will serialize against sched_move_task(). Update the comments and fix the task_group() lockdep test. Reported-and-tested-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1307115427.2353.3456.camel@twins Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-06-03 15:37:07 +00:00
* We use task_subsys_state_check() and extend the RCU verification with
* pi->lock and rq->lock because cpu_cgroup_attach() holds those locks for each
* task it moves into the cgroup. Therefore by holding either of those locks,
* we pin the task to the current cgroup.
sched: Fix PROVE_RCU vs cpu_cgroup PROVE_RCU has a few issues with the cpu_cgroup because the scheduler typically holds rq->lock around the css rcu derefs but the generic cgroup code doesn't (and can't) know about that lock. Provide means to add extra checks to the css dereference and use that in the scheduler to annotate its users. The addition of rq->lock to these checks is correct because the cgroup_subsys::attach() method takes the rq->lock for each task it moves, therefore by holding that lock, we ensure the task is pinned to the current cgroup and the RCU derefence is valid. That leaves one genuine race in __sched_setscheduler() where we used task_group() without holding any of the required locks and thus raced with the cgroup code. Solve this by moving the check under the appropriate lock. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-06-08 09:40:42 +00:00
*/
static inline struct task_group *task_group(struct task_struct *p)
{
sched: Add 'autogroup' scheduling feature: automated per session task groups A recurring complaint from CFS users is that parallel kbuild has a negative impact on desktop interactivity. This patch implements an idea from Linus, to automatically create task groups. Currently, only per session autogroups are implemented, but the patch leaves the way open for enhancement. Implementation: each task's signal struct contains an inherited pointer to a refcounted autogroup struct containing a task group pointer, the default for all tasks pointing to the init_task_group. When a task calls setsid(), a new task group is created, the process is moved into the new task group, and a reference to the preveious task group is dropped. Child processes inherit this task group thereafter, and increase it's refcount. When the last thread of a process exits, the process's reference is dropped, such that when the last process referencing an autogroup exits, the autogroup is destroyed. At runqueue selection time, IFF a task has no cgroup assignment, its current autogroup is used. Autogroup bandwidth is controllable via setting it's nice level through the proc filesystem: cat /proc/<pid>/autogroup Displays the task's group and the group's nice level. echo <nice level> > /proc/<pid>/autogroup Sets the task group's shares to the weight of nice <level> task. Setting nice level is rate limited for !admin users due to the abuse risk of task group locking. The feature is enabled from boot by default if CONFIG_SCHED_AUTOGROUP=y is selected, but can be disabled via the boot option noautogroup, and can also be turned on/off on the fly via: echo [01] > /proc/sys/kernel/sched_autogroup_enabled ... which will automatically move tasks to/from the root task group. Signed-off-by: Mike Galbraith <efault@gmx.de> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Markus Trippelsdorf <markus@trippelsdorf.de> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Paul Turner <pjt@google.com> Cc: Oleg Nesterov <oleg@redhat.com> [ Removed the task_group_path() debug code, and fixed !EVENTFD build failure. ] Signed-off-by: Ingo Molnar <mingo@elte.hu> LKML-Reference: <1290281700.28711.9.camel@maggy.simson.net> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-30 13:18:03 +00:00
struct task_group *tg;
sched: Fix PROVE_RCU vs cpu_cgroup PROVE_RCU has a few issues with the cpu_cgroup because the scheduler typically holds rq->lock around the css rcu derefs but the generic cgroup code doesn't (and can't) know about that lock. Provide means to add extra checks to the css dereference and use that in the scheduler to annotate its users. The addition of rq->lock to these checks is correct because the cgroup_subsys::attach() method takes the rq->lock for each task it moves, therefore by holding that lock, we ensure the task is pinned to the current cgroup and the RCU derefence is valid. That leaves one genuine race in __sched_setscheduler() where we used task_group() without holding any of the required locks and thus raced with the cgroup code. Solve this by moving the check under the appropriate lock. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-06-08 09:40:42 +00:00
struct cgroup_subsys_state *css;
css = task_subsys_state_check(p, cpu_cgroup_subsys_id,
sched: Fix/clarify set_task_cpu() locking rules Sergey reported a CONFIG_PROVE_RCU warning in push_rt_task where set_task_cpu() was called with both relevant rq->locks held, which should be sufficient for running tasks since holding its rq->lock will serialize against sched_move_task(). Update the comments and fix the task_group() lockdep test. Reported-and-tested-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1307115427.2353.3456.camel@twins Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-06-03 15:37:07 +00:00
lockdep_is_held(&p->pi_lock) ||
lockdep_is_held(&task_rq(p)->lock));
sched: Add 'autogroup' scheduling feature: automated per session task groups A recurring complaint from CFS users is that parallel kbuild has a negative impact on desktop interactivity. This patch implements an idea from Linus, to automatically create task groups. Currently, only per session autogroups are implemented, but the patch leaves the way open for enhancement. Implementation: each task's signal struct contains an inherited pointer to a refcounted autogroup struct containing a task group pointer, the default for all tasks pointing to the init_task_group. When a task calls setsid(), a new task group is created, the process is moved into the new task group, and a reference to the preveious task group is dropped. Child processes inherit this task group thereafter, and increase it's refcount. When the last thread of a process exits, the process's reference is dropped, such that when the last process referencing an autogroup exits, the autogroup is destroyed. At runqueue selection time, IFF a task has no cgroup assignment, its current autogroup is used. Autogroup bandwidth is controllable via setting it's nice level through the proc filesystem: cat /proc/<pid>/autogroup Displays the task's group and the group's nice level. echo <nice level> > /proc/<pid>/autogroup Sets the task group's shares to the weight of nice <level> task. Setting nice level is rate limited for !admin users due to the abuse risk of task group locking. The feature is enabled from boot by default if CONFIG_SCHED_AUTOGROUP=y is selected, but can be disabled via the boot option noautogroup, and can also be turned on/off on the fly via: echo [01] > /proc/sys/kernel/sched_autogroup_enabled ... which will automatically move tasks to/from the root task group. Signed-off-by: Mike Galbraith <efault@gmx.de> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Markus Trippelsdorf <markus@trippelsdorf.de> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Paul Turner <pjt@google.com> Cc: Oleg Nesterov <oleg@redhat.com> [ Removed the task_group_path() debug code, and fixed !EVENTFD build failure. ] Signed-off-by: Ingo Molnar <mingo@elte.hu> LKML-Reference: <1290281700.28711.9.camel@maggy.simson.net> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-30 13:18:03 +00:00
tg = container_of(css, struct task_group, css);
return autogroup_task_group(p, tg);
sched: Fix PROVE_RCU vs cpu_cgroup PROVE_RCU has a few issues with the cpu_cgroup because the scheduler typically holds rq->lock around the css rcu derefs but the generic cgroup code doesn't (and can't) know about that lock. Provide means to add extra checks to the css dereference and use that in the scheduler to annotate its users. The addition of rq->lock to these checks is correct because the cgroup_subsys::attach() method takes the rq->lock for each task it moves, therefore by holding that lock, we ensure the task is pinned to the current cgroup and the RCU derefence is valid. That leaves one genuine race in __sched_setscheduler() where we used task_group() without holding any of the required locks and thus raced with the cgroup code. Solve this by moving the check under the appropriate lock. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-06-08 09:40:42 +00:00
}
/* Change a task's cfs_rq and parent entity if it moves across CPUs/groups */
static inline void set_task_rq(struct task_struct *p, unsigned int cpu)
{
#ifdef CONFIG_FAIR_GROUP_SCHED
p->se.cfs_rq = task_group(p)->cfs_rq[cpu];
p->se.parent = task_group(p)->se[cpu];
#endif
#ifdef CONFIG_RT_GROUP_SCHED
p->rt.rt_rq = task_group(p)->rt_rq[cpu];
p->rt.parent = task_group(p)->rt_se[cpu];
#endif
}
#else /* CONFIG_CGROUP_SCHED */
static inline void set_task_rq(struct task_struct *p, unsigned int cpu) { }
static inline struct task_group *task_group(struct task_struct *p)
{
return NULL;
}
#endif /* CONFIG_CGROUP_SCHED */
sched: Fix the irqtime code to deal with u64 wraps Some ARM systems have a short sched_clock() [ which needs to be fixed too ], but this exposed a bug in the irq_time code as well, it doesn't deal with wraps at all. Fix the irq_time code to deal with u64 wraps by re-writing the code to only use delta increments, which avoids the whole issue. Reviewed-by: Venkatesh Pallipadi <venki@google.com> Reported-by: Mikael Pettersson <mikpe@it.uu.se> Tested-by: Mikael Pettersson <mikpe@it.uu.se> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1292242433.6803.199.camel@twins> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-12-09 13:15:34 +00:00
static void update_rq_clock_task(struct rq *rq, s64 delta);
sched: Do not account irq time to current task Scheduler accounts both softirq and interrupt processing times to the currently running task. This means, if the interrupt processing was for some other task in the system, then the current task ends up being penalized as it gets shorter runtime than otherwise. Change sched task accounting to acoount only actual task time from currently running task. Now update_curr(), modifies the delta_exec to depend on rq->clock_task. Note that this change only handles CONFIG_IRQ_TIME_ACCOUNTING case. We can extend this to CONFIG_VIRT_CPU_ACCOUNTING with minimal effort. But, thats for later. This change will impact scheduling behavior in interrupt heavy conditions. Tested on a 4-way system with eth0 handled by CPU 2 and a network heavy task (nc) running on CPU 3 (and no RSS/RFS). With that I have CPU 2 spending 75%+ of its time in irq processing. CPU 3 spending around 35% time running nc task. Now, if I run another CPU intensive task on CPU 2, without this change /proc/<pid>/schedstat shows 100% of time accounted to this task. With this change, it rightly shows less than 25% accounted to this task as remaining time is actually spent on irq processing. Signed-off-by: Venkatesh Pallipadi <venki@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1286237003-12406-7-git-send-email-venki@google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-05 00:03:21 +00:00
sched: Fix the irqtime code to deal with u64 wraps Some ARM systems have a short sched_clock() [ which needs to be fixed too ], but this exposed a bug in the irq_time code as well, it doesn't deal with wraps at all. Fix the irq_time code to deal with u64 wraps by re-writing the code to only use delta increments, which avoids the whole issue. Reviewed-by: Venkatesh Pallipadi <venki@google.com> Reported-by: Mikael Pettersson <mikpe@it.uu.se> Tested-by: Mikael Pettersson <mikpe@it.uu.se> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1292242433.6803.199.camel@twins> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-12-09 13:15:34 +00:00
static void update_rq_clock(struct rq *rq)
sched: add optional support for CONFIG_HAVE_UNSTABLE_SCHED_CLOCK this replaces the rq->clock stuff (and possibly cpu_clock()). - architectures that have an 'imperfect' hardware clock can set CONFIG_HAVE_UNSTABLE_SCHED_CLOCK - the 'jiffie' window might be superfulous when we update tick_gtod before the __update_sched_clock() call in sched_clock_tick() - cpu_clock() might be implemented as: sched_clock_cpu(smp_processor_id()) if the accuracy proves good enough - how far can TSC drift in a single jiffie when considering the filtering and idle hooks? [ mingo@elte.hu: various fixes and cleanups ] Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-05-03 16:29:28 +00:00
{
sched: Fix the irqtime code to deal with u64 wraps Some ARM systems have a short sched_clock() [ which needs to be fixed too ], but this exposed a bug in the irq_time code as well, it doesn't deal with wraps at all. Fix the irq_time code to deal with u64 wraps by re-writing the code to only use delta increments, which avoids the whole issue. Reviewed-by: Venkatesh Pallipadi <venki@google.com> Reported-by: Mikael Pettersson <mikpe@it.uu.se> Tested-by: Mikael Pettersson <mikpe@it.uu.se> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1292242433.6803.199.camel@twins> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-12-09 13:15:34 +00:00
s64 delta;
sched: Do not account irq time to current task Scheduler accounts both softirq and interrupt processing times to the currently running task. This means, if the interrupt processing was for some other task in the system, then the current task ends up being penalized as it gets shorter runtime than otherwise. Change sched task accounting to acoount only actual task time from currently running task. Now update_curr(), modifies the delta_exec to depend on rq->clock_task. Note that this change only handles CONFIG_IRQ_TIME_ACCOUNTING case. We can extend this to CONFIG_VIRT_CPU_ACCOUNTING with minimal effort. But, thats for later. This change will impact scheduling behavior in interrupt heavy conditions. Tested on a 4-way system with eth0 handled by CPU 2 and a network heavy task (nc) running on CPU 3 (and no RSS/RFS). With that I have CPU 2 spending 75%+ of its time in irq processing. CPU 3 spending around 35% time running nc task. Now, if I run another CPU intensive task on CPU 2, without this change /proc/<pid>/schedstat shows 100% of time accounted to this task. With this change, it rightly shows less than 25% accounted to this task as remaining time is actually spent on irq processing. Signed-off-by: Venkatesh Pallipadi <venki@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1286237003-12406-7-git-send-email-venki@google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-05 00:03:21 +00:00
sched, rt: Update rq clock when unthrottling of an otherwise idle CPU If an RT task is awakened while it's rt_rq is throttled, the time between wakeup/enqueue and unthrottle/selection may be accounted as rt_time if the CPU is idle. Set rq->skip_clock_update negative upon throttle release to tell put_prev_task() that we need a clock update. Reported-by: Thomas Giesel <skoe@directbox.com> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1304059010.7472.1.camel@marge.simson.net Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-29 06:36:50 +00:00
if (rq->skip_clock_update > 0)
Sched: fix skip_clock_update optimization idle_balance() drops/retakes rq->lock, leaving the previous task vulnerable to set_tsk_need_resched(). Clear it after we return from balancing instead, and in setup_thread_stack() as well, so no successfully descheduled or never scheduled task has it set. Need resched confused the skip_clock_update logic, which assumes that the next call to update_rq_clock() will come nearly immediately after being set. Make the optimization robust against the waking a sleeper before it sucessfully deschedules case by checking that the current task has not been dequeued before setting the flag, since it is that useless clock update we're trying to save, and clear unconditionally in schedule() proper instead of conditionally in put_prev_task(). Signed-off-by: Mike Galbraith <efault@gmx.de> Reported-by: Bjoern B. Brandenburg <bbb.lst@gmail.com> Tested-by: Yong Zhang <yong.zhang0@gmail.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: stable@kernel.org LKML-Reference: <1291802742.1417.9.camel@marge.simson.net> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-12-08 10:05:42 +00:00
return;
sched: Remove irq time from available CPU power The idea was suggested by Peter Zijlstra here: http://marc.info/?l=linux-kernel&m=127476934517534&w=2 irq time is technically not available to the tasks running on the CPU. This patch removes irq time from CPU power piggybacking on sched_rt_avg_update(). Tested this by keeping CPU X busy with a network intensive task having 75% oa a single CPU irq processing (hard+soft) on a 4-way system. And start seven cycle soakers on the system. Without this change, there will be two tasks on each CPU. With this change, there is a single task on irq busy CPU X and remaining 7 tasks are spread around among other 3 CPUs. Signed-off-by: Venkatesh Pallipadi <venki@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1286237003-12406-8-git-send-email-venki@google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-05 00:03:22 +00:00
sched: Fix the irqtime code to deal with u64 wraps Some ARM systems have a short sched_clock() [ which needs to be fixed too ], but this exposed a bug in the irq_time code as well, it doesn't deal with wraps at all. Fix the irq_time code to deal with u64 wraps by re-writing the code to only use delta increments, which avoids the whole issue. Reviewed-by: Venkatesh Pallipadi <venki@google.com> Reported-by: Mikael Pettersson <mikpe@it.uu.se> Tested-by: Mikael Pettersson <mikpe@it.uu.se> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1292242433.6803.199.camel@twins> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-12-09 13:15:34 +00:00
delta = sched_clock_cpu(cpu_of(rq)) - rq->clock;
rq->clock += delta;
update_rq_clock_task(rq, delta);
sched: add optional support for CONFIG_HAVE_UNSTABLE_SCHED_CLOCK this replaces the rq->clock stuff (and possibly cpu_clock()). - architectures that have an 'imperfect' hardware clock can set CONFIG_HAVE_UNSTABLE_SCHED_CLOCK - the 'jiffie' window might be superfulous when we update tick_gtod before the __update_sched_clock() call in sched_clock_tick() - cpu_clock() might be implemented as: sched_clock_cpu(smp_processor_id()) if the accuracy proves good enough - how far can TSC drift in a single jiffie when considering the filtering and idle hooks? [ mingo@elte.hu: various fixes and cleanups ] Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-05-03 16:29:28 +00:00
}
sched: move sched_feat() definitions move sched_feat() definitions so that it can be used sooner by generic code too. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Mike Galbraith <efault@gmx.de> Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-15 15:00:04 +00:00
/*
* Tunables that become constants when CONFIG_SCHED_DEBUG is off:
*/
#ifdef CONFIG_SCHED_DEBUG
# define const_debug __read_mostly
#else
# define const_debug static const
#endif
ftrace: fix wakeups Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-12 19:20:52 +00:00
/**
sched.c: fix kernel-doc for runqueue_is_locked() Fix kernel-doc warning for runqueue_is_locked(): Warning(kernel/sched.c:664): missing initial short description on line: Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-15 23:12:30 +00:00
* runqueue_is_locked - Returns true if the current cpu runqueue is locked
sched: Fix missing kernel-doc notation The following htmldocs warnings: Warning(kernel/sched.c:685): No description found for parameter 'cpu' Warning(kernel/sched.c:3676): No description found for parameter 'sd' Trigger because new parameters were added to update_rq_clock() and update_group_power() without updating the kernel-doc notation. Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <4AD29070.7070002@oracle.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-10-12 02:12:00 +00:00
* @cpu: the processor in question.
ftrace: fix wakeups Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-12 19:20:52 +00:00
*
* This interface allows printk to be called with the runqueue lock
* held and know whether or not it is OK to wake up the klogd.
*/
sched: Fix raciness in runqueue_is_locked() runqueue_is_locked() is unavoidably racy due to a poor interface design. It does cpu = get_cpu() ret = some_perpcu_thing(cpu); put_cpu(cpu); return ret; Its return value is unreliable. Fix. Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Steven Rostedt <rostedt@goodmis.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <200909191855.n8JItiko022148@imap1.linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-09-19 18:55:44 +00:00
int runqueue_is_locked(int cpu)
ftrace: fix wakeups Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-12 19:20:52 +00:00
{
sched: Convert rq->lock to raw_spinlock Convert locks which cannot be sleeping locks in preempt-rt to raw_spinlocks. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Ingo Molnar <mingo@elte.hu>
2009-11-17 13:28:38 +00:00
return raw_spin_is_locked(&cpu_rq(cpu)->lock);
ftrace: fix wakeups Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-12 19:20:52 +00:00
}
sched: move sched_feat() definitions move sched_feat() definitions so that it can be used sooner by generic code too. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Mike Galbraith <efault@gmx.de> Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-15 15:00:04 +00:00
/*
* Debugging: various feature bits
*/
sched: /debug/sched_features provide a text based interface to the scheduler features; this saves the 'user' from setting bits using decimal arithmetic. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 17:45:00 +00:00
#define SCHED_FEAT(name, enabled) \
__SCHED_FEAT_##name ,
sched: move sched_feat() definitions move sched_feat() definitions so that it can be used sooner by generic code too. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Mike Galbraith <efault@gmx.de> Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-15 15:00:04 +00:00
enum {
sched: /debug/sched_features provide a text based interface to the scheduler features; this saves the 'user' from setting bits using decimal arithmetic. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 17:45:00 +00:00
#include "sched_features.h"
sched: move sched_feat() definitions move sched_feat() definitions so that it can be used sooner by generic code too. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Mike Galbraith <efault@gmx.de> Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-15 15:00:04 +00:00
};
sched: /debug/sched_features provide a text based interface to the scheduler features; this saves the 'user' from setting bits using decimal arithmetic. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 17:45:00 +00:00
#undef SCHED_FEAT
#define SCHED_FEAT(name, enabled) \
(1UL << __SCHED_FEAT_##name) * enabled |
sched: move sched_feat() definitions move sched_feat() definitions so that it can be used sooner by generic code too. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Mike Galbraith <efault@gmx.de> Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-15 15:00:04 +00:00
const_debug unsigned int sysctl_sched_features =
sched: /debug/sched_features provide a text based interface to the scheduler features; this saves the 'user' from setting bits using decimal arithmetic. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 17:45:00 +00:00
#include "sched_features.h"
0;
#undef SCHED_FEAT
#ifdef CONFIG_SCHED_DEBUG
#define SCHED_FEAT(name, enabled) \
#name ,
sched: add statics, don't return void expressions Noticed by sparse: kernel/sched.c:760:20: warning: symbol 'sched_feat_names' was not declared. Should it be static? kernel/sched.c:767:5: warning: symbol 'sched_feat_open' was not declared. Should it be static? kernel/sched_fair.c:845:3: warning: returning void-valued expression kernel/sched.c:4386:3: warning: returning void-valued expression Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-25 01:17:55 +00:00
static __read_mostly char *sched_feat_names[] = {
sched: /debug/sched_features provide a text based interface to the scheduler features; this saves the 'user' from setting bits using decimal arithmetic. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 17:45:00 +00:00
#include "sched_features.h"
NULL
};
#undef SCHED_FEAT
sched: switch sched_features to seqfile Impact: cleanup So handling of sched_features read is simplified. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-30 07:23:32 +00:00
static int sched_feat_show(struct seq_file *m, void *v)
sched: /debug/sched_features provide a text based interface to the scheduler features; this saves the 'user' from setting bits using decimal arithmetic. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 17:45:00 +00:00
{
int i;
for (i = 0; sched_feat_names[i]; i++) {
sched: switch sched_features to seqfile Impact: cleanup So handling of sched_features read is simplified. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-30 07:23:32 +00:00
if (!(sysctl_sched_features & (1UL << i)))
seq_puts(m, "NO_");
seq_printf(m, "%s ", sched_feat_names[i]);
sched: /debug/sched_features provide a text based interface to the scheduler features; this saves the 'user' from setting bits using decimal arithmetic. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 17:45:00 +00:00
}
sched: switch sched_features to seqfile Impact: cleanup So handling of sched_features read is simplified. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-30 07:23:32 +00:00
seq_puts(m, "\n");
sched: /debug/sched_features provide a text based interface to the scheduler features; this saves the 'user' from setting bits using decimal arithmetic. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 17:45:00 +00:00
sched: switch sched_features to seqfile Impact: cleanup So handling of sched_features read is simplified. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-30 07:23:32 +00:00
return 0;
sched: /debug/sched_features provide a text based interface to the scheduler features; this saves the 'user' from setting bits using decimal arithmetic. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 17:45:00 +00:00
}
static ssize_t
sched_feat_write(struct file *filp, const char __user *ubuf,
size_t cnt, loff_t *ppos)
{
char buf[64];
sched: Fix string comparison in /proc/sched_features Fix incorrect handling of the following case: INTERACTIVE INTERACTIVE_SOMETHING_ELSE The comparison only checks up to each element's length. Changelog since v1: - Embellish using some Rostedtisms. [ mingo: ^^ == smaller and cleaner ] Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Reviewed-by: Steven Rostedt <rostedt@goodmis.org> Cc: <stable@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Tony Lindgren <tony@atomide.com> LKML-Reference: <20100913214700.GB16118@Krystal> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-09-13 21:47:00 +00:00
char *cmp;
sched: /debug/sched_features provide a text based interface to the scheduler features; this saves the 'user' from setting bits using decimal arithmetic. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 17:45:00 +00:00
int neg = 0;
int i;
if (cnt > 63)
cnt = 63;
if (copy_from_user(&buf, ubuf, cnt))
return -EFAULT;
buf[cnt] = 0;
sched: Fix string comparison in /proc/sched_features Fix incorrect handling of the following case: INTERACTIVE INTERACTIVE_SOMETHING_ELSE The comparison only checks up to each element's length. Changelog since v1: - Embellish using some Rostedtisms. [ mingo: ^^ == smaller and cleaner ] Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Reviewed-by: Steven Rostedt <rostedt@goodmis.org> Cc: <stable@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Tony Lindgren <tony@atomide.com> LKML-Reference: <20100913214700.GB16118@Krystal> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-09-13 21:47:00 +00:00
cmp = strstrip(buf);
sched: /debug/sched_features provide a text based interface to the scheduler features; this saves the 'user' from setting bits using decimal arithmetic. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 17:45:00 +00:00
sched: Fix strncmp operation One of the operands, buf, is incorrect, since it is stripped and the correct address for subsequent string comparing could change if leading white spaces, if any, are removed from buf. It is fixed by replacing buf with cmp. Signed-off-by: Hillf Danton <dhillf@gmail.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <AANLkTinOPuYsVovrZpbuCCmG5deEyc8WgA_A1RJx_YK7@mail.gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-01-06 12:58:12 +00:00
if (strncmp(cmp, "NO_", 3) == 0) {
sched: /debug/sched_features provide a text based interface to the scheduler features; this saves the 'user' from setting bits using decimal arithmetic. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 17:45:00 +00:00
neg = 1;
cmp += 3;
}
for (i = 0; sched_feat_names[i]; i++) {
sched: Fix string comparison in /proc/sched_features Fix incorrect handling of the following case: INTERACTIVE INTERACTIVE_SOMETHING_ELSE The comparison only checks up to each element's length. Changelog since v1: - Embellish using some Rostedtisms. [ mingo: ^^ == smaller and cleaner ] Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Reviewed-by: Steven Rostedt <rostedt@goodmis.org> Cc: <stable@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Tony Lindgren <tony@atomide.com> LKML-Reference: <20100913214700.GB16118@Krystal> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-09-13 21:47:00 +00:00
if (strcmp(cmp, sched_feat_names[i]) == 0) {
sched: /debug/sched_features provide a text based interface to the scheduler features; this saves the 'user' from setting bits using decimal arithmetic. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 17:45:00 +00:00
if (neg)
sysctl_sched_features &= ~(1UL << i);
else
sysctl_sched_features |= (1UL << i);
break;
}
}
if (!sched_feat_names[i])
return -EINVAL;
sched_feat_write(): Update ppos instead of file->f_pos sched_feat_write() should update ppos instead of file->f_pos. (This reduces some BKL dependencies of this code.) Signed-off-by: Jan Blunck <jblunck@suse.de> Cc: jkacur@redhat.com Cc: Arnd Bergmann <arnd@arndb.de> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Jamie Lokier <jamie@shareable.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Christoph Hellwig <hch@infradead.org> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> LKML-Reference: <1258735245-25826-8-git-send-email-jblunck@suse.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-11-20 16:40:37 +00:00
*ppos += cnt;
sched: /debug/sched_features provide a text based interface to the scheduler features; this saves the 'user' from setting bits using decimal arithmetic. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 17:45:00 +00:00
return cnt;
}
sched: switch sched_features to seqfile Impact: cleanup So handling of sched_features read is simplified. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-30 07:23:32 +00:00
static int sched_feat_open(struct inode *inode, struct file *filp)
{
return single_open(filp, sched_feat_show, NULL);
}
const: constify remaining file_operations [akpm@linux-foundation.org: fix KVM] Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Acked-by: Mike Frysinger <vapier@gentoo.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-10-01 22:43:56 +00:00
static const struct file_operations sched_feat_fops = {
sched: switch sched_features to seqfile Impact: cleanup So handling of sched_features read is simplified. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-30 07:23:32 +00:00
.open = sched_feat_open,
.write = sched_feat_write,
.read = seq_read,
.llseek = seq_lseek,
.release = single_release,
sched: /debug/sched_features provide a text based interface to the scheduler features; this saves the 'user' from setting bits using decimal arithmetic. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 17:45:00 +00:00
};
static __init int sched_init_debug(void)
{
debugfs_create_file("sched_features", 0644, NULL, NULL,
&sched_feat_fops);
return 0;
}
late_initcall(sched_init_debug);
#endif
#define sched_feat(x) (sysctl_sched_features & (1UL << __SCHED_FEAT_##x))
sched: move sched_feat() definitions move sched_feat() definitions so that it can be used sooner by generic code too. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Mike Galbraith <efault@gmx.de> Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-15 15:00:04 +00:00
sched: avoid large irq-latencies in smp-balancing SMP balancing is done with IRQs disabled and can iterate the full rq. When rqs are large this can cause large irq-latencies. Limit the nr of iterations on each run. This fixes a scheduling latency regression reported by the -rt folks. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Steven Rostedt <rostedt@goodmis.org> Tested-by: Gregory Haskins <ghaskins@novell.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-11-09 21:39:39 +00:00
/*
* Number of tasks to iterate in a single balance run.
* Limited because this is done with IRQs disabled.
*/
const_debug unsigned int sysctl_sched_nr_migrate = 32;
sched: Scale down cpu_power due to RT tasks Keep an average on the amount of time spend on RT tasks and use that fraction to scale down the cpu_power for regular tasks. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Tested-by: Andreas Herrmann <andreas.herrmann3@amd.com> Acked-by: Andreas Herrmann <andreas.herrmann3@amd.com> Acked-by: Gautham R Shenoy <ego@in.ibm.com> Cc: Balbir Singh <balbir@in.ibm.com> LKML-Reference: <20090901083826.287778431@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-09-01 08:34:37 +00:00
/*
* period over which we average the RT time consumption, measured
* in ms.
*
* default: 1s
*/
const_debug unsigned int sysctl_sched_time_avg = MSEC_PER_SEC;
sched: rt time limit Very simple time limit on the realtime scheduling classes. Allow the rq's realtime class to consume sched_rt_ratio of every sched_rt_period slice. If the class exceeds this quota the fair class will preempt the realtime class. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:29 +00:00
/*
sched: rt-group: interface Change the rt_ratio interface to rt_runtime_us, to match rt_period_us. This avoids picking a granularity for the ratio. Extend the /sys/kernel/uids/<uid>/ interface to allow setting the group's rt_runtime. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-13 14:45:39 +00:00
* period over which we measure -rt task cpu usage in us.
sched: rt time limit Very simple time limit on the realtime scheduling classes. Allow the rq's realtime class to consume sched_rt_ratio of every sched_rt_period slice. If the class exceeds this quota the fair class will preempt the realtime class. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:29 +00:00
* default: 1s
*/
sched: rt-group: interface Change the rt_ratio interface to rt_runtime_us, to match rt_period_us. This avoids picking a granularity for the ratio. Extend the /sys/kernel/uids/<uid>/ interface to allow setting the group's rt_runtime. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-13 14:45:39 +00:00
unsigned int sysctl_sched_rt_period = 1000000;
sched: rt time limit Very simple time limit on the realtime scheduling classes. Allow the rq's realtime class to consume sched_rt_ratio of every sched_rt_period slice. If the class exceeds this quota the fair class will preempt the realtime class. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:29 +00:00
sched: make early bootup sched_clock() use safer do not call sched_clock() too early. Not only might rq->idle not be set up - but pure per-cpu data might not be accessible either. this solves an ia64 early bootup hang with CONFIG_PRINTK_TIME=y. Tested-by: Tony Luck <tony.luck@gmail.com> Acked-by: Tony Luck <tony.luck@gmail.com> Acked-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-13 13:02:36 +00:00
static __read_mostly int scheduler_running;
sched: rt-group: interface Change the rt_ratio interface to rt_runtime_us, to match rt_period_us. This avoids picking a granularity for the ratio. Extend the /sys/kernel/uids/<uid>/ interface to allow setting the group's rt_runtime. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-13 14:45:39 +00:00
/*
* part of the period that we allow rt tasks to run in us.
* default: 0.95s
*/
int sysctl_sched_rt_runtime = 950000;
sched: rt time limit Very simple time limit on the realtime scheduling classes. Allow the rq's realtime class to consume sched_rt_ratio of every sched_rt_period slice. If the class exceeds this quota the fair class will preempt the realtime class. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:29 +00:00
sched: rt-group: synchonised bandwidth period Various SMP balancing algorithms require that the bandwidth period run in sync. Possible improvements are moving the rt_bandwidth thing into root_domain and keeping a span per rt_bandwidth which marks throttled cpus. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 17:44:57 +00:00
static inline u64 global_rt_period(void)
{
return (u64)sysctl_sched_rt_period * NSEC_PER_USEC;
}
static inline u64 global_rt_runtime(void)
{
sched: test runtime rather than period in global_rt_runtime() Test runtime rather than period Signed-off-by: Roel Kluin <roel.kluin@gmail.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-22 20:51:15 +00:00
if (sysctl_sched_rt_runtime < 0)
sched: rt-group: synchonised bandwidth period Various SMP balancing algorithms require that the bandwidth period run in sync. Possible improvements are moving the rt_bandwidth thing into root_domain and keeping a span per rt_bandwidth which marks throttled cpus. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 17:44:57 +00:00
return RUNTIME_INF;
return (u64)sysctl_sched_rt_runtime * NSEC_PER_USEC;
}
sched: rt time limit Very simple time limit on the realtime scheduling classes. Allow the rq's realtime class to consume sched_rt_ratio of every sched_rt_period slice. If the class exceeds this quota the fair class will preempt the realtime class. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:29 +00:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
#ifndef prepare_arch_switch
[PATCH] sched: cleanup context switch locking Instead of requiring architecture code to interact with the scheduler's locking implementation, provide a couple of defines that can be used by the architecture to request runqueue unlocked context switches, and ask for interrupts to be enabled over the context switch. Also replaces the "switch_lock" used by these architectures with an oncpu flag (note, not a potentially slow bitflag). This eliminates one bus locked memory operation when context switching, and simplifies the task_running function. Signed-off-by: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-25 21:57:23 +00:00
# define prepare_arch_switch(next) do { } while (0)
#endif
#ifndef finish_arch_switch
# define finish_arch_switch(prev) do { } while (0)
#endif
sched: fix crash on ia64, introduce task_current() Some services (e.g. sched_setscheduler(), rt_mutex_setprio() and sched_move_task()) must handle a given task differently in case it's the 'rq->curr' task on its run-queue. The task_running() interface is not suitable for determining such tasks for platforms with one of the following options: #define __ARCH_WANT_UNLOCKED_CTXSW #define __ARCH_WANT_INTERRUPTS_ON_CTXSW Due to the fact that it makes use of 'p->oncpu == 1' as a criterion but such a task is not necessarily 'rq->curr'. The detailed explanation is available here: https://lists.linux-foundation.org/pipermail/containers/2007-December/009262.html Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Tested-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Tested-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
2007-12-18 14:21:13 +00:00
static inline int task_current(struct rq *rq, struct task_struct *p)
{
return rq->curr == p;
}
[PATCH] sched: cleanup, convert sched.c-internal typedefs to struct convert: - runqueue_t to 'struct rq' - prio_array_t to 'struct prio_array' - migration_req_t to 'struct migration_req' I was the one who added these but they are both against the kernel coding style and also were used inconsistently at places. So just get rid of them at once, now that we are flushing the scheduler patch-queue anyway. Conversion was mostly scripted, the result was reviewed and all secondary whitespace and style impact (if any) was fixed up by hand. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-03 07:25:42 +00:00
static inline int task_running(struct rq *rq, struct task_struct *p)
[PATCH] sched: cleanup context switch locking Instead of requiring architecture code to interact with the scheduler's locking implementation, provide a couple of defines that can be used by the architecture to request runqueue unlocked context switches, and ask for interrupts to be enabled over the context switch. Also replaces the "switch_lock" used by these architectures with an oncpu flag (note, not a potentially slow bitflag). This eliminates one bus locked memory operation when context switching, and simplifies the task_running function. Signed-off-by: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-25 21:57:23 +00:00
{
sched: Always provide p->on_cpu Always provide p->on_cpu so that we can determine if its on a cpu without having to lock the rq. Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110405152728.785452014@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-05 15:23:40 +00:00
#ifdef CONFIG_SMP
return p->on_cpu;
#else
sched: fix crash on ia64, introduce task_current() Some services (e.g. sched_setscheduler(), rt_mutex_setprio() and sched_move_task()) must handle a given task differently in case it's the 'rq->curr' task on its run-queue. The task_running() interface is not suitable for determining such tasks for platforms with one of the following options: #define __ARCH_WANT_UNLOCKED_CTXSW #define __ARCH_WANT_INTERRUPTS_ON_CTXSW Due to the fact that it makes use of 'p->oncpu == 1' as a criterion but such a task is not necessarily 'rq->curr'. The detailed explanation is available here: https://lists.linux-foundation.org/pipermail/containers/2007-December/009262.html Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Tested-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Tested-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
2007-12-18 14:21:13 +00:00
return task_current(rq, p);
sched: Always provide p->on_cpu Always provide p->on_cpu so that we can determine if its on a cpu without having to lock the rq. Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110405152728.785452014@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-05 15:23:40 +00:00
#endif
[PATCH] sched: cleanup context switch locking Instead of requiring architecture code to interact with the scheduler's locking implementation, provide a couple of defines that can be used by the architecture to request runqueue unlocked context switches, and ask for interrupts to be enabled over the context switch. Also replaces the "switch_lock" used by these architectures with an oncpu flag (note, not a potentially slow bitflag). This eliminates one bus locked memory operation when context switching, and simplifies the task_running function. Signed-off-by: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-25 21:57:23 +00:00
}
sched: Always provide p->on_cpu Always provide p->on_cpu so that we can determine if its on a cpu without having to lock the rq. Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110405152728.785452014@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-05 15:23:40 +00:00
#ifndef __ARCH_WANT_UNLOCKED_CTXSW
[PATCH] sched: cleanup, convert sched.c-internal typedefs to struct convert: - runqueue_t to 'struct rq' - prio_array_t to 'struct prio_array' - migration_req_t to 'struct migration_req' I was the one who added these but they are both against the kernel coding style and also were used inconsistently at places. So just get rid of them at once, now that we are flushing the scheduler patch-queue anyway. Conversion was mostly scripted, the result was reviewed and all secondary whitespace and style impact (if any) was fixed up by hand. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-03 07:25:42 +00:00
static inline void prepare_lock_switch(struct rq *rq, struct task_struct *next)
[PATCH] sched: cleanup context switch locking Instead of requiring architecture code to interact with the scheduler's locking implementation, provide a couple of defines that can be used by the architecture to request runqueue unlocked context switches, and ask for interrupts to be enabled over the context switch. Also replaces the "switch_lock" used by these architectures with an oncpu flag (note, not a potentially slow bitflag). This eliminates one bus locked memory operation when context switching, and simplifies the task_running function. Signed-off-by: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-25 21:57:23 +00:00
{
sched: Always provide p->on_cpu Always provide p->on_cpu so that we can determine if its on a cpu without having to lock the rq. Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110405152728.785452014@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-05 15:23:40 +00:00
#ifdef CONFIG_SMP
/*
* We can optimise this out completely for !SMP, because the
* SMP rebalancing from interrupt is the only thing that cares
* here.
*/
next->on_cpu = 1;
#endif
[PATCH] sched: cleanup context switch locking Instead of requiring architecture code to interact with the scheduler's locking implementation, provide a couple of defines that can be used by the architecture to request runqueue unlocked context switches, and ask for interrupts to be enabled over the context switch. Also replaces the "switch_lock" used by these architectures with an oncpu flag (note, not a potentially slow bitflag). This eliminates one bus locked memory operation when context switching, and simplifies the task_running function. Signed-off-by: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-25 21:57:23 +00:00
}
[PATCH] sched: cleanup, convert sched.c-internal typedefs to struct convert: - runqueue_t to 'struct rq' - prio_array_t to 'struct prio_array' - migration_req_t to 'struct migration_req' I was the one who added these but they are both against the kernel coding style and also were used inconsistently at places. So just get rid of them at once, now that we are flushing the scheduler patch-queue anyway. Conversion was mostly scripted, the result was reviewed and all secondary whitespace and style impact (if any) was fixed up by hand. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-03 07:25:42 +00:00
static inline void finish_lock_switch(struct rq *rq, struct task_struct *prev)
[PATCH] sched: cleanup context switch locking Instead of requiring architecture code to interact with the scheduler's locking implementation, provide a couple of defines that can be used by the architecture to request runqueue unlocked context switches, and ask for interrupts to be enabled over the context switch. Also replaces the "switch_lock" used by these architectures with an oncpu flag (note, not a potentially slow bitflag). This eliminates one bus locked memory operation when context switching, and simplifies the task_running function. Signed-off-by: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-25 21:57:23 +00:00
{
sched: Always provide p->on_cpu Always provide p->on_cpu so that we can determine if its on a cpu without having to lock the rq. Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110405152728.785452014@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-05 15:23:40 +00:00
#ifdef CONFIG_SMP
/*
* After ->on_cpu is cleared, the task can be moved to a different CPU.
* We must ensure this doesn't happen until the switch is completely
* finished.
*/
smp_wmb();
prev->on_cpu = 0;
#endif
[PATCH] Fix spinlock owner debugging fix up the runqueue lock owner only if we truly did a context-switch with the runqueue lock held. Impacts ia64, mips, sparc64 and arm. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-13 09:17:59 +00:00
#ifdef CONFIG_DEBUG_SPINLOCK
/* this is a valid case when another task releases the spinlock */
rq->lock.owner = current;
#endif
[PATCH] lockdep: prove spinlock rwlock locking correctness Use the lock validator framework to prove spinlock and rwlock locking correctness. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-03 07:24:54 +00:00
/*
* If we are tracking spinlock dependencies then we have to
* fix up the runqueue lock - which gets 'carried over' from
* prev into current:
*/
spin_acquire(&rq->lock.dep_map, 0, 0, _THIS_IP_);
sched: Convert rq->lock to raw_spinlock Convert locks which cannot be sleeping locks in preempt-rt to raw_spinlocks. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Ingo Molnar <mingo@elte.hu>
2009-11-17 13:28:38 +00:00
raw_spin_unlock_irq(&rq->lock);
[PATCH] sched: cleanup context switch locking Instead of requiring architecture code to interact with the scheduler's locking implementation, provide a couple of defines that can be used by the architecture to request runqueue unlocked context switches, and ask for interrupts to be enabled over the context switch. Also replaces the "switch_lock" used by these architectures with an oncpu flag (note, not a potentially slow bitflag). This eliminates one bus locked memory operation when context switching, and simplifies the task_running function. Signed-off-by: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-25 21:57:23 +00:00
}
#else /* __ARCH_WANT_UNLOCKED_CTXSW */
[PATCH] sched: cleanup, convert sched.c-internal typedefs to struct convert: - runqueue_t to 'struct rq' - prio_array_t to 'struct prio_array' - migration_req_t to 'struct migration_req' I was the one who added these but they are both against the kernel coding style and also were used inconsistently at places. So just get rid of them at once, now that we are flushing the scheduler patch-queue anyway. Conversion was mostly scripted, the result was reviewed and all secondary whitespace and style impact (if any) was fixed up by hand. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-03 07:25:42 +00:00
static inline void prepare_lock_switch(struct rq *rq, struct task_struct *next)
[PATCH] sched: cleanup context switch locking Instead of requiring architecture code to interact with the scheduler's locking implementation, provide a couple of defines that can be used by the architecture to request runqueue unlocked context switches, and ask for interrupts to be enabled over the context switch. Also replaces the "switch_lock" used by these architectures with an oncpu flag (note, not a potentially slow bitflag). This eliminates one bus locked memory operation when context switching, and simplifies the task_running function. Signed-off-by: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-25 21:57:23 +00:00
{
#ifdef CONFIG_SMP
/*
* We can optimise this out completely for !SMP, because the
* SMP rebalancing from interrupt is the only thing that cares
* here.
*/
sched: Always provide p->on_cpu Always provide p->on_cpu so that we can determine if its on a cpu without having to lock the rq. Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110405152728.785452014@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-05 15:23:40 +00:00
next->on_cpu = 1;
[PATCH] sched: cleanup context switch locking Instead of requiring architecture code to interact with the scheduler's locking implementation, provide a couple of defines that can be used by the architecture to request runqueue unlocked context switches, and ask for interrupts to be enabled over the context switch. Also replaces the "switch_lock" used by these architectures with an oncpu flag (note, not a potentially slow bitflag). This eliminates one bus locked memory operation when context switching, and simplifies the task_running function. Signed-off-by: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-25 21:57:23 +00:00
#endif
#ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW
sched: Convert rq->lock to raw_spinlock Convert locks which cannot be sleeping locks in preempt-rt to raw_spinlocks. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Ingo Molnar <mingo@elte.hu>
2009-11-17 13:28:38 +00:00
raw_spin_unlock_irq(&rq->lock);
[PATCH] sched: cleanup context switch locking Instead of requiring architecture code to interact with the scheduler's locking implementation, provide a couple of defines that can be used by the architecture to request runqueue unlocked context switches, and ask for interrupts to be enabled over the context switch. Also replaces the "switch_lock" used by these architectures with an oncpu flag (note, not a potentially slow bitflag). This eliminates one bus locked memory operation when context switching, and simplifies the task_running function. Signed-off-by: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-25 21:57:23 +00:00
#else
sched: Convert rq->lock to raw_spinlock Convert locks which cannot be sleeping locks in preempt-rt to raw_spinlocks. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Ingo Molnar <mingo@elte.hu>
2009-11-17 13:28:38 +00:00
raw_spin_unlock(&rq->lock);
[PATCH] sched: cleanup context switch locking Instead of requiring architecture code to interact with the scheduler's locking implementation, provide a couple of defines that can be used by the architecture to request runqueue unlocked context switches, and ask for interrupts to be enabled over the context switch. Also replaces the "switch_lock" used by these architectures with an oncpu flag (note, not a potentially slow bitflag). This eliminates one bus locked memory operation when context switching, and simplifies the task_running function. Signed-off-by: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-25 21:57:23 +00:00
#endif
}
[PATCH] sched: cleanup, convert sched.c-internal typedefs to struct convert: - runqueue_t to 'struct rq' - prio_array_t to 'struct prio_array' - migration_req_t to 'struct migration_req' I was the one who added these but they are both against the kernel coding style and also were used inconsistently at places. So just get rid of them at once, now that we are flushing the scheduler patch-queue anyway. Conversion was mostly scripted, the result was reviewed and all secondary whitespace and style impact (if any) was fixed up by hand. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-03 07:25:42 +00:00
static inline void finish_lock_switch(struct rq *rq, struct task_struct *prev)
[PATCH] sched: cleanup context switch locking Instead of requiring architecture code to interact with the scheduler's locking implementation, provide a couple of defines that can be used by the architecture to request runqueue unlocked context switches, and ask for interrupts to be enabled over the context switch. Also replaces the "switch_lock" used by these architectures with an oncpu flag (note, not a potentially slow bitflag). This eliminates one bus locked memory operation when context switching, and simplifies the task_running function. Signed-off-by: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-25 21:57:23 +00:00
{
#ifdef CONFIG_SMP
/*
sched: Always provide p->on_cpu Always provide p->on_cpu so that we can determine if its on a cpu without having to lock the rq. Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110405152728.785452014@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-05 15:23:40 +00:00
* After ->on_cpu is cleared, the task can be moved to a different CPU.
[PATCH] sched: cleanup context switch locking Instead of requiring architecture code to interact with the scheduler's locking implementation, provide a couple of defines that can be used by the architecture to request runqueue unlocked context switches, and ask for interrupts to be enabled over the context switch. Also replaces the "switch_lock" used by these architectures with an oncpu flag (note, not a potentially slow bitflag). This eliminates one bus locked memory operation when context switching, and simplifies the task_running function. Signed-off-by: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-25 21:57:23 +00:00
* We must ensure this doesn't happen until the switch is completely
* finished.
*/
smp_wmb();
sched: Always provide p->on_cpu Always provide p->on_cpu so that we can determine if its on a cpu without having to lock the rq. Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110405152728.785452014@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-05 15:23:40 +00:00
prev->on_cpu = 0;
[PATCH] sched: cleanup context switch locking Instead of requiring architecture code to interact with the scheduler's locking implementation, provide a couple of defines that can be used by the architecture to request runqueue unlocked context switches, and ask for interrupts to be enabled over the context switch. Also replaces the "switch_lock" used by these architectures with an oncpu flag (note, not a potentially slow bitflag). This eliminates one bus locked memory operation when context switching, and simplifies the task_running function. Signed-off-by: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-25 21:57:23 +00:00
#endif
#ifndef __ARCH_WANT_INTERRUPTS_ON_CTXSW
local_irq_enable();
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
#endif
[PATCH] sched: cleanup context switch locking Instead of requiring architecture code to interact with the scheduler's locking implementation, provide a couple of defines that can be used by the architecture to request runqueue unlocked context switches, and ask for interrupts to be enabled over the context switch. Also replaces the "switch_lock" used by these architectures with an oncpu flag (note, not a potentially slow bitflag). This eliminates one bus locked memory operation when context switching, and simplifies the task_running function. Signed-off-by: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-25 21:57:23 +00:00
}
#endif /* __ARCH_WANT_UNLOCKED_CTXSW */
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
sched: Fix race between ttwu() and task_rq_lock() Thomas found that due to ttwu() changing a task's cpu without holding the rq->lock, task_rq_lock() might end up locking the wrong rq. Avoid this by serializing against TASK_WAKING. Reported-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1266241712.15770.420.camel@laptop> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2010-02-15 13:45:54 +00:00
/*
sched: Add p->pi_lock to task_rq_lock() In order to be able to call set_task_cpu() while either holding p->pi_lock or task_rq(p)->lock we need to hold both locks in order to stabilize task_rq(). This makes task_rq_lock() acquire both locks, and have __task_rq_lock() validate that p->pi_lock is held. This increases the locking overhead for most scheduler syscalls but allows reduction of rq->lock contention for some scheduler hot paths (ttwu). Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110405152729.232781355@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-05 15:23:51 +00:00
* __task_rq_lock - lock the rq @p resides on.
[PATCH] pi-futex: scheduler support for pi Add framework to boost/unboost the priority of RT tasks. This consists of: - caching the 'normal' priority in ->normal_prio - providing a functions to set/get the priority of the task - make sched_setscheduler() aware of boosting The effective_prio() cleanups also fix a priority-calculation bug pointed out by Andrey Gelman, in set_user_nice(). has_rt_policy() fix: Peter Williams <pwil3058@bigpond.net.au> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Cc: Andrey Gelman <agelman@012.net.il> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 09:54:51 +00:00
*/
[PATCH] sched: cleanup, convert sched.c-internal typedefs to struct convert: - runqueue_t to 'struct rq' - prio_array_t to 'struct prio_array' - migration_req_t to 'struct migration_req' I was the one who added these but they are both against the kernel coding style and also were used inconsistently at places. So just get rid of them at once, now that we are flushing the scheduler patch-queue anyway. Conversion was mostly scripted, the result was reviewed and all secondary whitespace and style impact (if any) was fixed up by hand. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-03 07:25:42 +00:00
static inline struct rq *__task_rq_lock(struct task_struct *p)
[PATCH] pi-futex: scheduler support for pi Add framework to boost/unboost the priority of RT tasks. This consists of: - caching the 'normal' priority in ->normal_prio - providing a functions to set/get the priority of the task - make sched_setscheduler() aware of boosting The effective_prio() cleanups also fix a priority-calculation bug pointed out by Andrey Gelman, in set_user_nice(). has_rt_policy() fix: Peter Williams <pwil3058@bigpond.net.au> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Cc: Andrey Gelman <agelman@012.net.il> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 09:54:51 +00:00
__acquires(rq->lock)
{
sched: Fix race between ttwu() and task_rq_lock() Thomas found that due to ttwu() changing a task's cpu without holding the rq->lock, task_rq_lock() might end up locking the wrong rq. Avoid this by serializing against TASK_WAKING. Reported-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1266241712.15770.420.camel@laptop> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2010-02-15 13:45:54 +00:00
struct rq *rq;
sched: Add p->pi_lock to task_rq_lock() In order to be able to call set_task_cpu() while either holding p->pi_lock or task_rq(p)->lock we need to hold both locks in order to stabilize task_rq(). This makes task_rq_lock() acquire both locks, and have __task_rq_lock() validate that p->pi_lock is held. This increases the locking overhead for most scheduler syscalls but allows reduction of rq->lock contention for some scheduler hot paths (ttwu). Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110405152729.232781355@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-05 15:23:51 +00:00
lockdep_assert_held(&p->pi_lock);
sched: cleanup: remove unnecessary gotos Replace loops implemented with gotos with real loops. Replace err = ...; goto x; x: return err; with return ...; No functional changes. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 15:00:14 +00:00
for (;;) {
sched: Fix race between ttwu() and task_rq_lock() Thomas found that due to ttwu() changing a task's cpu without holding the rq->lock, task_rq_lock() might end up locking the wrong rq. Avoid this by serializing against TASK_WAKING. Reported-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1266241712.15770.420.camel@laptop> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2010-02-15 13:45:54 +00:00
rq = task_rq(p);
sched: Convert rq->lock to raw_spinlock Convert locks which cannot be sleeping locks in preempt-rt to raw_spinlocks. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Ingo Molnar <mingo@elte.hu>
2009-11-17 13:28:38 +00:00
raw_spin_lock(&rq->lock);
sched: Optimize task_rq_lock() Now that we hold the rq->lock over set_task_cpu() again, we can do away with most of the TASK_WAKING checks and reduce them again to set_cpus_allowed_ptr(). Removes some conditionals from scheduling hot-paths. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Oleg Nesterov <oleg@redhat.com> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-03-25 20:05:16 +00:00
if (likely(rq == task_rq(p)))
sched: cleanup: remove unnecessary gotos Replace loops implemented with gotos with real loops. Replace err = ...; goto x; x: return err; with return ...; No functional changes. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 15:00:14 +00:00
return rq;
sched: Convert rq->lock to raw_spinlock Convert locks which cannot be sleeping locks in preempt-rt to raw_spinlocks. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Ingo Molnar <mingo@elte.hu>
2009-11-17 13:28:38 +00:00
raw_spin_unlock(&rq->lock);
[PATCH] pi-futex: scheduler support for pi Add framework to boost/unboost the priority of RT tasks. This consists of: - caching the 'normal' priority in ->normal_prio - providing a functions to set/get the priority of the task - make sched_setscheduler() aware of boosting The effective_prio() cleanups also fix a priority-calculation bug pointed out by Andrey Gelman, in set_user_nice(). has_rt_policy() fix: Peter Williams <pwil3058@bigpond.net.au> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Cc: Andrey Gelman <agelman@012.net.il> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 09:54:51 +00:00
}
}
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
/*
sched: Add p->pi_lock to task_rq_lock() In order to be able to call set_task_cpu() while either holding p->pi_lock or task_rq(p)->lock we need to hold both locks in order to stabilize task_rq(). This makes task_rq_lock() acquire both locks, and have __task_rq_lock() validate that p->pi_lock is held. This increases the locking overhead for most scheduler syscalls but allows reduction of rq->lock contention for some scheduler hot paths (ttwu). Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110405152729.232781355@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-05 15:23:51 +00:00
* task_rq_lock - lock p->pi_lock and lock the rq @p resides on.
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
*/
[PATCH] sched: cleanup, convert sched.c-internal typedefs to struct convert: - runqueue_t to 'struct rq' - prio_array_t to 'struct prio_array' - migration_req_t to 'struct migration_req' I was the one who added these but they are both against the kernel coding style and also were used inconsistently at places. So just get rid of them at once, now that we are flushing the scheduler patch-queue anyway. Conversion was mostly scripted, the result was reviewed and all secondary whitespace and style impact (if any) was fixed up by hand. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-03 07:25:42 +00:00
static struct rq *task_rq_lock(struct task_struct *p, unsigned long *flags)
sched: Add p->pi_lock to task_rq_lock() In order to be able to call set_task_cpu() while either holding p->pi_lock or task_rq(p)->lock we need to hold both locks in order to stabilize task_rq(). This makes task_rq_lock() acquire both locks, and have __task_rq_lock() validate that p->pi_lock is held. This increases the locking overhead for most scheduler syscalls but allows reduction of rq->lock contention for some scheduler hot paths (ttwu). Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110405152729.232781355@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-05 15:23:51 +00:00
__acquires(p->pi_lock)
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
__acquires(rq->lock)
{
[PATCH] sched: cleanup, convert sched.c-internal typedefs to struct convert: - runqueue_t to 'struct rq' - prio_array_t to 'struct prio_array' - migration_req_t to 'struct migration_req' I was the one who added these but they are both against the kernel coding style and also were used inconsistently at places. So just get rid of them at once, now that we are flushing the scheduler patch-queue anyway. Conversion was mostly scripted, the result was reviewed and all secondary whitespace and style impact (if any) was fixed up by hand. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-03 07:25:42 +00:00
struct rq *rq;
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
sched: cleanup: remove unnecessary gotos Replace loops implemented with gotos with real loops. Replace err = ...; goto x; x: return err; with return ...; No functional changes. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 15:00:14 +00:00
for (;;) {
sched: Add p->pi_lock to task_rq_lock() In order to be able to call set_task_cpu() while either holding p->pi_lock or task_rq(p)->lock we need to hold both locks in order to stabilize task_rq(). This makes task_rq_lock() acquire both locks, and have __task_rq_lock() validate that p->pi_lock is held. This increases the locking overhead for most scheduler syscalls but allows reduction of rq->lock contention for some scheduler hot paths (ttwu). Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110405152729.232781355@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-05 15:23:51 +00:00
raw_spin_lock_irqsave(&p->pi_lock, *flags);
sched: cleanup: remove unnecessary gotos Replace loops implemented with gotos with real loops. Replace err = ...; goto x; x: return err; with return ...; No functional changes. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 15:00:14 +00:00
rq = task_rq(p);
sched: Convert rq->lock to raw_spinlock Convert locks which cannot be sleeping locks in preempt-rt to raw_spinlocks. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Ingo Molnar <mingo@elte.hu>
2009-11-17 13:28:38 +00:00
raw_spin_lock(&rq->lock);
sched: Optimize task_rq_lock() Now that we hold the rq->lock over set_task_cpu() again, we can do away with most of the TASK_WAKING checks and reduce them again to set_cpus_allowed_ptr(). Removes some conditionals from scheduling hot-paths. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Oleg Nesterov <oleg@redhat.com> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-03-25 20:05:16 +00:00
if (likely(rq == task_rq(p)))
sched: cleanup: remove unnecessary gotos Replace loops implemented with gotos with real loops. Replace err = ...; goto x; x: return err; with return ...; No functional changes. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 15:00:14 +00:00
return rq;
sched: Add p->pi_lock to task_rq_lock() In order to be able to call set_task_cpu() while either holding p->pi_lock or task_rq(p)->lock we need to hold both locks in order to stabilize task_rq(). This makes task_rq_lock() acquire both locks, and have __task_rq_lock() validate that p->pi_lock is held. This increases the locking overhead for most scheduler syscalls but allows reduction of rq->lock contention for some scheduler hot paths (ttwu). Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110405152729.232781355@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-05 15:23:51 +00:00
raw_spin_unlock(&rq->lock);
raw_spin_unlock_irqrestore(&p->pi_lock, *flags);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
}
}
sched: uninline scheduler * save ~300 bytes * activate_idle_task() was moved to avoid a warning bloat-o-meter output: add/remove: 6/0 grow/shrink: 0/16 up/down: 438/-733 (-295) <=== function old new delta __enqueue_entity - 165 +165 finish_task_switch - 110 +110 update_curr_rt - 79 +79 __load_balance_iterator - 32 +32 __task_rq_unlock - 28 +28 find_process_by_pid - 24 +24 do_sched_setscheduler 133 123 -10 sys_sched_rr_get_interval 176 165 -11 sys_sched_getparam 156 145 -11 normalize_rt_tasks 482 470 -12 sched_getaffinity 112 99 -13 sys_sched_getscheduler 86 72 -14 sched_setaffinity 226 212 -14 sched_setscheduler 666 642 -24 load_balance_start_fair 33 9 -24 load_balance_next_fair 33 9 -24 dequeue_task_rt 133 67 -66 put_prev_task_rt 97 28 -69 schedule_tail 133 50 -83 schedule 682 594 -88 enqueue_entity 499 366 -133 task_new_fair 317 180 -137 Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 15:00:13 +00:00
static void __task_rq_unlock(struct rq *rq)
[PATCH] pi-futex: scheduler support for pi Add framework to boost/unboost the priority of RT tasks. This consists of: - caching the 'normal' priority in ->normal_prio - providing a functions to set/get the priority of the task - make sched_setscheduler() aware of boosting The effective_prio() cleanups also fix a priority-calculation bug pointed out by Andrey Gelman, in set_user_nice(). has_rt_policy() fix: Peter Williams <pwil3058@bigpond.net.au> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Cc: Andrey Gelman <agelman@012.net.il> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 09:54:51 +00:00
__releases(rq->lock)
{
sched: Convert rq->lock to raw_spinlock Convert locks which cannot be sleeping locks in preempt-rt to raw_spinlocks. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Ingo Molnar <mingo@elte.hu>
2009-11-17 13:28:38 +00:00
raw_spin_unlock(&rq->lock);
[PATCH] pi-futex: scheduler support for pi Add framework to boost/unboost the priority of RT tasks. This consists of: - caching the 'normal' priority in ->normal_prio - providing a functions to set/get the priority of the task - make sched_setscheduler() aware of boosting The effective_prio() cleanups also fix a priority-calculation bug pointed out by Andrey Gelman, in set_user_nice(). has_rt_policy() fix: Peter Williams <pwil3058@bigpond.net.au> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Cc: Andrey Gelman <agelman@012.net.il> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 09:54:51 +00:00
}
sched: Add p->pi_lock to task_rq_lock() In order to be able to call set_task_cpu() while either holding p->pi_lock or task_rq(p)->lock we need to hold both locks in order to stabilize task_rq(). This makes task_rq_lock() acquire both locks, and have __task_rq_lock() validate that p->pi_lock is held. This increases the locking overhead for most scheduler syscalls but allows reduction of rq->lock contention for some scheduler hot paths (ttwu). Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110405152729.232781355@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-05 15:23:51 +00:00
static inline void
task_rq_unlock(struct rq *rq, struct task_struct *p, unsigned long *flags)
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
__releases(rq->lock)
sched: Add p->pi_lock to task_rq_lock() In order to be able to call set_task_cpu() while either holding p->pi_lock or task_rq(p)->lock we need to hold both locks in order to stabilize task_rq(). This makes task_rq_lock() acquire both locks, and have __task_rq_lock() validate that p->pi_lock is held. This increases the locking overhead for most scheduler syscalls but allows reduction of rq->lock contention for some scheduler hot paths (ttwu). Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110405152729.232781355@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-05 15:23:51 +00:00
__releases(p->pi_lock)
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
{
sched: Add p->pi_lock to task_rq_lock() In order to be able to call set_task_cpu() while either holding p->pi_lock or task_rq(p)->lock we need to hold both locks in order to stabilize task_rq(). This makes task_rq_lock() acquire both locks, and have __task_rq_lock() validate that p->pi_lock is held. This increases the locking overhead for most scheduler syscalls but allows reduction of rq->lock contention for some scheduler hot paths (ttwu). Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110405152729.232781355@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-05 15:23:51 +00:00
raw_spin_unlock(&rq->lock);
raw_spin_unlock_irqrestore(&p->pi_lock, *flags);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
}
/*
[PATCH] sched.c: correct comment for this_rq_lock() Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Robert P. J. Day <rpjday@mindspring.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 10:20:00 +00:00
* this_rq_lock - lock this runqueue and disable interrupts.
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
*/
sched: uninline scheduler * save ~300 bytes * activate_idle_task() was moved to avoid a warning bloat-o-meter output: add/remove: 6/0 grow/shrink: 0/16 up/down: 438/-733 (-295) <=== function old new delta __enqueue_entity - 165 +165 finish_task_switch - 110 +110 update_curr_rt - 79 +79 __load_balance_iterator - 32 +32 __task_rq_unlock - 28 +28 find_process_by_pid - 24 +24 do_sched_setscheduler 133 123 -10 sys_sched_rr_get_interval 176 165 -11 sys_sched_getparam 156 145 -11 normalize_rt_tasks 482 470 -12 sched_getaffinity 112 99 -13 sys_sched_getscheduler 86 72 -14 sched_setaffinity 226 212 -14 sched_setscheduler 666 642 -24 load_balance_start_fair 33 9 -24 load_balance_next_fair 33 9 -24 dequeue_task_rt 133 67 -66 put_prev_task_rt 97 28 -69 schedule_tail 133 50 -83 schedule 682 594 -88 enqueue_entity 499 366 -133 task_new_fair 317 180 -137 Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 15:00:13 +00:00
static struct rq *this_rq_lock(void)
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
__acquires(rq->lock)
{
[PATCH] sched: cleanup, convert sched.c-internal typedefs to struct convert: - runqueue_t to 'struct rq' - prio_array_t to 'struct prio_array' - migration_req_t to 'struct migration_req' I was the one who added these but they are both against the kernel coding style and also were used inconsistently at places. So just get rid of them at once, now that we are flushing the scheduler patch-queue anyway. Conversion was mostly scripted, the result was reviewed and all secondary whitespace and style impact (if any) was fixed up by hand. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-03 07:25:42 +00:00
struct rq *rq;
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
local_irq_disable();
rq = this_rq();
sched: Convert rq->lock to raw_spinlock Convert locks which cannot be sleeping locks in preempt-rt to raw_spinlocks. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Ingo Molnar <mingo@elte.hu>
2009-11-17 13:28:38 +00:00
raw_spin_lock(&rq->lock);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
return rq;
}
sched: high-res preemption tick Use HR-timers (when available) to deliver an accurate preemption tick. The regular scheduler tick that runs at 1/HZ can be too coarse when nice level are used. The fairness system will still keep the cpu utilisation 'fair' by then delaying the task that got an excessive amount of CPU time but try to minimize this by delivering preemption points spot-on. The average frequency of this extra interrupt is sched_latency / nr_latency. Which need not be higher than 1/HZ, its just that the distribution within the sched_latency period is important. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:29 +00:00
#ifdef CONFIG_SCHED_HRTICK
/*
* Use HR-timers to deliver accurate preemption points.
*
* Its all a bit involved since we cannot program an hrt while holding the
* rq->lock. So what we do is store a state in in rq->hrtick_* and ask for a
* reschedule event.
*
* When we get rescheduled we reprogram the hrtick_timer outside of the
* rq->lock.
*/
/*
* Use hrtick when:
* - enabled by features
* - hrtimer is actually high res
*/
static inline int hrtick_enabled(struct rq *rq)
{
if (!sched_feat(HRTICK))
return 0;
sched: hrtick_enabled() should use cpu_active() Peter pointed out that hrtick_enabled() should use cpu_active(). Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-20 09:02:06 +00:00
if (!cpu_active(cpu_of(rq)))
sched: fix hrtick_start_fair and CPU-Hotplug Gautham R Shenoy reported: > While running the usual CPU-Hotplug stress tests on linux-2.6.25, > I noticed the following in the console logs. > > This is a wee bit difficult to reproduce. In the past 10 runs I hit this > only once. > > ------------[ cut here ]------------ > > WARNING: at kernel/sched.c:962 hrtick+0x2e/0x65() > > Just wondering if we are doing a good job at handling the cancellation > of any per-cpu scheduler timers during CPU-Hotplug. This looks like its indeed not cancelled at all and migrates the it to another cpu. Fix it via a proper hotplug notifier mechanism. Reported-by: Gautham R Shenoy <ego@in.ibm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: stable@kernel.org Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-29 08:02:46 +00:00
return 0;
sched: high-res preemption tick Use HR-timers (when available) to deliver an accurate preemption tick. The regular scheduler tick that runs at 1/HZ can be too coarse when nice level are used. The fairness system will still keep the cpu utilisation 'fair' by then delaying the task that got an excessive amount of CPU time but try to minimize this by delivering preemption points spot-on. The average frequency of this extra interrupt is sched_latency / nr_latency. Which need not be higher than 1/HZ, its just that the distribution within the sched_latency period is important. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:29 +00:00
return hrtimer_is_hres_active(&rq->hrtick_timer);
}
static void hrtick_clear(struct rq *rq)
{
if (hrtimer_active(&rq->hrtick_timer))
hrtimer_cancel(&rq->hrtick_timer);
}
/*
* High-resolution timer tick.
* Runs from hardirq context with interrupts disabled.
*/
static enum hrtimer_restart hrtick(struct hrtimer *timer)
{
struct rq *rq = container_of(timer, struct rq, hrtick_timer);
WARN_ON_ONCE(cpu_of(rq) != smp_processor_id());
sched: Convert rq->lock to raw_spinlock Convert locks which cannot be sleeping locks in preempt-rt to raw_spinlocks. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Ingo Molnar <mingo@elte.hu>
2009-11-17 13:28:38 +00:00
raw_spin_lock(&rq->lock);
sched: add optional support for CONFIG_HAVE_UNSTABLE_SCHED_CLOCK this replaces the rq->clock stuff (and possibly cpu_clock()). - architectures that have an 'imperfect' hardware clock can set CONFIG_HAVE_UNSTABLE_SCHED_CLOCK - the 'jiffie' window might be superfulous when we update tick_gtod before the __update_sched_clock() call in sched_clock_tick() - cpu_clock() might be implemented as: sched_clock_cpu(smp_processor_id()) if the accuracy proves good enough - how far can TSC drift in a single jiffie when considering the filtering and idle hooks? [ mingo@elte.hu: various fixes and cleanups ] Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-05-03 16:29:28 +00:00
update_rq_clock(rq);
sched: high-res preemption tick Use HR-timers (when available) to deliver an accurate preemption tick. The regular scheduler tick that runs at 1/HZ can be too coarse when nice level are used. The fairness system will still keep the cpu utilisation 'fair' by then delaying the task that got an excessive amount of CPU time but try to minimize this by delivering preemption points spot-on. The average frequency of this extra interrupt is sched_latency / nr_latency. Which need not be higher than 1/HZ, its just that the distribution within the sched_latency period is important. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:29 +00:00
rq->curr->sched_class->task_tick(rq, rq->curr, 1);
sched: Convert rq->lock to raw_spinlock Convert locks which cannot be sleeping locks in preempt-rt to raw_spinlocks. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Ingo Molnar <mingo@elte.hu>
2009-11-17 13:28:38 +00:00
raw_spin_unlock(&rq->lock);
sched: high-res preemption tick Use HR-timers (when available) to deliver an accurate preemption tick. The regular scheduler tick that runs at 1/HZ can be too coarse when nice level are used. The fairness system will still keep the cpu utilisation 'fair' by then delaying the task that got an excessive amount of CPU time but try to minimize this by delivering preemption points spot-on. The average frequency of this extra interrupt is sched_latency / nr_latency. Which need not be higher than 1/HZ, its just that the distribution within the sched_latency period is important. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:29 +00:00
return HRTIMER_NORESTART;
}
sched: fix defined-but-unused warning Fix this warning, which appears with !CONFIG_SMP: kernel/sched.c:1216: warning: `init_hrtick' defined but not used Signed-off-by: Rabin Vincent <rabin@rab.in> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-05-11 00:25:33 +00:00
#ifdef CONFIG_SMP
sched, x86: clean up hrtick implementation random uvesafb failures were reported against Gentoo: http://bugs.gentoo.org/show_bug.cgi?id=222799 and Mihai Moldovan bisected it back to: > 8f4d37ec073c17e2d4aa8851df5837d798606d6f is first bad commit > commit 8f4d37ec073c17e2d4aa8851df5837d798606d6f > Author: Peter Zijlstra <a.p.zijlstra@chello.nl> > Date: Fri Jan 25 21:08:29 2008 +0100 > > sched: high-res preemption tick Linus suspected it to be hrtick + vm86 interaction and observed: > Btw, Peter, Ingo: I think that commit is doing bad things. They aren't > _incorrect_ per se, but they are definitely bad. > > Why? > > Using random _TIF_WORK_MASK flags is really impolite for doing > "scheduling" work. There's a reason that arch/x86/kernel/entry_32.S > special-cases the _TIF_NEED_RESCHED flag: we don't want to exit out of > vm86 mode unnecessarily. > > See the "work_notifysig_v86" label, and how it does that > "save_v86_state()" thing etc etc. Right, I never liked having to fiddle with those TIF flags. Initially I needed it because the hrtimer base lock could not nest in the rq lock. That however is fixed these days. Currently the only reason left to fiddle with the TIF flags is remote wakeups. We cannot program a remote cpu's hrtimer. I've been thinking about using the new and improved IPI function call stuff to implement hrtimer_start_on(). However that does require that smp_call_function_single(.wait=0) works from interrupt context - /me looks at the latest series from Jens - Yes that does seem to be supported, good. Here's a stab at cleaning this stuff up ... Mihai reported test success as well. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Tested-by: Mihai Moldovan <ionic@ionic.de> Cc: Michal Januszewski <spock@gentoo.org> Cc: Antonino Daplas <adaplas@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-18 16:01:23 +00:00
/*
* called from hardirq (IPI) context
*/
static void __hrtick_start(void *arg)
sched: fix hrtick_start_fair and CPU-Hotplug Gautham R Shenoy reported: > While running the usual CPU-Hotplug stress tests on linux-2.6.25, > I noticed the following in the console logs. > > This is a wee bit difficult to reproduce. In the past 10 runs I hit this > only once. > > ------------[ cut here ]------------ > > WARNING: at kernel/sched.c:962 hrtick+0x2e/0x65() > > Just wondering if we are doing a good job at handling the cancellation > of any per-cpu scheduler timers during CPU-Hotplug. This looks like its indeed not cancelled at all and migrates the it to another cpu. Fix it via a proper hotplug notifier mechanism. Reported-by: Gautham R Shenoy <ego@in.ibm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: stable@kernel.org Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-29 08:02:46 +00:00
{
sched, x86: clean up hrtick implementation random uvesafb failures were reported against Gentoo: http://bugs.gentoo.org/show_bug.cgi?id=222799 and Mihai Moldovan bisected it back to: > 8f4d37ec073c17e2d4aa8851df5837d798606d6f is first bad commit > commit 8f4d37ec073c17e2d4aa8851df5837d798606d6f > Author: Peter Zijlstra <a.p.zijlstra@chello.nl> > Date: Fri Jan 25 21:08:29 2008 +0100 > > sched: high-res preemption tick Linus suspected it to be hrtick + vm86 interaction and observed: > Btw, Peter, Ingo: I think that commit is doing bad things. They aren't > _incorrect_ per se, but they are definitely bad. > > Why? > > Using random _TIF_WORK_MASK flags is really impolite for doing > "scheduling" work. There's a reason that arch/x86/kernel/entry_32.S > special-cases the _TIF_NEED_RESCHED flag: we don't want to exit out of > vm86 mode unnecessarily. > > See the "work_notifysig_v86" label, and how it does that > "save_v86_state()" thing etc etc. Right, I never liked having to fiddle with those TIF flags. Initially I needed it because the hrtimer base lock could not nest in the rq lock. That however is fixed these days. Currently the only reason left to fiddle with the TIF flags is remote wakeups. We cannot program a remote cpu's hrtimer. I've been thinking about using the new and improved IPI function call stuff to implement hrtimer_start_on(). However that does require that smp_call_function_single(.wait=0) works from interrupt context - /me looks at the latest series from Jens - Yes that does seem to be supported, good. Here's a stab at cleaning this stuff up ... Mihai reported test success as well. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Tested-by: Mihai Moldovan <ionic@ionic.de> Cc: Michal Januszewski <spock@gentoo.org> Cc: Antonino Daplas <adaplas@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-18 16:01:23 +00:00
struct rq *rq = arg;
sched: fix hrtick_start_fair and CPU-Hotplug Gautham R Shenoy reported: > While running the usual CPU-Hotplug stress tests on linux-2.6.25, > I noticed the following in the console logs. > > This is a wee bit difficult to reproduce. In the past 10 runs I hit this > only once. > > ------------[ cut here ]------------ > > WARNING: at kernel/sched.c:962 hrtick+0x2e/0x65() > > Just wondering if we are doing a good job at handling the cancellation > of any per-cpu scheduler timers during CPU-Hotplug. This looks like its indeed not cancelled at all and migrates the it to another cpu. Fix it via a proper hotplug notifier mechanism. Reported-by: Gautham R Shenoy <ego@in.ibm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: stable@kernel.org Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-29 08:02:46 +00:00
sched: Convert rq->lock to raw_spinlock Convert locks which cannot be sleeping locks in preempt-rt to raw_spinlocks. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Ingo Molnar <mingo@elte.hu>
2009-11-17 13:28:38 +00:00
raw_spin_lock(&rq->lock);
sched, x86: clean up hrtick implementation random uvesafb failures were reported against Gentoo: http://bugs.gentoo.org/show_bug.cgi?id=222799 and Mihai Moldovan bisected it back to: > 8f4d37ec073c17e2d4aa8851df5837d798606d6f is first bad commit > commit 8f4d37ec073c17e2d4aa8851df5837d798606d6f > Author: Peter Zijlstra <a.p.zijlstra@chello.nl> > Date: Fri Jan 25 21:08:29 2008 +0100 > > sched: high-res preemption tick Linus suspected it to be hrtick + vm86 interaction and observed: > Btw, Peter, Ingo: I think that commit is doing bad things. They aren't > _incorrect_ per se, but they are definitely bad. > > Why? > > Using random _TIF_WORK_MASK flags is really impolite for doing > "scheduling" work. There's a reason that arch/x86/kernel/entry_32.S > special-cases the _TIF_NEED_RESCHED flag: we don't want to exit out of > vm86 mode unnecessarily. > > See the "work_notifysig_v86" label, and how it does that > "save_v86_state()" thing etc etc. Right, I never liked having to fiddle with those TIF flags. Initially I needed it because the hrtimer base lock could not nest in the rq lock. That however is fixed these days. Currently the only reason left to fiddle with the TIF flags is remote wakeups. We cannot program a remote cpu's hrtimer. I've been thinking about using the new and improved IPI function call stuff to implement hrtimer_start_on(). However that does require that smp_call_function_single(.wait=0) works from interrupt context - /me looks at the latest series from Jens - Yes that does seem to be supported, good. Here's a stab at cleaning this stuff up ... Mihai reported test success as well. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Tested-by: Mihai Moldovan <ionic@ionic.de> Cc: Michal Januszewski <spock@gentoo.org> Cc: Antonino Daplas <adaplas@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-18 16:01:23 +00:00
hrtimer_restart(&rq->hrtick_timer);
rq->hrtick_csd_pending = 0;
sched: Convert rq->lock to raw_spinlock Convert locks which cannot be sleeping locks in preempt-rt to raw_spinlocks. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Ingo Molnar <mingo@elte.hu>
2009-11-17 13:28:38 +00:00
raw_spin_unlock(&rq->lock);
sched: fix hrtick_start_fair and CPU-Hotplug Gautham R Shenoy reported: > While running the usual CPU-Hotplug stress tests on linux-2.6.25, > I noticed the following in the console logs. > > This is a wee bit difficult to reproduce. In the past 10 runs I hit this > only once. > > ------------[ cut here ]------------ > > WARNING: at kernel/sched.c:962 hrtick+0x2e/0x65() > > Just wondering if we are doing a good job at handling the cancellation > of any per-cpu scheduler timers during CPU-Hotplug. This looks like its indeed not cancelled at all and migrates the it to another cpu. Fix it via a proper hotplug notifier mechanism. Reported-by: Gautham R Shenoy <ego@in.ibm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: stable@kernel.org Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-29 08:02:46 +00:00
}
sched, x86: clean up hrtick implementation random uvesafb failures were reported against Gentoo: http://bugs.gentoo.org/show_bug.cgi?id=222799 and Mihai Moldovan bisected it back to: > 8f4d37ec073c17e2d4aa8851df5837d798606d6f is first bad commit > commit 8f4d37ec073c17e2d4aa8851df5837d798606d6f > Author: Peter Zijlstra <a.p.zijlstra@chello.nl> > Date: Fri Jan 25 21:08:29 2008 +0100 > > sched: high-res preemption tick Linus suspected it to be hrtick + vm86 interaction and observed: > Btw, Peter, Ingo: I think that commit is doing bad things. They aren't > _incorrect_ per se, but they are definitely bad. > > Why? > > Using random _TIF_WORK_MASK flags is really impolite for doing > "scheduling" work. There's a reason that arch/x86/kernel/entry_32.S > special-cases the _TIF_NEED_RESCHED flag: we don't want to exit out of > vm86 mode unnecessarily. > > See the "work_notifysig_v86" label, and how it does that > "save_v86_state()" thing etc etc. Right, I never liked having to fiddle with those TIF flags. Initially I needed it because the hrtimer base lock could not nest in the rq lock. That however is fixed these days. Currently the only reason left to fiddle with the TIF flags is remote wakeups. We cannot program a remote cpu's hrtimer. I've been thinking about using the new and improved IPI function call stuff to implement hrtimer_start_on(). However that does require that smp_call_function_single(.wait=0) works from interrupt context - /me looks at the latest series from Jens - Yes that does seem to be supported, good. Here's a stab at cleaning this stuff up ... Mihai reported test success as well. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Tested-by: Mihai Moldovan <ionic@ionic.de> Cc: Michal Januszewski <spock@gentoo.org> Cc: Antonino Daplas <adaplas@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-18 16:01:23 +00:00
/*
* Called to set the hrtick timer state.
*
* called with rq->lock held and irqs disabled
*/
static void hrtick_start(struct rq *rq, u64 delay)
sched: fix hrtick_start_fair and CPU-Hotplug Gautham R Shenoy reported: > While running the usual CPU-Hotplug stress tests on linux-2.6.25, > I noticed the following in the console logs. > > This is a wee bit difficult to reproduce. In the past 10 runs I hit this > only once. > > ------------[ cut here ]------------ > > WARNING: at kernel/sched.c:962 hrtick+0x2e/0x65() > > Just wondering if we are doing a good job at handling the cancellation > of any per-cpu scheduler timers during CPU-Hotplug. This looks like its indeed not cancelled at all and migrates the it to another cpu. Fix it via a proper hotplug notifier mechanism. Reported-by: Gautham R Shenoy <ego@in.ibm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: stable@kernel.org Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-29 08:02:46 +00:00
{
sched, x86: clean up hrtick implementation random uvesafb failures were reported against Gentoo: http://bugs.gentoo.org/show_bug.cgi?id=222799 and Mihai Moldovan bisected it back to: > 8f4d37ec073c17e2d4aa8851df5837d798606d6f is first bad commit > commit 8f4d37ec073c17e2d4aa8851df5837d798606d6f > Author: Peter Zijlstra <a.p.zijlstra@chello.nl> > Date: Fri Jan 25 21:08:29 2008 +0100 > > sched: high-res preemption tick Linus suspected it to be hrtick + vm86 interaction and observed: > Btw, Peter, Ingo: I think that commit is doing bad things. They aren't > _incorrect_ per se, but they are definitely bad. > > Why? > > Using random _TIF_WORK_MASK flags is really impolite for doing > "scheduling" work. There's a reason that arch/x86/kernel/entry_32.S > special-cases the _TIF_NEED_RESCHED flag: we don't want to exit out of > vm86 mode unnecessarily. > > See the "work_notifysig_v86" label, and how it does that > "save_v86_state()" thing etc etc. Right, I never liked having to fiddle with those TIF flags. Initially I needed it because the hrtimer base lock could not nest in the rq lock. That however is fixed these days. Currently the only reason left to fiddle with the TIF flags is remote wakeups. We cannot program a remote cpu's hrtimer. I've been thinking about using the new and improved IPI function call stuff to implement hrtimer_start_on(). However that does require that smp_call_function_single(.wait=0) works from interrupt context - /me looks at the latest series from Jens - Yes that does seem to be supported, good. Here's a stab at cleaning this stuff up ... Mihai reported test success as well. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Tested-by: Mihai Moldovan <ionic@ionic.de> Cc: Michal Januszewski <spock@gentoo.org> Cc: Antonino Daplas <adaplas@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-18 16:01:23 +00:00
struct hrtimer *timer = &rq->hrtick_timer;
ktime_t time = ktime_add_ns(timer->base->get_time(), delay);
sched: fix hrtick_start_fair and CPU-Hotplug Gautham R Shenoy reported: > While running the usual CPU-Hotplug stress tests on linux-2.6.25, > I noticed the following in the console logs. > > This is a wee bit difficult to reproduce. In the past 10 runs I hit this > only once. > > ------------[ cut here ]------------ > > WARNING: at kernel/sched.c:962 hrtick+0x2e/0x65() > > Just wondering if we are doing a good job at handling the cancellation > of any per-cpu scheduler timers during CPU-Hotplug. This looks like its indeed not cancelled at all and migrates the it to another cpu. Fix it via a proper hotplug notifier mechanism. Reported-by: Gautham R Shenoy <ego@in.ibm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: stable@kernel.org Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-29 08:02:46 +00:00
hrtimer: convert kernel/* to the new hrtimer apis In order to be able to do range hrtimers we need to use accessor functions to the "expire" member of the hrtimer struct. This patch converts kernel/* to these accessors. Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
2008-09-01 22:02:30 +00:00
hrtimer_set_expires(timer, time);
sched, x86: clean up hrtick implementation random uvesafb failures were reported against Gentoo: http://bugs.gentoo.org/show_bug.cgi?id=222799 and Mihai Moldovan bisected it back to: > 8f4d37ec073c17e2d4aa8851df5837d798606d6f is first bad commit > commit 8f4d37ec073c17e2d4aa8851df5837d798606d6f > Author: Peter Zijlstra <a.p.zijlstra@chello.nl> > Date: Fri Jan 25 21:08:29 2008 +0100 > > sched: high-res preemption tick Linus suspected it to be hrtick + vm86 interaction and observed: > Btw, Peter, Ingo: I think that commit is doing bad things. They aren't > _incorrect_ per se, but they are definitely bad. > > Why? > > Using random _TIF_WORK_MASK flags is really impolite for doing > "scheduling" work. There's a reason that arch/x86/kernel/entry_32.S > special-cases the _TIF_NEED_RESCHED flag: we don't want to exit out of > vm86 mode unnecessarily. > > See the "work_notifysig_v86" label, and how it does that > "save_v86_state()" thing etc etc. Right, I never liked having to fiddle with those TIF flags. Initially I needed it because the hrtimer base lock could not nest in the rq lock. That however is fixed these days. Currently the only reason left to fiddle with the TIF flags is remote wakeups. We cannot program a remote cpu's hrtimer. I've been thinking about using the new and improved IPI function call stuff to implement hrtimer_start_on(). However that does require that smp_call_function_single(.wait=0) works from interrupt context - /me looks at the latest series from Jens - Yes that does seem to be supported, good. Here's a stab at cleaning this stuff up ... Mihai reported test success as well. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Tested-by: Mihai Moldovan <ionic@ionic.de> Cc: Michal Januszewski <spock@gentoo.org> Cc: Antonino Daplas <adaplas@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-18 16:01:23 +00:00
if (rq == this_rq()) {
hrtimer_restart(timer);
} else if (!rq->hrtick_csd_pending) {
generic-ipi: remove CSD_FLAG_WAIT Oleg noticed that we don't strictly need CSD_FLAG_WAIT, rework the code so that we can use CSD_FLAG_LOCK for both purposes. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Nick Piggin <npiggin@suse.de> Cc: Jens Axboe <jens.axboe@oracle.com> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-25 12:59:48 +00:00
__smp_call_function_single(cpu_of(rq), &rq->hrtick_csd, 0);
sched, x86: clean up hrtick implementation random uvesafb failures were reported against Gentoo: http://bugs.gentoo.org/show_bug.cgi?id=222799 and Mihai Moldovan bisected it back to: > 8f4d37ec073c17e2d4aa8851df5837d798606d6f is first bad commit > commit 8f4d37ec073c17e2d4aa8851df5837d798606d6f > Author: Peter Zijlstra <a.p.zijlstra@chello.nl> > Date: Fri Jan 25 21:08:29 2008 +0100 > > sched: high-res preemption tick Linus suspected it to be hrtick + vm86 interaction and observed: > Btw, Peter, Ingo: I think that commit is doing bad things. They aren't > _incorrect_ per se, but they are definitely bad. > > Why? > > Using random _TIF_WORK_MASK flags is really impolite for doing > "scheduling" work. There's a reason that arch/x86/kernel/entry_32.S > special-cases the _TIF_NEED_RESCHED flag: we don't want to exit out of > vm86 mode unnecessarily. > > See the "work_notifysig_v86" label, and how it does that > "save_v86_state()" thing etc etc. Right, I never liked having to fiddle with those TIF flags. Initially I needed it because the hrtimer base lock could not nest in the rq lock. That however is fixed these days. Currently the only reason left to fiddle with the TIF flags is remote wakeups. We cannot program a remote cpu's hrtimer. I've been thinking about using the new and improved IPI function call stuff to implement hrtimer_start_on(). However that does require that smp_call_function_single(.wait=0) works from interrupt context - /me looks at the latest series from Jens - Yes that does seem to be supported, good. Here's a stab at cleaning this stuff up ... Mihai reported test success as well. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Tested-by: Mihai Moldovan <ionic@ionic.de> Cc: Michal Januszewski <spock@gentoo.org> Cc: Antonino Daplas <adaplas@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-18 16:01:23 +00:00
rq->hrtick_csd_pending = 1;
}
sched: fix hrtick_start_fair and CPU-Hotplug Gautham R Shenoy reported: > While running the usual CPU-Hotplug stress tests on linux-2.6.25, > I noticed the following in the console logs. > > This is a wee bit difficult to reproduce. In the past 10 runs I hit this > only once. > > ------------[ cut here ]------------ > > WARNING: at kernel/sched.c:962 hrtick+0x2e/0x65() > > Just wondering if we are doing a good job at handling the cancellation > of any per-cpu scheduler timers during CPU-Hotplug. This looks like its indeed not cancelled at all and migrates the it to another cpu. Fix it via a proper hotplug notifier mechanism. Reported-by: Gautham R Shenoy <ego@in.ibm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: stable@kernel.org Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-29 08:02:46 +00:00
}
static int
hotplug_hrtick(struct notifier_block *nfb, unsigned long action, void *hcpu)
{
int cpu = (int)(long)hcpu;
switch (action) {
case CPU_UP_CANCELED:
case CPU_UP_CANCELED_FROZEN:
case CPU_DOWN_PREPARE:
case CPU_DOWN_PREPARE_FROZEN:
case CPU_DEAD:
case CPU_DEAD_FROZEN:
sched, x86: clean up hrtick implementation random uvesafb failures were reported against Gentoo: http://bugs.gentoo.org/show_bug.cgi?id=222799 and Mihai Moldovan bisected it back to: > 8f4d37ec073c17e2d4aa8851df5837d798606d6f is first bad commit > commit 8f4d37ec073c17e2d4aa8851df5837d798606d6f > Author: Peter Zijlstra <a.p.zijlstra@chello.nl> > Date: Fri Jan 25 21:08:29 2008 +0100 > > sched: high-res preemption tick Linus suspected it to be hrtick + vm86 interaction and observed: > Btw, Peter, Ingo: I think that commit is doing bad things. They aren't > _incorrect_ per se, but they are definitely bad. > > Why? > > Using random _TIF_WORK_MASK flags is really impolite for doing > "scheduling" work. There's a reason that arch/x86/kernel/entry_32.S > special-cases the _TIF_NEED_RESCHED flag: we don't want to exit out of > vm86 mode unnecessarily. > > See the "work_notifysig_v86" label, and how it does that > "save_v86_state()" thing etc etc. Right, I never liked having to fiddle with those TIF flags. Initially I needed it because the hrtimer base lock could not nest in the rq lock. That however is fixed these days. Currently the only reason left to fiddle with the TIF flags is remote wakeups. We cannot program a remote cpu's hrtimer. I've been thinking about using the new and improved IPI function call stuff to implement hrtimer_start_on(). However that does require that smp_call_function_single(.wait=0) works from interrupt context - /me looks at the latest series from Jens - Yes that does seem to be supported, good. Here's a stab at cleaning this stuff up ... Mihai reported test success as well. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Tested-by: Mihai Moldovan <ionic@ionic.de> Cc: Michal Januszewski <spock@gentoo.org> Cc: Antonino Daplas <adaplas@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-18 16:01:23 +00:00
hrtick_clear(cpu_rq(cpu));
sched: fix hrtick_start_fair and CPU-Hotplug Gautham R Shenoy reported: > While running the usual CPU-Hotplug stress tests on linux-2.6.25, > I noticed the following in the console logs. > > This is a wee bit difficult to reproduce. In the past 10 runs I hit this > only once. > > ------------[ cut here ]------------ > > WARNING: at kernel/sched.c:962 hrtick+0x2e/0x65() > > Just wondering if we are doing a good job at handling the cancellation > of any per-cpu scheduler timers during CPU-Hotplug. This looks like its indeed not cancelled at all and migrates the it to another cpu. Fix it via a proper hotplug notifier mechanism. Reported-by: Gautham R Shenoy <ego@in.ibm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: stable@kernel.org Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-29 08:02:46 +00:00
return NOTIFY_OK;
}
return NOTIFY_DONE;
}
sched: fix init_hrtick() section mismatch warning LD kernel/built-in.o WARNING: kernel/built-in.o(.text+0x326): Section mismatch in reference from the function init_hrtick() to the variable .cpuinit.data:hotplug_hrtick_nb.8 The function init_hrtick() references the variable __cpuinitdata hotplug_hrtick_nb.8. This is often because init_hrtick lacks a __cpuinitdata annotation or the annotation of hotplug_hrtick_nb.8 is wrong. Signed-off-by: Md.Rakib H. Mullick <rakib.mullick@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-22 21:55:45 +00:00
static __init void init_hrtick(void)
sched: fix hrtick_start_fair and CPU-Hotplug Gautham R Shenoy reported: > While running the usual CPU-Hotplug stress tests on linux-2.6.25, > I noticed the following in the console logs. > > This is a wee bit difficult to reproduce. In the past 10 runs I hit this > only once. > > ------------[ cut here ]------------ > > WARNING: at kernel/sched.c:962 hrtick+0x2e/0x65() > > Just wondering if we are doing a good job at handling the cancellation > of any per-cpu scheduler timers during CPU-Hotplug. This looks like its indeed not cancelled at all and migrates the it to another cpu. Fix it via a proper hotplug notifier mechanism. Reported-by: Gautham R Shenoy <ego@in.ibm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: stable@kernel.org Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-29 08:02:46 +00:00
{
hotcpu_notifier(hotplug_hrtick, 0);
}
sched, x86: clean up hrtick implementation random uvesafb failures were reported against Gentoo: http://bugs.gentoo.org/show_bug.cgi?id=222799 and Mihai Moldovan bisected it back to: > 8f4d37ec073c17e2d4aa8851df5837d798606d6f is first bad commit > commit 8f4d37ec073c17e2d4aa8851df5837d798606d6f > Author: Peter Zijlstra <a.p.zijlstra@chello.nl> > Date: Fri Jan 25 21:08:29 2008 +0100 > > sched: high-res preemption tick Linus suspected it to be hrtick + vm86 interaction and observed: > Btw, Peter, Ingo: I think that commit is doing bad things. They aren't > _incorrect_ per se, but they are definitely bad. > > Why? > > Using random _TIF_WORK_MASK flags is really impolite for doing > "scheduling" work. There's a reason that arch/x86/kernel/entry_32.S > special-cases the _TIF_NEED_RESCHED flag: we don't want to exit out of > vm86 mode unnecessarily. > > See the "work_notifysig_v86" label, and how it does that > "save_v86_state()" thing etc etc. Right, I never liked having to fiddle with those TIF flags. Initially I needed it because the hrtimer base lock could not nest in the rq lock. That however is fixed these days. Currently the only reason left to fiddle with the TIF flags is remote wakeups. We cannot program a remote cpu's hrtimer. I've been thinking about using the new and improved IPI function call stuff to implement hrtimer_start_on(). However that does require that smp_call_function_single(.wait=0) works from interrupt context - /me looks at the latest series from Jens - Yes that does seem to be supported, good. Here's a stab at cleaning this stuff up ... Mihai reported test success as well. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Tested-by: Mihai Moldovan <ionic@ionic.de> Cc: Michal Januszewski <spock@gentoo.org> Cc: Antonino Daplas <adaplas@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-18 16:01:23 +00:00
#else
/*
* Called to set the hrtick timer state.
*
* called with rq->lock held and irqs disabled
*/
static void hrtick_start(struct rq *rq, u64 delay)
{
hrtimer: fix rq->lock inversion (again) It appears I inadvertly introduced rq->lock recursion to the hrtimer_start() path when I delegated running already expired timers to softirq context. This patch fixes it by introducing a __hrtimer_start_range_ns() method that will not use raise_softirq_irqoff() but __raise_softirq_irqoff() which avoids the wakeup. It then also changes schedule() to check for pending softirqs and do the wakeup then, I'm not quite sure I like this last bit, nor am I convinced its really needed. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: paulus@samba.org LKML-Reference: <20090313112301.096138802@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-13 11:21:27 +00:00
__hrtimer_start_range_ns(&rq->hrtick_timer, ns_to_ktime(delay), 0,
timers: Identifying the existing pinned timers * Arun R Bharadwaj <arun@linux.vnet.ibm.com> [2009-04-16 12:11:36]: The following pinned hrtimers have been identified and marked: 1)sched_rt_period_timer 2)tick_sched_timer 3)stack_trace_timer_fn [ tglx: fixup the hrtimer pinned mode ] Signed-off-by: Arun R Bharadwaj <arun@linux.vnet.ibm.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2009-04-16 06:44:37 +00:00
HRTIMER_MODE_REL_PINNED, 0);
sched, x86: clean up hrtick implementation random uvesafb failures were reported against Gentoo: http://bugs.gentoo.org/show_bug.cgi?id=222799 and Mihai Moldovan bisected it back to: > 8f4d37ec073c17e2d4aa8851df5837d798606d6f is first bad commit > commit 8f4d37ec073c17e2d4aa8851df5837d798606d6f > Author: Peter Zijlstra <a.p.zijlstra@chello.nl> > Date: Fri Jan 25 21:08:29 2008 +0100 > > sched: high-res preemption tick Linus suspected it to be hrtick + vm86 interaction and observed: > Btw, Peter, Ingo: I think that commit is doing bad things. They aren't > _incorrect_ per se, but they are definitely bad. > > Why? > > Using random _TIF_WORK_MASK flags is really impolite for doing > "scheduling" work. There's a reason that arch/x86/kernel/entry_32.S > special-cases the _TIF_NEED_RESCHED flag: we don't want to exit out of > vm86 mode unnecessarily. > > See the "work_notifysig_v86" label, and how it does that > "save_v86_state()" thing etc etc. Right, I never liked having to fiddle with those TIF flags. Initially I needed it because the hrtimer base lock could not nest in the rq lock. That however is fixed these days. Currently the only reason left to fiddle with the TIF flags is remote wakeups. We cannot program a remote cpu's hrtimer. I've been thinking about using the new and improved IPI function call stuff to implement hrtimer_start_on(). However that does require that smp_call_function_single(.wait=0) works from interrupt context - /me looks at the latest series from Jens - Yes that does seem to be supported, good. Here's a stab at cleaning this stuff up ... Mihai reported test success as well. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Tested-by: Mihai Moldovan <ionic@ionic.de> Cc: Michal Januszewski <spock@gentoo.org> Cc: Antonino Daplas <adaplas@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-18 16:01:23 +00:00
}
sched: fix hrtick_start_fair and CPU-Hotplug Gautham R Shenoy reported: > While running the usual CPU-Hotplug stress tests on linux-2.6.25, > I noticed the following in the console logs. > > This is a wee bit difficult to reproduce. In the past 10 runs I hit this > only once. > > ------------[ cut here ]------------ > > WARNING: at kernel/sched.c:962 hrtick+0x2e/0x65() > > Just wondering if we are doing a good job at handling the cancellation > of any per-cpu scheduler timers during CPU-Hotplug. This looks like its indeed not cancelled at all and migrates the it to another cpu. Fix it via a proper hotplug notifier mechanism. Reported-by: Gautham R Shenoy <ego@in.ibm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: stable@kernel.org Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-29 08:02:46 +00:00
sched: clarify ifdef tangle - Add some comments to try to make the ifdef puzzle a bit clearer - Explicitly inline one of the three init_hrtick() implementations. Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-22 21:55:46 +00:00
static inline void init_hrtick(void)
sched: high-res preemption tick Use HR-timers (when available) to deliver an accurate preemption tick. The regular scheduler tick that runs at 1/HZ can be too coarse when nice level are used. The fairness system will still keep the cpu utilisation 'fair' by then delaying the task that got an excessive amount of CPU time but try to minimize this by delivering preemption points spot-on. The average frequency of this extra interrupt is sched_latency / nr_latency. Which need not be higher than 1/HZ, its just that the distribution within the sched_latency period is important. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:29 +00:00
{
}
sched, x86: clean up hrtick implementation random uvesafb failures were reported against Gentoo: http://bugs.gentoo.org/show_bug.cgi?id=222799 and Mihai Moldovan bisected it back to: > 8f4d37ec073c17e2d4aa8851df5837d798606d6f is first bad commit > commit 8f4d37ec073c17e2d4aa8851df5837d798606d6f > Author: Peter Zijlstra <a.p.zijlstra@chello.nl> > Date: Fri Jan 25 21:08:29 2008 +0100 > > sched: high-res preemption tick Linus suspected it to be hrtick + vm86 interaction and observed: > Btw, Peter, Ingo: I think that commit is doing bad things. They aren't > _incorrect_ per se, but they are definitely bad. > > Why? > > Using random _TIF_WORK_MASK flags is really impolite for doing > "scheduling" work. There's a reason that arch/x86/kernel/entry_32.S > special-cases the _TIF_NEED_RESCHED flag: we don't want to exit out of > vm86 mode unnecessarily. > > See the "work_notifysig_v86" label, and how it does that > "save_v86_state()" thing etc etc. Right, I never liked having to fiddle with those TIF flags. Initially I needed it because the hrtimer base lock could not nest in the rq lock. That however is fixed these days. Currently the only reason left to fiddle with the TIF flags is remote wakeups. We cannot program a remote cpu's hrtimer. I've been thinking about using the new and improved IPI function call stuff to implement hrtimer_start_on(). However that does require that smp_call_function_single(.wait=0) works from interrupt context - /me looks at the latest series from Jens - Yes that does seem to be supported, good. Here's a stab at cleaning this stuff up ... Mihai reported test success as well. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Tested-by: Mihai Moldovan <ionic@ionic.de> Cc: Michal Januszewski <spock@gentoo.org> Cc: Antonino Daplas <adaplas@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-18 16:01:23 +00:00
#endif /* CONFIG_SMP */
sched: high-res preemption tick Use HR-timers (when available) to deliver an accurate preemption tick. The regular scheduler tick that runs at 1/HZ can be too coarse when nice level are used. The fairness system will still keep the cpu utilisation 'fair' by then delaying the task that got an excessive amount of CPU time but try to minimize this by delivering preemption points spot-on. The average frequency of this extra interrupt is sched_latency / nr_latency. Which need not be higher than 1/HZ, its just that the distribution within the sched_latency period is important. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:29 +00:00
sched, x86: clean up hrtick implementation random uvesafb failures were reported against Gentoo: http://bugs.gentoo.org/show_bug.cgi?id=222799 and Mihai Moldovan bisected it back to: > 8f4d37ec073c17e2d4aa8851df5837d798606d6f is first bad commit > commit 8f4d37ec073c17e2d4aa8851df5837d798606d6f > Author: Peter Zijlstra <a.p.zijlstra@chello.nl> > Date: Fri Jan 25 21:08:29 2008 +0100 > > sched: high-res preemption tick Linus suspected it to be hrtick + vm86 interaction and observed: > Btw, Peter, Ingo: I think that commit is doing bad things. They aren't > _incorrect_ per se, but they are definitely bad. > > Why? > > Using random _TIF_WORK_MASK flags is really impolite for doing > "scheduling" work. There's a reason that arch/x86/kernel/entry_32.S > special-cases the _TIF_NEED_RESCHED flag: we don't want to exit out of > vm86 mode unnecessarily. > > See the "work_notifysig_v86" label, and how it does that > "save_v86_state()" thing etc etc. Right, I never liked having to fiddle with those TIF flags. Initially I needed it because the hrtimer base lock could not nest in the rq lock. That however is fixed these days. Currently the only reason left to fiddle with the TIF flags is remote wakeups. We cannot program a remote cpu's hrtimer. I've been thinking about using the new and improved IPI function call stuff to implement hrtimer_start_on(). However that does require that smp_call_function_single(.wait=0) works from interrupt context - /me looks at the latest series from Jens - Yes that does seem to be supported, good. Here's a stab at cleaning this stuff up ... Mihai reported test success as well. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Tested-by: Mihai Moldovan <ionic@ionic.de> Cc: Michal Januszewski <spock@gentoo.org> Cc: Antonino Daplas <adaplas@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-18 16:01:23 +00:00
static void init_rq_hrtick(struct rq *rq)
sched: high-res preemption tick Use HR-timers (when available) to deliver an accurate preemption tick. The regular scheduler tick that runs at 1/HZ can be too coarse when nice level are used. The fairness system will still keep the cpu utilisation 'fair' by then delaying the task that got an excessive amount of CPU time but try to minimize this by delivering preemption points spot-on. The average frequency of this extra interrupt is sched_latency / nr_latency. Which need not be higher than 1/HZ, its just that the distribution within the sched_latency period is important. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:29 +00:00
{
sched, x86: clean up hrtick implementation random uvesafb failures were reported against Gentoo: http://bugs.gentoo.org/show_bug.cgi?id=222799 and Mihai Moldovan bisected it back to: > 8f4d37ec073c17e2d4aa8851df5837d798606d6f is first bad commit > commit 8f4d37ec073c17e2d4aa8851df5837d798606d6f > Author: Peter Zijlstra <a.p.zijlstra@chello.nl> > Date: Fri Jan 25 21:08:29 2008 +0100 > > sched: high-res preemption tick Linus suspected it to be hrtick + vm86 interaction and observed: > Btw, Peter, Ingo: I think that commit is doing bad things. They aren't > _incorrect_ per se, but they are definitely bad. > > Why? > > Using random _TIF_WORK_MASK flags is really impolite for doing > "scheduling" work. There's a reason that arch/x86/kernel/entry_32.S > special-cases the _TIF_NEED_RESCHED flag: we don't want to exit out of > vm86 mode unnecessarily. > > See the "work_notifysig_v86" label, and how it does that > "save_v86_state()" thing etc etc. Right, I never liked having to fiddle with those TIF flags. Initially I needed it because the hrtimer base lock could not nest in the rq lock. That however is fixed these days. Currently the only reason left to fiddle with the TIF flags is remote wakeups. We cannot program a remote cpu's hrtimer. I've been thinking about using the new and improved IPI function call stuff to implement hrtimer_start_on(). However that does require that smp_call_function_single(.wait=0) works from interrupt context - /me looks at the latest series from Jens - Yes that does seem to be supported, good. Here's a stab at cleaning this stuff up ... Mihai reported test success as well. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Tested-by: Mihai Moldovan <ionic@ionic.de> Cc: Michal Januszewski <spock@gentoo.org> Cc: Antonino Daplas <adaplas@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-18 16:01:23 +00:00
#ifdef CONFIG_SMP
rq->hrtick_csd_pending = 0;
sched: high-res preemption tick Use HR-timers (when available) to deliver an accurate preemption tick. The regular scheduler tick that runs at 1/HZ can be too coarse when nice level are used. The fairness system will still keep the cpu utilisation 'fair' by then delaying the task that got an excessive amount of CPU time but try to minimize this by delivering preemption points spot-on. The average frequency of this extra interrupt is sched_latency / nr_latency. Which need not be higher than 1/HZ, its just that the distribution within the sched_latency period is important. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:29 +00:00
sched, x86: clean up hrtick implementation random uvesafb failures were reported against Gentoo: http://bugs.gentoo.org/show_bug.cgi?id=222799 and Mihai Moldovan bisected it back to: > 8f4d37ec073c17e2d4aa8851df5837d798606d6f is first bad commit > commit 8f4d37ec073c17e2d4aa8851df5837d798606d6f > Author: Peter Zijlstra <a.p.zijlstra@chello.nl> > Date: Fri Jan 25 21:08:29 2008 +0100 > > sched: high-res preemption tick Linus suspected it to be hrtick + vm86 interaction and observed: > Btw, Peter, Ingo: I think that commit is doing bad things. They aren't > _incorrect_ per se, but they are definitely bad. > > Why? > > Using random _TIF_WORK_MASK flags is really impolite for doing > "scheduling" work. There's a reason that arch/x86/kernel/entry_32.S > special-cases the _TIF_NEED_RESCHED flag: we don't want to exit out of > vm86 mode unnecessarily. > > See the "work_notifysig_v86" label, and how it does that > "save_v86_state()" thing etc etc. Right, I never liked having to fiddle with those TIF flags. Initially I needed it because the hrtimer base lock could not nest in the rq lock. That however is fixed these days. Currently the only reason left to fiddle with the TIF flags is remote wakeups. We cannot program a remote cpu's hrtimer. I've been thinking about using the new and improved IPI function call stuff to implement hrtimer_start_on(). However that does require that smp_call_function_single(.wait=0) works from interrupt context - /me looks at the latest series from Jens - Yes that does seem to be supported, good. Here's a stab at cleaning this stuff up ... Mihai reported test success as well. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Tested-by: Mihai Moldovan <ionic@ionic.de> Cc: Michal Januszewski <spock@gentoo.org> Cc: Antonino Daplas <adaplas@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-18 16:01:23 +00:00
rq->hrtick_csd.flags = 0;
rq->hrtick_csd.func = __hrtick_start;
rq->hrtick_csd.info = rq;
#endif
sched: high-res preemption tick Use HR-timers (when available) to deliver an accurate preemption tick. The regular scheduler tick that runs at 1/HZ can be too coarse when nice level are used. The fairness system will still keep the cpu utilisation 'fair' by then delaying the task that got an excessive amount of CPU time but try to minimize this by delivering preemption points spot-on. The average frequency of this extra interrupt is sched_latency / nr_latency. Which need not be higher than 1/HZ, its just that the distribution within the sched_latency period is important. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:29 +00:00
sched, x86: clean up hrtick implementation random uvesafb failures were reported against Gentoo: http://bugs.gentoo.org/show_bug.cgi?id=222799 and Mihai Moldovan bisected it back to: > 8f4d37ec073c17e2d4aa8851df5837d798606d6f is first bad commit > commit 8f4d37ec073c17e2d4aa8851df5837d798606d6f > Author: Peter Zijlstra <a.p.zijlstra@chello.nl> > Date: Fri Jan 25 21:08:29 2008 +0100 > > sched: high-res preemption tick Linus suspected it to be hrtick + vm86 interaction and observed: > Btw, Peter, Ingo: I think that commit is doing bad things. They aren't > _incorrect_ per se, but they are definitely bad. > > Why? > > Using random _TIF_WORK_MASK flags is really impolite for doing > "scheduling" work. There's a reason that arch/x86/kernel/entry_32.S > special-cases the _TIF_NEED_RESCHED flag: we don't want to exit out of > vm86 mode unnecessarily. > > See the "work_notifysig_v86" label, and how it does that > "save_v86_state()" thing etc etc. Right, I never liked having to fiddle with those TIF flags. Initially I needed it because the hrtimer base lock could not nest in the rq lock. That however is fixed these days. Currently the only reason left to fiddle with the TIF flags is remote wakeups. We cannot program a remote cpu's hrtimer. I've been thinking about using the new and improved IPI function call stuff to implement hrtimer_start_on(). However that does require that smp_call_function_single(.wait=0) works from interrupt context - /me looks at the latest series from Jens - Yes that does seem to be supported, good. Here's a stab at cleaning this stuff up ... Mihai reported test success as well. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Tested-by: Mihai Moldovan <ionic@ionic.de> Cc: Michal Januszewski <spock@gentoo.org> Cc: Antonino Daplas <adaplas@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-18 16:01:23 +00:00
hrtimer_init(&rq->hrtick_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
rq->hrtick_timer.function = hrtick;
sched: high-res preemption tick Use HR-timers (when available) to deliver an accurate preemption tick. The regular scheduler tick that runs at 1/HZ can be too coarse when nice level are used. The fairness system will still keep the cpu utilisation 'fair' by then delaying the task that got an excessive amount of CPU time but try to minimize this by delivering preemption points spot-on. The average frequency of this extra interrupt is sched_latency / nr_latency. Which need not be higher than 1/HZ, its just that the distribution within the sched_latency period is important. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:29 +00:00
}
sched: clarify ifdef tangle - Add some comments to try to make the ifdef puzzle a bit clearer - Explicitly inline one of the three init_hrtick() implementations. Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-22 21:55:46 +00:00
#else /* CONFIG_SCHED_HRTICK */
sched: high-res preemption tick Use HR-timers (when available) to deliver an accurate preemption tick. The regular scheduler tick that runs at 1/HZ can be too coarse when nice level are used. The fairness system will still keep the cpu utilisation 'fair' by then delaying the task that got an excessive amount of CPU time but try to minimize this by delivering preemption points spot-on. The average frequency of this extra interrupt is sched_latency / nr_latency. Which need not be higher than 1/HZ, its just that the distribution within the sched_latency period is important. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:29 +00:00
static inline void hrtick_clear(struct rq *rq)
{
}
static inline void init_rq_hrtick(struct rq *rq)
{
}
sched: fix hrtick_start_fair and CPU-Hotplug Gautham R Shenoy reported: > While running the usual CPU-Hotplug stress tests on linux-2.6.25, > I noticed the following in the console logs. > > This is a wee bit difficult to reproduce. In the past 10 runs I hit this > only once. > > ------------[ cut here ]------------ > > WARNING: at kernel/sched.c:962 hrtick+0x2e/0x65() > > Just wondering if we are doing a good job at handling the cancellation > of any per-cpu scheduler timers during CPU-Hotplug. This looks like its indeed not cancelled at all and migrates the it to another cpu. Fix it via a proper hotplug notifier mechanism. Reported-by: Gautham R Shenoy <ego@in.ibm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: stable@kernel.org Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-29 08:02:46 +00:00
static inline void init_hrtick(void)
{
}
sched: clarify ifdef tangle - Add some comments to try to make the ifdef puzzle a bit clearer - Explicitly inline one of the three init_hrtick() implementations. Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-22 21:55:46 +00:00
#endif /* CONFIG_SCHED_HRTICK */
sched: high-res preemption tick Use HR-timers (when available) to deliver an accurate preemption tick. The regular scheduler tick that runs at 1/HZ can be too coarse when nice level are used. The fairness system will still keep the cpu utilisation 'fair' by then delaying the task that got an excessive amount of CPU time but try to minimize this by delivering preemption points spot-on. The average frequency of this extra interrupt is sched_latency / nr_latency. Which need not be higher than 1/HZ, its just that the distribution within the sched_latency period is important. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:29 +00:00
sched: move around resched_task() move resched_task()/resched_cpu() into the 'public interfaces' section of sched.c, for use by kernel/sched_fair/rt/idletask.c Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-09 16:51:59 +00:00
/*
* resched_task - mark a task 'to be rescheduled now'.
*
* On UP this means the setting of the need_resched flag, on SMP it
* might also involve a cross-CPU call to trigger the scheduler on
* the target CPU.
*/
#ifdef CONFIG_SMP
#ifndef tsk_is_polling
#define tsk_is_polling(t) test_tsk_thread_flag(t, TIF_POLLING_NRFLAG)
#endif
sched, x86: clean up hrtick implementation random uvesafb failures were reported against Gentoo: http://bugs.gentoo.org/show_bug.cgi?id=222799 and Mihai Moldovan bisected it back to: > 8f4d37ec073c17e2d4aa8851df5837d798606d6f is first bad commit > commit 8f4d37ec073c17e2d4aa8851df5837d798606d6f > Author: Peter Zijlstra <a.p.zijlstra@chello.nl> > Date: Fri Jan 25 21:08:29 2008 +0100 > > sched: high-res preemption tick Linus suspected it to be hrtick + vm86 interaction and observed: > Btw, Peter, Ingo: I think that commit is doing bad things. They aren't > _incorrect_ per se, but they are definitely bad. > > Why? > > Using random _TIF_WORK_MASK flags is really impolite for doing > "scheduling" work. There's a reason that arch/x86/kernel/entry_32.S > special-cases the _TIF_NEED_RESCHED flag: we don't want to exit out of > vm86 mode unnecessarily. > > See the "work_notifysig_v86" label, and how it does that > "save_v86_state()" thing etc etc. Right, I never liked having to fiddle with those TIF flags. Initially I needed it because the hrtimer base lock could not nest in the rq lock. That however is fixed these days. Currently the only reason left to fiddle with the TIF flags is remote wakeups. We cannot program a remote cpu's hrtimer. I've been thinking about using the new and improved IPI function call stuff to implement hrtimer_start_on(). However that does require that smp_call_function_single(.wait=0) works from interrupt context - /me looks at the latest series from Jens - Yes that does seem to be supported, good. Here's a stab at cleaning this stuff up ... Mihai reported test success as well. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Tested-by: Mihai Moldovan <ionic@ionic.de> Cc: Michal Januszewski <spock@gentoo.org> Cc: Antonino Daplas <adaplas@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-18 16:01:23 +00:00
static void resched_task(struct task_struct *p)
sched: move around resched_task() move resched_task()/resched_cpu() into the 'public interfaces' section of sched.c, for use by kernel/sched_fair/rt/idletask.c Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-09 16:51:59 +00:00
{
int cpu;
sched: Convert rq->lock to raw_spinlock Convert locks which cannot be sleeping locks in preempt-rt to raw_spinlocks. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Ingo Molnar <mingo@elte.hu>
2009-11-17 13:28:38 +00:00
assert_raw_spin_locked(&task_rq(p)->lock);
sched: move around resched_task() move resched_task()/resched_cpu() into the 'public interfaces' section of sched.c, for use by kernel/sched_fair/rt/idletask.c Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-09 16:51:59 +00:00
sched: TIF_NEED_RESCHED -> need_reshed() cleanup Impact: cleanup Use test_tsk_need_resched(), set_tsk_need_resched(), need_resched() instead of using TIF_NEED_RESCHED. Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <49B10BA4.9070209@cn.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-06 11:40:20 +00:00
if (test_tsk_need_resched(p))
sched: move around resched_task() move resched_task()/resched_cpu() into the 'public interfaces' section of sched.c, for use by kernel/sched_fair/rt/idletask.c Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-09 16:51:59 +00:00
return;
sched: TIF_NEED_RESCHED -> need_reshed() cleanup Impact: cleanup Use test_tsk_need_resched(), set_tsk_need_resched(), need_resched() instead of using TIF_NEED_RESCHED. Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <49B10BA4.9070209@cn.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-06 11:40:20 +00:00
set_tsk_need_resched(p);
sched: move around resched_task() move resched_task()/resched_cpu() into the 'public interfaces' section of sched.c, for use by kernel/sched_fair/rt/idletask.c Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-09 16:51:59 +00:00
cpu = task_cpu(p);
if (cpu == smp_processor_id())
return;
/* NEED_RESCHED must be visible before we test polling */
smp_mb();
if (!tsk_is_polling(p))
smp_send_reschedule(cpu);
}
static void resched_cpu(int cpu)
{
struct rq *rq = cpu_rq(cpu);
unsigned long flags;
sched: Convert rq->lock to raw_spinlock Convert locks which cannot be sleeping locks in preempt-rt to raw_spinlocks. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Ingo Molnar <mingo@elte.hu>
2009-11-17 13:28:38 +00:00
if (!raw_spin_trylock_irqsave(&rq->lock, flags))
sched: move around resched_task() move resched_task()/resched_cpu() into the 'public interfaces' section of sched.c, for use by kernel/sched_fair/rt/idletask.c Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-09 16:51:59 +00:00
return;
resched_task(cpu_curr(cpu));
sched: Convert rq->lock to raw_spinlock Convert locks which cannot be sleeping locks in preempt-rt to raw_spinlocks. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Ingo Molnar <mingo@elte.hu>
2009-11-17 13:28:38 +00:00
raw_spin_unlock_irqrestore(&rq->lock, flags);
sched: move around resched_task() move resched_task()/resched_cpu() into the 'public interfaces' section of sched.c, for use by kernel/sched_fair/rt/idletask.c Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-09 16:51:59 +00:00
}
NOHZ: reevaluate idle sleep length after add_timer_on() add_timer_on() can add a timer on a CPU which is currently in a long idle sleep, but the timer wheel is not reevaluated by the nohz code on that CPU. So a timer can be delayed for quite a long time. This triggered a false positive in the clocksource watchdog code. To avoid this we need to wake up the idle CPU and enforce the reevaluation of the timer wheel for the next timer event. Add a function, which checks a given CPU for idle state, marks the idle task with NEED_RESCHED and sends a reschedule IPI to notify the other CPU of the change in the timer wheel. Call this function from add_timer_on(). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: stable@kernel.org -- include/linux/sched.h | 6 ++++++ kernel/sched.c | 43 +++++++++++++++++++++++++++++++++++++++++++ kernel/timer.c | 10 +++++++++- 3 files changed, 58 insertions(+), 1 deletion(-)
2008-03-22 08:20:24 +00:00
#ifdef CONFIG_NO_HZ
sched: Change nohz idle load balancing logic to push model In the new push model, all idle CPUs indeed go into nohz mode. There is still the concept of idle load balancer (performing the load balancing on behalf of all the idle cpu's in the system). Busy CPU kicks the nohz balancer when any of the nohz CPUs need idle load balancing. The kickee CPU does the idle load balancing on behalf of all idle CPUs instead of the normal idle balance. This addresses the below two problems with the current nohz ilb logic: * the idle load balancer continued to have periodic ticks during idle and wokeup frequently, even though it did not have any rebalancing to do on behalf of any of the idle CPUs. * On x86 and CPUs that have APIC timer stoppage on idle CPUs, this periodic wakeup can result in a periodic additional interrupt on a CPU doing the timer broadcast. Also currently we are migrating the unpinned timers from an idle to the cpu doing idle load balancing (when all the cpus in the system are idle, there is no idle load balancing cpu and timers get added to the same idle cpu where the request was made. So the existing optimization works only on semi idle system). And In semi idle system, we no longer have periodic ticks on the idle load balancer CPU. Using that cpu will add more delays to the timers than intended (as that cpu's timer base may not be uptodate wrt jiffies etc). This was causing mysterious slowdowns during boot etc. For now, in the semi idle case, use the nearest busy cpu for migrating timers from an idle cpu. This is good for power-savings anyway. Signed-off-by: Venkatesh Pallipadi <venki@google.com> Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Thomas Gleixner <tglx@linutronix.de> LKML-Reference: <1274486981.2840.46.camel@sbs-t61.sc.intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-05-22 00:09:41 +00:00
/*
* In the semi idle case, use the nearest busy cpu for migrating timers
* from an idle cpu. This is good for power-savings.
*
* We don't do similar optimization for completely idle system, as
* selecting an idle cpu will add more delays to the timers than intended
* (as that cpu's timer base may not be uptodate wrt jiffies etc).
*/
int get_nohz_timer_target(void)
{
int cpu = smp_processor_id();
int i;
struct sched_domain *sd;
sched: Fix sched_domain iterations vs. RCU Vladis Kletnieks reported a new RCU debug warning in the scheduler. Since commit dce840a08702b ("sched: Dynamically allocate sched_domain/ sched_group data-structures") the sched_domain trees are protected by RCU instead of RCU-sched. This means that we need to include rcu_read_lock() protection when we iterate them since disabling preemption doesn't suffice anymore. Reported-by: Valdis.Kletnieks@vt.edu Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1302882741.2388.241.camel@twins Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-18 09:24:34 +00:00
rcu_read_lock();
sched: Change nohz idle load balancing logic to push model In the new push model, all idle CPUs indeed go into nohz mode. There is still the concept of idle load balancer (performing the load balancing on behalf of all the idle cpu's in the system). Busy CPU kicks the nohz balancer when any of the nohz CPUs need idle load balancing. The kickee CPU does the idle load balancing on behalf of all idle CPUs instead of the normal idle balance. This addresses the below two problems with the current nohz ilb logic: * the idle load balancer continued to have periodic ticks during idle and wokeup frequently, even though it did not have any rebalancing to do on behalf of any of the idle CPUs. * On x86 and CPUs that have APIC timer stoppage on idle CPUs, this periodic wakeup can result in a periodic additional interrupt on a CPU doing the timer broadcast. Also currently we are migrating the unpinned timers from an idle to the cpu doing idle load balancing (when all the cpus in the system are idle, there is no idle load balancing cpu and timers get added to the same idle cpu where the request was made. So the existing optimization works only on semi idle system). And In semi idle system, we no longer have periodic ticks on the idle load balancer CPU. Using that cpu will add more delays to the timers than intended (as that cpu's timer base may not be uptodate wrt jiffies etc). This was causing mysterious slowdowns during boot etc. For now, in the semi idle case, use the nearest busy cpu for migrating timers from an idle cpu. This is good for power-savings anyway. Signed-off-by: Venkatesh Pallipadi <venki@google.com> Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Thomas Gleixner <tglx@linutronix.de> LKML-Reference: <1274486981.2840.46.camel@sbs-t61.sc.intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-05-22 00:09:41 +00:00
for_each_domain(cpu, sd) {
sched: Fix sched_domain iterations vs. RCU Vladis Kletnieks reported a new RCU debug warning in the scheduler. Since commit dce840a08702b ("sched: Dynamically allocate sched_domain/ sched_group data-structures") the sched_domain trees are protected by RCU instead of RCU-sched. This means that we need to include rcu_read_lock() protection when we iterate them since disabling preemption doesn't suffice anymore. Reported-by: Valdis.Kletnieks@vt.edu Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1302882741.2388.241.camel@twins Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-18 09:24:34 +00:00
for_each_cpu(i, sched_domain_span(sd)) {
if (!idle_cpu(i)) {
cpu = i;
goto unlock;
}
}
sched: Change nohz idle load balancing logic to push model In the new push model, all idle CPUs indeed go into nohz mode. There is still the concept of idle load balancer (performing the load balancing on behalf of all the idle cpu's in the system). Busy CPU kicks the nohz balancer when any of the nohz CPUs need idle load balancing. The kickee CPU does the idle load balancing on behalf of all idle CPUs instead of the normal idle balance. This addresses the below two problems with the current nohz ilb logic: * the idle load balancer continued to have periodic ticks during idle and wokeup frequently, even though it did not have any rebalancing to do on behalf of any of the idle CPUs. * On x86 and CPUs that have APIC timer stoppage on idle CPUs, this periodic wakeup can result in a periodic additional interrupt on a CPU doing the timer broadcast. Also currently we are migrating the unpinned timers from an idle to the cpu doing idle load balancing (when all the cpus in the system are idle, there is no idle load balancing cpu and timers get added to the same idle cpu where the request was made. So the existing optimization works only on semi idle system). And In semi idle system, we no longer have periodic ticks on the idle load balancer CPU. Using that cpu will add more delays to the timers than intended (as that cpu's timer base may not be uptodate wrt jiffies etc). This was causing mysterious slowdowns during boot etc. For now, in the semi idle case, use the nearest busy cpu for migrating timers from an idle cpu. This is good for power-savings anyway. Signed-off-by: Venkatesh Pallipadi <venki@google.com> Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Thomas Gleixner <tglx@linutronix.de> LKML-Reference: <1274486981.2840.46.camel@sbs-t61.sc.intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-05-22 00:09:41 +00:00
}
sched: Fix sched_domain iterations vs. RCU Vladis Kletnieks reported a new RCU debug warning in the scheduler. Since commit dce840a08702b ("sched: Dynamically allocate sched_domain/ sched_group data-structures") the sched_domain trees are protected by RCU instead of RCU-sched. This means that we need to include rcu_read_lock() protection when we iterate them since disabling preemption doesn't suffice anymore. Reported-by: Valdis.Kletnieks@vt.edu Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1302882741.2388.241.camel@twins Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-18 09:24:34 +00:00
unlock:
rcu_read_unlock();
sched: Change nohz idle load balancing logic to push model In the new push model, all idle CPUs indeed go into nohz mode. There is still the concept of idle load balancer (performing the load balancing on behalf of all the idle cpu's in the system). Busy CPU kicks the nohz balancer when any of the nohz CPUs need idle load balancing. The kickee CPU does the idle load balancing on behalf of all idle CPUs instead of the normal idle balance. This addresses the below two problems with the current nohz ilb logic: * the idle load balancer continued to have periodic ticks during idle and wokeup frequently, even though it did not have any rebalancing to do on behalf of any of the idle CPUs. * On x86 and CPUs that have APIC timer stoppage on idle CPUs, this periodic wakeup can result in a periodic additional interrupt on a CPU doing the timer broadcast. Also currently we are migrating the unpinned timers from an idle to the cpu doing idle load balancing (when all the cpus in the system are idle, there is no idle load balancing cpu and timers get added to the same idle cpu where the request was made. So the existing optimization works only on semi idle system). And In semi idle system, we no longer have periodic ticks on the idle load balancer CPU. Using that cpu will add more delays to the timers than intended (as that cpu's timer base may not be uptodate wrt jiffies etc). This was causing mysterious slowdowns during boot etc. For now, in the semi idle case, use the nearest busy cpu for migrating timers from an idle cpu. This is good for power-savings anyway. Signed-off-by: Venkatesh Pallipadi <venki@google.com> Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Thomas Gleixner <tglx@linutronix.de> LKML-Reference: <1274486981.2840.46.camel@sbs-t61.sc.intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-05-22 00:09:41 +00:00
return cpu;
}
NOHZ: reevaluate idle sleep length after add_timer_on() add_timer_on() can add a timer on a CPU which is currently in a long idle sleep, but the timer wheel is not reevaluated by the nohz code on that CPU. So a timer can be delayed for quite a long time. This triggered a false positive in the clocksource watchdog code. To avoid this we need to wake up the idle CPU and enforce the reevaluation of the timer wheel for the next timer event. Add a function, which checks a given CPU for idle state, marks the idle task with NEED_RESCHED and sends a reschedule IPI to notify the other CPU of the change in the timer wheel. Call this function from add_timer_on(). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: stable@kernel.org -- include/linux/sched.h | 6 ++++++ kernel/sched.c | 43 +++++++++++++++++++++++++++++++++++++++++++ kernel/timer.c | 10 +++++++++- 3 files changed, 58 insertions(+), 1 deletion(-)
2008-03-22 08:20:24 +00:00
/*
* When add_timer_on() enqueues a timer into the timer wheel of an
* idle CPU then this timer might expire before the next timer event
* which is scheduled to wake up that CPU. In case of a completely
* idle system the next event might even be infinite time into the
* future. wake_up_idle_cpu() ensures that the CPU is woken up and
* leaves the inner idle loop so the newly added timer is taken into
* account when the CPU goes back to idle and evaluates the timer
* wheel for the next timer event.
*/
void wake_up_idle_cpu(int cpu)
{
struct rq *rq = cpu_rq(cpu);
if (cpu == smp_processor_id())
return;
/*
* This is safe, as this function is called with the timer
* wheel base lock of (cpu) held. When the CPU is on the way
* to idle and has not yet set rq->curr to idle then it will
* be serialized on the timer wheel base lock and take the new
* timer into account automatically.
*/
if (rq->curr != rq->idle)
return;
/*
* We can set TIF_RESCHED on the idle task of the other CPU
* lockless. The worst case is that the other CPU runs the
* idle task through an additional NOOP schedule()
*/
sched: TIF_NEED_RESCHED -> need_reshed() cleanup Impact: cleanup Use test_tsk_need_resched(), set_tsk_need_resched(), need_resched() instead of using TIF_NEED_RESCHED. Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <49B10BA4.9070209@cn.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-06 11:40:20 +00:00
set_tsk_need_resched(rq->idle);
NOHZ: reevaluate idle sleep length after add_timer_on() add_timer_on() can add a timer on a CPU which is currently in a long idle sleep, but the timer wheel is not reevaluated by the nohz code on that CPU. So a timer can be delayed for quite a long time. This triggered a false positive in the clocksource watchdog code. To avoid this we need to wake up the idle CPU and enforce the reevaluation of the timer wheel for the next timer event. Add a function, which checks a given CPU for idle state, marks the idle task with NEED_RESCHED and sends a reschedule IPI to notify the other CPU of the change in the timer wheel. Call this function from add_timer_on(). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: stable@kernel.org -- include/linux/sched.h | 6 ++++++ kernel/sched.c | 43 +++++++++++++++++++++++++++++++++++++++++++ kernel/timer.c | 10 +++++++++- 3 files changed, 58 insertions(+), 1 deletion(-)
2008-03-22 08:20:24 +00:00
/* NEED_RESCHED must be visible before we test polling */
smp_mb();
if (!tsk_is_polling(rq->idle))
smp_send_reschedule(cpu);
}
sched: Rate-limit nohz Entering nohz code on every micro-idle is costing ~10% throughput for netperf TCP_RR when scheduling cross-cpu. Rate limiting entry fixes this, but raises ticks a bit. On my Q6600, an idle box goes from ~85 interrupts/sec to 128. The higher the context switch rate, the more nohz entry costs. With this patch and some cycle recovery patches in my tree, max cross cpu context switch rate is improved by ~16%, a large portion of which of which is this ratelimiting. Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1268301003.6785.28.camel@marge.simson.net> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-03-11 16:17:13 +00:00
sched: add comments for ifdefs in sched.c make sched.c easier to read. Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-30 12:23:45 +00:00
#endif /* CONFIG_NO_HZ */
NOHZ: reevaluate idle sleep length after add_timer_on() add_timer_on() can add a timer on a CPU which is currently in a long idle sleep, but the timer wheel is not reevaluated by the nohz code on that CPU. So a timer can be delayed for quite a long time. This triggered a false positive in the clocksource watchdog code. To avoid this we need to wake up the idle CPU and enforce the reevaluation of the timer wheel for the next timer event. Add a function, which checks a given CPU for idle state, marks the idle task with NEED_RESCHED and sends a reschedule IPI to notify the other CPU of the change in the timer wheel. Call this function from add_timer_on(). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: stable@kernel.org -- include/linux/sched.h | 6 ++++++ kernel/sched.c | 43 +++++++++++++++++++++++++++++++++++++++++++ kernel/timer.c | 10 +++++++++- 3 files changed, 58 insertions(+), 1 deletion(-)
2008-03-22 08:20:24 +00:00
sched: Scale down cpu_power due to RT tasks Keep an average on the amount of time spend on RT tasks and use that fraction to scale down the cpu_power for regular tasks. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Tested-by: Andreas Herrmann <andreas.herrmann3@amd.com> Acked-by: Andreas Herrmann <andreas.herrmann3@amd.com> Acked-by: Gautham R Shenoy <ego@in.ibm.com> Cc: Balbir Singh <balbir@in.ibm.com> LKML-Reference: <20090901083826.287778431@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-09-01 08:34:37 +00:00
static u64 sched_avg_period(void)
{
return (u64)sysctl_sched_time_avg * NSEC_PER_MSEC / 2;
}
static void sched_avg_update(struct rq *rq)
{
s64 period = sched_avg_period();
while ((s64)(rq->clock - rq->age_stamp) > period) {
sched: Prevent compiler from optimising the sched_avg_update() loop GCC 4.4.1 on ARM has been observed to replace the while loop in sched_avg_update with a call to uldivmod, resulting in the following build failure at link-time: kernel/built-in.o: In function `sched_avg_update': kernel/sched.c:1261: undefined reference to `__aeabi_uldivmod' kernel/sched.c:1261: undefined reference to `__aeabi_uldivmod' make: *** [.tmp_vmlinux1] Error 1 This patch introduces a fake data hazard to the loop body to prevent the compiler optimising the loop away. Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Russell King <rmk@arm.linux.org.uk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: <stable@kernel.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-05-24 19:11:43 +00:00
/*
* Inline assembly required to prevent the compiler
* optimising this loop into a divmod call.
* See __iter_div_u64_rem() for another example of this.
*/
asm("" : "+rm" (rq->age_stamp));
sched: Scale down cpu_power due to RT tasks Keep an average on the amount of time spend on RT tasks and use that fraction to scale down the cpu_power for regular tasks. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Tested-by: Andreas Herrmann <andreas.herrmann3@amd.com> Acked-by: Andreas Herrmann <andreas.herrmann3@amd.com> Acked-by: Gautham R Shenoy <ego@in.ibm.com> Cc: Balbir Singh <balbir@in.ibm.com> LKML-Reference: <20090901083826.287778431@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-09-01 08:34:37 +00:00
rq->age_stamp += period;
rq->rt_avg /= 2;
}
}
static void sched_rt_avg_update(struct rq *rq, u64 rt_delta)
{
rq->rt_avg += rt_delta;
sched_avg_update(rq);
}
sched: add comments for ifdefs in sched.c make sched.c easier to read. Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-30 12:23:45 +00:00
#else /* !CONFIG_SMP */
sched, x86: clean up hrtick implementation random uvesafb failures were reported against Gentoo: http://bugs.gentoo.org/show_bug.cgi?id=222799 and Mihai Moldovan bisected it back to: > 8f4d37ec073c17e2d4aa8851df5837d798606d6f is first bad commit > commit 8f4d37ec073c17e2d4aa8851df5837d798606d6f > Author: Peter Zijlstra <a.p.zijlstra@chello.nl> > Date: Fri Jan 25 21:08:29 2008 +0100 > > sched: high-res preemption tick Linus suspected it to be hrtick + vm86 interaction and observed: > Btw, Peter, Ingo: I think that commit is doing bad things. They aren't > _incorrect_ per se, but they are definitely bad. > > Why? > > Using random _TIF_WORK_MASK flags is really impolite for doing > "scheduling" work. There's a reason that arch/x86/kernel/entry_32.S > special-cases the _TIF_NEED_RESCHED flag: we don't want to exit out of > vm86 mode unnecessarily. > > See the "work_notifysig_v86" label, and how it does that > "save_v86_state()" thing etc etc. Right, I never liked having to fiddle with those TIF flags. Initially I needed it because the hrtimer base lock could not nest in the rq lock. That however is fixed these days. Currently the only reason left to fiddle with the TIF flags is remote wakeups. We cannot program a remote cpu's hrtimer. I've been thinking about using the new and improved IPI function call stuff to implement hrtimer_start_on(). However that does require that smp_call_function_single(.wait=0) works from interrupt context - /me looks at the latest series from Jens - Yes that does seem to be supported, good. Here's a stab at cleaning this stuff up ... Mihai reported test success as well. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Tested-by: Mihai Moldovan <ionic@ionic.de> Cc: Michal Januszewski <spock@gentoo.org> Cc: Antonino Daplas <adaplas@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-18 16:01:23 +00:00
static void resched_task(struct task_struct *p)
sched: move around resched_task() move resched_task()/resched_cpu() into the 'public interfaces' section of sched.c, for use by kernel/sched_fair/rt/idletask.c Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-09 16:51:59 +00:00
{
sched: Convert rq->lock to raw_spinlock Convert locks which cannot be sleeping locks in preempt-rt to raw_spinlocks. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Ingo Molnar <mingo@elte.hu>
2009-11-17 13:28:38 +00:00
assert_raw_spin_locked(&task_rq(p)->lock);
sched, x86: clean up hrtick implementation random uvesafb failures were reported against Gentoo: http://bugs.gentoo.org/show_bug.cgi?id=222799 and Mihai Moldovan bisected it back to: > 8f4d37ec073c17e2d4aa8851df5837d798606d6f is first bad commit > commit 8f4d37ec073c17e2d4aa8851df5837d798606d6f > Author: Peter Zijlstra <a.p.zijlstra@chello.nl> > Date: Fri Jan 25 21:08:29 2008 +0100 > > sched: high-res preemption tick Linus suspected it to be hrtick + vm86 interaction and observed: > Btw, Peter, Ingo: I think that commit is doing bad things. They aren't > _incorrect_ per se, but they are definitely bad. > > Why? > > Using random _TIF_WORK_MASK flags is really impolite for doing > "scheduling" work. There's a reason that arch/x86/kernel/entry_32.S > special-cases the _TIF_NEED_RESCHED flag: we don't want to exit out of > vm86 mode unnecessarily. > > See the "work_notifysig_v86" label, and how it does that > "save_v86_state()" thing etc etc. Right, I never liked having to fiddle with those TIF flags. Initially I needed it because the hrtimer base lock could not nest in the rq lock. That however is fixed these days. Currently the only reason left to fiddle with the TIF flags is remote wakeups. We cannot program a remote cpu's hrtimer. I've been thinking about using the new and improved IPI function call stuff to implement hrtimer_start_on(). However that does require that smp_call_function_single(.wait=0) works from interrupt context - /me looks at the latest series from Jens - Yes that does seem to be supported, good. Here's a stab at cleaning this stuff up ... Mihai reported test success as well. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Tested-by: Mihai Moldovan <ionic@ionic.de> Cc: Michal Januszewski <spock@gentoo.org> Cc: Antonino Daplas <adaplas@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-18 16:01:23 +00:00
set_tsk_need_resched(p);
sched: move around resched_task() move resched_task()/resched_cpu() into the 'public interfaces' section of sched.c, for use by kernel/sched_fair/rt/idletask.c Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-09 16:51:59 +00:00
}
sched: Scale down cpu_power due to RT tasks Keep an average on the amount of time spend on RT tasks and use that fraction to scale down the cpu_power for regular tasks. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Tested-by: Andreas Herrmann <andreas.herrmann3@amd.com> Acked-by: Andreas Herrmann <andreas.herrmann3@amd.com> Acked-by: Gautham R Shenoy <ego@in.ibm.com> Cc: Balbir Singh <balbir@in.ibm.com> LKML-Reference: <20090901083826.287778431@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-09-01 08:34:37 +00:00
static void sched_rt_avg_update(struct rq *rq, u64 rt_delta)
{
}
sched: Move sched_avg_update() to update_cpu_load() Currently sched_avg_update() (which updates rt_avg stats in the rq) is getting called from scale_rt_power() (in the load balance context) which doesn't take rq->lock. Fix it by moving the sched_avg_update() to more appropriate update_cpu_load() where the CFS load gets updated as well. Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1282596171.2694.3.camel@sbsiddha-MOBL3> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-08-23 20:42:51 +00:00
static void sched_avg_update(struct rq *rq)
{
}
sched: add comments for ifdefs in sched.c make sched.c easier to read. Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-30 12:23:45 +00:00
#endif /* CONFIG_SMP */
sched: move around resched_task() move resched_task()/resched_cpu() into the 'public interfaces' section of sched.c, for use by kernel/sched_fair/rt/idletask.c Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-09 16:51:59 +00:00
sched: cfs, add load-calculation methods add the new load-calculation methods of CFS. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-09 16:51:59 +00:00
#if BITS_PER_LONG == 32
# define WMULT_CONST (~0UL)
#else
# define WMULT_CONST (1UL << 32)
#endif
#define WMULT_SHIFT 32
sched: round a bit better round a tiny bit better in high-frequency rescheduling scenarios, by rounding around zero instead of rounding down. (this is pretty theoretical though) Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-08-09 09:16:51 +00:00
/*
* Shift right and round:
*/
sched: fix xtensa build warning rename RSR to SRR - 'RSR' is already defined on xtensa. found by Adrian Bunk. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-09-05 12:32:49 +00:00
#define SRR(x, y) (((x) + (1UL << ((y) - 1))) >> (y))
sched: round a bit better round a tiny bit better in high-frequency rescheduling scenarios, by rounding around zero instead of rounding down. (this is pretty theoretical though) Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-08-09 09:16:51 +00:00
sched: revert the revert of: weight calculations Try again.. initial commit: 8f1bc385cfbab474db6c27b5af1e439614f3025c revert: f9305d4a0968201b2818dbed0dc8cb0d4ee7aeb3 Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Cc: Mike Galbraith <efault@gmx.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-27 11:41:11 +00:00
/*
* delta *= weight / lw
*/
[PATCH] sched: uninline calc_delta_mine() uninline calc_delta_mine(): text data bss dec hex filename 29162 4162 24 33348 8244 sched.o.before 29039 4162 24 33225 81c9 sched.o.after Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-08-02 15:41:40 +00:00
static unsigned long
sched: cfs, add load-calculation methods add the new load-calculation methods of CFS. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-09 16:51:59 +00:00
calc_delta_mine(unsigned long delta_exec, unsigned long weight,
struct load_weight *lw)
{
u64 tmp;
sched: Increase SCHED_LOAD_SCALE resolution Introduce SCHED_LOAD_RESOLUTION, which scales is added to SCHED_LOAD_SHIFT and increases the resolution of SCHED_LOAD_SCALE. This patch sets the value of SCHED_LOAD_RESOLUTION to 10, scaling up the weights for all sched entities by a factor of 1024. With this extra resolution, we can handle deeper cgroup hiearchies and the scheduler can do better shares distribution and load load balancing on larger systems (especially for low weight task groups). This does not change the existing user interface, the scaled weights are only used internally. We do not modify prio_to_weight values or inverses, but use the original weights when calculating the inverse which is used to scale execution time delta in calc_delta_mine(). This ensures we do not lose accuracy when accounting time to the sched entities. Thanks to Nikunj Dadhania for fixing an bug in c_d_m() that broken fairness. Below is some analysis of the performance costs/improvements of this patch. 1. Micro-arch performance costs: Experiment was to run Ingo's pipe_test_100k 200 times with the task pinned to one cpu. I measured instruction, cycles and stalled-cycles for the runs. See: http://thread.gmane.org/gmane.linux.kernel/1129232/focus=1129389 for more info. -tip (baseline): Performance counter stats for '/root/load-scale/pipe-test-100k' (200 runs): 964,991,769 instructions # 0.82 insns per cycle # 0.33 stalled cycles per insn # ( +- 0.05% ) 1,171,186,635 cycles # 0.000 GHz ( +- 0.08% ) 306,373,664 stalled-cycles-backend # 26.16% backend cycles idle ( +- 0.28% ) 314,933,621 stalled-cycles-frontend # 26.89% frontend cycles idle ( +- 0.34% ) 1.122405684 seconds time elapsed ( +- 0.05% ) -tip+patches: Performance counter stats for './load-scale/pipe-test-100k' (200 runs): 963,624,821 instructions # 0.82 insns per cycle # 0.33 stalled cycles per insn # ( +- 0.04% ) 1,175,215,649 cycles # 0.000 GHz ( +- 0.08% ) 315,321,126 stalled-cycles-backend # 26.83% backend cycles idle ( +- 0.28% ) 316,835,873 stalled-cycles-frontend # 26.96% frontend cycles idle ( +- 0.29% ) 1.122238659 seconds time elapsed ( +- 0.06% ) With this patch, instructions decrease by ~0.10% and cycles increase by 0.27%. This doesn't look statistically significant. The number of stalled cycles in the backend increased from 26.16% to 26.83%. This can be attributed to the shifts we do in c_d_m() and other places. The fraction of stalled cycles in the frontend remains about the same, at 26.96% compared to 26.89% in -tip. 2. Balancing low-weight task groups Test setup: run 50 tasks with random sleep/busy times (biased around 100ms) in a low weight container (with cpu.shares = 2). Measure %idle as reported by mpstat over a 10s window. -tip (baseline): 06:47:48 PM CPU %usr %nice %sys %iowait %irq %soft %steal %guest %idle intr/s 06:47:49 PM all 94.32 0.00 0.06 0.00 0.00 0.00 0.00 0.00 5.62 15888.00 06:47:50 PM all 94.57 0.00 0.62 0.00 0.00 0.00 0.00 0.00 4.81 16180.00 06:47:51 PM all 94.69 0.00 0.06 0.00 0.00 0.00 0.00 0.00 5.25 15966.00 06:47:52 PM all 95.81 0.00 0.00 0.00 0.00 0.00 0.00 0.00 4.19 16053.00 06:47:53 PM all 94.88 0.06 0.00 0.00 0.00 0.00 0.00 0.00 5.06 15984.00 06:47:54 PM all 93.31 0.00 0.00 0.00 0.00 0.00 0.00 0.00 6.69 15806.00 06:47:55 PM all 94.19 0.00 0.06 0.00 0.00 0.00 0.00 0.00 5.75 15896.00 06:47:56 PM all 92.87 0.00 0.00 0.00 0.00 0.00 0.00 0.00 7.13 15716.00 06:47:57 PM all 94.88 0.00 0.00 0.00 0.00 0.00 0.00 0.00 5.12 15982.00 06:47:58 PM all 95.44 0.00 0.00 0.00 0.00 0.00 0.00 0.00 4.56 16075.00 Average: all 94.49 0.01 0.08 0.00 0.00 0.00 0.00 0.00 5.42 15954.60 -tip+patches: 06:47:03 PM CPU %usr %nice %sys %iowait %irq %soft %steal %guest %idle intr/s 06:47:04 PM all 100.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 16630.00 06:47:05 PM all 99.69 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.31 16580.20 06:47:06 PM all 99.69 0.00 0.06 0.00 0.00 0.00 0.00 0.00 0.25 16596.00 06:47:07 PM all 99.20 0.00 0.74 0.00 0.00 0.06 0.00 0.00 0.00 17838.61 06:47:08 PM all 100.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 16540.00 06:47:09 PM all 100.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 16575.00 06:47:10 PM all 100.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 16614.00 06:47:11 PM all 99.94 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.06 16588.00 06:47:12 PM all 99.94 0.00 0.06 0.00 0.00 0.00 0.00 0.00 0.00 16593.00 06:47:13 PM all 99.94 0.00 0.06 0.00 0.00 0.00 0.00 0.00 0.00 16551.00 Average: all 99.84 0.00 0.09 0.00 0.00 0.01 0.00 0.00 0.06 16711.58 We see an improvement in idle% on the system (drops from 5.42% on -tip to 0.06% with the patches). We see an improvement in idle% on the system (drops from 5.42% on -tip to 0.06% with the patches). Signed-off-by: Nikhil Rao <ncrao@google.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Nikunj A. Dadhania <nikunj@linux.vnet.ibm.com> Cc: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Cc: Stephan Barwolf <stephan.baerwolf@tu-ilmenau.de> Cc: Mike Galbraith <efault@gmx.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/1305754668-18792-1-git-send-email-ncrao@google.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-05-18 21:37:48 +00:00
/*
* weight can be less than 2^SCHED_LOAD_RESOLUTION for task group sched
* entities since MIN_SHARES = 2. Treat weight as 1 if less than
* 2^SCHED_LOAD_RESOLUTION.
*/
if (likely(weight > (1UL << SCHED_LOAD_RESOLUTION)))
tmp = (u64)delta_exec * scale_load_down(weight);
else
tmp = (u64)delta_exec;
sched: Fix and optimise calculation of the weight-inverse If the inverse loadweight should be zero, function "calc_delta_mine" calculates the inverse of "lw->weight" (in 32bit integer ops). This calculation is actually a little bit impure (because it is inverting something around "lw-weight"+1), especially when "lw->weight" becomes smaller. The correct inverse would be 1/lw->weight multiplied by "WMULT_CONST" for fixcomma-scaling it into integers. (So WMULT_CONST/lw->weight ...) The old, impure algorithm took two divisions for inverting lw->weight, the new, more exact one only takes one and an additional unlikely-if. Signed-off-by: Stephan Baerwolf <stephan.baerwolf@tu-ilmenau.de> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/n/tip-0pz0wnyalr4tk4ln11xwumdx@git.kernel.org [ This could explain some aritmetical issues for small shares but nothing concrete has been reported yet so we are not confident enough to queue this up in sched/urgent and for -stable backport. But if anyone finds this commit and sees it to fix some badness then we can certainly change our mind! ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-05-11 16:03:29 +00:00
sched: 64-bit: fix arithmetics overflow (overflow means weight >= 2^32 here, because inv_weigh = 2^32/weight) A weight of a cfs_rq is the sum of weights of which entities are queued on this cfs_rq, so it will overflow when there are too many entities. Although, overflow occurs very rarely, but it break fairness when it occurs. 64-bits systems have more memory than 32-bit systems and 64-bit systems can create more process usually, so overflow may occur more frequently. This patch guarantees fairness when overflow happens on 64-bit systems. Thanks to the optimization of compiler, it changes nothing on 32-bit. Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-12 08:43:07 +00:00
if (!lw->inv_weight) {
sched: Increase SCHED_LOAD_SCALE resolution Introduce SCHED_LOAD_RESOLUTION, which scales is added to SCHED_LOAD_SHIFT and increases the resolution of SCHED_LOAD_SCALE. This patch sets the value of SCHED_LOAD_RESOLUTION to 10, scaling up the weights for all sched entities by a factor of 1024. With this extra resolution, we can handle deeper cgroup hiearchies and the scheduler can do better shares distribution and load load balancing on larger systems (especially for low weight task groups). This does not change the existing user interface, the scaled weights are only used internally. We do not modify prio_to_weight values or inverses, but use the original weights when calculating the inverse which is used to scale execution time delta in calc_delta_mine(). This ensures we do not lose accuracy when accounting time to the sched entities. Thanks to Nikunj Dadhania for fixing an bug in c_d_m() that broken fairness. Below is some analysis of the performance costs/improvements of this patch. 1. Micro-arch performance costs: Experiment was to run Ingo's pipe_test_100k 200 times with the task pinned to one cpu. I measured instruction, cycles and stalled-cycles for the runs. See: http://thread.gmane.org/gmane.linux.kernel/1129232/focus=1129389 for more info. -tip (baseline): Performance counter stats for '/root/load-scale/pipe-test-100k' (200 runs): 964,991,769 instructions # 0.82 insns per cycle # 0.33 stalled cycles per insn # ( +- 0.05% ) 1,171,186,635 cycles # 0.000 GHz ( +- 0.08% ) 306,373,664 stalled-cycles-backend # 26.16% backend cycles idle ( +- 0.28% ) 314,933,621 stalled-cycles-frontend # 26.89% frontend cycles idle ( +- 0.34% ) 1.122405684 seconds time elapsed ( +- 0.05% ) -tip+patches: Performance counter stats for './load-scale/pipe-test-100k' (200 runs): 963,624,821 instructions # 0.82 insns per cycle # 0.33 stalled cycles per insn # ( +- 0.04% ) 1,175,215,649 cycles # 0.000 GHz ( +- 0.08% ) 315,321,126 stalled-cycles-backend # 26.83% backend cycles idle ( +- 0.28% ) 316,835,873 stalled-cycles-frontend # 26.96% frontend cycles idle ( +- 0.29% ) 1.122238659 seconds time elapsed ( +- 0.06% ) With this patch, instructions decrease by ~0.10% and cycles increase by 0.27%. This doesn't look statistically significant. The number of stalled cycles in the backend increased from 26.16% to 26.83%. This can be attributed to the shifts we do in c_d_m() and other places. The fraction of stalled cycles in the frontend remains about the same, at 26.96% compared to 26.89% in -tip. 2. Balancing low-weight task groups Test setup: run 50 tasks with random sleep/busy times (biased around 100ms) in a low weight container (with cpu.shares = 2). Measure %idle as reported by mpstat over a 10s window. -tip (baseline): 06:47:48 PM CPU %usr %nice %sys %iowait %irq %soft %steal %guest %idle intr/s 06:47:49 PM all 94.32 0.00 0.06 0.00 0.00 0.00 0.00 0.00 5.62 15888.00 06:47:50 PM all 94.57 0.00 0.62 0.00 0.00 0.00 0.00 0.00 4.81 16180.00 06:47:51 PM all 94.69 0.00 0.06 0.00 0.00 0.00 0.00 0.00 5.25 15966.00 06:47:52 PM all 95.81 0.00 0.00 0.00 0.00 0.00 0.00 0.00 4.19 16053.00 06:47:53 PM all 94.88 0.06 0.00 0.00 0.00 0.00 0.00 0.00 5.06 15984.00 06:47:54 PM all 93.31 0.00 0.00 0.00 0.00 0.00 0.00 0.00 6.69 15806.00 06:47:55 PM all 94.19 0.00 0.06 0.00 0.00 0.00 0.00 0.00 5.75 15896.00 06:47:56 PM all 92.87 0.00 0.00 0.00 0.00 0.00 0.00 0.00 7.13 15716.00 06:47:57 PM all 94.88 0.00 0.00 0.00 0.00 0.00 0.00 0.00 5.12 15982.00 06:47:58 PM all 95.44 0.00 0.00 0.00 0.00 0.00 0.00 0.00 4.56 16075.00 Average: all 94.49 0.01 0.08 0.00 0.00 0.00 0.00 0.00 5.42 15954.60 -tip+patches: 06:47:03 PM CPU %usr %nice %sys %iowait %irq %soft %steal %guest %idle intr/s 06:47:04 PM all 100.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 16630.00 06:47:05 PM all 99.69 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.31 16580.20 06:47:06 PM all 99.69 0.00 0.06 0.00 0.00 0.00 0.00 0.00 0.25 16596.00 06:47:07 PM all 99.20 0.00 0.74 0.00 0.00 0.06 0.00 0.00 0.00 17838.61 06:47:08 PM all 100.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 16540.00 06:47:09 PM all 100.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 16575.00 06:47:10 PM all 100.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 16614.00 06:47:11 PM all 99.94 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.06 16588.00 06:47:12 PM all 99.94 0.00 0.06 0.00 0.00 0.00 0.00 0.00 0.00 16593.00 06:47:13 PM all 99.94 0.00 0.06 0.00 0.00 0.00 0.00 0.00 0.00 16551.00 Average: all 99.84 0.00 0.09 0.00 0.00 0.01 0.00 0.00 0.06 16711.58 We see an improvement in idle% on the system (drops from 5.42% on -tip to 0.06% with the patches). We see an improvement in idle% on the system (drops from 5.42% on -tip to 0.06% with the patches). Signed-off-by: Nikhil Rao <ncrao@google.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Nikunj A. Dadhania <nikunj@linux.vnet.ibm.com> Cc: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Cc: Stephan Barwolf <stephan.baerwolf@tu-ilmenau.de> Cc: Mike Galbraith <efault@gmx.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/1305754668-18792-1-git-send-email-ncrao@google.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-05-18 21:37:48 +00:00
unsigned long w = scale_load_down(lw->weight);
if (BITS_PER_LONG > 32 && unlikely(w >= WMULT_CONST))
sched: 64-bit: fix arithmetics overflow (overflow means weight >= 2^32 here, because inv_weigh = 2^32/weight) A weight of a cfs_rq is the sum of weights of which entities are queued on this cfs_rq, so it will overflow when there are too many entities. Although, overflow occurs very rarely, but it break fairness when it occurs. 64-bits systems have more memory than 32-bit systems and 64-bit systems can create more process usually, so overflow may occur more frequently. This patch guarantees fairness when overflow happens on 64-bit systems. Thanks to the optimization of compiler, it changes nothing on 32-bit. Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-12 08:43:07 +00:00
lw->inv_weight = 1;
sched: Increase SCHED_LOAD_SCALE resolution Introduce SCHED_LOAD_RESOLUTION, which scales is added to SCHED_LOAD_SHIFT and increases the resolution of SCHED_LOAD_SCALE. This patch sets the value of SCHED_LOAD_RESOLUTION to 10, scaling up the weights for all sched entities by a factor of 1024. With this extra resolution, we can handle deeper cgroup hiearchies and the scheduler can do better shares distribution and load load balancing on larger systems (especially for low weight task groups). This does not change the existing user interface, the scaled weights are only used internally. We do not modify prio_to_weight values or inverses, but use the original weights when calculating the inverse which is used to scale execution time delta in calc_delta_mine(). This ensures we do not lose accuracy when accounting time to the sched entities. Thanks to Nikunj Dadhania for fixing an bug in c_d_m() that broken fairness. Below is some analysis of the performance costs/improvements of this patch. 1. Micro-arch performance costs: Experiment was to run Ingo's pipe_test_100k 200 times with the task pinned to one cpu. I measured instruction, cycles and stalled-cycles for the runs. See: http://thread.gmane.org/gmane.linux.kernel/1129232/focus=1129389 for more info. -tip (baseline): Performance counter stats for '/root/load-scale/pipe-test-100k' (200 runs): 964,991,769 instructions # 0.82 insns per cycle # 0.33 stalled cycles per insn # ( +- 0.05% ) 1,171,186,635 cycles # 0.000 GHz ( +- 0.08% ) 306,373,664 stalled-cycles-backend # 26.16% backend cycles idle ( +- 0.28% ) 314,933,621 stalled-cycles-frontend # 26.89% frontend cycles idle ( +- 0.34% ) 1.122405684 seconds time elapsed ( +- 0.05% ) -tip+patches: Performance counter stats for './load-scale/pipe-test-100k' (200 runs): 963,624,821 instructions # 0.82 insns per cycle # 0.33 stalled cycles per insn # ( +- 0.04% ) 1,175,215,649 cycles # 0.000 GHz ( +- 0.08% ) 315,321,126 stalled-cycles-backend # 26.83% backend cycles idle ( +- 0.28% ) 316,835,873 stalled-cycles-frontend # 26.96% frontend cycles idle ( +- 0.29% ) 1.122238659 seconds time elapsed ( +- 0.06% ) With this patch, instructions decrease by ~0.10% and cycles increase by 0.27%. This doesn't look statistically significant. The number of stalled cycles in the backend increased from 26.16% to 26.83%. This can be attributed to the shifts we do in c_d_m() and other places. The fraction of stalled cycles in the frontend remains about the same, at 26.96% compared to 26.89% in -tip. 2. Balancing low-weight task groups Test setup: run 50 tasks with random sleep/busy times (biased around 100ms) in a low weight container (with cpu.shares = 2). Measure %idle as reported by mpstat over a 10s window. -tip (baseline): 06:47:48 PM CPU %usr %nice %sys %iowait %irq %soft %steal %guest %idle intr/s 06:47:49 PM all 94.32 0.00 0.06 0.00 0.00 0.00 0.00 0.00 5.62 15888.00 06:47:50 PM all 94.57 0.00 0.62 0.00 0.00 0.00 0.00 0.00 4.81 16180.00 06:47:51 PM all 94.69 0.00 0.06 0.00 0.00 0.00 0.00 0.00 5.25 15966.00 06:47:52 PM all 95.81 0.00 0.00 0.00 0.00 0.00 0.00 0.00 4.19 16053.00 06:47:53 PM all 94.88 0.06 0.00 0.00 0.00 0.00 0.00 0.00 5.06 15984.00 06:47:54 PM all 93.31 0.00 0.00 0.00 0.00 0.00 0.00 0.00 6.69 15806.00 06:47:55 PM all 94.19 0.00 0.06 0.00 0.00 0.00 0.00 0.00 5.75 15896.00 06:47:56 PM all 92.87 0.00 0.00 0.00 0.00 0.00 0.00 0.00 7.13 15716.00 06:47:57 PM all 94.88 0.00 0.00 0.00 0.00 0.00 0.00 0.00 5.12 15982.00 06:47:58 PM all 95.44 0.00 0.00 0.00 0.00 0.00 0.00 0.00 4.56 16075.00 Average: all 94.49 0.01 0.08 0.00 0.00 0.00 0.00 0.00 5.42 15954.60 -tip+patches: 06:47:03 PM CPU %usr %nice %sys %iowait %irq %soft %steal %guest %idle intr/s 06:47:04 PM all 100.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 16630.00 06:47:05 PM all 99.69 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.31 16580.20 06:47:06 PM all 99.69 0.00 0.06 0.00 0.00 0.00 0.00 0.00 0.25 16596.00 06:47:07 PM all 99.20 0.00 0.74 0.00 0.00 0.06 0.00 0.00 0.00 17838.61 06:47:08 PM all 100.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 16540.00 06:47:09 PM all 100.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 16575.00 06:47:10 PM all 100.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 16614.00 06:47:11 PM all 99.94 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.06 16588.00 06:47:12 PM all 99.94 0.00 0.06 0.00 0.00 0.00 0.00 0.00 0.00 16593.00 06:47:13 PM all 99.94 0.00 0.06 0.00 0.00 0.00 0.00 0.00 0.00 16551.00 Average: all 99.84 0.00 0.09 0.00 0.00 0.01 0.00 0.00 0.06 16711.58 We see an improvement in idle% on the system (drops from 5.42% on -tip to 0.06% with the patches). We see an improvement in idle% on the system (drops from 5.42% on -tip to 0.06% with the patches). Signed-off-by: Nikhil Rao <ncrao@google.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Nikunj A. Dadhania <nikunj@linux.vnet.ibm.com> Cc: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Cc: Stephan Barwolf <stephan.baerwolf@tu-ilmenau.de> Cc: Mike Galbraith <efault@gmx.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/1305754668-18792-1-git-send-email-ncrao@google.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-05-18 21:37:48 +00:00
else if (unlikely(!w))
lw->inv_weight = WMULT_CONST;
sched: 64-bit: fix arithmetics overflow (overflow means weight >= 2^32 here, because inv_weigh = 2^32/weight) A weight of a cfs_rq is the sum of weights of which entities are queued on this cfs_rq, so it will overflow when there are too many entities. Although, overflow occurs very rarely, but it break fairness when it occurs. 64-bits systems have more memory than 32-bit systems and 64-bit systems can create more process usually, so overflow may occur more frequently. This patch guarantees fairness when overflow happens on 64-bit systems. Thanks to the optimization of compiler, it changes nothing on 32-bit. Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-12 08:43:07 +00:00
else
sched: Increase SCHED_LOAD_SCALE resolution Introduce SCHED_LOAD_RESOLUTION, which scales is added to SCHED_LOAD_SHIFT and increases the resolution of SCHED_LOAD_SCALE. This patch sets the value of SCHED_LOAD_RESOLUTION to 10, scaling up the weights for all sched entities by a factor of 1024. With this extra resolution, we can handle deeper cgroup hiearchies and the scheduler can do better shares distribution and load load balancing on larger systems (especially for low weight task groups). This does not change the existing user interface, the scaled weights are only used internally. We do not modify prio_to_weight values or inverses, but use the original weights when calculating the inverse which is used to scale execution time delta in calc_delta_mine(). This ensures we do not lose accuracy when accounting time to the sched entities. Thanks to Nikunj Dadhania for fixing an bug in c_d_m() that broken fairness. Below is some analysis of the performance costs/improvements of this patch. 1. Micro-arch performance costs: Experiment was to run Ingo's pipe_test_100k 200 times with the task pinned to one cpu. I measured instruction, cycles and stalled-cycles for the runs. See: http://thread.gmane.org/gmane.linux.kernel/1129232/focus=1129389 for more info. -tip (baseline): Performance counter stats for '/root/load-scale/pipe-test-100k' (200 runs): 964,991,769 instructions # 0.82 insns per cycle # 0.33 stalled cycles per insn # ( +- 0.05% ) 1,171,186,635 cycles # 0.000 GHz ( +- 0.08% ) 306,373,664 stalled-cycles-backend # 26.16% backend cycles idle ( +- 0.28% ) 314,933,621 stalled-cycles-frontend # 26.89% frontend cycles idle ( +- 0.34% ) 1.122405684 seconds time elapsed ( +- 0.05% ) -tip+patches: Performance counter stats for './load-scale/pipe-test-100k' (200 runs): 963,624,821 instructions # 0.82 insns per cycle # 0.33 stalled cycles per insn # ( +- 0.04% ) 1,175,215,649 cycles # 0.000 GHz ( +- 0.08% ) 315,321,126 stalled-cycles-backend # 26.83% backend cycles idle ( +- 0.28% ) 316,835,873 stalled-cycles-frontend # 26.96% frontend cycles idle ( +- 0.29% ) 1.122238659 seconds time elapsed ( +- 0.06% ) With this patch, instructions decrease by ~0.10% and cycles increase by 0.27%. This doesn't look statistically significant. The number of stalled cycles in the backend increased from 26.16% to 26.83%. This can be attributed to the shifts we do in c_d_m() and other places. The fraction of stalled cycles in the frontend remains about the same, at 26.96% compared to 26.89% in -tip. 2. Balancing low-weight task groups Test setup: run 50 tasks with random sleep/busy times (biased around 100ms) in a low weight container (with cpu.shares = 2). Measure %idle as reported by mpstat over a 10s window. -tip (baseline): 06:47:48 PM CPU %usr %nice %sys %iowait %irq %soft %steal %guest %idle intr/s 06:47:49 PM all 94.32 0.00 0.06 0.00 0.00 0.00 0.00 0.00 5.62 15888.00 06:47:50 PM all 94.57 0.00 0.62 0.00 0.00 0.00 0.00 0.00 4.81 16180.00 06:47:51 PM all 94.69 0.00 0.06 0.00 0.00 0.00 0.00 0.00 5.25 15966.00 06:47:52 PM all 95.81 0.00 0.00 0.00 0.00 0.00 0.00 0.00 4.19 16053.00 06:47:53 PM all 94.88 0.06 0.00 0.00 0.00 0.00 0.00 0.00 5.06 15984.00 06:47:54 PM all 93.31 0.00 0.00 0.00 0.00 0.00 0.00 0.00 6.69 15806.00 06:47:55 PM all 94.19 0.00 0.06 0.00 0.00 0.00 0.00 0.00 5.75 15896.00 06:47:56 PM all 92.87 0.00 0.00 0.00 0.00 0.00 0.00 0.00 7.13 15716.00 06:47:57 PM all 94.88 0.00 0.00 0.00 0.00 0.00 0.00 0.00 5.12 15982.00 06:47:58 PM all 95.44 0.00 0.00 0.00 0.00 0.00 0.00 0.00 4.56 16075.00 Average: all 94.49 0.01 0.08 0.00 0.00 0.00 0.00 0.00 5.42 15954.60 -tip+patches: 06:47:03 PM CPU %usr %nice %sys %iowait %irq %soft %steal %guest %idle intr/s 06:47:04 PM all 100.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 16630.00 06:47:05 PM all 99.69 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.31 16580.20 06:47:06 PM all 99.69 0.00 0.06 0.00 0.00 0.00 0.00 0.00 0.25 16596.00 06:47:07 PM all 99.20 0.00 0.74 0.00 0.00 0.06 0.00 0.00 0.00 17838.61 06:47:08 PM all 100.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 16540.00 06:47:09 PM all 100.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 16575.00 06:47:10 PM all 100.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 16614.00 06:47:11 PM all 99.94 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.06 16588.00 06:47:12 PM all 99.94 0.00 0.06 0.00 0.00 0.00 0.00 0.00 0.00 16593.00 06:47:13 PM all 99.94 0.00 0.06 0.00 0.00 0.00 0.00 0.00 0.00 16551.00 Average: all 99.84 0.00 0.09 0.00 0.00 0.01 0.00 0.00 0.06 16711.58 We see an improvement in idle% on the system (drops from 5.42% on -tip to 0.06% with the patches). We see an improvement in idle% on the system (drops from 5.42% on -tip to 0.06% with the patches). Signed-off-by: Nikhil Rao <ncrao@google.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Nikunj A. Dadhania <nikunj@linux.vnet.ibm.com> Cc: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Cc: Stephan Barwolf <stephan.baerwolf@tu-ilmenau.de> Cc: Mike Galbraith <efault@gmx.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/1305754668-18792-1-git-send-email-ncrao@google.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-05-18 21:37:48 +00:00
lw->inv_weight = WMULT_CONST / w;
sched: 64-bit: fix arithmetics overflow (overflow means weight >= 2^32 here, because inv_weigh = 2^32/weight) A weight of a cfs_rq is the sum of weights of which entities are queued on this cfs_rq, so it will overflow when there are too many entities. Although, overflow occurs very rarely, but it break fairness when it occurs. 64-bits systems have more memory than 32-bit systems and 64-bit systems can create more process usually, so overflow may occur more frequently. This patch guarantees fairness when overflow happens on 64-bit systems. Thanks to the optimization of compiler, it changes nothing on 32-bit. Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-12 08:43:07 +00:00
}
sched: cfs, add load-calculation methods add the new load-calculation methods of CFS. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-09 16:51:59 +00:00
/*
* Check whether we'd overflow the 64-bit multiplication:
*/
sched: round a bit better round a tiny bit better in high-frequency rescheduling scenarios, by rounding around zero instead of rounding down. (this is pretty theoretical though) Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-08-09 09:16:51 +00:00
if (unlikely(tmp > WMULT_CONST))
sched: fix xtensa build warning rename RSR to SRR - 'RSR' is already defined on xtensa. found by Adrian Bunk. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-09-05 12:32:49 +00:00
tmp = SRR(SRR(tmp, WMULT_SHIFT/2) * lw->inv_weight,
sched: round a bit better round a tiny bit better in high-frequency rescheduling scenarios, by rounding around zero instead of rounding down. (this is pretty theoretical though) Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-08-09 09:16:51 +00:00
WMULT_SHIFT/2);
else
sched: fix xtensa build warning rename RSR to SRR - 'RSR' is already defined on xtensa. found by Adrian Bunk. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-09-05 12:32:49 +00:00
tmp = SRR(tmp * lw->inv_weight, WMULT_SHIFT);
sched: cfs, add load-calculation methods add the new load-calculation methods of CFS. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-09 16:51:59 +00:00
[PATCH] sched: calc_delta_mine(): use fixed limit use fixed limit in calc_delta_mine() - this saves an instruction :) Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-08-02 15:41:40 +00:00
return (unsigned long)min(tmp, (u64)(unsigned long)LONG_MAX);
sched: cfs, add load-calculation methods add the new load-calculation methods of CFS. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-09 16:51:59 +00:00
}
sched: speed up update_load_add/_sub() speed up update_load_add/_sub() by not delaying the division - this reduces CPU pipeline dependencies. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Mike Galbraith <efault@gmx.de> Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-15 15:00:04 +00:00
static inline void update_load_add(struct load_weight *lw, unsigned long inc)
sched: cfs, add load-calculation methods add the new load-calculation methods of CFS. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-09 16:51:59 +00:00
{
lw->weight += inc;
sched: fix update_load_add()/sub() Clear the cached inverse value when updating load. This is needed for calc_delta_mine() to work correctly when using the rq load. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
2008-03-14 22:48:28 +00:00
lw->inv_weight = 0;
sched: cfs, add load-calculation methods add the new load-calculation methods of CFS. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-09 16:51:59 +00:00
}
sched: speed up update_load_add/_sub() speed up update_load_add/_sub() by not delaying the division - this reduces CPU pipeline dependencies. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Mike Galbraith <efault@gmx.de> Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-15 15:00:04 +00:00
static inline void update_load_sub(struct load_weight *lw, unsigned long dec)
sched: cfs, add load-calculation methods add the new load-calculation methods of CFS. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-09 16:51:59 +00:00
{
lw->weight -= dec;
sched: fix update_load_add()/sub() Clear the cached inverse value when updating load. This is needed for calc_delta_mine() to work correctly when using the rq load. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
2008-03-14 22:48:28 +00:00
lw->inv_weight = 0;
sched: cfs, add load-calculation methods add the new load-calculation methods of CFS. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-09 16:51:59 +00:00
}
sched: Rewrite tg_shares_up) By tracking a per-cpu load-avg for each cfs_rq and folding it into a global task_group load on each tick we can rework tg_shares_up to be strictly per-cpu. This should improve cpu-cgroup performance for smp systems significantly. [ Paul: changed to use queueing cfs_rq + bug fixes ] Signed-off-by: Paul Turner <pjt@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20101115234937.580480400@google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-15 23:47:00 +00:00
static inline void update_load_set(struct load_weight *lw, unsigned long w)
{
lw->weight = w;
lw->inv_weight = 0;
}
[PATCH] sched: implement smpnice Problem: The introduction of separate run queues per CPU has brought with it "nice" enforcement problems that are best described by a simple example. For the sake of argument suppose that on a single CPU machine with a nice==19 hard spinner and a nice==0 hard spinner running that the nice==0 task gets 95% of the CPU and the nice==19 task gets 5% of the CPU. Now suppose that there is a system with 2 CPUs and 2 nice==19 hard spinners and 2 nice==0 hard spinners running. The user of this system would be entitled to expect that the nice==0 tasks each get 95% of a CPU and the nice==19 tasks only get 5% each. However, whether this expectation is met is pretty much down to luck as there are four equally likely distributions of the tasks to the CPUs that the load balancing code will consider to be balanced with loads of 2.0 for each CPU. Two of these distributions involve one nice==0 and one nice==19 task per CPU and in these circumstances the users expectations will be met. The other two distributions both involve both nice==0 tasks being on one CPU and both nice==19 being on the other CPU and each task will get 50% of a CPU and the user's expectations will not be met. Solution: The solution to this problem that is implemented in the attached patch is to use weighted loads when determining if the system is balanced and, when an imbalance is detected, to move an amount of weighted load between run queues (as opposed to a number of tasks) to restore the balance. Once again, the easiest way to explain why both of these measures are necessary is to use a simple example. Suppose that (in a slight variation of the above example) that we have a two CPU system with 4 nice==0 and 4 nice=19 hard spinning tasks running and that the 4 nice==0 tasks are on one CPU and the 4 nice==19 tasks are on the other CPU. The weighted loads for the two CPUs would be 4.0 and 0.2 respectively and the load balancing code would move 2 tasks resulting in one CPU with a load of 2.0 and the other with load of 2.2. If this was considered to be a big enough imbalance to justify moving a task and that task was moved using the current move_tasks() then it would move the highest priority task that it found and this would result in one CPU with a load of 3.0 and the other with a load of 1.2 which would result in the movement of a task in the opposite direction and so on -- infinite loop. If, on the other hand, an amount of load to be moved is calculated from the imbalance (in this case 0.1) and move_tasks() skips tasks until it find ones whose contributions to the weighted load are less than this amount it would move two of the nice==19 tasks resulting in a system with 2 nice==0 and 2 nice=19 on each CPU with loads of 2.1 for each CPU. One of the advantages of this mechanism is that on a system where all tasks have nice==0 the load balancing calculations would be mathematically identical to the current load balancing code. Notes: struct task_struct: has a new field load_weight which (in a trade off of space for speed) stores the contribution that this task makes to a CPU's weighted load when it is runnable. struct runqueue: has a new field raw_weighted_load which is the sum of the load_weight values for the currently runnable tasks on this run queue. This field always needs to be updated when nr_running is updated so two new inline functions inc_nr_running() and dec_nr_running() have been created to make sure that this happens. This also offers a convenient way to optimize away this part of the smpnice mechanism when CONFIG_SMP is not defined. int try_to_wake_up(): in this function the value SCHED_LOAD_BALANCE is used to represent the load contribution of a single task in various calculations in the code that decides which CPU to put the waking task on. While this would be a valid on a system where the nice values for the runnable tasks were distributed evenly around zero it will lead to anomalous load balancing if the distribution is skewed in either direction. To overcome this problem SCHED_LOAD_SCALE has been replaced by the load_weight for the relevant task or by the average load_weight per task for the queue in question (as appropriate). int move_tasks(): The modifications to this function were complicated by the fact that active_load_balance() uses it to move exactly one task without checking whether an imbalance actually exists. This precluded the simple overloading of max_nr_move with max_load_move and necessitated the addition of the latter as an extra argument to the function. The internal implementation is then modified to move up to max_nr_move tasks and max_load_move of weighted load. This slightly complicates the code where move_tasks() is called and if ever active_load_balance() is changed to not use move_tasks() the implementation of move_tasks() should be simplified accordingly. struct sched_group *find_busiest_group(): Similar to try_to_wake_up(), there are places in this function where SCHED_LOAD_SCALE is used to represent the load contribution of a single task and the same issues are created. A similar solution is adopted except that it is now the average per task contribution to a group's load (as opposed to a run queue) that is required. As this value is not directly available from the group it is calculated on the fly as the queues in the groups are visited when determining the busiest group. A key change to this function is that it is no longer to scale down *imbalance on exit as move_tasks() uses the load in its scaled form. void set_user_nice(): has been modified to update the task's load_weight field when it's nice value and also to ensure that its run queue's raw_weighted_load field is updated if it was runnable. From: "Siddha, Suresh B" <suresh.b.siddha@intel.com> With smpnice, sched groups with highest priority tasks can mask the imbalance between the other sched groups with in the same domain. This patch fixes some of the listed down scenarios by not considering the sched groups which are lightly loaded. a) on a simple 4-way MP system, if we have one high priority and 4 normal priority tasks, with smpnice we would like to see the high priority task scheduled on one cpu, two other cpus getting one normal task each and the fourth cpu getting the remaining two normal tasks. but with current smpnice extra normal priority task keeps jumping from one cpu to another cpu having the normal priority task. This is because of the busiest_has_loaded_cpus, nr_loaded_cpus logic.. We are not including the cpu with high priority task in max_load calculations but including that in total and avg_load calcuations.. leading to max_load < avg_load and load balance between cpus running normal priority tasks(2 Vs 1) will always show imbalanace as one normal priority and the extra normal priority task will keep moving from one cpu to another cpu having normal priority task.. b) 4-way system with HT (8 logical processors). Package-P0 T0 has a highest priority task, T1 is idle. Package-P1 Both T0 and T1 have 1 normal priority task each.. P2 and P3 are idle. With this patch, one of the normal priority tasks on P1 will be moved to P2 or P3.. c) With the current weighted smp nice calculations, it doesn't always make sense to look at the highest weighted runqueue in the busy group.. Consider a load balance scenario on a DP with HT system, with Package-0 containing one high priority and one low priority, Package-1 containing one low priority(with other thread being idle).. Package-1 thinks that it need to take the low priority thread from Package-0. And find_busiest_queue() returns the cpu thread with highest priority task.. And ultimately(with help of active load balance) we move high priority task to Package-1. And same continues with Package-0 now, moving high priority task from package-1 to package-0.. Even without the presence of active load balance, load balance will fail to balance the above scenario.. Fix find_busiest_queue to use "imbalance" when it is lightly loaded. [kernel@kolivas.org: sched: store weighted load on up] [kernel@kolivas.org: sched: add discrete weighted cpu load function] [suresh.b.siddha@intel.com: sched: remove dead code] Signed-off-by: Peter Williams <pwil3058@bigpond.com.au> Cc: "Siddha, Suresh B" <suresh.b.siddha@intel.com> Cc: "Chen, Kenneth W" <kenneth.w.chen@intel.com> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Con Kolivas <kernel@kolivas.org> Cc: John Hawkes <hawkes@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 09:54:34 +00:00
/*
* To aid in avoiding the subversion of "niceness" due to uneven distribution
* of tasks with abnormal "nice" values across CPUs the contribution that
* each task makes to its run queue's load is weighted according to its
sched: style cleanups style cleanup of various changes that were done recently. no code changed: text data bss dec hex filename 23680 2542 28 26250 668a sched.o.before 23680 2542 28 26250 668a sched.o.after Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-12-05 14:46:09 +00:00
* scheduling class and "nice" value. For SCHED_NORMAL tasks this is just a
[PATCH] sched: implement smpnice Problem: The introduction of separate run queues per CPU has brought with it "nice" enforcement problems that are best described by a simple example. For the sake of argument suppose that on a single CPU machine with a nice==19 hard spinner and a nice==0 hard spinner running that the nice==0 task gets 95% of the CPU and the nice==19 task gets 5% of the CPU. Now suppose that there is a system with 2 CPUs and 2 nice==19 hard spinners and 2 nice==0 hard spinners running. The user of this system would be entitled to expect that the nice==0 tasks each get 95% of a CPU and the nice==19 tasks only get 5% each. However, whether this expectation is met is pretty much down to luck as there are four equally likely distributions of the tasks to the CPUs that the load balancing code will consider to be balanced with loads of 2.0 for each CPU. Two of these distributions involve one nice==0 and one nice==19 task per CPU and in these circumstances the users expectations will be met. The other two distributions both involve both nice==0 tasks being on one CPU and both nice==19 being on the other CPU and each task will get 50% of a CPU and the user's expectations will not be met. Solution: The solution to this problem that is implemented in the attached patch is to use weighted loads when determining if the system is balanced and, when an imbalance is detected, to move an amount of weighted load between run queues (as opposed to a number of tasks) to restore the balance. Once again, the easiest way to explain why both of these measures are necessary is to use a simple example. Suppose that (in a slight variation of the above example) that we have a two CPU system with 4 nice==0 and 4 nice=19 hard spinning tasks running and that the 4 nice==0 tasks are on one CPU and the 4 nice==19 tasks are on the other CPU. The weighted loads for the two CPUs would be 4.0 and 0.2 respectively and the load balancing code would move 2 tasks resulting in one CPU with a load of 2.0 and the other with load of 2.2. If this was considered to be a big enough imbalance to justify moving a task and that task was moved using the current move_tasks() then it would move the highest priority task that it found and this would result in one CPU with a load of 3.0 and the other with a load of 1.2 which would result in the movement of a task in the opposite direction and so on -- infinite loop. If, on the other hand, an amount of load to be moved is calculated from the imbalance (in this case 0.1) and move_tasks() skips tasks until it find ones whose contributions to the weighted load are less than this amount it would move two of the nice==19 tasks resulting in a system with 2 nice==0 and 2 nice=19 on each CPU with loads of 2.1 for each CPU. One of the advantages of this mechanism is that on a system where all tasks have nice==0 the load balancing calculations would be mathematically identical to the current load balancing code. Notes: struct task_struct: has a new field load_weight which (in a trade off of space for speed) stores the contribution that this task makes to a CPU's weighted load when it is runnable. struct runqueue: has a new field raw_weighted_load which is the sum of the load_weight values for the currently runnable tasks on this run queue. This field always needs to be updated when nr_running is updated so two new inline functions inc_nr_running() and dec_nr_running() have been created to make sure that this happens. This also offers a convenient way to optimize away this part of the smpnice mechanism when CONFIG_SMP is not defined. int try_to_wake_up(): in this function the value SCHED_LOAD_BALANCE is used to represent the load contribution of a single task in various calculations in the code that decides which CPU to put the waking task on. While this would be a valid on a system where the nice values for the runnable tasks were distributed evenly around zero it will lead to anomalous load balancing if the distribution is skewed in either direction. To overcome this problem SCHED_LOAD_SCALE has been replaced by the load_weight for the relevant task or by the average load_weight per task for the queue in question (as appropriate). int move_tasks(): The modifications to this function were complicated by the fact that active_load_balance() uses it to move exactly one task without checking whether an imbalance actually exists. This precluded the simple overloading of max_nr_move with max_load_move and necessitated the addition of the latter as an extra argument to the function. The internal implementation is then modified to move up to max_nr_move tasks and max_load_move of weighted load. This slightly complicates the code where move_tasks() is called and if ever active_load_balance() is changed to not use move_tasks() the implementation of move_tasks() should be simplified accordingly. struct sched_group *find_busiest_group(): Similar to try_to_wake_up(), there are places in this function where SCHED_LOAD_SCALE is used to represent the load contribution of a single task and the same issues are created. A similar solution is adopted except that it is now the average per task contribution to a group's load (as opposed to a run queue) that is required. As this value is not directly available from the group it is calculated on the fly as the queues in the groups are visited when determining the busiest group. A key change to this function is that it is no longer to scale down *imbalance on exit as move_tasks() uses the load in its scaled form. void set_user_nice(): has been modified to update the task's load_weight field when it's nice value and also to ensure that its run queue's raw_weighted_load field is updated if it was runnable. From: "Siddha, Suresh B" <suresh.b.siddha@intel.com> With smpnice, sched groups with highest priority tasks can mask the imbalance between the other sched groups with in the same domain. This patch fixes some of the listed down scenarios by not considering the sched groups which are lightly loaded. a) on a simple 4-way MP system, if we have one high priority and 4 normal priority tasks, with smpnice we would like to see the high priority task scheduled on one cpu, two other cpus getting one normal task each and the fourth cpu getting the remaining two normal tasks. but with current smpnice extra normal priority task keeps jumping from one cpu to another cpu having the normal priority task. This is because of the busiest_has_loaded_cpus, nr_loaded_cpus logic.. We are not including the cpu with high priority task in max_load calculations but including that in total and avg_load calcuations.. leading to max_load < avg_load and load balance between cpus running normal priority tasks(2 Vs 1) will always show imbalanace as one normal priority and the extra normal priority task will keep moving from one cpu to another cpu having normal priority task.. b) 4-way system with HT (8 logical processors). Package-P0 T0 has a highest priority task, T1 is idle. Package-P1 Both T0 and T1 have 1 normal priority task each.. P2 and P3 are idle. With this patch, one of the normal priority tasks on P1 will be moved to P2 or P3.. c) With the current weighted smp nice calculations, it doesn't always make sense to look at the highest weighted runqueue in the busy group.. Consider a load balance scenario on a DP with HT system, with Package-0 containing one high priority and one low priority, Package-1 containing one low priority(with other thread being idle).. Package-1 thinks that it need to take the low priority thread from Package-0. And find_busiest_queue() returns the cpu thread with highest priority task.. And ultimately(with help of active load balance) we move high priority task to Package-1. And same continues with Package-0 now, moving high priority task from package-1 to package-0.. Even without the presence of active load balance, load balance will fail to balance the above scenario.. Fix find_busiest_queue to use "imbalance" when it is lightly loaded. [kernel@kolivas.org: sched: store weighted load on up] [kernel@kolivas.org: sched: add discrete weighted cpu load function] [suresh.b.siddha@intel.com: sched: remove dead code] Signed-off-by: Peter Williams <pwil3058@bigpond.com.au> Cc: "Siddha, Suresh B" <suresh.b.siddha@intel.com> Cc: "Chen, Kenneth W" <kenneth.w.chen@intel.com> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Con Kolivas <kernel@kolivas.org> Cc: John Hawkes <hawkes@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 09:54:34 +00:00
* scaled version of the new time slice allocation that they receive on time
* slice expiry etc.
*/
sched: SCHED_IDLE weight change Increase the SCHED_IDLE weight from 2 to 3, this gives much more stable vruntime numbers. time advanced in 100ms: weight=2 64765.988352 67012.881408 88501.412352 weight=3 35496.181411 34130.971298 35497.411573 Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-15 13:53:37 +00:00
#define WEIGHT_IDLEPRIO 3
#define WMULT_IDLEPRIO 1431655765
sched: cfs core code apply the CFS core code. this change switches over the scheduler core to CFS's modular design and makes use of kernel/sched_fair/rt/idletask.c to implement Linux's scheduling policies. thanks to Andrew Morton and Thomas Gleixner for lots of detailed review feedback and for fixlets. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
2007-07-09 16:51:59 +00:00
/*
* Nice levels are multiplicative, with a gentle 10% change for every
* nice level changed. I.e. when a CPU-bound task goes from nice 0 to
* nice 1, it will get ~10% less CPU time than another CPU-bound task
* that remained on nice 0.
*
* The "10% effect" is relative and cumulative: from _any_ nice level,
* if you go up 1 level, it's -10% CPU usage, if you go down 1 level
[PATCH] sched: improve weight-array comments improve the comments around the wmult array (which controls the weight of niced tasks). Clarify that to achieve a 10% difference in CPU utilization, a weight multiplier of 1.25 has to be used. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-16 07:46:30 +00:00
* it's +10% CPU usage. (to achieve that we use a multiplier of 1.25.
* If a task goes up by ~10% and another task goes down by ~10% then
* the relative distance between them is ~25%.)
sched: cfs core code apply the CFS core code. this change switches over the scheduler core to CFS's modular design and makes use of kernel/sched_fair/rt/idletask.c to implement Linux's scheduling policies. thanks to Andrew Morton and Thomas Gleixner for lots of detailed review feedback and for fixlets. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
2007-07-09 16:51:59 +00:00
*/
static const int prio_to_weight[40] = {
sched: make the multiplication table more accurate do small deltas in the weight and multiplication constant table so that the worst-case numeric error is better than 1:100000000. (8 digits) the current error table is: nice mult * inv_mult error ------------------------------------------ -20: 88761 * 48388 -0.0000000065 -19: 71755 * 59856 -0.0000000037 -18: 56483 * 76040 0.0000000056 -17: 46273 * 92818 0.0000000042 -16: 36291 * 118348 -0.0000000065 -15: 29154 * 147320 -0.0000000037 -14: 23254 * 184698 -0.0000000009 -13: 18705 * 229616 -0.0000000037 -12: 14949 * 287308 -0.0000000009 -11: 11916 * 360437 -0.0000000009 -10: 9548 * 449829 -0.0000000009 -9: 7620 * 563644 -0.0000000037 -8: 6100 * 704093 0.0000000009 -7: 4904 * 875809 0.0000000093 -6: 3906 * 1099582 -0.0000000009 -5: 3121 * 1376151 -0.0000000058 -4: 2501 * 1717300 0.0000000009 -3: 1991 * 2157191 -0.0000000035 -2: 1586 * 2708050 0.0000000009 -1: 1277 * 3363326 0.0000000014 0: 1024 * 4194304 0.0000000000 1: 820 * 5237765 0.0000000009 2: 655 * 6557202 0.0000000033 3: 526 * 8165337 -0.0000000079 4: 423 * 10153587 0.0000000012 5: 335 * 12820798 0.0000000079 6: 272 * 15790321 0.0000000037 7: 215 * 19976592 -0.0000000037 8: 172 * 24970740 -0.0000000037 9: 137 * 31350126 -0.0000000079 10: 110 * 39045157 -0.0000000061 11: 87 * 49367440 -0.0000000037 12: 70 * 61356676 0.0000000056 13: 56 * 76695844 -0.0000000075 14: 45 * 95443717 -0.0000000072 15: 36 * 119304647 -0.0000000009 16: 29 * 148102320 -0.0000000037 17: 23 * 186737708 -0.0000000028 18: 18 * 238609294 -0.0000000009 19: 15 * 286331153 -0.0000000002 Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-08-09 09:16:51 +00:00
/* -20 */ 88761, 71755, 56483, 46273, 36291,
/* -15 */ 29154, 23254, 18705, 14949, 11916,
/* -10 */ 9548, 7620, 6100, 4904, 3906,
/* -5 */ 3121, 2501, 1991, 1586, 1277,
/* 0 */ 1024, 820, 655, 526, 423,
/* 5 */ 335, 272, 215, 172, 137,
/* 10 */ 110, 87, 70, 56, 45,
/* 15 */ 36, 29, 23, 18, 15,
sched: cfs core code apply the CFS core code. this change switches over the scheduler core to CFS's modular design and makes use of kernel/sched_fair/rt/idletask.c to implement Linux's scheduling policies. thanks to Andrew Morton and Thomas Gleixner for lots of detailed review feedback and for fixlets. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
2007-07-09 16:51:59 +00:00
};
[PATCH] sched: document prio_to_wmult[] document prio_to_wmult[]. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-16 07:46:31 +00:00
/*
* Inverse (2^32/x) values of the prio_to_weight[] array, precalculated.
*
* In cases where the weight does not change often, we can use the
* precalculated inverse to speed up arithmetics by turning divisions
* into multiplications:
*/
sched: cfs core code apply the CFS core code. this change switches over the scheduler core to CFS's modular design and makes use of kernel/sched_fair/rt/idletask.c to implement Linux's scheduling policies. thanks to Andrew Morton and Thomas Gleixner for lots of detailed review feedback and for fixlets. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
2007-07-09 16:51:59 +00:00
static const u32 prio_to_wmult[40] = {
sched: make the multiplication table more accurate do small deltas in the weight and multiplication constant table so that the worst-case numeric error is better than 1:100000000. (8 digits) the current error table is: nice mult * inv_mult error ------------------------------------------ -20: 88761 * 48388 -0.0000000065 -19: 71755 * 59856 -0.0000000037 -18: 56483 * 76040 0.0000000056 -17: 46273 * 92818 0.0000000042 -16: 36291 * 118348 -0.0000000065 -15: 29154 * 147320 -0.0000000037 -14: 23254 * 184698 -0.0000000009 -13: 18705 * 229616 -0.0000000037 -12: 14949 * 287308 -0.0000000009 -11: 11916 * 360437 -0.0000000009 -10: 9548 * 449829 -0.0000000009 -9: 7620 * 563644 -0.0000000037 -8: 6100 * 704093 0.0000000009 -7: 4904 * 875809 0.0000000093 -6: 3906 * 1099582 -0.0000000009 -5: 3121 * 1376151 -0.0000000058 -4: 2501 * 1717300 0.0000000009 -3: 1991 * 2157191 -0.0000000035 -2: 1586 * 2708050 0.0000000009 -1: 1277 * 3363326 0.0000000014 0: 1024 * 4194304 0.0000000000 1: 820 * 5237765 0.0000000009 2: 655 * 6557202 0.0000000033 3: 526 * 8165337 -0.0000000079 4: 423 * 10153587 0.0000000012 5: 335 * 12820798 0.0000000079 6: 272 * 15790321 0.0000000037 7: 215 * 19976592 -0.0000000037 8: 172 * 24970740 -0.0000000037 9: 137 * 31350126 -0.0000000079 10: 110 * 39045157 -0.0000000061 11: 87 * 49367440 -0.0000000037 12: 70 * 61356676 0.0000000056 13: 56 * 76695844 -0.0000000075 14: 45 * 95443717 -0.0000000072 15: 36 * 119304647 -0.0000000009 16: 29 * 148102320 -0.0000000037 17: 23 * 186737708 -0.0000000028 18: 18 * 238609294 -0.0000000009 19: 15 * 286331153 -0.0000000002 Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-08-09 09:16:51 +00:00
/* -20 */ 48388, 59856, 76040, 92818, 118348,
/* -15 */ 147320, 184698, 229616, 287308, 360437,
/* -10 */ 449829, 563644, 704093, 875809, 1099582,
/* -5 */ 1376151, 1717300, 2157191, 2708050, 3363326,
/* 0 */ 4194304, 5237765, 6557202, 8165337, 10153587,
/* 5 */ 12820798, 15790321, 19976592, 24970740, 31350126,
/* 10 */ 39045157, 49367440, 61356676, 76695844, 95443717,
/* 15 */ 119304647, 148102320, 186737708, 238609294, 286331153,
sched: cfs core code apply the CFS core code. this change switches over the scheduler core to CFS's modular design and makes use of kernel/sched_fair/rt/idletask.c to implement Linux's scheduling policies. thanks to Andrew Morton and Thomas Gleixner for lots of detailed review feedback and for fixlets. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
2007-07-09 16:51:59 +00:00
};
[PATCH] sched: implement smpnice Problem: The introduction of separate run queues per CPU has brought with it "nice" enforcement problems that are best described by a simple example. For the sake of argument suppose that on a single CPU machine with a nice==19 hard spinner and a nice==0 hard spinner running that the nice==0 task gets 95% of the CPU and the nice==19 task gets 5% of the CPU. Now suppose that there is a system with 2 CPUs and 2 nice==19 hard spinners and 2 nice==0 hard spinners running. The user of this system would be entitled to expect that the nice==0 tasks each get 95% of a CPU and the nice==19 tasks only get 5% each. However, whether this expectation is met is pretty much down to luck as there are four equally likely distributions of the tasks to the CPUs that the load balancing code will consider to be balanced with loads of 2.0 for each CPU. Two of these distributions involve one nice==0 and one nice==19 task per CPU and in these circumstances the users expectations will be met. The other two distributions both involve both nice==0 tasks being on one CPU and both nice==19 being on the other CPU and each task will get 50% of a CPU and the user's expectations will not be met. Solution: The solution to this problem that is implemented in the attached patch is to use weighted loads when determining if the system is balanced and, when an imbalance is detected, to move an amount of weighted load between run queues (as opposed to a number of tasks) to restore the balance. Once again, the easiest way to explain why both of these measures are necessary is to use a simple example. Suppose that (in a slight variation of the above example) that we have a two CPU system with 4 nice==0 and 4 nice=19 hard spinning tasks running and that the 4 nice==0 tasks are on one CPU and the 4 nice==19 tasks are on the other CPU. The weighted loads for the two CPUs would be 4.0 and 0.2 respectively and the load balancing code would move 2 tasks resulting in one CPU with a load of 2.0 and the other with load of 2.2. If this was considered to be a big enough imbalance to justify moving a task and that task was moved using the current move_tasks() then it would move the highest priority task that it found and this would result in one CPU with a load of 3.0 and the other with a load of 1.2 which would result in the movement of a task in the opposite direction and so on -- infinite loop. If, on the other hand, an amount of load to be moved is calculated from the imbalance (in this case 0.1) and move_tasks() skips tasks until it find ones whose contributions to the weighted load are less than this amount it would move two of the nice==19 tasks resulting in a system with 2 nice==0 and 2 nice=19 on each CPU with loads of 2.1 for each CPU. One of the advantages of this mechanism is that on a system where all tasks have nice==0 the load balancing calculations would be mathematically identical to the current load balancing code. Notes: struct task_struct: has a new field load_weight which (in a trade off of space for speed) stores the contribution that this task makes to a CPU's weighted load when it is runnable. struct runqueue: has a new field raw_weighted_load which is the sum of the load_weight values for the currently runnable tasks on this run queue. This field always needs to be updated when nr_running is updated so two new inline functions inc_nr_running() and dec_nr_running() have been created to make sure that this happens. This also offers a convenient way to optimize away this part of the smpnice mechanism when CONFIG_SMP is not defined. int try_to_wake_up(): in this function the value SCHED_LOAD_BALANCE is used to represent the load contribution of a single task in various calculations in the code that decides which CPU to put the waking task on. While this would be a valid on a system where the nice values for the runnable tasks were distributed evenly around zero it will lead to anomalous load balancing if the distribution is skewed in either direction. To overcome this problem SCHED_LOAD_SCALE has been replaced by the load_weight for the relevant task or by the average load_weight per task for the queue in question (as appropriate). int move_tasks(): The modifications to this function were complicated by the fact that active_load_balance() uses it to move exactly one task without checking whether an imbalance actually exists. This precluded the simple overloading of max_nr_move with max_load_move and necessitated the addition of the latter as an extra argument to the function. The internal implementation is then modified to move up to max_nr_move tasks and max_load_move of weighted load. This slightly complicates the code where move_tasks() is called and if ever active_load_balance() is changed to not use move_tasks() the implementation of move_tasks() should be simplified accordingly. struct sched_group *find_busiest_group(): Similar to try_to_wake_up(), there are places in this function where SCHED_LOAD_SCALE is used to represent the load contribution of a single task and the same issues are created. A similar solution is adopted except that it is now the average per task contribution to a group's load (as opposed to a run queue) that is required. As this value is not directly available from the group it is calculated on the fly as the queues in the groups are visited when determining the busiest group. A key change to this function is that it is no longer to scale down *imbalance on exit as move_tasks() uses the load in its scaled form. void set_user_nice(): has been modified to update the task's load_weight field when it's nice value and also to ensure that its run queue's raw_weighted_load field is updated if it was runnable. From: "Siddha, Suresh B" <suresh.b.siddha@intel.com> With smpnice, sched groups with highest priority tasks can mask the imbalance between the other sched groups with in the same domain. This patch fixes some of the listed down scenarios by not considering the sched groups which are lightly loaded. a) on a simple 4-way MP system, if we have one high priority and 4 normal priority tasks, with smpnice we would like to see the high priority task scheduled on one cpu, two other cpus getting one normal task each and the fourth cpu getting the remaining two normal tasks. but with current smpnice extra normal priority task keeps jumping from one cpu to another cpu having the normal priority task. This is because of the busiest_has_loaded_cpus, nr_loaded_cpus logic.. We are not including the cpu with high priority task in max_load calculations but including that in total and avg_load calcuations.. leading to max_load < avg_load and load balance between cpus running normal priority tasks(2 Vs 1) will always show imbalanace as one normal priority and the extra normal priority task will keep moving from one cpu to another cpu having normal priority task.. b) 4-way system with HT (8 logical processors). Package-P0 T0 has a highest priority task, T1 is idle. Package-P1 Both T0 and T1 have 1 normal priority task each.. P2 and P3 are idle. With this patch, one of the normal priority tasks on P1 will be moved to P2 or P3.. c) With the current weighted smp nice calculations, it doesn't always make sense to look at the highest weighted runqueue in the busy group.. Consider a load balance scenario on a DP with HT system, with Package-0 containing one high priority and one low priority, Package-1 containing one low priority(with other thread being idle).. Package-1 thinks that it need to take the low priority thread from Package-0. And find_busiest_queue() returns the cpu thread with highest priority task.. And ultimately(with help of active load balance) we move high priority task to Package-1. And same continues with Package-0 now, moving high priority task from package-1 to package-0.. Even without the presence of active load balance, load balance will fail to balance the above scenario.. Fix find_busiest_queue to use "imbalance" when it is lightly loaded. [kernel@kolivas.org: sched: store weighted load on up] [kernel@kolivas.org: sched: add discrete weighted cpu load function] [suresh.b.siddha@intel.com: sched: remove dead code] Signed-off-by: Peter Williams <pwil3058@bigpond.com.au> Cc: "Siddha, Suresh B" <suresh.b.siddha@intel.com> Cc: "Chen, Kenneth W" <kenneth.w.chen@intel.com> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Con Kolivas <kernel@kolivas.org> Cc: John Hawkes <hawkes@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 09:54:34 +00:00
cpuacct: add per-cgroup utime/stime statistics Add per-cgroup cpuacct controller statistics like the system and user time consumed by the group of tasks. Changelog: v7 - Changed the name of the statistic from utime to user and from stime to system so that in future we could easily add other statistics like irq, softirq, steal times etc easily. v6 - Fixed a bug in the error path of cpuacct_create() (pointed by Li Zefan). v5 - In cpuacct_stats_show(), use cputime64_to_clock_t() since we are operating on a 64bit variable here. v4 - Remove comments in cpuacct_update_stats() which explained why rcu_read_lock() was needed (as per Peter Zijlstra's review comments). - Don't say that percpu_counter_read() is broken in Documentation/cpuacct.txt as per KAMEZAWA Hiroyuki's review comments. v3 - Fix a small race in the cpuacct hierarchy walk. v2 - stime and utime now exported in clock_t units instead of msecs. - Addressed the code review comments from Balbir and Li Zefan. - Moved to -tip tree. v1 - Moved the stime/utime accounting to cpuacct controller. Earlier versions - http://lkml.org/lkml/2009/2/25/129 Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com> Signed-off-by: Balaji Rao <balajirrao@gmail.com> Cc: Dhaval Giani <dhaval@linux.vnet.ibm.com> Cc: Paul Menage <menage@google.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Reviewed-by: Li Zefan <lizf@cn.fujitsu.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com> Tested-by: Balbir Singh <balbir@linux.vnet.ibm.com> LKML-Reference: <20090331043222.GA4093@in.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-31 04:32:22 +00:00
/* Time spent by the tasks of the cpu accounting group executing in ... */
enum cpuacct_stat_index {
CPUACCT_STAT_USER, /* ... user mode */
CPUACCT_STAT_SYSTEM, /* ... kernel mode */
CPUACCT_STAT_NSTATS,
};
sched: cpu accounting controller (V2) Commit cfb5285660aad4931b2ebbfa902ea48a37dfffa1 removed a useful feature for us, which provided a cpu accounting resource controller. This feature would be useful if someone wants to group tasks only for accounting purpose and doesnt really want to exercise any control over their cpu consumption. The patch below reintroduces the feature. It is based on Paul Menage's original patch (Commit 62d0df64065e7c135d0002f069444fbdfc64768f), with these differences: - Removed load average information. I felt it needs more thought (esp to deal with SMP and virtualized platforms) and can be added for 2.6.25 after more discussions. - Convert group cpu usage to be nanosecond accurate (as rest of the cfs stats are) and invoke cpuacct_charge() from the respective scheduler classes - Make accounting scalable on SMP systems by splitting the usage counter to be per-cpu - Move the code from kernel/cpu_acct.c to kernel/sched.c (since the code is not big enough to warrant a new file and also this rightly needs to live inside the scheduler. Also things like accessing rq->lock while reading cpu usage becomes easier if the code lived in kernel/sched.c) The patch also modifies the cpu controller not to provide the same accounting information. Tested-by: Balbir Singh <balbir@linux.vnet.ibm.com> Tested the patches on top of 2.6.24-rc3. The patches work fine. Ran some simple tests like cpuspin (spin on the cpu), ran several tasks in the same group and timed them. Compared their time stamps with cpuacct.usage. Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-12-02 19:04:49 +00:00
#ifdef CONFIG_CGROUP_CPUACCT
static void cpuacct_charge(struct task_struct *tsk, u64 cputime);
cpuacct: add per-cgroup utime/stime statistics Add per-cgroup cpuacct controller statistics like the system and user time consumed by the group of tasks. Changelog: v7 - Changed the name of the statistic from utime to user and from stime to system so that in future we could easily add other statistics like irq, softirq, steal times etc easily. v6 - Fixed a bug in the error path of cpuacct_create() (pointed by Li Zefan). v5 - In cpuacct_stats_show(), use cputime64_to_clock_t() since we are operating on a 64bit variable here. v4 - Remove comments in cpuacct_update_stats() which explained why rcu_read_lock() was needed (as per Peter Zijlstra's review comments). - Don't say that percpu_counter_read() is broken in Documentation/cpuacct.txt as per KAMEZAWA Hiroyuki's review comments. v3 - Fix a small race in the cpuacct hierarchy walk. v2 - stime and utime now exported in clock_t units instead of msecs. - Addressed the code review comments from Balbir and Li Zefan. - Moved to -tip tree. v1 - Moved the stime/utime accounting to cpuacct controller. Earlier versions - http://lkml.org/lkml/2009/2/25/129 Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com> Signed-off-by: Balaji Rao <balajirrao@gmail.com> Cc: Dhaval Giani <dhaval@linux.vnet.ibm.com> Cc: Paul Menage <menage@google.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Reviewed-by: Li Zefan <lizf@cn.fujitsu.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com> Tested-by: Balbir Singh <balbir@linux.vnet.ibm.com> LKML-Reference: <20090331043222.GA4093@in.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-31 04:32:22 +00:00
static void cpuacct_update_stats(struct task_struct *tsk,
enum cpuacct_stat_index idx, cputime_t val);
sched: cpu accounting controller (V2) Commit cfb5285660aad4931b2ebbfa902ea48a37dfffa1 removed a useful feature for us, which provided a cpu accounting resource controller. This feature would be useful if someone wants to group tasks only for accounting purpose and doesnt really want to exercise any control over their cpu consumption. The patch below reintroduces the feature. It is based on Paul Menage's original patch (Commit 62d0df64065e7c135d0002f069444fbdfc64768f), with these differences: - Removed load average information. I felt it needs more thought (esp to deal with SMP and virtualized platforms) and can be added for 2.6.25 after more discussions. - Convert group cpu usage to be nanosecond accurate (as rest of the cfs stats are) and invoke cpuacct_charge() from the respective scheduler classes - Make accounting scalable on SMP systems by splitting the usage counter to be per-cpu - Move the code from kernel/cpu_acct.c to kernel/sched.c (since the code is not big enough to warrant a new file and also this rightly needs to live inside the scheduler. Also things like accessing rq->lock while reading cpu usage becomes easier if the code lived in kernel/sched.c) The patch also modifies the cpu controller not to provide the same accounting information. Tested-by: Balbir Singh <balbir@linux.vnet.ibm.com> Tested the patches on top of 2.6.24-rc3. The patches work fine. Ran some simple tests like cpuspin (spin on the cpu), ran several tasks in the same group and timed them. Compared their time stamps with cpuacct.usage. Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-12-02 19:04:49 +00:00
#else
static inline void cpuacct_charge(struct task_struct *tsk, u64 cputime) {}
cpuacct: add per-cgroup utime/stime statistics Add per-cgroup cpuacct controller statistics like the system and user time consumed by the group of tasks. Changelog: v7 - Changed the name of the statistic from utime to user and from stime to system so that in future we could easily add other statistics like irq, softirq, steal times etc easily. v6 - Fixed a bug in the error path of cpuacct_create() (pointed by Li Zefan). v5 - In cpuacct_stats_show(), use cputime64_to_clock_t() since we are operating on a 64bit variable here. v4 - Remove comments in cpuacct_update_stats() which explained why rcu_read_lock() was needed (as per Peter Zijlstra's review comments). - Don't say that percpu_counter_read() is broken in Documentation/cpuacct.txt as per KAMEZAWA Hiroyuki's review comments. v3 - Fix a small race in the cpuacct hierarchy walk. v2 - stime and utime now exported in clock_t units instead of msecs. - Addressed the code review comments from Balbir and Li Zefan. - Moved to -tip tree. v1 - Moved the stime/utime accounting to cpuacct controller. Earlier versions - http://lkml.org/lkml/2009/2/25/129 Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com> Signed-off-by: Balaji Rao <balajirrao@gmail.com> Cc: Dhaval Giani <dhaval@linux.vnet.ibm.com> Cc: Paul Menage <menage@google.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Reviewed-by: Li Zefan <lizf@cn.fujitsu.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com> Tested-by: Balbir Singh <balbir@linux.vnet.ibm.com> LKML-Reference: <20090331043222.GA4093@in.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-31 04:32:22 +00:00
static inline void cpuacct_update_stats(struct task_struct *tsk,
enum cpuacct_stat_index idx, cputime_t val) {}
sched: cpu accounting controller (V2) Commit cfb5285660aad4931b2ebbfa902ea48a37dfffa1 removed a useful feature for us, which provided a cpu accounting resource controller. This feature would be useful if someone wants to group tasks only for accounting purpose and doesnt really want to exercise any control over their cpu consumption. The patch below reintroduces the feature. It is based on Paul Menage's original patch (Commit 62d0df64065e7c135d0002f069444fbdfc64768f), with these differences: - Removed load average information. I felt it needs more thought (esp to deal with SMP and virtualized platforms) and can be added for 2.6.25 after more discussions. - Convert group cpu usage to be nanosecond accurate (as rest of the cfs stats are) and invoke cpuacct_charge() from the respective scheduler classes - Make accounting scalable on SMP systems by splitting the usage counter to be per-cpu - Move the code from kernel/cpu_acct.c to kernel/sched.c (since the code is not big enough to warrant a new file and also this rightly needs to live inside the scheduler. Also things like accessing rq->lock while reading cpu usage becomes easier if the code lived in kernel/sched.c) The patch also modifies the cpu controller not to provide the same accounting information. Tested-by: Balbir Singh <balbir@linux.vnet.ibm.com> Tested the patches on top of 2.6.24-rc3. The patches work fine. Ran some simple tests like cpuspin (spin on the cpu), ran several tasks in the same group and timed them. Compared their time stamps with cpuacct.usage. Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-12-02 19:04:49 +00:00
#endif
sched: fair-group: SMP-nice for group scheduling Implement SMP nice support for the full group hierarchy. On each load-balance action, compile a sched_domain wide view of the full task_group tree. We compute the domain wide view when walking down the hierarchy, and readjust the weights when walking back up. After collecting and readjusting the domain wide view, we try to balance the tasks within the task_groups. The current approach is a naively balance each task group until we've moved the targeted amount of load. Inspired by Srivatsa Vaddsgiri's previous code and Abhishek Chandra's H-SMP paper. XXX: there will be some numerical issues due to the limited nature of SCHED_LOAD_SCALE wrt to representing a task_groups influence on the total weight. When the tree is deep enough, or the task weight small enough, we'll run out of bits. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> CC: Abhishek Chandra <chandra@cs.umn.edu> CC: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 17:45:00 +00:00
static inline void inc_cpu_load(struct rq *rq, unsigned long load)
{
update_load_add(&rq->load, load);
}
static inline void dec_cpu_load(struct rq *rq, unsigned long load)
{
update_load_sub(&rq->load, load);
}
sched: Validate CFS quota hierarchies Add constraints validation for CFS bandwidth hierarchies. Validate that: max(child bandwidth) <= parent_bandwidth In a quota limited hierarchy, an unconstrained entity (e.g. bandwidth==RUNTIME_INF) inherits the bandwidth of its parent. This constraint is chosen over sum(child_bandwidth) as notion of over-commit is valuable within SCHED_OTHER. Some basic code from the RT case is re-factored for reuse. Signed-off-by: Paul Turner <pjt@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110721184757.083774572@google.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-21 16:43:29 +00:00
#if defined(CONFIG_RT_GROUP_SCHED) || (defined(CONFIG_FAIR_GROUP_SCHED) && \
(defined(CONFIG_SMP) || defined(CONFIG_CFS_BANDWIDTH)))
sched: extract walk_tg_tree() Extract walk_tg_tree() and make it a little more generic so we can use it in the schedulablity test. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-19 10:33:05 +00:00
typedef int (*tg_visitor)(struct task_group *, void *);
sched: revert revert of: fair-group: SMP-nice for group scheduling Try again.. Initial commit: 18d95a2832c1392a2d63227a7a6d433cb9f2037e Revert: 6363ca57c76b7b83639ca8c83fc285fa26a7880e Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Cc: Mike Galbraith <efault@gmx.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-27 11:41:14 +00:00
/*
* Iterate the full tree, calling @down when first entering a node and @up when
* leaving it for the final time.
*/
sched: extract walk_tg_tree() Extract walk_tg_tree() and make it a little more generic so we can use it in the schedulablity test. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-19 10:33:05 +00:00
static int walk_tg_tree(tg_visitor down, tg_visitor up, void *data)
sched: revert revert of: fair-group: SMP-nice for group scheduling Try again.. Initial commit: 18d95a2832c1392a2d63227a7a6d433cb9f2037e Revert: 6363ca57c76b7b83639ca8c83fc285fa26a7880e Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Cc: Mike Galbraith <efault@gmx.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-27 11:41:14 +00:00
{
struct task_group *parent, *child;
sched: extract walk_tg_tree() Extract walk_tg_tree() and make it a little more generic so we can use it in the schedulablity test. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-19 10:33:05 +00:00
int ret;
sched: revert revert of: fair-group: SMP-nice for group scheduling Try again.. Initial commit: 18d95a2832c1392a2d63227a7a6d433cb9f2037e Revert: 6363ca57c76b7b83639ca8c83fc285fa26a7880e Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Cc: Mike Galbraith <efault@gmx.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-27 11:41:14 +00:00
rcu_read_lock();
parent = &root_task_group;
down:
sched: extract walk_tg_tree() Extract walk_tg_tree() and make it a little more generic so we can use it in the schedulablity test. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-19 10:33:05 +00:00
ret = (*down)(parent, data);
if (ret)
goto out_unlock;
sched: revert revert of: fair-group: SMP-nice for group scheduling Try again.. Initial commit: 18d95a2832c1392a2d63227a7a6d433cb9f2037e Revert: 6363ca57c76b7b83639ca8c83fc285fa26a7880e Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Cc: Mike Galbraith <efault@gmx.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-27 11:41:14 +00:00
list_for_each_entry_rcu(child, &parent->children, siblings) {
parent = child;
goto down;
up:
continue;
}
sched: extract walk_tg_tree() Extract walk_tg_tree() and make it a little more generic so we can use it in the schedulablity test. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-19 10:33:05 +00:00
ret = (*up)(parent, data);
if (ret)
goto out_unlock;
sched: revert revert of: fair-group: SMP-nice for group scheduling Try again.. Initial commit: 18d95a2832c1392a2d63227a7a6d433cb9f2037e Revert: 6363ca57c76b7b83639ca8c83fc285fa26a7880e Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Cc: Mike Galbraith <efault@gmx.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-27 11:41:14 +00:00
child = parent;
parent = parent->parent;
if (parent)
goto up;
sched: extract walk_tg_tree() Extract walk_tg_tree() and make it a little more generic so we can use it in the schedulablity test. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-19 10:33:05 +00:00
out_unlock:
sched: revert revert of: fair-group: SMP-nice for group scheduling Try again.. Initial commit: 18d95a2832c1392a2d63227a7a6d433cb9f2037e Revert: 6363ca57c76b7b83639ca8c83fc285fa26a7880e Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Cc: Mike Galbraith <efault@gmx.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-27 11:41:14 +00:00
rcu_read_unlock();
sched: extract walk_tg_tree() Extract walk_tg_tree() and make it a little more generic so we can use it in the schedulablity test. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-19 10:33:05 +00:00
return ret;
sched: revert revert of: fair-group: SMP-nice for group scheduling Try again.. Initial commit: 18d95a2832c1392a2d63227a7a6d433cb9f2037e Revert: 6363ca57c76b7b83639ca8c83fc285fa26a7880e Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Cc: Mike Galbraith <efault@gmx.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-27 11:41:14 +00:00
}
sched: extract walk_tg_tree() Extract walk_tg_tree() and make it a little more generic so we can use it in the schedulablity test. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-19 10:33:05 +00:00
static int tg_nop(struct task_group *tg, void *data)
{
return 0;
sched: revert revert of: fair-group: SMP-nice for group scheduling Try again.. Initial commit: 18d95a2832c1392a2d63227a7a6d433cb9f2037e Revert: 6363ca57c76b7b83639ca8c83fc285fa26a7880e Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Cc: Mike Galbraith <efault@gmx.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-27 11:41:14 +00:00
}
sched: extract walk_tg_tree() Extract walk_tg_tree() and make it a little more generic so we can use it in the schedulablity test. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-19 10:33:05 +00:00
#endif
#ifdef CONFIG_SMP
sched: Move code around In preparation to other code movement, move weighted_cpuload(), source_load() and target_load() before the class includes. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-09-10 11:35:28 +00:00
/* Used instead of source_load when we know the type == 0 */
static unsigned long weighted_cpuload(const int cpu)
{
return cpu_rq(cpu)->load.weight;
}
/*
* Return a low guess at the load of a migration-source cpu weighted
* according to the scheduling class and "nice" value.
*
* We want to under-estimate the load of migration sources, to
* balance conservatively.
*/
static unsigned long source_load(int cpu, int type)
{
struct rq *rq = cpu_rq(cpu);
unsigned long total = weighted_cpuload(cpu);
if (type == 0 || !sched_feat(LB_BIAS))
return total;
return min(rq->cpu_load[type-1], total);
}
/*
* Return a high guess at the load of a migration-target cpu weighted
* according to the scheduling class and "nice" value.
*/
static unsigned long target_load(int cpu, int type)
{
struct rq *rq = cpu_rq(cpu);
unsigned long total = weighted_cpuload(cpu);
if (type == 0 || !sched_feat(LB_BIAS))
return total;
return max(rq->cpu_load[type-1], total);
}
sched: Weaken SD_POWERSAVINGS_BALANCE One of the problems of power-saving balancing is that under certain scenarios it is too slow and allows tons of real work to pile up. Avoid this by ignoring the powersave stuff when there's real work to be done. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-09-10 12:40:57 +00:00
static unsigned long power_of(int cpu)
{
sched: Fix wake_affine() vs RT tasks Mike reports that since e9e9250b (sched: Scale down cpu_power due to RT tasks), wake_affine() goes funny on RT tasks due to them still having a !0 weight and wake_affine() still subtracts that from the rq weight. Since nobody should be using se->weight for RT tasks, set the value to zero. Also, since we now use ->cpu_power to normalize rq weights to account for RT cpu usage, add that factor into the imbalance computation. Reported-by: Mike Galbraith <efault@gmx.de> Tested-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1275316109.27810.22969.camel@twins> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-05-31 10:37:30 +00:00
return cpu_rq(cpu)->cpu_power;
sched: Weaken SD_POWERSAVINGS_BALANCE One of the problems of power-saving balancing is that under certain scenarios it is too slow and allows tons of real work to pile up. Avoid this by ignoring the powersave stuff when there's real work to be done. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-09-10 12:40:57 +00:00
}
sched: extract walk_tg_tree() Extract walk_tg_tree() and make it a little more generic so we can use it in the schedulablity test. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-19 10:33:05 +00:00
static int task_hot(struct task_struct *p, u64 now, struct sched_domain *sd);
static unsigned long cpu_avg_load_per_task(int cpu)
{
struct rq *rq = cpu_rq(cpu);
sched: prevent divide by zero error in cpu_avg_load_per_task, update Regarding the bug addressed in: 4cd4262: sched: prevent divide by zero error in cpu_avg_load_per_task Linus points out that the fix is not complete: > There's nothing that keeps gcc from deciding not to reload > rq->nr_running. > > Of course, in _practice_, I don't think gcc ever will (if it decides > that it will spill, gcc is likely going to decide that it will > literally spill the local variable to the stack rather than decide to > reload off the pointer), but it's a valid compiler optimization, and > it even has a name (rematerialization). > > So I suspect that your patch does fix the bug, but it still leaves the > fairly unlikely _potential_ for it to re-appear at some point. > > We have ACCESS_ONCE() as a macro to guarantee that the compiler > doesn't rematerialize a pointer access. That also would clarify > the fact that we access something unsafe outside a lock. So make sure our nr_running value is immutable and cannot change after we check it for nonzero. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-29 19:45:15 +00:00
unsigned long nr_running = ACCESS_ONCE(rq->nr_running);
sched: extract walk_tg_tree() Extract walk_tg_tree() and make it a little more generic so we can use it in the schedulablity test. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-19 10:33:05 +00:00
sched: prevent divide by zero error in cpu_avg_load_per_task Impact: fix divide by zero crash in scheduler rebalance irq While testing the branch profiler, I hit this crash: divide error: 0000 [#1] PREEMPT SMP [...] RIP: 0010:[<ffffffff8024a008>] [<ffffffff8024a008>] cpu_avg_load_per_task+0x50/0x7f [...] Call Trace: <IRQ> <0> [<ffffffff8024fd43>] find_busiest_group+0x3e5/0xcaa [<ffffffff8025da75>] rebalance_domains+0x2da/0xa21 [<ffffffff80478769>] ? find_next_bit+0x1b2/0x1e6 [<ffffffff8025e2ce>] run_rebalance_domains+0x112/0x19f [<ffffffff8026d7c2>] __do_softirq+0xa8/0x232 [<ffffffff8020ea7c>] call_softirq+0x1c/0x3e [<ffffffff8021047a>] do_softirq+0x94/0x1cd [<ffffffff8026d5eb>] irq_exit+0x6b/0x10e [<ffffffff8022e6ec>] smp_apic_timer_interrupt+0xd3/0xff [<ffffffff8020e4b3>] apic_timer_interrupt+0x13/0x20 The code for cpu_avg_load_per_task has: if (rq->nr_running) rq->avg_load_per_task = rq->load.weight / rq->nr_running; The runqueue lock is not held here, and there is nothing that prevents the rq->nr_running from going to zero after it passes the if condition. The branch profiler simply made the race window bigger. This patch saves off the rq->nr_running to a local variable and uses that for both the condition and the division. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Peter Zijlstra <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-27 02:04:24 +00:00
if (nr_running)
sched: Remove rq->avg_load_per_task Since commit a2d47777 ("sched: fix stale value in average load per task") the variable rq->avg_load_per_task is no longer required. Remove it. Signed-off-by: Jan H. Schönherr <schnhrr@cs.tu-berlin.de> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1312189408-17172-1-git-send-email-schnhrr@cs.tu-berlin.de Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-08-01 09:03:28 +00:00
return rq->load.weight / nr_running;
sched: extract walk_tg_tree() Extract walk_tg_tree() and make it a little more generic so we can use it in the schedulablity test. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-19 10:33:05 +00:00
sched: Remove rq->avg_load_per_task Since commit a2d47777 ("sched: fix stale value in average load per task") the variable rq->avg_load_per_task is no longer required. Remove it. Signed-off-by: Jan H. Schönherr <schnhrr@cs.tu-berlin.de> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1312189408-17172-1-git-send-email-schnhrr@cs.tu-berlin.de Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-08-01 09:03:28 +00:00
return 0;
sched: extract walk_tg_tree() Extract walk_tg_tree() and make it a little more generic so we can use it in the schedulablity test. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-19 10:33:05 +00:00
}
sched: make double-lock-balance fair double_lock balance() currently favors logically lower cpus since they often do not have to release their own lock to acquire a second lock. The result is that logically higher cpus can get starved when there is a lot of pressure on the RQs. This can result in higher latencies on higher cpu-ids. This patch makes the algorithm more fair by forcing all paths to have to release both locks before acquiring them again. Since callsites to double_lock_balance already consider it a potential preemption/reschedule point, they have the proper logic to recheck for atomicity violations. Signed-off-by: Gregory Haskins <ghaskins@novell.com>
2008-12-29 14:39:51 +00:00
#ifdef CONFIG_PREEMPT
sched: Fix double_rq_lock() compile warning Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-09-15 12:23:18 +00:00
static void double_rq_lock(struct rq *rq1, struct rq *rq2);
sched: move double_unlock_balance() higher Move double_lock_balance()/double_unlock_balance() higher to fix the following with gcc-3.4.6: CC kernel/sched.o In file included from kernel/sched.c:1605: kernel/sched_rt.c: In function `find_lock_lowest_rq': kernel/sched_rt.c:914: sorry, unimplemented: inlining failed in call to 'double_unlock_balance': function body not available kernel/sched_rt.c:1077: sorry, unimplemented: called from here make[2]: *** [kernel/sched.o] Error 1 Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-28 19:08:00 +00:00
/*
sched: make double-lock-balance fair double_lock balance() currently favors logically lower cpus since they often do not have to release their own lock to acquire a second lock. The result is that logically higher cpus can get starved when there is a lot of pressure on the RQs. This can result in higher latencies on higher cpu-ids. This patch makes the algorithm more fair by forcing all paths to have to release both locks before acquiring them again. Since callsites to double_lock_balance already consider it a potential preemption/reschedule point, they have the proper logic to recheck for atomicity violations. Signed-off-by: Gregory Haskins <ghaskins@novell.com>
2008-12-29 14:39:51 +00:00
* fair double_lock_balance: Safely acquires both rq->locks in a fair
* way at the expense of forcing extra atomic operations in all
* invocations. This assures that the double_lock is acquired using the
* same underlying policy as the spinlock_t on this architecture, which
* reduces latency compared to the unfair variant below. However, it
* also adds more overhead and therefore may reduce throughput.
sched: move double_unlock_balance() higher Move double_lock_balance()/double_unlock_balance() higher to fix the following with gcc-3.4.6: CC kernel/sched.o In file included from kernel/sched.c:1605: kernel/sched_rt.c: In function `find_lock_lowest_rq': kernel/sched_rt.c:914: sorry, unimplemented: inlining failed in call to 'double_unlock_balance': function body not available kernel/sched_rt.c:1077: sorry, unimplemented: called from here make[2]: *** [kernel/sched.o] Error 1 Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-28 19:08:00 +00:00
*/
sched: make double-lock-balance fair double_lock balance() currently favors logically lower cpus since they often do not have to release their own lock to acquire a second lock. The result is that logically higher cpus can get starved when there is a lot of pressure on the RQs. This can result in higher latencies on higher cpu-ids. This patch makes the algorithm more fair by forcing all paths to have to release both locks before acquiring them again. Since callsites to double_lock_balance already consider it a potential preemption/reschedule point, they have the proper logic to recheck for atomicity violations. Signed-off-by: Gregory Haskins <ghaskins@novell.com>
2008-12-29 14:39:51 +00:00
static inline int _double_lock_balance(struct rq *this_rq, struct rq *busiest)
__releases(this_rq->lock)
__acquires(busiest->lock)
__acquires(this_rq->lock)
{
sched: Convert rq->lock to raw_spinlock Convert locks which cannot be sleeping locks in preempt-rt to raw_spinlocks. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Ingo Molnar <mingo@elte.hu>
2009-11-17 13:28:38 +00:00
raw_spin_unlock(&this_rq->lock);
sched: make double-lock-balance fair double_lock balance() currently favors logically lower cpus since they often do not have to release their own lock to acquire a second lock. The result is that logically higher cpus can get starved when there is a lot of pressure on the RQs. This can result in higher latencies on higher cpu-ids. This patch makes the algorithm more fair by forcing all paths to have to release both locks before acquiring them again. Since callsites to double_lock_balance already consider it a potential preemption/reschedule point, they have the proper logic to recheck for atomicity violations. Signed-off-by: Gregory Haskins <ghaskins@novell.com>
2008-12-29 14:39:51 +00:00
double_rq_lock(this_rq, busiest);
return 1;
}
#else
/*
* Unfair double_lock_balance: Optimizes throughput at the expense of
* latency by eliminating extra atomic operations when the locks are
* already in proper order on entry. This favors lower cpu-ids and will
* grant the double lock to lower cpus over higher ids under contention,
* regardless of entry order into the function.
*/
static int _double_lock_balance(struct rq *this_rq, struct rq *busiest)
sched: move double_unlock_balance() higher Move double_lock_balance()/double_unlock_balance() higher to fix the following with gcc-3.4.6: CC kernel/sched.o In file included from kernel/sched.c:1605: kernel/sched_rt.c: In function `find_lock_lowest_rq': kernel/sched_rt.c:914: sorry, unimplemented: inlining failed in call to 'double_unlock_balance': function body not available kernel/sched_rt.c:1077: sorry, unimplemented: called from here make[2]: *** [kernel/sched.o] Error 1 Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-28 19:08:00 +00:00
__releases(this_rq->lock)
__acquires(busiest->lock)
__acquires(this_rq->lock)
{
int ret = 0;
sched: Convert rq->lock to raw_spinlock Convert locks which cannot be sleeping locks in preempt-rt to raw_spinlocks. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Ingo Molnar <mingo@elte.hu>
2009-11-17 13:28:38 +00:00
if (unlikely(!raw_spin_trylock(&busiest->lock))) {
sched: move double_unlock_balance() higher Move double_lock_balance()/double_unlock_balance() higher to fix the following with gcc-3.4.6: CC kernel/sched.o In file included from kernel/sched.c:1605: kernel/sched_rt.c: In function `find_lock_lowest_rq': kernel/sched_rt.c:914: sorry, unimplemented: inlining failed in call to 'double_unlock_balance': function body not available kernel/sched_rt.c:1077: sorry, unimplemented: called from here make[2]: *** [kernel/sched.o] Error 1 Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-28 19:08:00 +00:00
if (busiest < this_rq) {
sched: Convert rq->lock to raw_spinlock Convert locks which cannot be sleeping locks in preempt-rt to raw_spinlocks. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Ingo Molnar <mingo@elte.hu>
2009-11-17 13:28:38 +00:00
raw_spin_unlock(&this_rq->lock);
raw_spin_lock(&busiest->lock);
raw_spin_lock_nested(&this_rq->lock,
SINGLE_DEPTH_NESTING);
sched: move double_unlock_balance() higher Move double_lock_balance()/double_unlock_balance() higher to fix the following with gcc-3.4.6: CC kernel/sched.o In file included from kernel/sched.c:1605: kernel/sched_rt.c: In function `find_lock_lowest_rq': kernel/sched_rt.c:914: sorry, unimplemented: inlining failed in call to 'double_unlock_balance': function body not available kernel/sched_rt.c:1077: sorry, unimplemented: called from here make[2]: *** [kernel/sched.o] Error 1 Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-28 19:08:00 +00:00
ret = 1;
} else
sched: Convert rq->lock to raw_spinlock Convert locks which cannot be sleeping locks in preempt-rt to raw_spinlocks. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Ingo Molnar <mingo@elte.hu>
2009-11-17 13:28:38 +00:00
raw_spin_lock_nested(&busiest->lock,
SINGLE_DEPTH_NESTING);
sched: move double_unlock_balance() higher Move double_lock_balance()/double_unlock_balance() higher to fix the following with gcc-3.4.6: CC kernel/sched.o In file included from kernel/sched.c:1605: kernel/sched_rt.c: In function `find_lock_lowest_rq': kernel/sched_rt.c:914: sorry, unimplemented: inlining failed in call to 'double_unlock_balance': function body not available kernel/sched_rt.c:1077: sorry, unimplemented: called from here make[2]: *** [kernel/sched.o] Error 1 Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-28 19:08:00 +00:00
}
return ret;
}
sched: make double-lock-balance fair double_lock balance() currently favors logically lower cpus since they often do not have to release their own lock to acquire a second lock. The result is that logically higher cpus can get starved when there is a lot of pressure on the RQs. This can result in higher latencies on higher cpu-ids. This patch makes the algorithm more fair by forcing all paths to have to release both locks before acquiring them again. Since callsites to double_lock_balance already consider it a potential preemption/reschedule point, they have the proper logic to recheck for atomicity violations. Signed-off-by: Gregory Haskins <ghaskins@novell.com>
2008-12-29 14:39:51 +00:00
#endif /* CONFIG_PREEMPT */
/*
* double_lock_balance - lock the busiest runqueue, this_rq is locked already.
*/
static int double_lock_balance(struct rq *this_rq, struct rq *busiest)
{
if (unlikely(!irqs_disabled())) {
/* printk() doesn't work good under rq->lock */
sched: Convert rq->lock to raw_spinlock Convert locks which cannot be sleeping locks in preempt-rt to raw_spinlocks. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Ingo Molnar <mingo@elte.hu>
2009-11-17 13:28:38 +00:00
raw_spin_unlock(&this_rq->lock);
sched: make double-lock-balance fair double_lock balance() currently favors logically lower cpus since they often do not have to release their own lock to acquire a second lock. The result is that logically higher cpus can get starved when there is a lot of pressure on the RQs. This can result in higher latencies on higher cpu-ids. This patch makes the algorithm more fair by forcing all paths to have to release both locks before acquiring them again. Since callsites to double_lock_balance already consider it a potential preemption/reschedule point, they have the proper logic to recheck for atomicity violations. Signed-off-by: Gregory Haskins <ghaskins@novell.com>
2008-12-29 14:39:51 +00:00
BUG_ON(1);
}
return _double_lock_balance(this_rq, busiest);
}
sched: move double_unlock_balance() higher Move double_lock_balance()/double_unlock_balance() higher to fix the following with gcc-3.4.6: CC kernel/sched.o In file included from kernel/sched.c:1605: kernel/sched_rt.c: In function `find_lock_lowest_rq': kernel/sched_rt.c:914: sorry, unimplemented: inlining failed in call to 'double_unlock_balance': function body not available kernel/sched_rt.c:1077: sorry, unimplemented: called from here make[2]: *** [kernel/sched.o] Error 1 Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-28 19:08:00 +00:00
static inline void double_unlock_balance(struct rq *this_rq, struct rq *busiest)
__releases(busiest->lock)
{
sched: Convert rq->lock to raw_spinlock Convert locks which cannot be sleeping locks in preempt-rt to raw_spinlocks. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Ingo Molnar <mingo@elte.hu>
2009-11-17 13:28:38 +00:00
raw_spin_unlock(&busiest->lock);
sched: move double_unlock_balance() higher Move double_lock_balance()/double_unlock_balance() higher to fix the following with gcc-3.4.6: CC kernel/sched.o In file included from kernel/sched.c:1605: kernel/sched_rt.c: In function `find_lock_lowest_rq': kernel/sched_rt.c:914: sorry, unimplemented: inlining failed in call to 'double_unlock_balance': function body not available kernel/sched_rt.c:1077: sorry, unimplemented: called from here make[2]: *** [kernel/sched.o] Error 1 Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-28 19:08:00 +00:00
lock_set_subclass(&this_rq->lock.dep_map, 0, _RET_IP_);
}
sched: Move load balance code into sched_fair.c Straight fwd code movement. Since non of the load-balance abstractions are used anymore, do away with them and simplify the code some. In preparation move the code around. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-17 16:00:43 +00:00
/*
* double_rq_lock - safely lock two runqueues
*
* Note this does not disable interrupts like task_rq_lock,
* you need to do so manually before calling.
*/
static void double_rq_lock(struct rq *rq1, struct rq *rq2)
__acquires(rq1->lock)
__acquires(rq2->lock)
{
BUG_ON(!irqs_disabled());
if (rq1 == rq2) {
raw_spin_lock(&rq1->lock);
__acquire(rq2->lock); /* Fake it out ;) */
} else {
if (rq1 < rq2) {
raw_spin_lock(&rq1->lock);
raw_spin_lock_nested(&rq2->lock, SINGLE_DEPTH_NESTING);
} else {
raw_spin_lock(&rq2->lock);
raw_spin_lock_nested(&rq1->lock, SINGLE_DEPTH_NESTING);
}
}
}
/*
* double_rq_unlock - safely unlock two runqueues
*
* Note this does not restore interrupts like task_rq_unlock,
* you need to do so manually after calling.
*/
static void double_rq_unlock(struct rq *rq1, struct rq *rq2)
__releases(rq1->lock)
__releases(rq2->lock)
{
raw_spin_unlock(&rq1->lock);
if (rq1 != rq2)
raw_spin_unlock(&rq2->lock);
else
__release(rq2->lock);
}
sched: Add yield_to(task, preempt) functionality Currently only implemented for fair class tasks. Add a yield_to_task method() to the fair scheduling class. allowing the caller of yield_to() to accelerate another thread in it's thread group, task group. Implemented via a scheduler hint, using cfs_rq->next to encourage the target being selected. We can rely on pick_next_entity to keep things fair, so noone can accelerate a thread that has already used its fair share of CPU time. This also means callers should only call yield_to when they really mean it. Calling it too often can result in the scheduler just ignoring the hint. Signed-off-by: Rik van Riel <riel@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20110201095051.4ddb7738@annuminas.surriel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-02-01 14:50:51 +00:00
#else /* CONFIG_SMP */
/*
* double_rq_lock - safely lock two runqueues
*
* Note this does not disable interrupts like task_rq_lock,
* you need to do so manually before calling.
*/
static void double_rq_lock(struct rq *rq1, struct rq *rq2)
__acquires(rq1->lock)
__acquires(rq2->lock)
{
BUG_ON(!irqs_disabled());
BUG_ON(rq1 != rq2);
raw_spin_lock(&rq1->lock);
__acquire(rq2->lock); /* Fake it out ;) */
}
/*
* double_rq_unlock - safely unlock two runqueues
*
* Note this does not restore interrupts like task_rq_unlock,
* you need to do so manually after calling.
*/
static void double_rq_unlock(struct rq *rq1, struct rq *rq2)
__releases(rq1->lock)
__releases(rq2->lock)
{
BUG_ON(rq1 != rq2);
raw_spin_unlock(&rq1->lock);
__release(rq2->lock);
}
sched: fair-group: SMP-nice for group scheduling Implement SMP nice support for the full group hierarchy. On each load-balance action, compile a sched_domain wide view of the full task_group tree. We compute the domain wide view when walking down the hierarchy, and readjust the weights when walking back up. After collecting and readjusting the domain wide view, we try to balance the tasks within the task_groups. The current approach is a naively balance each task group until we've moved the targeted amount of load. Inspired by Srivatsa Vaddsgiri's previous code and Abhishek Chandra's H-SMP paper. XXX: there will be some numerical issues due to the limited nature of SCHED_LOAD_SCALE wrt to representing a task_groups influence on the total weight. When the tree is deep enough, or the task weight small enough, we'll run out of bits. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> CC: Abhishek Chandra <chandra@cs.umn.edu> CC: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 17:45:00 +00:00
#endif
sched: Cure load average vs NO_HZ woes Chase reported that due to us decrementing calc_load_task prematurely (before the next LOAD_FREQ sample), the load average could be scewed by as much as the number of CPUs in the machine. This patch, based on Chase's patch, cures the problem by keeping the delta of the CPU going into NO_HZ idle separately and folding that in on the next LOAD_FREQ update. This restores the balance and we get strict LOAD_FREQ period samples. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Chase Douglas <chase.douglas@canonical.com> LKML-Reference: <1271934490.1776.343.camel@laptop> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-04-22 19:50:19 +00:00
static void calc_load_account_idle(struct rq *this_rq);
sched: Fix missing sched tunable recalculation on cpu add/remove Based on Peter Zijlstras patch suggestion this enables recalculation of the scheduler tunables in response of a change in the number of cpus. It also adds a max of eight cpus that are considered in that scaling. Signed-off-by: Christian Ehrhardt <ehrhardt@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1259579808-11357-2-git-send-email-ehrhardt@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-11-30 11:16:46 +00:00
static void update_sysctl(void);
sched: Update normalized values on user updates via proc The normalized values are also recalculated in case the scaling factor changes. This patch updates the internally used scheduler tuning values that are normalized to one cpu in case a user sets new values via sysfs. Together with patch 2 of this series this allows to let user configured values scale (or not) to cpu add/remove events taking place later. Signed-off-by: Christian Ehrhardt <ehrhardt@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1259579808-11357-4-git-send-email-ehrhardt@linux.vnet.ibm.com> [ v2: fix warning ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-11-30 11:16:48 +00:00
static int get_update_sysctl_factor(void);
sched: Avoid side-effect of tickless idle on update_cpu_load tickless idle has a negative side effect on update_cpu_load(), which in turn can affect load balancing behavior. update_cpu_load() is supposed to be called every tick, to keep track of various load indicies. With tickless idle, there are no scheduler ticks called on the idle CPUs. Idle CPUs may still do load balancing (with idle_load_balance CPU) using the stale cpu_load. It will also cause problems when all CPUs go idle for a while and become active again. In this case loads would not degrade as expected. This is how rq->nr_load_updates change looks like under different conditions: <cpu_num> <nr_load_updates change> All CPUS idle for 10 seconds (HZ=1000) 0 1621 10 496 11 139 12 875 13 1672 14 12 15 21 1 1472 2 2426 3 1161 4 2108 5 1525 6 701 7 249 8 766 9 1967 One CPU busy rest idle for 10 seconds 0 10003 10 601 11 95 12 966 13 1597 14 114 15 98 1 3457 2 93 3 6679 4 1425 5 1479 6 595 7 193 8 633 9 1687 All CPUs busy for 10 seconds 0 10026 10 10026 11 10026 12 10026 13 10025 14 10025 15 10025 1 10026 2 10026 3 10026 4 10026 5 10026 6 10026 7 10026 8 10026 9 10026 That is update_cpu_load works properly only when all CPUs are busy. If all are idle, all the CPUs get way lower updates. And when few CPUs are busy and rest are idle, only busy and ilb CPU does proper updates and rest of the idle CPUs will do lower updates. The patch keeps track of when a last update was done and fixes up the load avg based on current time. On one of my test system SPECjbb with warehouse 1..numcpus, patch improves throughput numbers by ~1% (average of 6 runs). On another test system (with different domain hierarchy) there is no noticable change in perf. Signed-off-by: Venkatesh Pallipadi <venki@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Thomas Gleixner <tglx@linutronix.de> LKML-Reference: <AANLkTilLtDWQsAUrIxJ6s04WTgmw9GuOODc5AOrYsaR5@mail.gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-05-18 01:14:43 +00:00
static void update_cpu_load(struct rq *this_rq);
sched, timers: move calc_load() to scheduler Dimitri Sivanich noticed that xtime_lock is held write locked across calc_load() which iterates over all online CPUs. That can cause long latencies for xtime_lock readers on large SMP systems. The load average calculation is an rough estimate anyway so there is no real need to protect the readers vs. the update. It's not a problem when the avenrun array is updated while a reader copies the values. Instead of iterating over all online CPUs let the scheduler_tick code update the number of active tasks shortly before the avenrun update happens. The avenrun update itself is handled by the CPU which calls do_timer(). [ Impact: reduce xtime_lock write locked section ] Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org>
2009-04-11 08:43:41 +00:00
sched: Sanitize fork() handling Currently we try to do task placement in wake_up_new_task() after we do the load-balance pass in sched_fork(). This yields complicated semantics in that we have to deal with tasks on different RQs and the set_task_cpu() calls in copy_process() and sched_fork() Rename ->task_new() to ->task_fork() and call it from sched_fork() before the balancing, this gives the policy a clear point to place the task. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-11-27 16:32:46 +00:00
static inline void __set_task_cpu(struct task_struct *p, unsigned int cpu)
{
set_task_rq(p, cpu);
#ifdef CONFIG_SMP
/*
* After ->cpu is set up to a new value, task_rq_lock(p, ...) can be
* successfuly executed on another CPU. We must ensure that updates of
* per-task data have been completed by this moment.
*/
smp_wmb();
task_thread_info(p)->cpu = cpu;
#endif
}
sched, timers: move calc_load() to scheduler Dimitri Sivanich noticed that xtime_lock is held write locked across calc_load() which iterates over all online CPUs. That can cause long latencies for xtime_lock readers on large SMP systems. The load average calculation is an rough estimate anyway so there is no real need to protect the readers vs. the update. It's not a problem when the avenrun array is updated while a reader copies the values. Instead of iterating over all online CPUs let the scheduler_tick code update the number of active tasks shortly before the avenrun update happens. The avenrun update itself is handled by the CPU which calls do_timer(). [ Impact: reduce xtime_lock write locked section ] Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org>
2009-04-11 08:43:41 +00:00
sched: Move load balance code into sched_fair.c Straight fwd code movement. Since non of the load-balance abstractions are used anymore, do away with them and simplify the code some. In preparation move the code around. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-17 16:00:43 +00:00
static const struct sched_class rt_sched_class;
sched: cfs core code apply the CFS core code. this change switches over the scheduler core to CFS's modular design and makes use of kernel/sched_fair/rt/idletask.c to implement Linux's scheduling policies. thanks to Andrew Morton and Thomas Gleixner for lots of detailed review feedback and for fixlets. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
2007-07-09 16:51:59 +00:00
sched: Create special class for stop/migrate work In order to separate the stop/migrate work thread from the SCHED_FIFO implementation, create a special class for it that is of higher priority than SCHED_FIFO itself. This currently solves a problem where cpu-hotplug consumes so much cpu-time that the SCHED_FIFO class gets throttled, but has the bandwidth replenishment timer pending on the now dead cpu. It is also required for when we add the planned deadline scheduling class above SCHED_FIFO, as the stop/migrate thread still needs to transcent those tasks. Tested-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1285165776.2275.1022.camel@laptop> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-09-22 11:53:15 +00:00
#define sched_class_highest (&stop_sched_class)
sched: fix cpupri hotplug support The RT folks over at RedHat found an issue w.r.t. hotplug support which was traced to problems with the cpupri infrastructure in the scheduler: https://bugzilla.redhat.com/show_bug.cgi?id=449676 This bug affects 23-rt12+, 24-rtX, 25-rtX, and sched-devel. This patch applies to 25.4-rt4, though it should trivially apply to most cpupri enabled kernels mentioned above. It turned out that the issue was that offline cpus could get inadvertently registered with cpupri so that they were erroneously selected during migration decisions. The end result would be an OOPS as the offline cpu had tasks routed to it. This patch generalizes the old join/leave domain interface into an online/offline interface, and adjusts the root-domain/hotplug code to utilize it. I was able to easily reproduce the issue prior to this patch, and am no longer able to reproduce it after this patch. I can offline cpus indefinately and everything seems to be in working order. Thanks to Arnaldo (acme), Thomas, and Peter for doing the legwork to point me in the right direction. Also thank you to Peter for reviewing the early iterations of this patch. Signed-off-by: Gregory Haskins <ghaskins@novell.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-06-04 19:04:05 +00:00
#define for_each_class(class) \
for (class = sched_class_highest; class; class = class->next)
sched: cfs core code apply the CFS core code. this change switches over the scheduler core to CFS's modular design and makes use of kernel/sched_fair/rt/idletask.c to implement Linux's scheduling policies. thanks to Andrew Morton and Thomas Gleixner for lots of detailed review feedback and for fixlets. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
2007-07-09 16:51:59 +00:00
sched: Move load balance code into sched_fair.c Straight fwd code movement. Since non of the load-balance abstractions are used anymore, do away with them and simplify the code some. In preparation move the code around. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-17 16:00:43 +00:00
#include "sched_stats.h"
sched: revert revert of: fair-group: SMP-nice for group scheduling Try again.. Initial commit: 18d95a2832c1392a2d63227a7a6d433cb9f2037e Revert: 6363ca57c76b7b83639ca8c83fc285fa26a7880e Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Cc: Mike Galbraith <efault@gmx.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-27 11:41:14 +00:00
static void inc_nr_running(struct rq *rq)
[PATCH] sched: move load-calculation functions move load-calculation functions so that they can use the per-policy declarations and methods. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-08-02 15:41:40 +00:00
{
rq->nr_running++;
}
sched: revert revert of: fair-group: SMP-nice for group scheduling Try again.. Initial commit: 18d95a2832c1392a2d63227a7a6d433cb9f2037e Revert: 6363ca57c76b7b83639ca8c83fc285fa26a7880e Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Cc: Mike Galbraith <efault@gmx.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-27 11:41:14 +00:00
static void dec_nr_running(struct rq *rq)
[PATCH] sched: move load-calculation functions move load-calculation functions so that they can use the per-policy declarations and methods. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-08-02 15:41:40 +00:00
{
rq->nr_running--;
}
sched: cfs, add load-calculation methods add the new load-calculation methods of CFS. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-09 16:51:59 +00:00
static void set_load_weight(struct task_struct *p)
{
sched: Cleanup set_load_weight() Avoid using long repetitious names; make this simpler and nicer to read. No functional change introduced in this patch. Signed-off-by: Nikhil Rao <ncrao@google.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Nikunj A. Dadhania <nikunj@linux.vnet.ibm.com> Cc: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Cc: Stephan Barwolf <stephan.baerwolf@tu-ilmenau.de> Cc: Mike Galbraith <efault@gmx.de> Link: http://lkml.kernel.org/r/1305738580-9924-2-git-send-email-ncrao@google.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-05-18 17:09:38 +00:00
int prio = p->static_prio - MAX_RT_PRIO;
struct load_weight *load = &p->se.load;
sched: cfs core code apply the CFS core code. this change switches over the scheduler core to CFS's modular design and makes use of kernel/sched_fair/rt/idletask.c to implement Linux's scheduling policies. thanks to Andrew Morton and Thomas Gleixner for lots of detailed review feedback and for fixlets. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
2007-07-09 16:51:59 +00:00
/*
* SCHED_IDLE tasks get minimal weight:
*/
if (p->policy == SCHED_IDLE) {
sched: Increase SCHED_LOAD_SCALE resolution Introduce SCHED_LOAD_RESOLUTION, which scales is added to SCHED_LOAD_SHIFT and increases the resolution of SCHED_LOAD_SCALE. This patch sets the value of SCHED_LOAD_RESOLUTION to 10, scaling up the weights for all sched entities by a factor of 1024. With this extra resolution, we can handle deeper cgroup hiearchies and the scheduler can do better shares distribution and load load balancing on larger systems (especially for low weight task groups). This does not change the existing user interface, the scaled weights are only used internally. We do not modify prio_to_weight values or inverses, but use the original weights when calculating the inverse which is used to scale execution time delta in calc_delta_mine(). This ensures we do not lose accuracy when accounting time to the sched entities. Thanks to Nikunj Dadhania for fixing an bug in c_d_m() that broken fairness. Below is some analysis of the performance costs/improvements of this patch. 1. Micro-arch performance costs: Experiment was to run Ingo's pipe_test_100k 200 times with the task pinned to one cpu. I measured instruction, cycles and stalled-cycles for the runs. See: http://thread.gmane.org/gmane.linux.kernel/1129232/focus=1129389 for more info. -tip (baseline): Performance counter stats for '/root/load-scale/pipe-test-100k' (200 runs): 964,991,769 instructions # 0.82 insns per cycle # 0.33 stalled cycles per insn # ( +- 0.05% ) 1,171,186,635 cycles # 0.000 GHz ( +- 0.08% ) 306,373,664 stalled-cycles-backend # 26.16% backend cycles idle ( +- 0.28% ) 314,933,621 stalled-cycles-frontend # 26.89% frontend cycles idle ( +- 0.34% ) 1.122405684 seconds time elapsed ( +- 0.05% ) -tip+patches: Performance counter stats for './load-scale/pipe-test-100k' (200 runs): 963,624,821 instructions # 0.82 insns per cycle # 0.33 stalled cycles per insn # ( +- 0.04% ) 1,175,215,649 cycles # 0.000 GHz ( +- 0.08% ) 315,321,126 stalled-cycles-backend # 26.83% backend cycles idle ( +- 0.28% ) 316,835,873 stalled-cycles-frontend # 26.96% frontend cycles idle ( +- 0.29% ) 1.122238659 seconds time elapsed ( +- 0.06% ) With this patch, instructions decrease by ~0.10% and cycles increase by 0.27%. This doesn't look statistically significant. The number of stalled cycles in the backend increased from 26.16% to 26.83%. This can be attributed to the shifts we do in c_d_m() and other places. The fraction of stalled cycles in the frontend remains about the same, at 26.96% compared to 26.89% in -tip. 2. Balancing low-weight task groups Test setup: run 50 tasks with random sleep/busy times (biased around 100ms) in a low weight container (with cpu.shares = 2). Measure %idle as reported by mpstat over a 10s window. -tip (baseline): 06:47:48 PM CPU %usr %nice %sys %iowait %irq %soft %steal %guest %idle intr/s 06:47:49 PM all 94.32 0.00 0.06 0.00 0.00 0.00 0.00 0.00 5.62 15888.00 06:47:50 PM all 94.57 0.00 0.62 0.00 0.00 0.00 0.00 0.00 4.81 16180.00 06:47:51 PM all 94.69 0.00 0.06 0.00 0.00 0.00 0.00 0.00 5.25 15966.00 06:47:52 PM all 95.81 0.00 0.00 0.00 0.00 0.00 0.00 0.00 4.19 16053.00 06:47:53 PM all 94.88 0.06 0.00 0.00 0.00 0.00 0.00 0.00 5.06 15984.00 06:47:54 PM all 93.31 0.00 0.00 0.00 0.00 0.00 0.00 0.00 6.69 15806.00 06:47:55 PM all 94.19 0.00 0.06 0.00 0.00 0.00 0.00 0.00 5.75 15896.00 06:47:56 PM all 92.87 0.00 0.00 0.00 0.00 0.00 0.00 0.00 7.13 15716.00 06:47:57 PM all 94.88 0.00 0.00 0.00 0.00 0.00 0.00 0.00 5.12 15982.00 06:47:58 PM all 95.44 0.00 0.00 0.00 0.00 0.00 0.00 0.00 4.56 16075.00 Average: all 94.49 0.01 0.08 0.00 0.00 0.00 0.00 0.00 5.42 15954.60 -tip+patches: 06:47:03 PM CPU %usr %nice %sys %iowait %irq %soft %steal %guest %idle intr/s 06:47:04 PM all 100.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 16630.00 06:47:05 PM all 99.69 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.31 16580.20 06:47:06 PM all 99.69 0.00 0.06 0.00 0.00 0.00 0.00 0.00 0.25 16596.00 06:47:07 PM all 99.20 0.00 0.74 0.00 0.00 0.06 0.00 0.00 0.00 17838.61 06:47:08 PM all 100.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 16540.00 06:47:09 PM all 100.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 16575.00 06:47:10 PM all 100.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 16614.00 06:47:11 PM all 99.94 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.06 16588.00 06:47:12 PM all 99.94 0.00 0.06 0.00 0.00 0.00 0.00 0.00 0.00 16593.00 06:47:13 PM all 99.94 0.00 0.06 0.00 0.00 0.00 0.00 0.00 0.00 16551.00 Average: all 99.84 0.00 0.09 0.00 0.00 0.01 0.00 0.00 0.06 16711.58 We see an improvement in idle% on the system (drops from 5.42% on -tip to 0.06% with the patches). We see an improvement in idle% on the system (drops from 5.42% on -tip to 0.06% with the patches). Signed-off-by: Nikhil Rao <ncrao@google.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Nikunj A. Dadhania <nikunj@linux.vnet.ibm.com> Cc: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Cc: Stephan Barwolf <stephan.baerwolf@tu-ilmenau.de> Cc: Mike Galbraith <efault@gmx.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/1305754668-18792-1-git-send-email-ncrao@google.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-05-18 21:37:48 +00:00
load->weight = scale_load(WEIGHT_IDLEPRIO);
sched: Cleanup set_load_weight() Avoid using long repetitious names; make this simpler and nicer to read. No functional change introduced in this patch. Signed-off-by: Nikhil Rao <ncrao@google.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Nikunj A. Dadhania <nikunj@linux.vnet.ibm.com> Cc: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Cc: Stephan Barwolf <stephan.baerwolf@tu-ilmenau.de> Cc: Mike Galbraith <efault@gmx.de> Link: http://lkml.kernel.org/r/1305738580-9924-2-git-send-email-ncrao@google.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-05-18 17:09:38 +00:00
load->inv_weight = WMULT_IDLEPRIO;
sched: cfs core code apply the CFS core code. this change switches over the scheduler core to CFS's modular design and makes use of kernel/sched_fair/rt/idletask.c to implement Linux's scheduling policies. thanks to Andrew Morton and Thomas Gleixner for lots of detailed review feedback and for fixlets. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
2007-07-09 16:51:59 +00:00
return;
}
sched: cleanup: move dequeue/enqueue_task() cleanup: move dequeue/enqueue_task() to a more logical place, to not split up __normal_prio()/normal_prio(). Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-09 16:51:59 +00:00
sched: Increase SCHED_LOAD_SCALE resolution Introduce SCHED_LOAD_RESOLUTION, which scales is added to SCHED_LOAD_SHIFT and increases the resolution of SCHED_LOAD_SCALE. This patch sets the value of SCHED_LOAD_RESOLUTION to 10, scaling up the weights for all sched entities by a factor of 1024. With this extra resolution, we can handle deeper cgroup hiearchies and the scheduler can do better shares distribution and load load balancing on larger systems (especially for low weight task groups). This does not change the existing user interface, the scaled weights are only used internally. We do not modify prio_to_weight values or inverses, but use the original weights when calculating the inverse which is used to scale execution time delta in calc_delta_mine(). This ensures we do not lose accuracy when accounting time to the sched entities. Thanks to Nikunj Dadhania for fixing an bug in c_d_m() that broken fairness. Below is some analysis of the performance costs/improvements of this patch. 1. Micro-arch performance costs: Experiment was to run Ingo's pipe_test_100k 200 times with the task pinned to one cpu. I measured instruction, cycles and stalled-cycles for the runs. See: http://thread.gmane.org/gmane.linux.kernel/1129232/focus=1129389 for more info. -tip (baseline): Performance counter stats for '/root/load-scale/pipe-test-100k' (200 runs): 964,991,769 instructions # 0.82 insns per cycle # 0.33 stalled cycles per insn # ( +- 0.05% ) 1,171,186,635 cycles # 0.000 GHz ( +- 0.08% ) 306,373,664 stalled-cycles-backend # 26.16% backend cycles idle ( +- 0.28% ) 314,933,621 stalled-cycles-frontend # 26.89% frontend cycles idle ( +- 0.34% ) 1.122405684 seconds time elapsed ( +- 0.05% ) -tip+patches: Performance counter stats for './load-scale/pipe-test-100k' (200 runs): 963,624,821 instructions # 0.82 insns per cycle # 0.33 stalled cycles per insn # ( +- 0.04% ) 1,175,215,649 cycles # 0.000 GHz ( +- 0.08% ) 315,321,126 stalled-cycles-backend # 26.83% backend cycles idle ( +- 0.28% ) 316,835,873 stalled-cycles-frontend # 26.96% frontend cycles idle ( +- 0.29% ) 1.122238659 seconds time elapsed ( +- 0.06% ) With this patch, instructions decrease by ~0.10% and cycles increase by 0.27%. This doesn't look statistically significant. The number of stalled cycles in the backend increased from 26.16% to 26.83%. This can be attributed to the shifts we do in c_d_m() and other places. The fraction of stalled cycles in the frontend remains about the same, at 26.96% compared to 26.89% in -tip. 2. Balancing low-weight task groups Test setup: run 50 tasks with random sleep/busy times (biased around 100ms) in a low weight container (with cpu.shares = 2). Measure %idle as reported by mpstat over a 10s window. -tip (baseline): 06:47:48 PM CPU %usr %nice %sys %iowait %irq %soft %steal %guest %idle intr/s 06:47:49 PM all 94.32 0.00 0.06 0.00 0.00 0.00 0.00 0.00 5.62 15888.00 06:47:50 PM all 94.57 0.00 0.62 0.00 0.00 0.00 0.00 0.00 4.81 16180.00 06:47:51 PM all 94.69 0.00 0.06 0.00 0.00 0.00 0.00 0.00 5.25 15966.00 06:47:52 PM all 95.81 0.00 0.00 0.00 0.00 0.00 0.00 0.00 4.19 16053.00 06:47:53 PM all 94.88 0.06 0.00 0.00 0.00 0.00 0.00 0.00 5.06 15984.00 06:47:54 PM all 93.31 0.00 0.00 0.00 0.00 0.00 0.00 0.00 6.69 15806.00 06:47:55 PM all 94.19 0.00 0.06 0.00 0.00 0.00 0.00 0.00 5.75 15896.00 06:47:56 PM all 92.87 0.00 0.00 0.00 0.00 0.00 0.00 0.00 7.13 15716.00 06:47:57 PM all 94.88 0.00 0.00 0.00 0.00 0.00 0.00 0.00 5.12 15982.00 06:47:58 PM all 95.44 0.00 0.00 0.00 0.00 0.00 0.00 0.00 4.56 16075.00 Average: all 94.49 0.01 0.08 0.00 0.00 0.00 0.00 0.00 5.42 15954.60 -tip+patches: 06:47:03 PM CPU %usr %nice %sys %iowait %irq %soft %steal %guest %idle intr/s 06:47:04 PM all 100.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 16630.00 06:47:05 PM all 99.69 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.31 16580.20 06:47:06 PM all 99.69 0.00 0.06 0.00 0.00 0.00 0.00 0.00 0.25 16596.00 06:47:07 PM all 99.20 0.00 0.74 0.00 0.00 0.06 0.00 0.00 0.00 17838.61 06:47:08 PM all 100.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 16540.00 06:47:09 PM all 100.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 16575.00 06:47:10 PM all 100.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 16614.00 06:47:11 PM all 99.94 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.06 16588.00 06:47:12 PM all 99.94 0.00 0.06 0.00 0.00 0.00 0.00 0.00 0.00 16593.00 06:47:13 PM all 99.94 0.00 0.06 0.00 0.00 0.00 0.00 0.00 0.00 16551.00 Average: all 99.84 0.00 0.09 0.00 0.00 0.01 0.00 0.00 0.06 16711.58 We see an improvement in idle% on the system (drops from 5.42% on -tip to 0.06% with the patches). We see an improvement in idle% on the system (drops from 5.42% on -tip to 0.06% with the patches). Signed-off-by: Nikhil Rao <ncrao@google.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Nikunj A. Dadhania <nikunj@linux.vnet.ibm.com> Cc: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Cc: Stephan Barwolf <stephan.baerwolf@tu-ilmenau.de> Cc: Mike Galbraith <efault@gmx.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/1305754668-18792-1-git-send-email-ncrao@google.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-05-18 21:37:48 +00:00
load->weight = scale_load(prio_to_weight[prio]);
sched: Cleanup set_load_weight() Avoid using long repetitious names; make this simpler and nicer to read. No functional change introduced in this patch. Signed-off-by: Nikhil Rao <ncrao@google.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Nikunj A. Dadhania <nikunj@linux.vnet.ibm.com> Cc: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Cc: Stephan Barwolf <stephan.baerwolf@tu-ilmenau.de> Cc: Mike Galbraith <efault@gmx.de> Link: http://lkml.kernel.org/r/1305738580-9924-2-git-send-email-ncrao@google.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-05-18 17:09:38 +00:00
load->inv_weight = prio_to_wmult[prio];
sched: cleanup: move dequeue/enqueue_task() cleanup: move dequeue/enqueue_task() to a more logical place, to not split up __normal_prio()/normal_prio(). Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-09 16:51:59 +00:00
}
sched: Add enqueue/dequeue flags In order to reduce the dependency on TASK_WAKING rework the enqueue interface to support a proper flags field. Replace the int wakeup, bool head arguments with an int flags argument and create the following flags: ENQUEUE_WAKEUP - the enqueue is a wakeup of a sleeping task, ENQUEUE_WAKING - the enqueue has relative vruntime due to having sched_class::task_waking() called, ENQUEUE_HEAD - the waking task should be places on the head of the priority queue (where appropriate). For symmetry also convert sched_class::dequeue() to a flags scheme. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-03-24 15:38:48 +00:00
static void enqueue_task(struct rq *rq, struct task_struct *p, int flags)
sched: add avg-overlap support to RT tasks We have the notion of tracking process-coupling (a.k.a. buddy-wake) via the p->se.last_wake / p->se.avg_overlap facilities, but it is only used for cfs to cfs interactions. There is no reason why an rt to cfs interaction cannot share in establishing a relationhip in a similar manner. Because PREEMPT_RT runs many kernel threads as FIFO priority, we often times have heavy interaction between RT threads waking CFS applications. This patch offers a substantial boost (50-60%+) in perfomance under those circumstances. Signed-off-by: Gregory Haskins <ghaskins@novell.com> Cc: npiggin@suse.de Cc: rostedt@goodmis.org Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-27 20:30:00 +00:00
{
sched: Cleanup/optimize clock updates Now that we no longer depend on the clock being updated prior to enqueueing on migratory wakeup, we can clean up a bit, placing calls to update_rq_clock() exactly where they are needed, ie on enqueue, dequeue and schedule events. In the case of a freshly enqueued task immediately preempting, we can skip the update during preemption, as the clock was just updated by the enqueue event. We also save an unneeded call during a migratory wakeup by not updating the previous runqueue, where update_curr() won't be invoked. Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1268301199.6785.32.camel@marge.simson.net> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-03-11 16:16:20 +00:00
update_rq_clock(rq);
sched: cfs core code apply the CFS core code. this change switches over the scheduler core to CFS's modular design and makes use of kernel/sched_fair/rt/idletask.c to implement Linux's scheduling policies. thanks to Andrew Morton and Thomas Gleixner for lots of detailed review feedback and for fixlets. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
2007-07-09 16:51:59 +00:00
sched_info_queued(p);
sched: Add enqueue/dequeue flags In order to reduce the dependency on TASK_WAKING rework the enqueue interface to support a proper flags field. Replace the int wakeup, bool head arguments with an int flags argument and create the following flags: ENQUEUE_WAKEUP - the enqueue is a wakeup of a sleeping task, ENQUEUE_WAKING - the enqueue has relative vruntime due to having sched_class::task_waking() called, ENQUEUE_HEAD - the waking task should be places on the head of the priority queue (where appropriate). For symmetry also convert sched_class::dequeue() to a flags scheme. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-03-24 15:38:48 +00:00
p->sched_class->enqueue_task(rq, p, flags);
sched: cleanup: move dequeue/enqueue_task() cleanup: move dequeue/enqueue_task() to a more logical place, to not split up __normal_prio()/normal_prio(). Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-09 16:51:59 +00:00
}
sched: Add enqueue/dequeue flags In order to reduce the dependency on TASK_WAKING rework the enqueue interface to support a proper flags field. Replace the int wakeup, bool head arguments with an int flags argument and create the following flags: ENQUEUE_WAKEUP - the enqueue is a wakeup of a sleeping task, ENQUEUE_WAKING - the enqueue has relative vruntime due to having sched_class::task_waking() called, ENQUEUE_HEAD - the waking task should be places on the head of the priority queue (where appropriate). For symmetry also convert sched_class::dequeue() to a flags scheme. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-03-24 15:38:48 +00:00
static void dequeue_task(struct rq *rq, struct task_struct *p, int flags)
sched: cleanup: move dequeue/enqueue_task() cleanup: move dequeue/enqueue_task() to a more logical place, to not split up __normal_prio()/normal_prio(). Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-09 16:51:59 +00:00
{
sched: Cleanup/optimize clock updates Now that we no longer depend on the clock being updated prior to enqueueing on migratory wakeup, we can clean up a bit, placing calls to update_rq_clock() exactly where they are needed, ie on enqueue, dequeue and schedule events. In the case of a freshly enqueued task immediately preempting, we can skip the update during preemption, as the clock was just updated by the enqueue event. We also save an unneeded call during a migratory wakeup by not updating the previous runqueue, where update_curr() won't be invoked. Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1268301199.6785.32.camel@marge.simson.net> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-03-11 16:16:20 +00:00
update_rq_clock(rq);
sched: fix accounting in task delay accounting & migration On Thu, Jun 19, 2008 at 12:27:14PM +0200, Peter Zijlstra wrote: > On Thu, 2008-06-05 at 10:50 +0530, Ankita Garg wrote: > > > Thanks Peter for the explanation... > > > > I agree with the above and that is the reason why I did not see weird > > values with cpu_time. But, run_delay still would suffer skews as the end > > points for delta could be taken on different cpus due to migration (more > > so on RT kernel due to the push-pull operations). With the below patch, > > I could not reproduce the issue I had seen earlier. After every dequeue, > > we take the delta and start wait measurements from zero when moved to a > > different rq. > > OK, so task delay delay accounting is broken because it doesn't take > migration into account. > > What you've done is make it symmetric wrt enqueue, and account it like > > cpu0 cpu1 > > enqueue > <wait-d1> > dequeue > enqueue > <wait-d2> > run > > Where you add both d1 and d2 to the run_delay,.. right? > Thanks for reviewing the patch. The above is exactly what I have done. > This seems like a good fix, however it looks like the patch will break > compilation in !CONFIG_SCHEDSTATS && !CONFIG_TASK_DELAY_ACCT, of it > failing to provide a stub for sched_info_dequeue() in that case. Fixed. Pl. find the new patch below. Signed-off-by: Ankita Garg <ankita@in.ibm.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Gregory Haskins <ghaskins@novell.com> Cc: rostedt@goodmis.org Cc: suresh.b.siddha@intel.com Cc: aneesh.kumar@linux.vnet.ibm.com Cc: dhaval@linux.vnet.ibm.com Cc: vatsa@linux.vnet.ibm.com Cc: David Bahi <DBahi@novell.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-01 09:00:06 +00:00
sched_info_dequeued(p);
sched: Add enqueue/dequeue flags In order to reduce the dependency on TASK_WAKING rework the enqueue interface to support a proper flags field. Replace the int wakeup, bool head arguments with an int flags argument and create the following flags: ENQUEUE_WAKEUP - the enqueue is a wakeup of a sleeping task, ENQUEUE_WAKING - the enqueue has relative vruntime due to having sched_class::task_waking() called, ENQUEUE_HEAD - the waking task should be places on the head of the priority queue (where appropriate). For symmetry also convert sched_class::dequeue() to a flags scheme. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-03-24 15:38:48 +00:00
p->sched_class->dequeue_task(rq, p, flags);
sched: cleanup: move dequeue/enqueue_task() cleanup: move dequeue/enqueue_task() to a more logical place, to not split up __normal_prio()/normal_prio(). Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-09 16:51:59 +00:00
}
sched: Move load balance code into sched_fair.c Straight fwd code movement. Since non of the load-balance abstractions are used anymore, do away with them and simplify the code some. In preparation move the code around. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-17 16:00:43 +00:00
/*
* activate_task - move a task to the runqueue.
*/
sched: Add enqueue/dequeue flags In order to reduce the dependency on TASK_WAKING rework the enqueue interface to support a proper flags field. Replace the int wakeup, bool head arguments with an int flags argument and create the following flags: ENQUEUE_WAKEUP - the enqueue is a wakeup of a sleeping task, ENQUEUE_WAKING - the enqueue has relative vruntime due to having sched_class::task_waking() called, ENQUEUE_HEAD - the waking task should be places on the head of the priority queue (where appropriate). For symmetry also convert sched_class::dequeue() to a flags scheme. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-03-24 15:38:48 +00:00
static void activate_task(struct rq *rq, struct task_struct *p, int flags)
sched: Move load balance code into sched_fair.c Straight fwd code movement. Since non of the load-balance abstractions are used anymore, do away with them and simplify the code some. In preparation move the code around. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-17 16:00:43 +00:00
{
if (task_contributes_to_load(p))
rq->nr_uninterruptible--;
sched: Add enqueue/dequeue flags In order to reduce the dependency on TASK_WAKING rework the enqueue interface to support a proper flags field. Replace the int wakeup, bool head arguments with an int flags argument and create the following flags: ENQUEUE_WAKEUP - the enqueue is a wakeup of a sleeping task, ENQUEUE_WAKING - the enqueue has relative vruntime due to having sched_class::task_waking() called, ENQUEUE_HEAD - the waking task should be places on the head of the priority queue (where appropriate). For symmetry also convert sched_class::dequeue() to a flags scheme. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-03-24 15:38:48 +00:00
enqueue_task(rq, p, flags);
sched: Move load balance code into sched_fair.c Straight fwd code movement. Since non of the load-balance abstractions are used anymore, do away with them and simplify the code some. In preparation move the code around. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-17 16:00:43 +00:00
}
/*
* deactivate_task - remove a task from the runqueue.
*/
sched: Add enqueue/dequeue flags In order to reduce the dependency on TASK_WAKING rework the enqueue interface to support a proper flags field. Replace the int wakeup, bool head arguments with an int flags argument and create the following flags: ENQUEUE_WAKEUP - the enqueue is a wakeup of a sleeping task, ENQUEUE_WAKING - the enqueue has relative vruntime due to having sched_class::task_waking() called, ENQUEUE_HEAD - the waking task should be places on the head of the priority queue (where appropriate). For symmetry also convert sched_class::dequeue() to a flags scheme. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-03-24 15:38:48 +00:00
static void deactivate_task(struct rq *rq, struct task_struct *p, int flags)
sched: Move load balance code into sched_fair.c Straight fwd code movement. Since non of the load-balance abstractions are used anymore, do away with them and simplify the code some. In preparation move the code around. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-17 16:00:43 +00:00
{
if (task_contributes_to_load(p))
rq->nr_uninterruptible++;
sched: Add enqueue/dequeue flags In order to reduce the dependency on TASK_WAKING rework the enqueue interface to support a proper flags field. Replace the int wakeup, bool head arguments with an int flags argument and create the following flags: ENQUEUE_WAKEUP - the enqueue is a wakeup of a sleeping task, ENQUEUE_WAKING - the enqueue has relative vruntime due to having sched_class::task_waking() called, ENQUEUE_HEAD - the waking task should be places on the head of the priority queue (where appropriate). For symmetry also convert sched_class::dequeue() to a flags scheme. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-03-24 15:38:48 +00:00
dequeue_task(rq, p, flags);
sched: Move load balance code into sched_fair.c Straight fwd code movement. Since non of the load-balance abstractions are used anymore, do away with them and simplify the code some. In preparation move the code around. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-17 16:00:43 +00:00
}
sched: Add IRQ_TIME_ACCOUNTING, finer accounting of irq time s390/powerpc/ia64 have support for CONFIG_VIRT_CPU_ACCOUNTING which does the fine granularity accounting of user, system, hardirq, softirq times. Adding that option on archs like x86 will be challenging however, given the state of TSC reliability on various platforms and also the overhead it will add in syscall entry exit. Instead, add a lighter variant that only does finer accounting of hardirq and softirq times, providing precise irq times (instead of timer tick based samples). This accounting is added with a new config option CONFIG_IRQ_TIME_ACCOUNTING so that there won't be any overhead for users not interested in paying the perf penalty. This accounting is based on sched_clock, with the code being generic. So, other archs may find it useful as well. This patch just adds the core logic and does not enable this logic yet. Signed-off-by: Venkatesh Pallipadi <venki@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1286237003-12406-5-git-send-email-venki@google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-05 00:03:19 +00:00
#ifdef CONFIG_IRQ_TIME_ACCOUNTING
sched: Do not account irq time to current task Scheduler accounts both softirq and interrupt processing times to the currently running task. This means, if the interrupt processing was for some other task in the system, then the current task ends up being penalized as it gets shorter runtime than otherwise. Change sched task accounting to acoount only actual task time from currently running task. Now update_curr(), modifies the delta_exec to depend on rq->clock_task. Note that this change only handles CONFIG_IRQ_TIME_ACCOUNTING case. We can extend this to CONFIG_VIRT_CPU_ACCOUNTING with minimal effort. But, thats for later. This change will impact scheduling behavior in interrupt heavy conditions. Tested on a 4-way system with eth0 handled by CPU 2 and a network heavy task (nc) running on CPU 3 (and no RSS/RFS). With that I have CPU 2 spending 75%+ of its time in irq processing. CPU 3 spending around 35% time running nc task. Now, if I run another CPU intensive task on CPU 2, without this change /proc/<pid>/schedstat shows 100% of time accounted to this task. With this change, it rightly shows less than 25% accounted to this task as remaining time is actually spent on irq processing. Signed-off-by: Venkatesh Pallipadi <venki@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1286237003-12406-7-git-send-email-venki@google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-05 00:03:21 +00:00
/*
* There are no locks covering percpu hardirq/softirq time.
* They are only modified in account_system_vtime, on corresponding CPU
* with interrupts disabled. So, writes are safe.
* They are read and saved off onto struct rq in update_rq_clock().
* This may result in other CPU reading this CPU's irq time and can
* race with irq/account_system_vtime on this CPU. We would either get old
sched: Fix the irqtime code for 32bit Since the irqtime accounting is using non-atomic u64 and can be read from remote cpus (writes are strictly cpu local, reads are not) we have to deal with observing partial updates. When we do observe partial updates the clock movement (in particular, ->clock_task movement) will go funny (in either direction), a subsequent clock update (observing the full update) will make it go funny in the oposite direction. Since we rely on these clocks to be strictly monotonic we cannot suffer backwards motion. One possible solution would be to simply ignore all backwards deltas, but that will lead to accounting artefacts, most notable: clock_task + irq_time != clock, this inaccuracy would end up in user visible stats. Therefore serialize the reads using a seqcount. Reviewed-by: Venkatesh Pallipadi <venki@google.com> Reported-by: Mikael Pettersson <mikpe@it.uu.se> Tested-by: Mikael Pettersson <mikpe@it.uu.se> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1292242434.6803.200.camel@twins> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-12-09 13:15:34 +00:00
* or new value with a side effect of accounting a slice of irq time to wrong
* task when irq is in progress while we read rq->clock. That is a worthy
* compromise in place of having locks on each irq in account_system_time.
sched: Do not account irq time to current task Scheduler accounts both softirq and interrupt processing times to the currently running task. This means, if the interrupt processing was for some other task in the system, then the current task ends up being penalized as it gets shorter runtime than otherwise. Change sched task accounting to acoount only actual task time from currently running task. Now update_curr(), modifies the delta_exec to depend on rq->clock_task. Note that this change only handles CONFIG_IRQ_TIME_ACCOUNTING case. We can extend this to CONFIG_VIRT_CPU_ACCOUNTING with minimal effort. But, thats for later. This change will impact scheduling behavior in interrupt heavy conditions. Tested on a 4-way system with eth0 handled by CPU 2 and a network heavy task (nc) running on CPU 3 (and no RSS/RFS). With that I have CPU 2 spending 75%+ of its time in irq processing. CPU 3 spending around 35% time running nc task. Now, if I run another CPU intensive task on CPU 2, without this change /proc/<pid>/schedstat shows 100% of time accounted to this task. With this change, it rightly shows less than 25% accounted to this task as remaining time is actually spent on irq processing. Signed-off-by: Venkatesh Pallipadi <venki@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1286237003-12406-7-git-send-email-venki@google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-05 00:03:21 +00:00
*/
sched: Add IRQ_TIME_ACCOUNTING, finer accounting of irq time s390/powerpc/ia64 have support for CONFIG_VIRT_CPU_ACCOUNTING which does the fine granularity accounting of user, system, hardirq, softirq times. Adding that option on archs like x86 will be challenging however, given the state of TSC reliability on various platforms and also the overhead it will add in syscall entry exit. Instead, add a lighter variant that only does finer accounting of hardirq and softirq times, providing precise irq times (instead of timer tick based samples). This accounting is added with a new config option CONFIG_IRQ_TIME_ACCOUNTING so that there won't be any overhead for users not interested in paying the perf penalty. This accounting is based on sched_clock, with the code being generic. So, other archs may find it useful as well. This patch just adds the core logic and does not enable this logic yet. Signed-off-by: Venkatesh Pallipadi <venki@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1286237003-12406-5-git-send-email-venki@google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-05 00:03:19 +00:00
static DEFINE_PER_CPU(u64, cpu_hardirq_time);
static DEFINE_PER_CPU(u64, cpu_softirq_time);
static DEFINE_PER_CPU(u64, irq_start_time);
static int sched_clock_irqtime;
void enable_sched_clock_irqtime(void)
{
sched_clock_irqtime = 1;
}
void disable_sched_clock_irqtime(void)
{
sched_clock_irqtime = 0;
}
sched: Fix the irqtime code for 32bit Since the irqtime accounting is using non-atomic u64 and can be read from remote cpus (writes are strictly cpu local, reads are not) we have to deal with observing partial updates. When we do observe partial updates the clock movement (in particular, ->clock_task movement) will go funny (in either direction), a subsequent clock update (observing the full update) will make it go funny in the oposite direction. Since we rely on these clocks to be strictly monotonic we cannot suffer backwards motion. One possible solution would be to simply ignore all backwards deltas, but that will lead to accounting artefacts, most notable: clock_task + irq_time != clock, this inaccuracy would end up in user visible stats. Therefore serialize the reads using a seqcount. Reviewed-by: Venkatesh Pallipadi <venki@google.com> Reported-by: Mikael Pettersson <mikpe@it.uu.se> Tested-by: Mikael Pettersson <mikpe@it.uu.se> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1292242434.6803.200.camel@twins> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-12-09 13:15:34 +00:00
#ifndef CONFIG_64BIT
static DEFINE_PER_CPU(seqcount_t, irq_time_seq);
static inline void irq_time_write_begin(void)
{
__this_cpu_inc(irq_time_seq.sequence);
smp_wmb();
}
static inline void irq_time_write_end(void)
{
smp_wmb();
__this_cpu_inc(irq_time_seq.sequence);
}
static inline u64 irq_time_read(int cpu)
{
u64 irq_time;
unsigned seq;
do {
seq = read_seqcount_begin(&per_cpu(irq_time_seq, cpu));
irq_time = per_cpu(cpu_softirq_time, cpu) +
per_cpu(cpu_hardirq_time, cpu);
} while (read_seqcount_retry(&per_cpu(irq_time_seq, cpu), seq));
return irq_time;
}
#else /* CONFIG_64BIT */
static inline void irq_time_write_begin(void)
{
}
static inline void irq_time_write_end(void)
{
}
static inline u64 irq_time_read(int cpu)
sched: Do not account irq time to current task Scheduler accounts both softirq and interrupt processing times to the currently running task. This means, if the interrupt processing was for some other task in the system, then the current task ends up being penalized as it gets shorter runtime than otherwise. Change sched task accounting to acoount only actual task time from currently running task. Now update_curr(), modifies the delta_exec to depend on rq->clock_task. Note that this change only handles CONFIG_IRQ_TIME_ACCOUNTING case. We can extend this to CONFIG_VIRT_CPU_ACCOUNTING with minimal effort. But, thats for later. This change will impact scheduling behavior in interrupt heavy conditions. Tested on a 4-way system with eth0 handled by CPU 2 and a network heavy task (nc) running on CPU 3 (and no RSS/RFS). With that I have CPU 2 spending 75%+ of its time in irq processing. CPU 3 spending around 35% time running nc task. Now, if I run another CPU intensive task on CPU 2, without this change /proc/<pid>/schedstat shows 100% of time accounted to this task. With this change, it rightly shows less than 25% accounted to this task as remaining time is actually spent on irq processing. Signed-off-by: Venkatesh Pallipadi <venki@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1286237003-12406-7-git-send-email-venki@google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-05 00:03:21 +00:00
{
return per_cpu(cpu_softirq_time, cpu) + per_cpu(cpu_hardirq_time, cpu);
}
sched: Fix the irqtime code for 32bit Since the irqtime accounting is using non-atomic u64 and can be read from remote cpus (writes are strictly cpu local, reads are not) we have to deal with observing partial updates. When we do observe partial updates the clock movement (in particular, ->clock_task movement) will go funny (in either direction), a subsequent clock update (observing the full update) will make it go funny in the oposite direction. Since we rely on these clocks to be strictly monotonic we cannot suffer backwards motion. One possible solution would be to simply ignore all backwards deltas, but that will lead to accounting artefacts, most notable: clock_task + irq_time != clock, this inaccuracy would end up in user visible stats. Therefore serialize the reads using a seqcount. Reviewed-by: Venkatesh Pallipadi <venki@google.com> Reported-by: Mikael Pettersson <mikpe@it.uu.se> Tested-by: Mikael Pettersson <mikpe@it.uu.se> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1292242434.6803.200.camel@twins> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-12-09 13:15:34 +00:00
#endif /* CONFIG_64BIT */
sched: Do not account irq time to current task Scheduler accounts both softirq and interrupt processing times to the currently running task. This means, if the interrupt processing was for some other task in the system, then the current task ends up being penalized as it gets shorter runtime than otherwise. Change sched task accounting to acoount only actual task time from currently running task. Now update_curr(), modifies the delta_exec to depend on rq->clock_task. Note that this change only handles CONFIG_IRQ_TIME_ACCOUNTING case. We can extend this to CONFIG_VIRT_CPU_ACCOUNTING with minimal effort. But, thats for later. This change will impact scheduling behavior in interrupt heavy conditions. Tested on a 4-way system with eth0 handled by CPU 2 and a network heavy task (nc) running on CPU 3 (and no RSS/RFS). With that I have CPU 2 spending 75%+ of its time in irq processing. CPU 3 spending around 35% time running nc task. Now, if I run another CPU intensive task on CPU 2, without this change /proc/<pid>/schedstat shows 100% of time accounted to this task. With this change, it rightly shows less than 25% accounted to this task as remaining time is actually spent on irq processing. Signed-off-by: Venkatesh Pallipadi <venki@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1286237003-12406-7-git-send-email-venki@google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-05 00:03:21 +00:00
sched: Fix the irqtime code to deal with u64 wraps Some ARM systems have a short sched_clock() [ which needs to be fixed too ], but this exposed a bug in the irq_time code as well, it doesn't deal with wraps at all. Fix the irq_time code to deal with u64 wraps by re-writing the code to only use delta increments, which avoids the whole issue. Reviewed-by: Venkatesh Pallipadi <venki@google.com> Reported-by: Mikael Pettersson <mikpe@it.uu.se> Tested-by: Mikael Pettersson <mikpe@it.uu.se> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1292242433.6803.199.camel@twins> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-12-09 13:15:34 +00:00
/*
* Called before incrementing preempt_count on {soft,}irq_enter
* and before decrementing preempt_count on {soft,}irq_exit.
*/
sched: Add IRQ_TIME_ACCOUNTING, finer accounting of irq time s390/powerpc/ia64 have support for CONFIG_VIRT_CPU_ACCOUNTING which does the fine granularity accounting of user, system, hardirq, softirq times. Adding that option on archs like x86 will be challenging however, given the state of TSC reliability on various platforms and also the overhead it will add in syscall entry exit. Instead, add a lighter variant that only does finer accounting of hardirq and softirq times, providing precise irq times (instead of timer tick based samples). This accounting is added with a new config option CONFIG_IRQ_TIME_ACCOUNTING so that there won't be any overhead for users not interested in paying the perf penalty. This accounting is based on sched_clock, with the code being generic. So, other archs may find it useful as well. This patch just adds the core logic and does not enable this logic yet. Signed-off-by: Venkatesh Pallipadi <venki@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1286237003-12406-5-git-send-email-venki@google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-05 00:03:19 +00:00
void account_system_vtime(struct task_struct *curr)
{
unsigned long flags;
sched: Fix the irqtime code to deal with u64 wraps Some ARM systems have a short sched_clock() [ which needs to be fixed too ], but this exposed a bug in the irq_time code as well, it doesn't deal with wraps at all. Fix the irq_time code to deal with u64 wraps by re-writing the code to only use delta increments, which avoids the whole issue. Reviewed-by: Venkatesh Pallipadi <venki@google.com> Reported-by: Mikael Pettersson <mikpe@it.uu.se> Tested-by: Mikael Pettersson <mikpe@it.uu.se> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1292242433.6803.199.camel@twins> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-12-09 13:15:34 +00:00
s64 delta;
sched: Add IRQ_TIME_ACCOUNTING, finer accounting of irq time s390/powerpc/ia64 have support for CONFIG_VIRT_CPU_ACCOUNTING which does the fine granularity accounting of user, system, hardirq, softirq times. Adding that option on archs like x86 will be challenging however, given the state of TSC reliability on various platforms and also the overhead it will add in syscall entry exit. Instead, add a lighter variant that only does finer accounting of hardirq and softirq times, providing precise irq times (instead of timer tick based samples). This accounting is added with a new config option CONFIG_IRQ_TIME_ACCOUNTING so that there won't be any overhead for users not interested in paying the perf penalty. This accounting is based on sched_clock, with the code being generic. So, other archs may find it useful as well. This patch just adds the core logic and does not enable this logic yet. Signed-off-by: Venkatesh Pallipadi <venki@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1286237003-12406-5-git-send-email-venki@google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-05 00:03:19 +00:00
int cpu;
if (!sched_clock_irqtime)
return;
local_irq_save(flags);
cpu = smp_processor_id();
sched: Fix the irqtime code to deal with u64 wraps Some ARM systems have a short sched_clock() [ which needs to be fixed too ], but this exposed a bug in the irq_time code as well, it doesn't deal with wraps at all. Fix the irq_time code to deal with u64 wraps by re-writing the code to only use delta increments, which avoids the whole issue. Reviewed-by: Venkatesh Pallipadi <venki@google.com> Reported-by: Mikael Pettersson <mikpe@it.uu.se> Tested-by: Mikael Pettersson <mikpe@it.uu.se> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1292242433.6803.199.camel@twins> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-12-09 13:15:34 +00:00
delta = sched_clock_cpu(cpu) - __this_cpu_read(irq_start_time);
__this_cpu_add(irq_start_time, delta);
sched: Fix the irqtime code for 32bit Since the irqtime accounting is using non-atomic u64 and can be read from remote cpus (writes are strictly cpu local, reads are not) we have to deal with observing partial updates. When we do observe partial updates the clock movement (in particular, ->clock_task movement) will go funny (in either direction), a subsequent clock update (observing the full update) will make it go funny in the oposite direction. Since we rely on these clocks to be strictly monotonic we cannot suffer backwards motion. One possible solution would be to simply ignore all backwards deltas, but that will lead to accounting artefacts, most notable: clock_task + irq_time != clock, this inaccuracy would end up in user visible stats. Therefore serialize the reads using a seqcount. Reviewed-by: Venkatesh Pallipadi <venki@google.com> Reported-by: Mikael Pettersson <mikpe@it.uu.se> Tested-by: Mikael Pettersson <mikpe@it.uu.se> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1292242434.6803.200.camel@twins> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-12-09 13:15:34 +00:00
irq_time_write_begin();
sched: Add IRQ_TIME_ACCOUNTING, finer accounting of irq time s390/powerpc/ia64 have support for CONFIG_VIRT_CPU_ACCOUNTING which does the fine granularity accounting of user, system, hardirq, softirq times. Adding that option on archs like x86 will be challenging however, given the state of TSC reliability on various platforms and also the overhead it will add in syscall entry exit. Instead, add a lighter variant that only does finer accounting of hardirq and softirq times, providing precise irq times (instead of timer tick based samples). This accounting is added with a new config option CONFIG_IRQ_TIME_ACCOUNTING so that there won't be any overhead for users not interested in paying the perf penalty. This accounting is based on sched_clock, with the code being generic. So, other archs may find it useful as well. This patch just adds the core logic and does not enable this logic yet. Signed-off-by: Venkatesh Pallipadi <venki@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1286237003-12406-5-git-send-email-venki@google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-05 00:03:19 +00:00
/*
* We do not account for softirq time from ksoftirqd here.
* We want to continue accounting softirq time to ksoftirqd thread
* in that case, so as not to confuse scheduler with a special task
* that do not consume any time, but still wants to run.
*/
if (hardirq_count())
sched: Fix the irqtime code to deal with u64 wraps Some ARM systems have a short sched_clock() [ which needs to be fixed too ], but this exposed a bug in the irq_time code as well, it doesn't deal with wraps at all. Fix the irq_time code to deal with u64 wraps by re-writing the code to only use delta increments, which avoids the whole issue. Reviewed-by: Venkatesh Pallipadi <venki@google.com> Reported-by: Mikael Pettersson <mikpe@it.uu.se> Tested-by: Mikael Pettersson <mikpe@it.uu.se> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1292242433.6803.199.camel@twins> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-12-09 13:15:34 +00:00
__this_cpu_add(cpu_hardirq_time, delta);
softirqs: Free up pf flag PF_KSOFTIRQD Cleanup patch, freeing up PF_KSOFTIRQD and use per_cpu ksoftirqd pointer instead, as suggested by Eric Dumazet. Tested-by: Shaun Ruffell <sruffell@digium.com> Signed-off-by: Venkatesh Pallipadi <venki@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1292980144-28796-2-git-send-email-venki@google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-12-22 01:09:00 +00:00
else if (in_serving_softirq() && curr != this_cpu_ksoftirqd())
sched: Fix the irqtime code to deal with u64 wraps Some ARM systems have a short sched_clock() [ which needs to be fixed too ], but this exposed a bug in the irq_time code as well, it doesn't deal with wraps at all. Fix the irq_time code to deal with u64 wraps by re-writing the code to only use delta increments, which avoids the whole issue. Reviewed-by: Venkatesh Pallipadi <venki@google.com> Reported-by: Mikael Pettersson <mikpe@it.uu.se> Tested-by: Mikael Pettersson <mikpe@it.uu.se> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1292242433.6803.199.camel@twins> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-12-09 13:15:34 +00:00
__this_cpu_add(cpu_softirq_time, delta);
sched: Add IRQ_TIME_ACCOUNTING, finer accounting of irq time s390/powerpc/ia64 have support for CONFIG_VIRT_CPU_ACCOUNTING which does the fine granularity accounting of user, system, hardirq, softirq times. Adding that option on archs like x86 will be challenging however, given the state of TSC reliability on various platforms and also the overhead it will add in syscall entry exit. Instead, add a lighter variant that only does finer accounting of hardirq and softirq times, providing precise irq times (instead of timer tick based samples). This accounting is added with a new config option CONFIG_IRQ_TIME_ACCOUNTING so that there won't be any overhead for users not interested in paying the perf penalty. This accounting is based on sched_clock, with the code being generic. So, other archs may find it useful as well. This patch just adds the core logic and does not enable this logic yet. Signed-off-by: Venkatesh Pallipadi <venki@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1286237003-12406-5-git-send-email-venki@google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-05 00:03:19 +00:00
sched: Fix the irqtime code for 32bit Since the irqtime accounting is using non-atomic u64 and can be read from remote cpus (writes are strictly cpu local, reads are not) we have to deal with observing partial updates. When we do observe partial updates the clock movement (in particular, ->clock_task movement) will go funny (in either direction), a subsequent clock update (observing the full update) will make it go funny in the oposite direction. Since we rely on these clocks to be strictly monotonic we cannot suffer backwards motion. One possible solution would be to simply ignore all backwards deltas, but that will lead to accounting artefacts, most notable: clock_task + irq_time != clock, this inaccuracy would end up in user visible stats. Therefore serialize the reads using a seqcount. Reviewed-by: Venkatesh Pallipadi <venki@google.com> Reported-by: Mikael Pettersson <mikpe@it.uu.se> Tested-by: Mikael Pettersson <mikpe@it.uu.se> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1292242434.6803.200.camel@twins> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-12-09 13:15:34 +00:00
irq_time_write_end();
sched: Add IRQ_TIME_ACCOUNTING, finer accounting of irq time s390/powerpc/ia64 have support for CONFIG_VIRT_CPU_ACCOUNTING which does the fine granularity accounting of user, system, hardirq, softirq times. Adding that option on archs like x86 will be challenging however, given the state of TSC reliability on various platforms and also the overhead it will add in syscall entry exit. Instead, add a lighter variant that only does finer accounting of hardirq and softirq times, providing precise irq times (instead of timer tick based samples). This accounting is added with a new config option CONFIG_IRQ_TIME_ACCOUNTING so that there won't be any overhead for users not interested in paying the perf penalty. This accounting is based on sched_clock, with the code being generic. So, other archs may find it useful as well. This patch just adds the core logic and does not enable this logic yet. Signed-off-by: Venkatesh Pallipadi <venki@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1286237003-12406-5-git-send-email-venki@google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-05 00:03:19 +00:00
local_irq_restore(flags);
}
sched: Export account_system_vtime() KVM uses it for example: ERROR: "account_system_vtime" [arch/x86/kvm/kvm.ko] undefined! Cc: Venkatesh Pallipadi <venki@google.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1286237003-12406-3-git-send-email-venki@google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-18 18:00:37 +00:00
EXPORT_SYMBOL_GPL(account_system_vtime);
sched: Add IRQ_TIME_ACCOUNTING, finer accounting of irq time s390/powerpc/ia64 have support for CONFIG_VIRT_CPU_ACCOUNTING which does the fine granularity accounting of user, system, hardirq, softirq times. Adding that option on archs like x86 will be challenging however, given the state of TSC reliability on various platforms and also the overhead it will add in syscall entry exit. Instead, add a lighter variant that only does finer accounting of hardirq and softirq times, providing precise irq times (instead of timer tick based samples). This accounting is added with a new config option CONFIG_IRQ_TIME_ACCOUNTING so that there won't be any overhead for users not interested in paying the perf penalty. This accounting is based on sched_clock, with the code being generic. So, other archs may find it useful as well. This patch just adds the core logic and does not enable this logic yet. Signed-off-by: Venkatesh Pallipadi <venki@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1286237003-12406-5-git-send-email-venki@google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-05 00:03:19 +00:00
KVM guest: Steal time accounting This patch accounts steal time time in account_process_tick. If one or more tick is considered stolen in the current accounting cycle, user/system accounting is skipped. Idle is fine, since the hypervisor does not report steal time if the guest is halted. Accounting steal time from the core scheduler give us the advantage of direct acess to the runqueue data. In a later opportunity, it can be used to tweak cpu power and make the scheduler aware of the time it lost. [avi: <asm/paravirt.h> doesn't exist on many archs] Signed-off-by: Glauber Costa <glommer@redhat.com> Acked-by: Rik van Riel <riel@redhat.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Tested-by: Eric B Munson <emunson@mgebm.net> CC: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> CC: Anthony Liguori <aliguori@us.ibm.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-07-11 19:28:17 +00:00
#endif /* CONFIG_IRQ_TIME_ACCOUNTING */
#ifdef CONFIG_PARAVIRT
static inline u64 steal_ticks(u64 steal)
sched: Remove irq time from available CPU power The idea was suggested by Peter Zijlstra here: http://marc.info/?l=linux-kernel&m=127476934517534&w=2 irq time is technically not available to the tasks running on the CPU. This patch removes irq time from CPU power piggybacking on sched_rt_avg_update(). Tested this by keeping CPU X busy with a network intensive task having 75% oa a single CPU irq processing (hard+soft) on a 4-way system. And start seven cycle soakers on the system. Without this change, there will be two tasks on each CPU. With this change, there is a single task on irq busy CPU X and remaining 7 tasks are spread around among other 3 CPUs. Signed-off-by: Venkatesh Pallipadi <venki@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1286237003-12406-8-git-send-email-venki@google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-05 00:03:22 +00:00
{
KVM guest: Steal time accounting This patch accounts steal time time in account_process_tick. If one or more tick is considered stolen in the current accounting cycle, user/system accounting is skipped. Idle is fine, since the hypervisor does not report steal time if the guest is halted. Accounting steal time from the core scheduler give us the advantage of direct acess to the runqueue data. In a later opportunity, it can be used to tweak cpu power and make the scheduler aware of the time it lost. [avi: <asm/paravirt.h> doesn't exist on many archs] Signed-off-by: Glauber Costa <glommer@redhat.com> Acked-by: Rik van Riel <riel@redhat.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Tested-by: Eric B Munson <emunson@mgebm.net> CC: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> CC: Anthony Liguori <aliguori@us.ibm.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-07-11 19:28:17 +00:00
if (unlikely(steal > NSEC_PER_SEC))
return div_u64(steal, TICK_NSEC);
sched: Fix the irqtime code to deal with u64 wraps Some ARM systems have a short sched_clock() [ which needs to be fixed too ], but this exposed a bug in the irq_time code as well, it doesn't deal with wraps at all. Fix the irq_time code to deal with u64 wraps by re-writing the code to only use delta increments, which avoids the whole issue. Reviewed-by: Venkatesh Pallipadi <venki@google.com> Reported-by: Mikael Pettersson <mikpe@it.uu.se> Tested-by: Mikael Pettersson <mikpe@it.uu.se> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1292242433.6803.199.camel@twins> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-12-09 13:15:34 +00:00
KVM guest: Steal time accounting This patch accounts steal time time in account_process_tick. If one or more tick is considered stolen in the current accounting cycle, user/system accounting is skipped. Idle is fine, since the hypervisor does not report steal time if the guest is halted. Accounting steal time from the core scheduler give us the advantage of direct acess to the runqueue data. In a later opportunity, it can be used to tweak cpu power and make the scheduler aware of the time it lost. [avi: <asm/paravirt.h> doesn't exist on many archs] Signed-off-by: Glauber Costa <glommer@redhat.com> Acked-by: Rik van Riel <riel@redhat.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Tested-by: Eric B Munson <emunson@mgebm.net> CC: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> CC: Anthony Liguori <aliguori@us.ibm.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-07-11 19:28:17 +00:00
return __iter_div_u64_rem(steal, TICK_NSEC, &steal);
}
#endif
sched: Fix the irqtime code to deal with u64 wraps Some ARM systems have a short sched_clock() [ which needs to be fixed too ], but this exposed a bug in the irq_time code as well, it doesn't deal with wraps at all. Fix the irq_time code to deal with u64 wraps by re-writing the code to only use delta increments, which avoids the whole issue. Reviewed-by: Venkatesh Pallipadi <venki@google.com> Reported-by: Mikael Pettersson <mikpe@it.uu.se> Tested-by: Mikael Pettersson <mikpe@it.uu.se> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1292242433.6803.199.camel@twins> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-12-09 13:15:34 +00:00
static void update_rq_clock_task(struct rq *rq, s64 delta)
sched: Remove irq time from available CPU power The idea was suggested by Peter Zijlstra here: http://marc.info/?l=linux-kernel&m=127476934517534&w=2 irq time is technically not available to the tasks running on the CPU. This patch removes irq time from CPU power piggybacking on sched_rt_avg_update(). Tested this by keeping CPU X busy with a network intensive task having 75% oa a single CPU irq processing (hard+soft) on a 4-way system. And start seven cycle soakers on the system. Without this change, there will be two tasks on each CPU. With this change, there is a single task on irq busy CPU X and remaining 7 tasks are spread around among other 3 CPUs. Signed-off-by: Venkatesh Pallipadi <venki@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1286237003-12406-8-git-send-email-venki@google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-05 00:03:22 +00:00
{
sched: adjust scheduler cpu power for stolen time This patch makes update_rq_clock() aware of steal time. The mechanism of operation is not different from irq_time, and follows the same principles. This lives in a CONFIG option itself, and can be compiled out independently of the rest of steal time reporting. The effect of disabling it is that the scheduler will still report steal time (that cannot be disabled), but won't use this information for cpu power adjustments. Everytime update_rq_clock_task() is invoked, we query information about how much time was stolen since last call, and feed it into sched_rt_avg_update(). Although steal time reporting in account_process_tick() keeps track of the last time we read the steal clock, in prev_steal_time, this patch do it independently using another field, prev_steal_time_rq. This is because otherwise, information about time accounted in update_process_tick() would never reach us in update_rq_clock(). Signed-off-by: Glauber Costa <glommer@redhat.com> Acked-by: Rik van Riel <riel@redhat.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Tested-by: Eric B Munson <emunson@mgebm.net> CC: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> CC: Anthony Liguori <aliguori@us.ibm.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-07-11 19:28:18 +00:00
/*
* In theory, the compile should just see 0 here, and optimize out the call
* to sched_rt_avg_update. But I don't trust it...
*/
#if defined(CONFIG_IRQ_TIME_ACCOUNTING) || defined(CONFIG_PARAVIRT_TIME_ACCOUNTING)
s64 steal = 0, irq_delta = 0;
#endif
#ifdef CONFIG_IRQ_TIME_ACCOUNTING
sched: Fix the irqtime code for 32bit Since the irqtime accounting is using non-atomic u64 and can be read from remote cpus (writes are strictly cpu local, reads are not) we have to deal with observing partial updates. When we do observe partial updates the clock movement (in particular, ->clock_task movement) will go funny (in either direction), a subsequent clock update (observing the full update) will make it go funny in the oposite direction. Since we rely on these clocks to be strictly monotonic we cannot suffer backwards motion. One possible solution would be to simply ignore all backwards deltas, but that will lead to accounting artefacts, most notable: clock_task + irq_time != clock, this inaccuracy would end up in user visible stats. Therefore serialize the reads using a seqcount. Reviewed-by: Venkatesh Pallipadi <venki@google.com> Reported-by: Mikael Pettersson <mikpe@it.uu.se> Tested-by: Mikael Pettersson <mikpe@it.uu.se> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1292242434.6803.200.camel@twins> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-12-09 13:15:34 +00:00
irq_delta = irq_time_read(cpu_of(rq)) - rq->prev_irq_time;
sched: Fix the irqtime code to deal with u64 wraps Some ARM systems have a short sched_clock() [ which needs to be fixed too ], but this exposed a bug in the irq_time code as well, it doesn't deal with wraps at all. Fix the irq_time code to deal with u64 wraps by re-writing the code to only use delta increments, which avoids the whole issue. Reviewed-by: Venkatesh Pallipadi <venki@google.com> Reported-by: Mikael Pettersson <mikpe@it.uu.se> Tested-by: Mikael Pettersson <mikpe@it.uu.se> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1292242433.6803.199.camel@twins> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-12-09 13:15:34 +00:00
/*
* Since irq_time is only updated on {soft,}irq_exit, we might run into
* this case when a previous update_rq_clock() happened inside a
* {soft,}irq region.
*
* When this happens, we stop ->clock_task and only update the
* prev_irq_time stamp to account for the part that fit, so that a next
* update will consume the rest. This ensures ->clock_task is
* monotonic.
*
* It does however cause some slight miss-attribution of {soft,}irq
* time, a more accurate solution would be to update the irq_time using
* the current rq->clock timestamp, except that would require using
* atomic ops.
*/
if (irq_delta > delta)
irq_delta = delta;
rq->prev_irq_time += irq_delta;
delta -= irq_delta;
sched: adjust scheduler cpu power for stolen time This patch makes update_rq_clock() aware of steal time. The mechanism of operation is not different from irq_time, and follows the same principles. This lives in a CONFIG option itself, and can be compiled out independently of the rest of steal time reporting. The effect of disabling it is that the scheduler will still report steal time (that cannot be disabled), but won't use this information for cpu power adjustments. Everytime update_rq_clock_task() is invoked, we query information about how much time was stolen since last call, and feed it into sched_rt_avg_update(). Although steal time reporting in account_process_tick() keeps track of the last time we read the steal clock, in prev_steal_time, this patch do it independently using another field, prev_steal_time_rq. This is because otherwise, information about time accounted in update_process_tick() would never reach us in update_rq_clock(). Signed-off-by: Glauber Costa <glommer@redhat.com> Acked-by: Rik van Riel <riel@redhat.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Tested-by: Eric B Munson <emunson@mgebm.net> CC: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> CC: Anthony Liguori <aliguori@us.ibm.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-07-11 19:28:18 +00:00
#endif
#ifdef CONFIG_PARAVIRT_TIME_ACCOUNTING
if (static_branch((&paravirt_steal_rq_enabled))) {
u64 st;
steal = paravirt_steal_clock(cpu_of(rq));
steal -= rq->prev_steal_time_rq;
if (unlikely(steal > delta))
steal = delta;
st = steal_ticks(steal);
steal = st * TICK_NSEC;
rq->prev_steal_time_rq += steal;
delta -= steal;
}
#endif
sched: Fix the irqtime code to deal with u64 wraps Some ARM systems have a short sched_clock() [ which needs to be fixed too ], but this exposed a bug in the irq_time code as well, it doesn't deal with wraps at all. Fix the irq_time code to deal with u64 wraps by re-writing the code to only use delta increments, which avoids the whole issue. Reviewed-by: Venkatesh Pallipadi <venki@google.com> Reported-by: Mikael Pettersson <mikpe@it.uu.se> Tested-by: Mikael Pettersson <mikpe@it.uu.se> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1292242433.6803.199.camel@twins> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-12-09 13:15:34 +00:00
rq->clock_task += delta;
sched: adjust scheduler cpu power for stolen time This patch makes update_rq_clock() aware of steal time. The mechanism of operation is not different from irq_time, and follows the same principles. This lives in a CONFIG option itself, and can be compiled out independently of the rest of steal time reporting. The effect of disabling it is that the scheduler will still report steal time (that cannot be disabled), but won't use this information for cpu power adjustments. Everytime update_rq_clock_task() is invoked, we query information about how much time was stolen since last call, and feed it into sched_rt_avg_update(). Although steal time reporting in account_process_tick() keeps track of the last time we read the steal clock, in prev_steal_time, this patch do it independently using another field, prev_steal_time_rq. This is because otherwise, information about time accounted in update_process_tick() would never reach us in update_rq_clock(). Signed-off-by: Glauber Costa <glommer@redhat.com> Acked-by: Rik van Riel <riel@redhat.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Tested-by: Eric B Munson <emunson@mgebm.net> CC: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> CC: Anthony Liguori <aliguori@us.ibm.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-07-11 19:28:18 +00:00
#if defined(CONFIG_IRQ_TIME_ACCOUNTING) || defined(CONFIG_PARAVIRT_TIME_ACCOUNTING)
if ((irq_delta + steal) && sched_feat(NONTASK_POWER))
sched_rt_avg_update(rq, irq_delta + steal);
#endif
sched: Remove irq time from available CPU power The idea was suggested by Peter Zijlstra here: http://marc.info/?l=linux-kernel&m=127476934517534&w=2 irq time is technically not available to the tasks running on the CPU. This patch removes irq time from CPU power piggybacking on sched_rt_avg_update(). Tested this by keeping CPU X busy with a network intensive task having 75% oa a single CPU irq processing (hard+soft) on a 4-way system. And start seven cycle soakers on the system. Without this change, there will be two tasks on each CPU. With this change, there is a single task on irq busy CPU X and remaining 7 tasks are spread around among other 3 CPUs. Signed-off-by: Venkatesh Pallipadi <venki@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1286237003-12406-8-git-send-email-venki@google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-05 00:03:22 +00:00
}
sched: adjust scheduler cpu power for stolen time This patch makes update_rq_clock() aware of steal time. The mechanism of operation is not different from irq_time, and follows the same principles. This lives in a CONFIG option itself, and can be compiled out independently of the rest of steal time reporting. The effect of disabling it is that the scheduler will still report steal time (that cannot be disabled), but won't use this information for cpu power adjustments. Everytime update_rq_clock_task() is invoked, we query information about how much time was stolen since last call, and feed it into sched_rt_avg_update(). Although steal time reporting in account_process_tick() keeps track of the last time we read the steal clock, in prev_steal_time, this patch do it independently using another field, prev_steal_time_rq. This is because otherwise, information about time accounted in update_process_tick() would never reach us in update_rq_clock(). Signed-off-by: Glauber Costa <glommer@redhat.com> Acked-by: Rik van Riel <riel@redhat.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Tested-by: Eric B Munson <emunson@mgebm.net> CC: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> CC: Anthony Liguori <aliguori@us.ibm.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-07-11 19:28:18 +00:00
#ifdef CONFIG_IRQ_TIME_ACCOUNTING
sched: Export ns irqtimes through /proc/stat CONFIG_IRQ_TIME_ACCOUNTING adds ns granularity irq time on each CPU. This info is already used in scheduler to do proper task chargeback (earlier patches). This patch retro-fits this ns granularity hardirq and softirq information to /proc/stat irq and softirq fields. The update is still done on timer tick, where we look at accumulated ns hardirq/softirq time and account the tick to user/system/irq/hardirq/guest accordingly. No new interface added. Earlier versions looked at adding this as new fields in some /proc files. This one seems to be the best in terms of impact to existing apps, even though it has somewhat more kernel code than earlier versions. Tested-by: Shaun Ruffell <sruffell@digium.com> Signed-off-by: Venkatesh Pallipadi <venki@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1292980144-28796-5-git-send-email-venki@google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-12-22 01:09:03 +00:00
static int irqtime_account_hi_update(void)
{
struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat;
unsigned long flags;
u64 latest_ns;
int ret = 0;
local_irq_save(flags);
latest_ns = this_cpu_read(cpu_hardirq_time);
if (cputime64_gt(nsecs_to_cputime64(latest_ns), cpustat->irq))
ret = 1;
local_irq_restore(flags);
return ret;
}
static int irqtime_account_si_update(void)
{
struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat;
unsigned long flags;
u64 latest_ns;
int ret = 0;
local_irq_save(flags);
latest_ns = this_cpu_read(cpu_softirq_time);
if (cputime64_gt(nsecs_to_cputime64(latest_ns), cpustat->softirq))
ret = 1;
local_irq_restore(flags);
return ret;
}
sched: Fix the irqtime code to deal with u64 wraps Some ARM systems have a short sched_clock() [ which needs to be fixed too ], but this exposed a bug in the irq_time code as well, it doesn't deal with wraps at all. Fix the irq_time code to deal with u64 wraps by re-writing the code to only use delta increments, which avoids the whole issue. Reviewed-by: Venkatesh Pallipadi <venki@google.com> Reported-by: Mikael Pettersson <mikpe@it.uu.se> Tested-by: Mikael Pettersson <mikpe@it.uu.se> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1292242433.6803.199.camel@twins> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-12-09 13:15:34 +00:00
#else /* CONFIG_IRQ_TIME_ACCOUNTING */
sched: Do not account irq time to current task Scheduler accounts both softirq and interrupt processing times to the currently running task. This means, if the interrupt processing was for some other task in the system, then the current task ends up being penalized as it gets shorter runtime than otherwise. Change sched task accounting to acoount only actual task time from currently running task. Now update_curr(), modifies the delta_exec to depend on rq->clock_task. Note that this change only handles CONFIG_IRQ_TIME_ACCOUNTING case. We can extend this to CONFIG_VIRT_CPU_ACCOUNTING with minimal effort. But, thats for later. This change will impact scheduling behavior in interrupt heavy conditions. Tested on a 4-way system with eth0 handled by CPU 2 and a network heavy task (nc) running on CPU 3 (and no RSS/RFS). With that I have CPU 2 spending 75%+ of its time in irq processing. CPU 3 spending around 35% time running nc task. Now, if I run another CPU intensive task on CPU 2, without this change /proc/<pid>/schedstat shows 100% of time accounted to this task. With this change, it rightly shows less than 25% accounted to this task as remaining time is actually spent on irq processing. Signed-off-by: Venkatesh Pallipadi <venki@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1286237003-12406-7-git-send-email-venki@google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-05 00:03:21 +00:00
sched: Export ns irqtimes through /proc/stat CONFIG_IRQ_TIME_ACCOUNTING adds ns granularity irq time on each CPU. This info is already used in scheduler to do proper task chargeback (earlier patches). This patch retro-fits this ns granularity hardirq and softirq information to /proc/stat irq and softirq fields. The update is still done on timer tick, where we look at accumulated ns hardirq/softirq time and account the tick to user/system/irq/hardirq/guest accordingly. No new interface added. Earlier versions looked at adding this as new fields in some /proc files. This one seems to be the best in terms of impact to existing apps, even though it has somewhat more kernel code than earlier versions. Tested-by: Shaun Ruffell <sruffell@digium.com> Signed-off-by: Venkatesh Pallipadi <venki@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1292980144-28796-5-git-send-email-venki@google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-12-22 01:09:03 +00:00
#define sched_clock_irqtime (0)
sched: adjust scheduler cpu power for stolen time This patch makes update_rq_clock() aware of steal time. The mechanism of operation is not different from irq_time, and follows the same principles. This lives in a CONFIG option itself, and can be compiled out independently of the rest of steal time reporting. The effect of disabling it is that the scheduler will still report steal time (that cannot be disabled), but won't use this information for cpu power adjustments. Everytime update_rq_clock_task() is invoked, we query information about how much time was stolen since last call, and feed it into sched_rt_avg_update(). Although steal time reporting in account_process_tick() keeps track of the last time we read the steal clock, in prev_steal_time, this patch do it independently using another field, prev_steal_time_rq. This is because otherwise, information about time accounted in update_process_tick() would never reach us in update_rq_clock(). Signed-off-by: Glauber Costa <glommer@redhat.com> Acked-by: Rik van Riel <riel@redhat.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Tested-by: Eric B Munson <emunson@mgebm.net> CC: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> CC: Anthony Liguori <aliguori@us.ibm.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-07-11 19:28:18 +00:00
#endif
sched: Add IRQ_TIME_ACCOUNTING, finer accounting of irq time s390/powerpc/ia64 have support for CONFIG_VIRT_CPU_ACCOUNTING which does the fine granularity accounting of user, system, hardirq, softirq times. Adding that option on archs like x86 will be challenging however, given the state of TSC reliability on various platforms and also the overhead it will add in syscall entry exit. Instead, add a lighter variant that only does finer accounting of hardirq and softirq times, providing precise irq times (instead of timer tick based samples). This accounting is added with a new config option CONFIG_IRQ_TIME_ACCOUNTING so that there won't be any overhead for users not interested in paying the perf penalty. This accounting is based on sched_clock, with the code being generic. So, other archs may find it useful as well. This patch just adds the core logic and does not enable this logic yet. Signed-off-by: Venkatesh Pallipadi <venki@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1286237003-12406-5-git-send-email-venki@google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-05 00:03:19 +00:00
sched: Move load balance code into sched_fair.c Straight fwd code movement. Since non of the load-balance abstractions are used anymore, do away with them and simplify the code some. In preparation move the code around. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-17 16:00:43 +00:00
#include "sched_idletask.c"
#include "sched_fair.c"
#include "sched_rt.c"
sched: Add 'autogroup' scheduling feature: automated per session task groups A recurring complaint from CFS users is that parallel kbuild has a negative impact on desktop interactivity. This patch implements an idea from Linus, to automatically create task groups. Currently, only per session autogroups are implemented, but the patch leaves the way open for enhancement. Implementation: each task's signal struct contains an inherited pointer to a refcounted autogroup struct containing a task group pointer, the default for all tasks pointing to the init_task_group. When a task calls setsid(), a new task group is created, the process is moved into the new task group, and a reference to the preveious task group is dropped. Child processes inherit this task group thereafter, and increase it's refcount. When the last thread of a process exits, the process's reference is dropped, such that when the last process referencing an autogroup exits, the autogroup is destroyed. At runqueue selection time, IFF a task has no cgroup assignment, its current autogroup is used. Autogroup bandwidth is controllable via setting it's nice level through the proc filesystem: cat /proc/<pid>/autogroup Displays the task's group and the group's nice level. echo <nice level> > /proc/<pid>/autogroup Sets the task group's shares to the weight of nice <level> task. Setting nice level is rate limited for !admin users due to the abuse risk of task group locking. The feature is enabled from boot by default if CONFIG_SCHED_AUTOGROUP=y is selected, but can be disabled via the boot option noautogroup, and can also be turned on/off on the fly via: echo [01] > /proc/sys/kernel/sched_autogroup_enabled ... which will automatically move tasks to/from the root task group. Signed-off-by: Mike Galbraith <efault@gmx.de> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Markus Trippelsdorf <markus@trippelsdorf.de> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Paul Turner <pjt@google.com> Cc: Oleg Nesterov <oleg@redhat.com> [ Removed the task_group_path() debug code, and fixed !EVENTFD build failure. ] Signed-off-by: Ingo Molnar <mingo@elte.hu> LKML-Reference: <1290281700.28711.9.camel@maggy.simson.net> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-30 13:18:03 +00:00
#include "sched_autogroup.c"
sched: Create special class for stop/migrate work In order to separate the stop/migrate work thread from the SCHED_FIFO implementation, create a special class for it that is of higher priority than SCHED_FIFO itself. This currently solves a problem where cpu-hotplug consumes so much cpu-time that the SCHED_FIFO class gets throttled, but has the bandwidth replenishment timer pending on the now dead cpu. It is also required for when we add the planned deadline scheduling class above SCHED_FIFO, as the stop/migrate thread still needs to transcent those tasks. Tested-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1285165776.2275.1022.camel@laptop> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-09-22 11:53:15 +00:00
#include "sched_stoptask.c"
sched: Move load balance code into sched_fair.c Straight fwd code movement. Since non of the load-balance abstractions are used anymore, do away with them and simplify the code some. In preparation move the code around. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-17 16:00:43 +00:00
#ifdef CONFIG_SCHED_DEBUG
# include "sched_debug.c"
#endif
sched: Create special class for stop/migrate work In order to separate the stop/migrate work thread from the SCHED_FIFO implementation, create a special class for it that is of higher priority than SCHED_FIFO itself. This currently solves a problem where cpu-hotplug consumes so much cpu-time that the SCHED_FIFO class gets throttled, but has the bandwidth replenishment timer pending on the now dead cpu. It is also required for when we add the planned deadline scheduling class above SCHED_FIFO, as the stop/migrate thread still needs to transcent those tasks. Tested-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1285165776.2275.1022.camel@laptop> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-09-22 11:53:15 +00:00
void sched_set_stop_task(int cpu, struct task_struct *stop)
{
struct sched_param param = { .sched_priority = MAX_RT_PRIO - 1 };
struct task_struct *old_stop = cpu_rq(cpu)->stop;
if (stop) {
/*
* Make it appear like a SCHED_FIFO task, its something
* userspace knows about and won't get confused about.
*
* Also, it will make PI more or less work without too
* much confusion -- but then, stop work should not
* rely on PI working anyway.
*/
sched_setscheduler_nocheck(stop, SCHED_FIFO, &param);
stop->sched_class = &stop_sched_class;
}
cpu_rq(cpu)->stop = stop;
if (old_stop) {
/*
* Reset it back to a normal scheduling class so that
* it can die in pieces.
*/
old_stop->sched_class = &rt_sched_class;
}
}
sched: clean up __normal_prio() position clean up: move __normal_prio() in head of normal_prio(). no code changed. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-09 16:51:59 +00:00
/*
sched: cfs core code apply the CFS core code. this change switches over the scheduler core to CFS's modular design and makes use of kernel/sched_fair/rt/idletask.c to implement Linux's scheduling policies. thanks to Andrew Morton and Thomas Gleixner for lots of detailed review feedback and for fixlets. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
2007-07-09 16:51:59 +00:00
* __normal_prio - return the priority that is based on the static prio
sched: clean up __normal_prio() position clean up: move __normal_prio() in head of normal_prio(). no code changed. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-09 16:51:59 +00:00
*/
static inline int __normal_prio(struct task_struct *p)
{
sched: cfs core code apply the CFS core code. this change switches over the scheduler core to CFS's modular design and makes use of kernel/sched_fair/rt/idletask.c to implement Linux's scheduling policies. thanks to Andrew Morton and Thomas Gleixner for lots of detailed review feedback and for fixlets. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
2007-07-09 16:51:59 +00:00
return p->static_prio;
sched: clean up __normal_prio() position clean up: move __normal_prio() in head of normal_prio(). no code changed. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-09 16:51:59 +00:00
}
[PATCH] pi-futex: scheduler support for pi Add framework to boost/unboost the priority of RT tasks. This consists of: - caching the 'normal' priority in ->normal_prio - providing a functions to set/get the priority of the task - make sched_setscheduler() aware of boosting The effective_prio() cleanups also fix a priority-calculation bug pointed out by Andrey Gelman, in set_user_nice(). has_rt_policy() fix: Peter Williams <pwil3058@bigpond.net.au> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Cc: Andrey Gelman <agelman@012.net.il> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 09:54:51 +00:00
/*
* Calculate the expected normal priority: i.e. priority
* without taking RT-inheritance into account. Might be
* boosted by interactivity modifiers. Changes upon fork,
* setprio syscalls, and whenever the interactivity
* estimator recalculates.
*/
[PATCH] sched: cleanup, remove task_t, convert to struct task_struct cleanup: remove task_t and convert all the uses to struct task_struct. I introduced it for the scheduler anno and it was a mistake. Conversion was mostly scripted, the result was reviewed and all secondary whitespace and style impact (if any) was fixed up by hand. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-03 07:25:41 +00:00
static inline int normal_prio(struct task_struct *p)
[PATCH] pi-futex: scheduler support for pi Add framework to boost/unboost the priority of RT tasks. This consists of: - caching the 'normal' priority in ->normal_prio - providing a functions to set/get the priority of the task - make sched_setscheduler() aware of boosting The effective_prio() cleanups also fix a priority-calculation bug pointed out by Andrey Gelman, in set_user_nice(). has_rt_policy() fix: Peter Williams <pwil3058@bigpond.net.au> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Cc: Andrey Gelman <agelman@012.net.il> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 09:54:51 +00:00
{
int prio;
sched: clean up the rt priority macros clean up the rt priority macros, pointed out by Andrew Morton. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-09 16:51:59 +00:00
if (task_has_rt_policy(p))
[PATCH] pi-futex: scheduler support for pi Add framework to boost/unboost the priority of RT tasks. This consists of: - caching the 'normal' priority in ->normal_prio - providing a functions to set/get the priority of the task - make sched_setscheduler() aware of boosting The effective_prio() cleanups also fix a priority-calculation bug pointed out by Andrey Gelman, in set_user_nice(). has_rt_policy() fix: Peter Williams <pwil3058@bigpond.net.au> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Cc: Andrey Gelman <agelman@012.net.il> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 09:54:51 +00:00
prio = MAX_RT_PRIO-1 - p->rt_priority;
else
prio = __normal_prio(p);
return prio;
}
/*
* Calculate the current priority, i.e. the priority
* taken into account by the scheduler. This value might
* be boosted by RT tasks, or might be boosted by
* interactivity modifiers. Will be RT if the task got
* RT-boosted. If not then it returns p->normal_prio.
*/
[PATCH] sched: cleanup, remove task_t, convert to struct task_struct cleanup: remove task_t and convert all the uses to struct task_struct. I introduced it for the scheduler anno and it was a mistake. Conversion was mostly scripted, the result was reviewed and all secondary whitespace and style impact (if any) was fixed up by hand. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-03 07:25:41 +00:00
static int effective_prio(struct task_struct *p)
[PATCH] pi-futex: scheduler support for pi Add framework to boost/unboost the priority of RT tasks. This consists of: - caching the 'normal' priority in ->normal_prio - providing a functions to set/get the priority of the task - make sched_setscheduler() aware of boosting The effective_prio() cleanups also fix a priority-calculation bug pointed out by Andrey Gelman, in set_user_nice(). has_rt_policy() fix: Peter Williams <pwil3058@bigpond.net.au> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Cc: Andrey Gelman <agelman@012.net.il> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 09:54:51 +00:00
{
p->normal_prio = normal_prio(p);
/*
* If we are RT tasks or we were boosted to RT priority,
* keep the priority unchanged. Otherwise, update priority
* to the normal priority:
*/
if (!rt_prio(p->prio))
return p->normal_prio;
return p->prio;
}
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
/**
* task_curr - is this task currently executing on a CPU?
* @p: the task in question.
*/
[PATCH] sched: cleanup, remove task_t, convert to struct task_struct cleanup: remove task_t and convert all the uses to struct task_struct. I introduced it for the scheduler anno and it was a mistake. Conversion was mostly scripted, the result was reviewed and all secondary whitespace and style impact (if any) was fixed up by hand. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-03 07:25:41 +00:00
inline int task_curr(const struct task_struct *p)
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
{
return cpu_curr(task_cpu(p)) == p;
}
sched: RT-balance, add new methods to sched_class Dmitry Adamushko found that the current implementation of the RT balancing code left out changes to the sched_setscheduler and rt_mutex_setprio. This patch addresses this issue by adding methods to the schedule classes to handle being switched out of (switched_from) and being switched into (switched_to) a sched_class. Also a method for changing of priorities is also added (prio_changed). This patch also removes some duplicate logic between rt_mutex_setprio and sched_setscheduler. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:22 +00:00
static inline void check_class_changed(struct rq *rq, struct task_struct *p,
const struct sched_class *prev_class,
sched: Fix switch_from_fair() When a task is taken out of the fair class we must ensure the vruntime is properly normalized because when we put it back in it will assume to be normalized. The case that goes wrong is when changing away from the fair class while sleeping. Sleeping tasks have non-normalized vruntime in order to make sleeper-fairness work. So treat the switch away from fair as a wakeup and preserve the relative vruntime. Also update sysrq-n to call the ->switch_{to,from} methods. Reported-by: Onkalo Samu <samu.p.onkalo@nokia.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-01-17 16:03:27 +00:00
int oldprio)
sched: RT-balance, add new methods to sched_class Dmitry Adamushko found that the current implementation of the RT balancing code left out changes to the sched_setscheduler and rt_mutex_setprio. This patch addresses this issue by adding methods to the schedule classes to handle being switched out of (switched_from) and being switched into (switched_to) a sched_class. Also a method for changing of priorities is also added (prio_changed). This patch also removes some duplicate logic between rt_mutex_setprio and sched_setscheduler. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:22 +00:00
{
if (prev_class != p->sched_class) {
if (prev_class->switched_from)
sched: Fix switch_from_fair() When a task is taken out of the fair class we must ensure the vruntime is properly normalized because when we put it back in it will assume to be normalized. The case that goes wrong is when changing away from the fair class while sleeping. Sleeping tasks have non-normalized vruntime in order to make sleeper-fairness work. So treat the switch away from fair as a wakeup and preserve the relative vruntime. Also update sysrq-n to call the ->switch_{to,from} methods. Reported-by: Onkalo Samu <samu.p.onkalo@nokia.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-01-17 16:03:27 +00:00
prev_class->switched_from(rq, p);
p->sched_class->switched_to(rq, p);
} else if (oldprio != p->prio)
p->sched_class->prio_changed(rq, p, oldprio);
sched: RT-balance, add new methods to sched_class Dmitry Adamushko found that the current implementation of the RT balancing code left out changes to the sched_setscheduler and rt_mutex_setprio. This patch addresses this issue by adding methods to the schedule classes to handle being switched out of (switched_from) and being switched into (switched_to) a sched_class. Also a method for changing of priorities is also added (prio_changed). This patch also removes some duplicate logic between rt_mutex_setprio and sched_setscheduler. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:22 +00:00
}
sched: Fix cross-sched-class wakeup preemption Instead of dealing with sched classes inside each check_preempt_curr() implementation, pull out this logic into the generic wakeup preemption path. This fixes a hang in KVM (and others) where we are waiting for the stop machine thread to run ... Reported-by: Markus Trippelsdorf <markus@trippelsdorf.de> Tested-by: Marcelo Tosatti <mtosatti@redhat.com> Tested-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1288891946.2039.31.camel@laptop> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-31 11:37:04 +00:00
static void check_preempt_curr(struct rq *rq, struct task_struct *p, int flags)
{
const struct sched_class *class;
if (p->sched_class == rq->curr->sched_class) {
rq->curr->sched_class->check_preempt_curr(rq, p, flags);
} else {
for_each_class(class) {
if (class == rq->curr->sched_class)
break;
if (class == p->sched_class) {
resched_task(rq->curr);
break;
}
}
}
/*
* A queue event has occurred, and we're going to schedule. In
* this case, we can save a useless back to back clock update.
*/
sched: Provide p->on_rq Provide a generic p->on_rq because the p->se.on_rq semantics are unfavourable for lockless wakeups but needed for sched_fair. In particular, p->on_rq is only cleared when we actually dequeue the task in schedule() and not on any random dequeue as done by things like __migrate_task() and __sched_setscheduler(). This also allows us to remove p->se usage from !sched_fair code. Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110405152728.949545047@chello.nl
2011-04-05 15:23:44 +00:00
if (rq->curr->on_rq && test_tsk_need_resched(rq->curr))
sched: Fix cross-sched-class wakeup preemption Instead of dealing with sched classes inside each check_preempt_curr() implementation, pull out this logic into the generic wakeup preemption path. This fixes a hang in KVM (and others) where we are waiting for the stop machine thread to run ... Reported-by: Markus Trippelsdorf <markus@trippelsdorf.de> Tested-by: Marcelo Tosatti <mtosatti@redhat.com> Tested-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1288891946.2039.31.camel@laptop> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-31 11:37:04 +00:00
rq->skip_clock_update = 1;
}
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
#ifdef CONFIG_SMP
sched: debug, improve migration statistics add new migration statistics when SCHED_DEBUG and SCHEDSTATS is enabled. Available in /proc/<PID>/sched. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 15:00:18 +00:00
/*
* Is this task likely cache-hot:
*/
sched: de-SCHED_OTHER-ize the RT path The current wake-up code path tries to determine if it can optimize the wake-up to "this_cpu" by computing load calculations. The problem is that these calculations are only relevant to SCHED_OTHER tasks where load is king. For RT tasks, priority is king. So the load calculation is completely wasted bandwidth. Therefore, we create a new sched_class interface to help with pre-wakeup routing decisions and move the load calculation as a function of CFS task's class. Signed-off-by: Gregory Haskins <ghaskins@novell.com> Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:09 +00:00
static int
sched: debug, improve migration statistics add new migration statistics when SCHED_DEBUG and SCHEDSTATS is enabled. Available in /proc/<PID>/sched. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 15:00:18 +00:00
task_hot(struct task_struct *p, u64 now, struct sched_domain *sd)
{
s64 delta;
sched: Fix task_hot() test order Make sure not to access sched_fair fields before verifying it is indeed a sched_fair task. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> CC: stable@kernel.org LKML-Reference: <20091216170517.577998058@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-16 17:04:33 +00:00
if (p->sched_class != &fair_sched_class)
return 0;
sched: Do not consider SCHED_IDLE tasks to be cache hot This patch adds a check in task_hot to return if the task has SCHED_IDLE policy. SCHED_IDLE tasks have very low weight, and when run with regular workloads, are typically scheduled many milliseconds apart. There is no need to consider these tasks hot for load balancing. Signed-off-by: Nikhil Rao <ncrao@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1287173550-30365-2-git-send-email-ncrao@google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-13 19:09:35 +00:00
if (unlikely(p->policy == SCHED_IDLE))
return 0;
sched: wakeup-buddy tasks are cache-hot Wakeup-buddy tasks are cache-hot - this makes it a bit harder for the load-balancer to tear them apart. (but it's still possible, if the load is sufficiently assymetric) Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-03-15 16:10:34 +00:00
/*
* Buddy candidates are cache hot:
*/
sched: Strengthen buddies and mitigate buddy induced latencies This patch restores the effectiveness of LAST_BUDDY in preventing pgsql+oltp from collapsing due to wakeup preemption. It also switches LAST_BUDDY to exclusively do what it does best, namely mitigate the effects of aggressive wakeup preemption, which improves vmark throughput markedly, and restores mysql+oltp scalability. Since buddies are about scalability, enable them beginning at the point where we begin expanding sched_latency, namely sched_nr_latency. Previously, buddies were cleared aggressively, which seriously reduced their effectiveness. Not clearing aggressively however, produces a small drop in mysql+oltp throughput immediately after peak, indicating that LAST_BUDDY is actually doing some harm. This is right at the point where X on the desktop in competition with another load wants low latency service. Ergo, do not enable until we need to scale. To mitigate latency induced by buddies, or by a task just missing wakeup preemption, check latency at tick time. Last hunk prevents buddies from stymieing BALANCE_NEWIDLE via CACHE_HOT_BUDDY. Supporting performance tests: tip = v2.6.32-rc5-1497-ga525b32 tipx = NO_GENTLE_FAIR_SLEEPERS NEXT_BUDDY granularity knobs = 31 knobs + 31 buddies tip+x = NO_GENTLE_FAIR_SLEEPERS granularity knobs = 31 knobs (Three run averages except where noted.) vmark: ------ tip 108466 messages per second tip+ 125307 messages per second tip+x 125335 messages per second tipx 117781 messages per second 2.6.31.3 122729 messages per second mysql+oltp: ----------- clients 1 2 4 8 16 32 64 128 256 .......................................................................................... tip 9949.89 18690.20 34801.24 34460.04 32682.88 30765.97 28305.27 25059.64 19548.08 tip+ 10013.90 18526.84 34900.38 34420.14 33069.83 32083.40 30578.30 28010.71 25605.47 tipx 9698.71 18002.70 34477.56 33420.01 32634.30 31657.27 29932.67 26827.52 21487.18 2.6.31.3 8243.11 18784.20 34404.83 33148.38 31900.32 31161.90 29663.81 25995.94 18058.86 pgsql+oltp: ----------- clients 1 2 4 8 16 32 64 128 256 .......................................................................................... tip 13686.37 26609.25 51934.28 51347.81 49479.51 45312.65 36691.91 26851.57 24145.35 tip+ (1x) 13907.85 27135.87 52951.98 52514.04 51742.52 50705.43 49947.97 48374.19 46227.94 tip+x 13906.78 27065.81 52951.19 52542.59 52176.11 51815.94 50838.90 49439.46 46891.00 tipx 13742.46 26769.81 52351.99 51891.73 51320.79 50938.98 50248.65 48908.70 46553.84 2.6.31.3 13815.35 26906.46 52683.34 52061.31 51937.10 51376.80 50474.28 49394.47 47003.25 Signed-off-by: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-10-23 21:09:22 +00:00
if (sched_feat(CACHE_HOT_BUDDY) && this_rq()->nr_running &&
sched: backward looking buddy Impact: improve/change/fix wakeup-buddy scheduling Currently we only have a forward looking buddy, that is, we prefer to schedule to the task we last woke up, under the presumption that its going to consume the data we just produced, and therefore will have cache hot benefits. This allows co-waking producer/consumer task pairs to run ahead of the pack for a little while, keeping their cache warm. Without this, we would interleave all pairs, utterly trashing the cache. This patch introduces a backward looking buddy, that is, suppose that in the above scenario, the consumer preempts the producer before it can go to sleep, we will therefore miss the wakeup from consumer to producer (its already running, after all), breaking the cycle and reverting to the cache-trashing interleaved schedule pattern. The backward buddy will try to schedule back to the task that woke us up in case the forward buddy is not available, under the assumption that the last task will be the one with the most cache hot task around barring current. This will basically allow a task to continue after it got preempted. In order to avoid starvation, we allow either buddy to get wakeup_gran ahead of the pack. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-04 20:25:09 +00:00
(&p->se == cfs_rq_of(&p->se)->next ||
&p->se == cfs_rq_of(&p->se)->last))
sched: wakeup-buddy tasks are cache-hot Wakeup-buddy tasks are cache-hot - this makes it a bit harder for the load-balancer to tear them apart. (but it's still possible, if the load is sufficiently assymetric) Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-03-15 16:10:34 +00:00
return 1;
sched: allow the immediate migration of cache-cold tasks allow the immediate migration of cache-cold tasks. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 15:00:18 +00:00
if (sysctl_sched_migration_cost == -1)
return 1;
if (sysctl_sched_migration_cost == 0)
return 0;
sched: debug, improve migration statistics add new migration statistics when SCHED_DEBUG and SCHEDSTATS is enabled. Available in /proc/<PID>/sched. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 15:00:18 +00:00
delta = now - p->se.exec_start;
return delta < (s64)sysctl_sched_migration_cost;
}
sched: cfs core code apply the CFS core code. this change switches over the scheduler core to CFS's modular design and makes use of kernel/sched_fair/rt/idletask.c to implement Linux's scheduling policies. thanks to Andrew Morton and Thomas Gleixner for lots of detailed review feedback and for fixlets. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
2007-07-09 16:51:59 +00:00
void set_task_cpu(struct task_struct *p, unsigned int new_cpu)
sched: uninline set_task_cpu() uninline set_task_cpu(): CFS will add more code to it. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-09 16:51:58 +00:00
{
sched: Ensure set_task_cpu() is never called on blocked tasks In order to clean up the set_task_cpu() rq dependencies we need to ensure it is never called on blocked tasks because such usage does not pair with consistent rq->lock usage. This puts the migration burden on ttwu(). Furthermore we need to close a race against changing ->cpus_allowed, since select_task_rq() runs with only preemption disabled. For sched_fork() this is safe because the child isn't in the tasklist yet, for wakeup we fix this by synchronizing set_cpus_allowed_ptr() against TASK_WAKING, which leaves sched_exec to be a problem This also closes a hole in (6ad4c1888 sched: Fix balance vs hotplug race) where ->select_task_rq() doesn't validate the result against the sched_domain/root_domain. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> LKML-Reference: <20091216170517.807938893@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-16 17:04:36 +00:00
#ifdef CONFIG_SCHED_DEBUG
/*
* We should never call set_task_cpu() on a blocked task,
* ttwu() will sort out the placement.
*/
sched: Fix broken assertion There's a preemption race in the set_task_cpu() debug check in that when we get preempted after setting task->state we'd still be on the rq proper, but fail the test. Check for preempted tasks, since those are always on the RQ. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20091217121830.137155561@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-17 12:16:31 +00:00
WARN_ON_ONCE(p->state != TASK_RUNNING && p->state != TASK_WAKING &&
!(task_thread_info(p)->preempt_count & PREEMPT_ACTIVE));
sched: Add p->pi_lock to task_rq_lock() In order to be able to call set_task_cpu() while either holding p->pi_lock or task_rq(p)->lock we need to hold both locks in order to stabilize task_rq(). This makes task_rq_lock() acquire both locks, and have __task_rq_lock() validate that p->pi_lock is held. This increases the locking overhead for most scheduler syscalls but allows reduction of rq->lock contention for some scheduler hot paths (ttwu). Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110405152729.232781355@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-05 15:23:51 +00:00
#ifdef CONFIG_LOCKDEP
sched: Fix/clarify set_task_cpu() locking rules Sergey reported a CONFIG_PROVE_RCU warning in push_rt_task where set_task_cpu() was called with both relevant rq->locks held, which should be sufficient for running tasks since holding its rq->lock will serialize against sched_move_task(). Update the comments and fix the task_group() lockdep test. Reported-and-tested-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1307115427.2353.3456.camel@twins Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-06-03 15:37:07 +00:00
/*
* The caller should hold either p->pi_lock or rq->lock, when changing
* a task's CPU. ->pi_lock for waking tasks, rq->lock for runnable tasks.
*
* sched_move_task() holds both and thus holding either pins the cgroup,
* see set_task_rq().
*
* Furthermore, all task_rq users should acquire both locks, see
* task_rq_lock().
*/
sched: Add p->pi_lock to task_rq_lock() In order to be able to call set_task_cpu() while either holding p->pi_lock or task_rq(p)->lock we need to hold both locks in order to stabilize task_rq(). This makes task_rq_lock() acquire both locks, and have __task_rq_lock() validate that p->pi_lock is held. This increases the locking overhead for most scheduler syscalls but allows reduction of rq->lock contention for some scheduler hot paths (ttwu). Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110405152729.232781355@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-05 15:23:51 +00:00
WARN_ON_ONCE(debug_locks && !(lockdep_is_held(&p->pi_lock) ||
lockdep_is_held(&task_rq(p)->lock)));
#endif
sched: Ensure set_task_cpu() is never called on blocked tasks In order to clean up the set_task_cpu() rq dependencies we need to ensure it is never called on blocked tasks because such usage does not pair with consistent rq->lock usage. This puts the migration burden on ttwu(). Furthermore we need to close a race against changing ->cpus_allowed, since select_task_rq() runs with only preemption disabled. For sched_fork() this is safe because the child isn't in the tasklist yet, for wakeup we fix this by synchronizing set_cpus_allowed_ptr() against TASK_WAKING, which leaves sched_exec to be a problem This also closes a hole in (6ad4c1888 sched: Fix balance vs hotplug race) where ->select_task_rq() doesn't validate the result against the sched_domain/root_domain. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> LKML-Reference: <20091216170517.807938893@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-16 17:04:36 +00:00
#endif
tracepoint: trace_sched_migrate_task(): remove parameter The orig_cpu parameter in trace_sched_migrate_task() is not necessary, it can be got by using task_cpu(p) in the probe. [ Impact: micro-optimization ] Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> [ modified from Mathieu's patch. The original patch is at: http://marc.info/?l=linux-kernel&m=123791201716239&w=2 ] Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> Cc: fweisbec@gmail.com Cc: rostedt@goodmis.org Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: zhaolei@cn.fujitsu.com Cc: laijs@cn.fujitsu.com LKML-Reference: <49FFFDB7.1050402@cn.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-05-05 08:49:59 +00:00
trace_sched_migrate_task(p, new_cpu);
sched: fix tracepoints in scheduler The trace point only caught one of many places where a task changes cpu, put it in the right place to we get all of them. Change the signature while we're at it. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-10 07:08:22 +00:00
sched: Revert 738d2be, simplify set_task_cpu() Effectively reverts 738d2be4301007f054541c5c4bf7fb6a361c9b3a. As demonstrated by Eric, we really need to call __set_task_cpu() early in the fork() path to properly initialize the various task state -- specifically the cgroup state through set_task_rq(). [ we could probably fix this by explicitly calling __set_task_cpu() from sched_fork(), but lets try that for the next cycle and simply revert to the old behaviour for now. ] Reported-by: Eric Paris <eparis@redhat.com> Tested-by: Eric Paris <eparis@redhat.com>, Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: efault@gmx.de LKML-Reference: <1261492999.4937.36.camel@laptop> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-22 14:43:19 +00:00
if (task_cpu(p) != new_cpu) {
p->se.nr_migrations++;
perf: Remove the nmi parameter from the swevent and overflow interface The nmi parameter indicated if we could do wakeups from the current context, if not, we would set some state and self-IPI and let the resulting interrupt do the wakeup. For the various event classes: - hardware: nmi=0; PMI is in fact an NMI or we run irq_work_run from the PMI-tail (ARM etc.) - tracepoint: nmi=0; since tracepoint could be from NMI context. - software: nmi=[0,1]; some, like the schedule thing cannot perform wakeups, and hence need 0. As one can see, there is very little nmi=1 usage, and the down-side of not using it is that on some platforms some software events can have a jiffy delay in wakeup (when arch_irq_work_raise isn't implemented). The up-side however is that we can remove the nmi parameter and save a bunch of conditionals in fast paths. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Michael Cree <mcree@orcon.net.nz> Cc: Will Deacon <will.deacon@arm.com> Cc: Deng-Cheng Zhu <dengcheng.zhu@gmail.com> Cc: Anton Blanchard <anton@samba.org> Cc: Eric B Munson <emunson@mgebm.net> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Paul Mundt <lethal@linux-sh.org> Cc: David S. Miller <davem@davemloft.net> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Jason Wessel <jason.wessel@windriver.com> Cc: Don Zickus <dzickus@redhat.com> Link: http://lkml.kernel.org/n/tip-agjev8eu666tvknpb3iaj0fg@git.kernel.org Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-06-27 12:41:57 +00:00
perf_sw_event(PERF_COUNT_SW_CPU_MIGRATIONS, 1, NULL, 0);
sched: Revert 738d2be, simplify set_task_cpu() Effectively reverts 738d2be4301007f054541c5c4bf7fb6a361c9b3a. As demonstrated by Eric, we really need to call __set_task_cpu() early in the fork() path to properly initialize the various task state -- specifically the cgroup state through set_task_rq(). [ we could probably fix this by explicitly calling __set_task_cpu() from sched_fork(), but lets try that for the next cycle and simply revert to the old behaviour for now. ] Reported-by: Eric Paris <eparis@redhat.com> Tested-by: Eric Paris <eparis@redhat.com>, Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: efault@gmx.de LKML-Reference: <1261492999.4937.36.camel@laptop> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-22 14:43:19 +00:00
}
sched: cfs core code apply the CFS core code. this change switches over the scheduler core to CFS's modular design and makes use of kernel/sched_fair/rt/idletask.c to implement Linux's scheduling policies. thanks to Andrew Morton and Thomas Gleixner for lots of detailed review feedback and for fixlets. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
2007-07-09 16:51:59 +00:00
__set_task_cpu(p, new_cpu);
sched: uninline set_task_cpu() uninline set_task_cpu(): CFS will add more code to it. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-09 16:51:58 +00:00
}
sched: replace migration_thread with cpu_stop Currently migration_thread is serving three purposes - migration pusher, context to execute active_load_balance() and forced context switcher for expedited RCU synchronize_sched. All three roles are hardcoded into migration_thread() and determining which job is scheduled is slightly messy. This patch kills migration_thread and replaces all three uses with cpu_stop. The three different roles of migration_thread() are splitted into three separate cpu_stop callbacks - migration_cpu_stop(), active_load_balance_cpu_stop() and synchronize_sched_expedited_cpu_stop() - and each use case now simply asks cpu_stop to execute the callback as necessary. synchronize_sched_expedited() was implemented with private preallocated resources and custom multi-cpu queueing and waiting logic, both of which are provided by cpu_stop. synchronize_sched_expedited_count is made atomic and all other shared resources along with the mutex are dropped. synchronize_sched_expedited() also implemented a check to detect cases where not all the callback got executed on their assigned cpus and fall back to synchronize_sched(). If called with cpu hotplug blocked, cpu_stop already guarantees that and the condition cannot happen; otherwise, stop_machine() would break. However, this patch preserves the paranoid check using a cpumask to record on which cpus the stopper ran so that it can serve as a bisection point if something actually goes wrong theree. Because the internal execution state is no longer visible, rcu_expedited_torture_stats() is removed. This patch also renames cpu_stop threads to from "stopper/%d" to "migration/%d". The names of these threads ultimately don't matter and there's no reason to make unnecessary userland visible changes. With this patch applied, stop_machine() and sched now share the same resources. stop_machine() is faster without wasting any resources and sched migration users are much cleaner. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Dipankar Sarma <dipankar@in.ibm.com> Cc: Josh Triplett <josh@freedesktop.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Dimitri Sivanich <sivanich@sgi.com>
2010-05-06 16:49:21 +00:00
struct migration_arg {
[PATCH] sched: cleanup, remove task_t, convert to struct task_struct cleanup: remove task_t and convert all the uses to struct task_struct. I introduced it for the scheduler anno and it was a mistake. Conversion was mostly scripted, the result was reviewed and all secondary whitespace and style impact (if any) was fixed up by hand. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-03 07:25:41 +00:00
struct task_struct *task;
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
int dest_cpu;
[PATCH] sched: cleanup, convert sched.c-internal typedefs to struct convert: - runqueue_t to 'struct rq' - prio_array_t to 'struct prio_array' - migration_req_t to 'struct migration_req' I was the one who added these but they are both against the kernel coding style and also were used inconsistently at places. So just get rid of them at once, now that we are flushing the scheduler patch-queue anyway. Conversion was mostly scripted, the result was reviewed and all secondary whitespace and style impact (if any) was fixed up by hand. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-03 07:25:42 +00:00
};
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
sched: replace migration_thread with cpu_stop Currently migration_thread is serving three purposes - migration pusher, context to execute active_load_balance() and forced context switcher for expedited RCU synchronize_sched. All three roles are hardcoded into migration_thread() and determining which job is scheduled is slightly messy. This patch kills migration_thread and replaces all three uses with cpu_stop. The three different roles of migration_thread() are splitted into three separate cpu_stop callbacks - migration_cpu_stop(), active_load_balance_cpu_stop() and synchronize_sched_expedited_cpu_stop() - and each use case now simply asks cpu_stop to execute the callback as necessary. synchronize_sched_expedited() was implemented with private preallocated resources and custom multi-cpu queueing and waiting logic, both of which are provided by cpu_stop. synchronize_sched_expedited_count is made atomic and all other shared resources along with the mutex are dropped. synchronize_sched_expedited() also implemented a check to detect cases where not all the callback got executed on their assigned cpus and fall back to synchronize_sched(). If called with cpu hotplug blocked, cpu_stop already guarantees that and the condition cannot happen; otherwise, stop_machine() would break. However, this patch preserves the paranoid check using a cpumask to record on which cpus the stopper ran so that it can serve as a bisection point if something actually goes wrong theree. Because the internal execution state is no longer visible, rcu_expedited_torture_stats() is removed. This patch also renames cpu_stop threads to from "stopper/%d" to "migration/%d". The names of these threads ultimately don't matter and there's no reason to make unnecessary userland visible changes. With this patch applied, stop_machine() and sched now share the same resources. stop_machine() is faster without wasting any resources and sched migration users are much cleaner. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Dipankar Sarma <dipankar@in.ibm.com> Cc: Josh Triplett <josh@freedesktop.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Dimitri Sivanich <sivanich@sgi.com>
2010-05-06 16:49:21 +00:00
static int migration_cpu_stop(void *data);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
/*
* wait_task_inactive - wait for a thread to unschedule.
*
tracehook: wait_task_inactive This extends wait_task_inactive() with a new argument so it can be used in a "soft" mode where it will check for the task changing state unexpectedly and back off. There is no change to existing callers. This lays the groundwork to allow robust, noninvasive tracing that can try to sample a blocked thread but back off safely if it wakes up. Signed-off-by: Roland McGrath <roland@redhat.com> Cc: Oleg Nesterov <oleg@tv-sign.ru> Reviewed-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-26 02:45:58 +00:00
* If @match_state is nonzero, it's the @p->state value just checked and
* not expected to change. If it changes, i.e. @p might have woken up,
* then return zero. When we succeed in waiting for @p to be off its CPU,
* we return a positive number (its total switch count). If a second call
* a short while later returns the same number, the caller can be sure that
* @p has remained unscheduled the whole time.
*
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
* The caller must ensure that the task *will* unschedule sometime soon,
* else this function might spin for a *long* time. This function can't
* be called with interrupts off, or it may introduce deadlock with
* smp_call_function() if an IPI is sent by the same process we are
* waiting to become inactive.
*/
tracehook: wait_task_inactive This extends wait_task_inactive() with a new argument so it can be used in a "soft" mode where it will check for the task changing state unexpectedly and back off. There is no change to existing callers. This lays the groundwork to allow robust, noninvasive tracing that can try to sample a blocked thread but back off safely if it wakes up. Signed-off-by: Roland McGrath <roland@redhat.com> Cc: Oleg Nesterov <oleg@tv-sign.ru> Reviewed-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-26 02:45:58 +00:00
unsigned long wait_task_inactive(struct task_struct *p, long match_state)
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
{
unsigned long flags;
sched: cfs core code apply the CFS core code. this change switches over the scheduler core to CFS's modular design and makes use of kernel/sched_fair/rt/idletask.c to implement Linux's scheduling policies. thanks to Andrew Morton and Thomas Gleixner for lots of detailed review feedback and for fixlets. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
2007-07-09 16:51:59 +00:00
int running, on_rq;
tracehook: wait_task_inactive This extends wait_task_inactive() with a new argument so it can be used in a "soft" mode where it will check for the task changing state unexpectedly and back off. There is no change to existing callers. This lays the groundwork to allow robust, noninvasive tracing that can try to sample a blocked thread but back off safely if it wakes up. Signed-off-by: Roland McGrath <roland@redhat.com> Cc: Oleg Nesterov <oleg@tv-sign.ru> Reviewed-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-26 02:45:58 +00:00
unsigned long ncsw;
[PATCH] sched: cleanup, convert sched.c-internal typedefs to struct convert: - runqueue_t to 'struct rq' - prio_array_t to 'struct prio_array' - migration_req_t to 'struct migration_req' I was the one who added these but they are both against the kernel coding style and also were used inconsistently at places. So just get rid of them at once, now that we are flushing the scheduler patch-queue anyway. Conversion was mostly scripted, the result was reviewed and all secondary whitespace and style impact (if any) was fixed up by hand. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-03 07:25:42 +00:00
struct rq *rq;
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
sched: cleanup: remove unnecessary gotos Replace loops implemented with gotos with real loops. Replace err = ...; goto x; x: return err; with return ...; No functional changes. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 15:00:14 +00:00
for (;;) {
/*
* We do the initial early heuristics without holding
* any task-queue locks at all. We'll only try to get
* the runqueue lock when things look like they will
* work out!
*/
rq = task_rq(p);
Fix possible runqueue lock starvation in wait_task_inactive() Miklos Szeredi reported very long pauses (several seconds, sometimes more) on his T60 (with a Core2Duo) which he managed to track down to wait_task_inactive()'s open-coded busy-loop. He observed that an interrupt on one core tries to acquire the runqueue-lock but does not succeed in doing so for a very long time - while wait_task_inactive() on the other core loops waiting for the first core to deschedule a task (which it wont do while spinning in an interrupt handler). This rewrites wait_task_inactive() to do all its waiting optimistically without any locks taken at all, and then just double-check the end result with the proper runqueue lock held over just a very short section. If there were races in the optimistic wait, of a preemption event scheduled the process away, we simply re-synchronize, and start over. So the code now looks like this: repeat: /* Unlocked, optimistic looping! */ rq = task_rq(p); while (task_running(rq, p)) cpu_relax(); /* Get the *real* values */ rq = task_rq_lock(p, &flags); running = task_running(rq, p); array = p->array; task_rq_unlock(rq, &flags); /* Check them.. */ if (unlikely(running)) { cpu_relax(); goto repeat; } /* Preempted away? Yield if so.. */ if (unlikely(array)) { yield(); goto repeat; } Basically, that first "while()" loop is done entirely without any locking at all (and doesn't check for the case where the target process might have been preempted away), and so it's possibly "incorrect", but we don't really care. Both the runqueue used, and the "task_running()" check might be the wrong tests, but they won't oops - they just mean that we could possibly get the wrong results due to lack of locking and exit the loop early in the case of a race condition. So once we've exited the loop, we then get the proper (and careful) rq lock, and check the running/runnable state _safely_. And if it turns out that our quick-and-dirty and unsafe loop was wrong after all, we just go back and try it all again. (The patch also adds a lot of comments, which is the actual bulk of it all, to make it more obvious why we can do these things without holding the locks). Thanks to Miklos for all the testing and tracking it down. Tested-by: Miklos Szeredi <miklos@szeredi.hu> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-06-18 16:34:40 +00:00
sched: cleanup: remove unnecessary gotos Replace loops implemented with gotos with real loops. Replace err = ...; goto x; x: return err; with return ...; No functional changes. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 15:00:14 +00:00
/*
* If the task is actively running on another CPU
* still, just relax and busy-wait without holding
* any locks.
*
* NOTE! Since we don't hold any locks, it's not
* even sure that "rq" stays as the right runqueue!
* But we don't care, since "task_running()" will
* return false if the runqueue has changed and p
* is actually now running somewhere else!
*/
tracehook: wait_task_inactive This extends wait_task_inactive() with a new argument so it can be used in a "soft" mode where it will check for the task changing state unexpectedly and back off. There is no change to existing callers. This lays the groundwork to allow robust, noninvasive tracing that can try to sample a blocked thread but back off safely if it wakes up. Signed-off-by: Roland McGrath <roland@redhat.com> Cc: Oleg Nesterov <oleg@tv-sign.ru> Reviewed-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-26 02:45:58 +00:00
while (task_running(rq, p)) {
if (match_state && unlikely(p->state != match_state))
return 0;
sched: cleanup: remove unnecessary gotos Replace loops implemented with gotos with real loops. Replace err = ...; goto x; x: return err; with return ...; No functional changes. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 15:00:14 +00:00
cpu_relax();
tracehook: wait_task_inactive This extends wait_task_inactive() with a new argument so it can be used in a "soft" mode where it will check for the task changing state unexpectedly and back off. There is no change to existing callers. This lays the groundwork to allow robust, noninvasive tracing that can try to sample a blocked thread but back off safely if it wakes up. Signed-off-by: Roland McGrath <roland@redhat.com> Cc: Oleg Nesterov <oleg@tv-sign.ru> Reviewed-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-26 02:45:58 +00:00
}
Fix possible runqueue lock starvation in wait_task_inactive() Miklos Szeredi reported very long pauses (several seconds, sometimes more) on his T60 (with a Core2Duo) which he managed to track down to wait_task_inactive()'s open-coded busy-loop. He observed that an interrupt on one core tries to acquire the runqueue-lock but does not succeed in doing so for a very long time - while wait_task_inactive() on the other core loops waiting for the first core to deschedule a task (which it wont do while spinning in an interrupt handler). This rewrites wait_task_inactive() to do all its waiting optimistically without any locks taken at all, and then just double-check the end result with the proper runqueue lock held over just a very short section. If there were races in the optimistic wait, of a preemption event scheduled the process away, we simply re-synchronize, and start over. So the code now looks like this: repeat: /* Unlocked, optimistic looping! */ rq = task_rq(p); while (task_running(rq, p)) cpu_relax(); /* Get the *real* values */ rq = task_rq_lock(p, &flags); running = task_running(rq, p); array = p->array; task_rq_unlock(rq, &flags); /* Check them.. */ if (unlikely(running)) { cpu_relax(); goto repeat; } /* Preempted away? Yield if so.. */ if (unlikely(array)) { yield(); goto repeat; } Basically, that first "while()" loop is done entirely without any locking at all (and doesn't check for the case where the target process might have been preempted away), and so it's possibly "incorrect", but we don't really care. Both the runqueue used, and the "task_running()" check might be the wrong tests, but they won't oops - they just mean that we could possibly get the wrong results due to lack of locking and exit the loop early in the case of a race condition. So once we've exited the loop, we then get the proper (and careful) rq lock, and check the running/runnable state _safely_. And if it turns out that our quick-and-dirty and unsafe loop was wrong after all, we just go back and try it all again. (The patch also adds a lot of comments, which is the actual bulk of it all, to make it more obvious why we can do these things without holding the locks). Thanks to Miklos for all the testing and tracking it down. Tested-by: Miklos Szeredi <miklos@szeredi.hu> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-06-18 16:34:40 +00:00
sched: cleanup: remove unnecessary gotos Replace loops implemented with gotos with real loops. Replace err = ...; goto x; x: return err; with return ...; No functional changes. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 15:00:14 +00:00
/*
* Ok, time to look more closely! We need the rq
* lock now, to be *sure*. If we're wrong, we'll
* just go back and repeat.
*/
rq = task_rq_lock(p, &flags);
sched: Remove rq argument to the tracepoints struct rq isn't visible outside of sched.o so its near useless to expose the pointer, also there are no users of it, so remove it. Acked-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1272997616.1642.207.camel@laptop> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-05-04 18:36:56 +00:00
trace_sched_wait_task(p);
sched: cleanup: remove unnecessary gotos Replace loops implemented with gotos with real loops. Replace err = ...; goto x; x: return err; with return ...; No functional changes. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 15:00:14 +00:00
running = task_running(rq, p);
sched: Provide p->on_rq Provide a generic p->on_rq because the p->se.on_rq semantics are unfavourable for lockless wakeups but needed for sched_fair. In particular, p->on_rq is only cleared when we actually dequeue the task in schedule() and not on any random dequeue as done by things like __migrate_task() and __sched_setscheduler(). This also allows us to remove p->se usage from !sched_fair code. Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110405152728.949545047@chello.nl
2011-04-05 15:23:44 +00:00
on_rq = p->on_rq;
tracehook: wait_task_inactive This extends wait_task_inactive() with a new argument so it can be used in a "soft" mode where it will check for the task changing state unexpectedly and back off. There is no change to existing callers. This lays the groundwork to allow robust, noninvasive tracing that can try to sample a blocked thread but back off safely if it wakes up. Signed-off-by: Roland McGrath <roland@redhat.com> Cc: Oleg Nesterov <oleg@tv-sign.ru> Reviewed-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-26 02:45:58 +00:00
ncsw = 0;
wait_task_inactive(): don't consider task->nivcsw If wait_task_inactive() returns success the task was deactivated. In that case schedule() always increments ->nvcsw which alone can be used as a "generation counter". If the next call returns the same number, we can be sure that the task was unscheduled. Otherwise, because we know that .on_rq == 0 again, ->nvcsw should have been changed in between. Q: perhaps it is better to do "ncsw = (p->nvcsw << 1) | 1" ? This decreases the possibility of "was it unscheduled" false positive when ->nvcsw == 0. Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-20 23:54:44 +00:00
if (!match_state || p->state == match_state)
wait_task_inactive: "improve" the returned value for ->nvcsw == 0 wait_task_inactive() returns 1 when p->nvcsw == 0 || p->nvcsw == 1. This means that two subsequent calls can return the same number while the task was scheduled in between. Change the code to return "nvcsw | LONG_MIN" instead of "nvcsw ?: 1", now the overlap always needs LONG_MAX schedules. Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-20 23:54:44 +00:00
ncsw = p->nvcsw | LONG_MIN; /* sets MSB */
sched: Add p->pi_lock to task_rq_lock() In order to be able to call set_task_cpu() while either holding p->pi_lock or task_rq(p)->lock we need to hold both locks in order to stabilize task_rq(). This makes task_rq_lock() acquire both locks, and have __task_rq_lock() validate that p->pi_lock is held. This increases the locking overhead for most scheduler syscalls but allows reduction of rq->lock contention for some scheduler hot paths (ttwu). Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110405152729.232781355@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-05 15:23:51 +00:00
task_rq_unlock(rq, p, &flags);
Fix possible runqueue lock starvation in wait_task_inactive() Miklos Szeredi reported very long pauses (several seconds, sometimes more) on his T60 (with a Core2Duo) which he managed to track down to wait_task_inactive()'s open-coded busy-loop. He observed that an interrupt on one core tries to acquire the runqueue-lock but does not succeed in doing so for a very long time - while wait_task_inactive() on the other core loops waiting for the first core to deschedule a task (which it wont do while spinning in an interrupt handler). This rewrites wait_task_inactive() to do all its waiting optimistically without any locks taken at all, and then just double-check the end result with the proper runqueue lock held over just a very short section. If there were races in the optimistic wait, of a preemption event scheduled the process away, we simply re-synchronize, and start over. So the code now looks like this: repeat: /* Unlocked, optimistic looping! */ rq = task_rq(p); while (task_running(rq, p)) cpu_relax(); /* Get the *real* values */ rq = task_rq_lock(p, &flags); running = task_running(rq, p); array = p->array; task_rq_unlock(rq, &flags); /* Check them.. */ if (unlikely(running)) { cpu_relax(); goto repeat; } /* Preempted away? Yield if so.. */ if (unlikely(array)) { yield(); goto repeat; } Basically, that first "while()" loop is done entirely without any locking at all (and doesn't check for the case where the target process might have been preempted away), and so it's possibly "incorrect", but we don't really care. Both the runqueue used, and the "task_running()" check might be the wrong tests, but they won't oops - they just mean that we could possibly get the wrong results due to lack of locking and exit the loop early in the case of a race condition. So once we've exited the loop, we then get the proper (and careful) rq lock, and check the running/runnable state _safely_. And if it turns out that our quick-and-dirty and unsafe loop was wrong after all, we just go back and try it all again. (The patch also adds a lot of comments, which is the actual bulk of it all, to make it more obvious why we can do these things without holding the locks). Thanks to Miklos for all the testing and tracking it down. Tested-by: Miklos Szeredi <miklos@szeredi.hu> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-06-18 16:34:40 +00:00
tracehook: wait_task_inactive This extends wait_task_inactive() with a new argument so it can be used in a "soft" mode where it will check for the task changing state unexpectedly and back off. There is no change to existing callers. This lays the groundwork to allow robust, noninvasive tracing that can try to sample a blocked thread but back off safely if it wakes up. Signed-off-by: Roland McGrath <roland@redhat.com> Cc: Oleg Nesterov <oleg@tv-sign.ru> Reviewed-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-26 02:45:58 +00:00
/*
* If it changed from the expected state, bail out now.
*/
if (unlikely(!ncsw))
break;
sched: cleanup: remove unnecessary gotos Replace loops implemented with gotos with real loops. Replace err = ...; goto x; x: return err; with return ...; No functional changes. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 15:00:14 +00:00
/*
* Was it really running after all now that we
* checked with the proper locks actually held?
*
* Oops. Go back and try again..
*/
if (unlikely(running)) {
cpu_relax();
continue;
}
Fix possible runqueue lock starvation in wait_task_inactive() Miklos Szeredi reported very long pauses (several seconds, sometimes more) on his T60 (with a Core2Duo) which he managed to track down to wait_task_inactive()'s open-coded busy-loop. He observed that an interrupt on one core tries to acquire the runqueue-lock but does not succeed in doing so for a very long time - while wait_task_inactive() on the other core loops waiting for the first core to deschedule a task (which it wont do while spinning in an interrupt handler). This rewrites wait_task_inactive() to do all its waiting optimistically without any locks taken at all, and then just double-check the end result with the proper runqueue lock held over just a very short section. If there were races in the optimistic wait, of a preemption event scheduled the process away, we simply re-synchronize, and start over. So the code now looks like this: repeat: /* Unlocked, optimistic looping! */ rq = task_rq(p); while (task_running(rq, p)) cpu_relax(); /* Get the *real* values */ rq = task_rq_lock(p, &flags); running = task_running(rq, p); array = p->array; task_rq_unlock(rq, &flags); /* Check them.. */ if (unlikely(running)) { cpu_relax(); goto repeat; } /* Preempted away? Yield if so.. */ if (unlikely(array)) { yield(); goto repeat; } Basically, that first "while()" loop is done entirely without any locking at all (and doesn't check for the case where the target process might have been preempted away), and so it's possibly "incorrect", but we don't really care. Both the runqueue used, and the "task_running()" check might be the wrong tests, but they won't oops - they just mean that we could possibly get the wrong results due to lack of locking and exit the loop early in the case of a race condition. So once we've exited the loop, we then get the proper (and careful) rq lock, and check the running/runnable state _safely_. And if it turns out that our quick-and-dirty and unsafe loop was wrong after all, we just go back and try it all again. (The patch also adds a lot of comments, which is the actual bulk of it all, to make it more obvious why we can do these things without holding the locks). Thanks to Miklos for all the testing and tracking it down. Tested-by: Miklos Szeredi <miklos@szeredi.hu> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-06-18 16:34:40 +00:00
sched: cleanup: remove unnecessary gotos Replace loops implemented with gotos with real loops. Replace err = ...; goto x; x: return err; with return ...; No functional changes. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 15:00:14 +00:00
/*
* It's not enough that it's not actively running,
* it must be off the runqueue _entirely_, and not
* preempted!
*
sched: fix typos in documentation Fixed typos in function documentation. Signed-off-by: Luis Henriques <henrix@sapo.pt> LKML-Reference: <20090316195809.GA6073@hades.domain.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-16 19:58:09 +00:00
* So if it was still runnable (but just not actively
sched: cleanup: remove unnecessary gotos Replace loops implemented with gotos with real loops. Replace err = ...; goto x; x: return err; with return ...; No functional changes. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 15:00:14 +00:00
* running right now), it's preempted, and we should
* yield - it could be a while.
*/
if (unlikely(on_rq)) {
sched: Switch wait_task_inactive to schedule_hrtimeout() When we force thread hard and soft interrupts the startup of ksoftirqd would hang in kthread_bind() when wait_task_inactive() calls schedule_timeout_uninterruptible() because there is no softirq yet which will wake us up. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <20110223234956.677109139@linutronix.de>
2011-02-23 23:52:21 +00:00
ktime_t to = ktime_set(0, NSEC_PER_SEC/HZ);
set_current_state(TASK_UNINTERRUPTIBLE);
schedule_hrtimeout(&to, HRTIMER_MODE_REL);
sched: cleanup: remove unnecessary gotos Replace loops implemented with gotos with real loops. Replace err = ...; goto x; x: return err; with return ...; No functional changes. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 15:00:14 +00:00
continue;
}
Fix possible runqueue lock starvation in wait_task_inactive() Miklos Szeredi reported very long pauses (several seconds, sometimes more) on his T60 (with a Core2Duo) which he managed to track down to wait_task_inactive()'s open-coded busy-loop. He observed that an interrupt on one core tries to acquire the runqueue-lock but does not succeed in doing so for a very long time - while wait_task_inactive() on the other core loops waiting for the first core to deschedule a task (which it wont do while spinning in an interrupt handler). This rewrites wait_task_inactive() to do all its waiting optimistically without any locks taken at all, and then just double-check the end result with the proper runqueue lock held over just a very short section. If there were races in the optimistic wait, of a preemption event scheduled the process away, we simply re-synchronize, and start over. So the code now looks like this: repeat: /* Unlocked, optimistic looping! */ rq = task_rq(p); while (task_running(rq, p)) cpu_relax(); /* Get the *real* values */ rq = task_rq_lock(p, &flags); running = task_running(rq, p); array = p->array; task_rq_unlock(rq, &flags); /* Check them.. */ if (unlikely(running)) { cpu_relax(); goto repeat; } /* Preempted away? Yield if so.. */ if (unlikely(array)) { yield(); goto repeat; } Basically, that first "while()" loop is done entirely without any locking at all (and doesn't check for the case where the target process might have been preempted away), and so it's possibly "incorrect", but we don't really care. Both the runqueue used, and the "task_running()" check might be the wrong tests, but they won't oops - they just mean that we could possibly get the wrong results due to lack of locking and exit the loop early in the case of a race condition. So once we've exited the loop, we then get the proper (and careful) rq lock, and check the running/runnable state _safely_. And if it turns out that our quick-and-dirty and unsafe loop was wrong after all, we just go back and try it all again. (The patch also adds a lot of comments, which is the actual bulk of it all, to make it more obvious why we can do these things without holding the locks). Thanks to Miklos for all the testing and tracking it down. Tested-by: Miklos Szeredi <miklos@szeredi.hu> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-06-18 16:34:40 +00:00
sched: cleanup: remove unnecessary gotos Replace loops implemented with gotos with real loops. Replace err = ...; goto x; x: return err; with return ...; No functional changes. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 15:00:14 +00:00
/*
* Ahh, all good. It wasn't running, and it wasn't
* runnable, which means that it will never become
* running in the future either. We're all done!
*/
break;
}
tracehook: wait_task_inactive This extends wait_task_inactive() with a new argument so it can be used in a "soft" mode where it will check for the task changing state unexpectedly and back off. There is no change to existing callers. This lays the groundwork to allow robust, noninvasive tracing that can try to sample a blocked thread but back off safely if it wakes up. Signed-off-by: Roland McGrath <roland@redhat.com> Cc: Oleg Nesterov <oleg@tv-sign.ru> Reviewed-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-26 02:45:58 +00:00
return ncsw;
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
}
/***
* kick_process - kick a running thread to enter/exit the kernel
* @p: the to-be-kicked thread
*
* Cause a process which is running on another CPU to enter
* kernel-mode, without any delay. (to get signals handled.)
*
Fix common misspellings Fixes generated by 'codespell' and manually reviewed. Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
2011-03-31 01:57:33 +00:00
* NOTE: this function doesn't have to take the runqueue lock,
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
* because all it wants to ensure is that the remote task enters
* the kernel. If the IPI races and the task has been migrated
* to another CPU then no harm is done and the purpose has been
* achieved as well.
*/
[PATCH] sched: cleanup, remove task_t, convert to struct task_struct cleanup: remove task_t and convert all the uses to struct task_struct. I introduced it for the scheduler anno and it was a mistake. Conversion was mostly scripted, the result was reviewed and all secondary whitespace and style impact (if any) was fixed up by hand. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-03 07:25:41 +00:00
void kick_process(struct task_struct *p)
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
{
int cpu;
preempt_disable();
cpu = task_cpu(p);
if ((cpu != smp_processor_id()) && task_curr(p))
smp_send_reschedule(cpu);
preempt_enable();
}
sched: export kick_process lguest needs kick_process: wake_up_process() does nothing if a process is running, which isn't sufficient (we need it in the kernel). And lguest support is usually modular. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Ingo Molnar <mingo@elte.hu>
2009-06-13 04:27:00 +00:00
EXPORT_SYMBOL_GPL(kick_process);
[PATCH] sched: consolidate sbe sbf Consolidate balance-on-exec with balance-on-fork. This is made easy by the sched-domains RCU patches. As well as the general goodness of code reduction, this allows the runqueues to be unlocked during balance-on-fork. schedstats is a problem. Maybe just have balance-on-event instead of distinguishing fork and exec? Signed-off-by: Nick Piggin <nickpiggin@yahoo.com.au> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-25 21:57:29 +00:00
#endif /* CONFIG_SMP */
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
sched: Consolidate select_task_rq() callers Small cleanup. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> [ v2: build fix ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-11-25 12:31:39 +00:00
#ifdef CONFIG_SMP
sched: sched_exec(): Remove the select_fallback_rq() logic sched_exec()->select_task_rq() reads/updates ->cpus_allowed lockless. This can race with other CPUs updating our ->cpus_allowed, and this looks meaningless to me. The task is current and running, it must have online cpus in ->cpus_allowed, the fallback mode is bogus. And, if ->sched_class returns the "wrong" cpu, this likely means we raced with set_cpus_allowed() which was called for reason, why should sched_exec() retry and call ->select_task_rq() again? Change the code to call sched_class->select_task_rq() directly and do nothing if the returned cpu is wrong after re-checking under rq->lock. From now task_struct->cpus_allowed is always stable under TASK_WAKING, select_fallback_rq() is always called under rq-lock or the caller or the caller owns TASK_WAKING (select_task_rq). Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20100315091019.GA9141@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-03-15 09:10:19 +00:00
/*
sched: Serialize p->cpus_allowed and ttwu() using p->pi_lock Currently p->pi_lock already serializes p->sched_class, also put p->cpus_allowed and try_to_wake_up() under it, this prepares the way to do the first part of ttwu() without holding rq->lock. By having p->sched_class and p->cpus_allowed serialized by p->pi_lock, we prepare the way to call select_task_rq() without holding rq->lock. Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110405152728.990364093@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-05 15:23:45 +00:00
* ->cpus_allowed is protected by both rq->lock and p->pi_lock
sched: sched_exec(): Remove the select_fallback_rq() logic sched_exec()->select_task_rq() reads/updates ->cpus_allowed lockless. This can race with other CPUs updating our ->cpus_allowed, and this looks meaningless to me. The task is current and running, it must have online cpus in ->cpus_allowed, the fallback mode is bogus. And, if ->sched_class returns the "wrong" cpu, this likely means we raced with set_cpus_allowed() which was called for reason, why should sched_exec() retry and call ->select_task_rq() again? Change the code to call sched_class->select_task_rq() directly and do nothing if the returned cpu is wrong after re-checking under rq->lock. From now task_struct->cpus_allowed is always stable under TASK_WAKING, select_fallback_rq() is always called under rq-lock or the caller or the caller owns TASK_WAKING (select_task_rq). Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20100315091019.GA9141@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-03-15 09:10:19 +00:00
*/
sched: Fix select_task_rq() vs hotplug issues Since select_task_rq() is now responsible for guaranteeing ->cpus_allowed and cpu_active_mask, we need to verify this. select_task_rq_rt() can blindly return smp_processor_id()/task_cpu() without checking the valid masks, select_task_rq_fair() can do the same in the rare case that all SD_flags are disabled. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> LKML-Reference: <20091216170517.961475466@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-16 17:04:38 +00:00
static int select_fallback_rq(int cpu, struct task_struct *p)
{
int dest_cpu;
const struct cpumask *nodemask = cpumask_of_node(cpu_to_node(cpu));
/* Look for allowed, online CPU in same node. */
for_each_cpu_and(dest_cpu, nodemask, cpu_active_mask)
if (cpumask_test_cpu(dest_cpu, &p->cpus_allowed))
return dest_cpu;
/* Any allowed, online CPU? */
dest_cpu = cpumask_any_and(&p->cpus_allowed, cpu_active_mask);
if (dest_cpu < nr_cpu_ids)
return dest_cpu;
/* No more Mr. Nice Guy. */
sched: Simplify cpu-hot-unplug task migration While discussing the need for sched_idle_next(), Oleg remarked that since try_to_wake_up() ensures sleeping tasks will end up running on a sane cpu, we can do away with migrate_live_tasks(). If we then extend the existing hack of migrating current from CPU_DYING to migrating the full rq worth of tasks from CPU_DYING, the need for the sched_idle_next() abomination disappears as well, since idle will be the only possible thread left after the migration thread stops. This greatly simplifies the hot-unplug task migration path, as can be seen from the resulting code reduction (and about half the new lines are comments). Suggested-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1289851597.2109.547.camel@laptop> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-13 18:32:29 +00:00
dest_cpu = cpuset_cpus_allowed_fallback(p);
/*
* Don't tell them about moving exiting tasks or
* kernel threads (both mm NULL), since they never
* leave kernel.
*/
if (p->mm && printk_ratelimit()) {
printk(KERN_INFO "process %d (%s) no longer affine to cpu%d\n",
task_pid_nr(p), p->comm, cpu);
sched: Fix select_task_rq() vs hotplug issues Since select_task_rq() is now responsible for guaranteeing ->cpus_allowed and cpu_active_mask, we need to verify this. select_task_rq_rt() can blindly return smp_processor_id()/task_cpu() without checking the valid masks, select_task_rq_fair() can do the same in the rare case that all SD_flags are disabled. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> LKML-Reference: <20091216170517.961475466@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-16 17:04:38 +00:00
}
return dest_cpu;
}
sched: Ensure set_task_cpu() is never called on blocked tasks In order to clean up the set_task_cpu() rq dependencies we need to ensure it is never called on blocked tasks because such usage does not pair with consistent rq->lock usage. This puts the migration burden on ttwu(). Furthermore we need to close a race against changing ->cpus_allowed, since select_task_rq() runs with only preemption disabled. For sched_fork() this is safe because the child isn't in the tasklist yet, for wakeup we fix this by synchronizing set_cpus_allowed_ptr() against TASK_WAKING, which leaves sched_exec to be a problem This also closes a hole in (6ad4c1888 sched: Fix balance vs hotplug race) where ->select_task_rq() doesn't validate the result against the sched_domain/root_domain. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> LKML-Reference: <20091216170517.807938893@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-16 17:04:36 +00:00
/*
sched: Serialize p->cpus_allowed and ttwu() using p->pi_lock Currently p->pi_lock already serializes p->sched_class, also put p->cpus_allowed and try_to_wake_up() under it, this prepares the way to do the first part of ttwu() without holding rq->lock. By having p->sched_class and p->cpus_allowed serialized by p->pi_lock, we prepare the way to call select_task_rq() without holding rq->lock. Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110405152728.990364093@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-05 15:23:45 +00:00
* The caller (fork, wakeup) owns p->pi_lock, ->cpus_allowed is stable.
sched: Ensure set_task_cpu() is never called on blocked tasks In order to clean up the set_task_cpu() rq dependencies we need to ensure it is never called on blocked tasks because such usage does not pair with consistent rq->lock usage. This puts the migration burden on ttwu(). Furthermore we need to close a race against changing ->cpus_allowed, since select_task_rq() runs with only preemption disabled. For sched_fork() this is safe because the child isn't in the tasklist yet, for wakeup we fix this by synchronizing set_cpus_allowed_ptr() against TASK_WAKING, which leaves sched_exec to be a problem This also closes a hole in (6ad4c1888 sched: Fix balance vs hotplug race) where ->select_task_rq() doesn't validate the result against the sched_domain/root_domain. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> LKML-Reference: <20091216170517.807938893@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-16 17:04:36 +00:00
*/
sched: Consolidate select_task_rq() callers Small cleanup. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> [ v2: build fix ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-11-25 12:31:39 +00:00
static inline
sched: Drop the rq argument to sched_class::select_task_rq() In preparation of calling select_task_rq() without rq->lock held, drop the dependency on the rq argument. Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110405152729.031077745@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-05 15:23:46 +00:00
int select_task_rq(struct task_struct *p, int sd_flags, int wake_flags)
sched: Consolidate select_task_rq() callers Small cleanup. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> [ v2: build fix ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-11-25 12:31:39 +00:00
{
sched: Drop the rq argument to sched_class::select_task_rq() In preparation of calling select_task_rq() without rq->lock held, drop the dependency on the rq argument. Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110405152729.031077745@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-05 15:23:46 +00:00
int cpu = p->sched_class->select_task_rq(p, sd_flags, wake_flags);
sched: Ensure set_task_cpu() is never called on blocked tasks In order to clean up the set_task_cpu() rq dependencies we need to ensure it is never called on blocked tasks because such usage does not pair with consistent rq->lock usage. This puts the migration burden on ttwu(). Furthermore we need to close a race against changing ->cpus_allowed, since select_task_rq() runs with only preemption disabled. For sched_fork() this is safe because the child isn't in the tasklist yet, for wakeup we fix this by synchronizing set_cpus_allowed_ptr() against TASK_WAKING, which leaves sched_exec to be a problem This also closes a hole in (6ad4c1888 sched: Fix balance vs hotplug race) where ->select_task_rq() doesn't validate the result against the sched_domain/root_domain. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> LKML-Reference: <20091216170517.807938893@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-16 17:04:36 +00:00
/*
* In order not to call set_task_cpu() on a blocking task we need
* to rely on ttwu() to place the task on a valid ->cpus_allowed
* cpu.
*
* Since this is common to all placement strategies, this lives here.
*
* [ this allows ->select_task() to simply return task_cpu(p) and
* not worry about this generic constraint ]
*/
if (unlikely(!cpumask_test_cpu(cpu, &p->cpus_allowed) ||
sched: Fix hotplug hang The hot-unplug kstopmachine usage does a wakeup after deactivating the cpu, hence we cannot use cpu_active() here but must rely on the good olde online. Reported-by: Sachin Sant <sachinp@in.ibm.com> Reported-by: Jens Axboe <jens.axboe@oracle.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Tested-by: Jens Axboe <jens.axboe@oracle.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> LKML-Reference: <1261326987.4314.24.camel@laptop> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-20 16:36:27 +00:00
!cpu_online(cpu)))
sched: Fix select_task_rq() vs hotplug issues Since select_task_rq() is now responsible for guaranteeing ->cpus_allowed and cpu_active_mask, we need to verify this. select_task_rq_rt() can blindly return smp_processor_id()/task_cpu() without checking the valid masks, select_task_rq_fair() can do the same in the rare case that all SD_flags are disabled. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> LKML-Reference: <20091216170517.961475466@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-16 17:04:38 +00:00
cpu = select_fallback_rq(task_cpu(p), p);
sched: Ensure set_task_cpu() is never called on blocked tasks In order to clean up the set_task_cpu() rq dependencies we need to ensure it is never called on blocked tasks because such usage does not pair with consistent rq->lock usage. This puts the migration burden on ttwu(). Furthermore we need to close a race against changing ->cpus_allowed, since select_task_rq() runs with only preemption disabled. For sched_fork() this is safe because the child isn't in the tasklist yet, for wakeup we fix this by synchronizing set_cpus_allowed_ptr() against TASK_WAKING, which leaves sched_exec to be a problem This also closes a hole in (6ad4c1888 sched: Fix balance vs hotplug race) where ->select_task_rq() doesn't validate the result against the sched_domain/root_domain. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> LKML-Reference: <20091216170517.807938893@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-16 17:04:36 +00:00
return cpu;
sched: Consolidate select_task_rq() callers Small cleanup. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> [ v2: build fix ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-11-25 12:31:39 +00:00
}
sched: Fix UP update_avg() build warning update_avg() is only used for SMP builds, move it to the nearest SMP block. Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <1271309399.14779.17.camel@marge.simson.net> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-04-15 05:29:59 +00:00
static void update_avg(u64 *avg, u64 sample)
{
s64 diff = sample - *avg;
*avg += diff >> 3;
}
sched: Consolidate select_task_rq() callers Small cleanup. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> [ v2: build fix ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-11-25 12:31:39 +00:00
#endif
sched: Clean up ttwu() stats Collect all ttwu() stat code into a single function and ensure its always called for an actual wakeup (changing p->state to TASK_RUNNING). Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110405152728.908177058@chello.nl
2011-04-05 15:23:43 +00:00
static void
sched: Remove rq argument from ttwu_stat() In order to call ttwu_stat() without holding rq->lock we must remove its rq argument. Since we need to change rq stats, account to the local rq instead of the task rq, this is safe since we have IRQs disabled. Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110405152729.394638826@chello.nl
2011-04-05 15:23:55 +00:00
ttwu_stat(struct task_struct *p, int cpu, int wake_flags)
sched: refactor try_to_wake_up() Factor ttwu_activate() and ttwu_woken_up() out of try_to_wake_up(). The factoring out doesn't affect try_to_wake_up() much code-generation-wise. Depending on configuration options, it ends up generating the same object code as before or slightly different one due to different register assignment. This is to help future implementation of try_to_wake_up_local(). Mike Galbraith suggested rename to ttwu_post_activation() from ttwu_woken_up() and comment update in try_to_wake_up(). Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Ingo Molnar <mingo@elte.hu>
2009-12-03 06:08:03 +00:00
{
sched: Clean up ttwu() stats Collect all ttwu() stat code into a single function and ensure its always called for an actual wakeup (changing p->state to TASK_RUNNING). Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110405152728.908177058@chello.nl
2011-04-05 15:23:43 +00:00
#ifdef CONFIG_SCHEDSTATS
sched: Remove rq argument from ttwu_stat() In order to call ttwu_stat() without holding rq->lock we must remove its rq argument. Since we need to change rq stats, account to the local rq instead of the task rq, this is safe since we have IRQs disabled. Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110405152729.394638826@chello.nl
2011-04-05 15:23:55 +00:00
struct rq *rq = this_rq();
sched: Clean up ttwu() stats Collect all ttwu() stat code into a single function and ensure its always called for an actual wakeup (changing p->state to TASK_RUNNING). Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110405152728.908177058@chello.nl
2011-04-05 15:23:43 +00:00
#ifdef CONFIG_SMP
int this_cpu = smp_processor_id();
if (cpu == this_cpu) {
schedstat_inc(rq, ttwu_local);
schedstat_inc(p, se.statistics.nr_wakeups_local);
} else {
struct sched_domain *sd;
schedstat_inc(p, se.statistics.nr_wakeups_remote);
sched: Fix sched_domain iterations vs. RCU Vladis Kletnieks reported a new RCU debug warning in the scheduler. Since commit dce840a08702b ("sched: Dynamically allocate sched_domain/ sched_group data-structures") the sched_domain trees are protected by RCU instead of RCU-sched. This means that we need to include rcu_read_lock() protection when we iterate them since disabling preemption doesn't suffice anymore. Reported-by: Valdis.Kletnieks@vt.edu Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1302882741.2388.241.camel@twins Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-18 09:24:34 +00:00
rcu_read_lock();
sched: Clean up ttwu() stats Collect all ttwu() stat code into a single function and ensure its always called for an actual wakeup (changing p->state to TASK_RUNNING). Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110405152728.908177058@chello.nl
2011-04-05 15:23:43 +00:00
for_each_domain(this_cpu, sd) {
if (cpumask_test_cpu(cpu, sched_domain_span(sd))) {
schedstat_inc(sd, ttwu_wake_remote);
break;
}
}
sched: Fix sched_domain iterations vs. RCU Vladis Kletnieks reported a new RCU debug warning in the scheduler. Since commit dce840a08702b ("sched: Dynamically allocate sched_domain/ sched_group data-structures") the sched_domain trees are protected by RCU instead of RCU-sched. This means that we need to include rcu_read_lock() protection when we iterate them since disabling preemption doesn't suffice anymore. Reported-by: Valdis.Kletnieks@vt.edu Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1302882741.2388.241.camel@twins Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-18 09:24:34 +00:00
rcu_read_unlock();
sched: Clean up ttwu() stats Collect all ttwu() stat code into a single function and ensure its always called for an actual wakeup (changing p->state to TASK_RUNNING). Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110405152728.908177058@chello.nl
2011-04-05 15:23:43 +00:00
}
sched: Fix schedstat.nr_wakeups_migrate While looking over the code I found that with the ttwu rework the nr_wakeups_migrate test broke since we now switch cpus prior to calling ttwu_stat(), hence the test is always true. Cure this by passing the migration state in wake_flags. Also move the whole test under CONFIG_SMP, its hard to migrate tasks on UP :-) Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/n/tip-pwwxl7gdqs5676f1d4cx6pj7@git.kernel.org Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-05-31 08:49:20 +00:00
if (wake_flags & WF_MIGRATED)
schedstat_inc(p, se.statistics.nr_wakeups_migrate);
sched: Clean up ttwu() stats Collect all ttwu() stat code into a single function and ensure its always called for an actual wakeup (changing p->state to TASK_RUNNING). Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110405152728.908177058@chello.nl
2011-04-05 15:23:43 +00:00
#endif /* CONFIG_SMP */
schedstat_inc(rq, ttwu_count);
sched: refactor try_to_wake_up() Factor ttwu_activate() and ttwu_woken_up() out of try_to_wake_up(). The factoring out doesn't affect try_to_wake_up() much code-generation-wise. Depending on configuration options, it ends up generating the same object code as before or slightly different one due to different register assignment. This is to help future implementation of try_to_wake_up_local(). Mike Galbraith suggested rename to ttwu_post_activation() from ttwu_woken_up() and comment update in try_to_wake_up(). Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Ingo Molnar <mingo@elte.hu>
2009-12-03 06:08:03 +00:00
schedstat_inc(p, se.statistics.nr_wakeups);
sched: Clean up ttwu() stats Collect all ttwu() stat code into a single function and ensure its always called for an actual wakeup (changing p->state to TASK_RUNNING). Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110405152728.908177058@chello.nl
2011-04-05 15:23:43 +00:00
if (wake_flags & WF_SYNC)
sched: refactor try_to_wake_up() Factor ttwu_activate() and ttwu_woken_up() out of try_to_wake_up(). The factoring out doesn't affect try_to_wake_up() much code-generation-wise. Depending on configuration options, it ends up generating the same object code as before or slightly different one due to different register assignment. This is to help future implementation of try_to_wake_up_local(). Mike Galbraith suggested rename to ttwu_post_activation() from ttwu_woken_up() and comment update in try_to_wake_up(). Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Ingo Molnar <mingo@elte.hu>
2009-12-03 06:08:03 +00:00
schedstat_inc(p, se.statistics.nr_wakeups_sync);
sched: Clean up ttwu() stats Collect all ttwu() stat code into a single function and ensure its always called for an actual wakeup (changing p->state to TASK_RUNNING). Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110405152728.908177058@chello.nl
2011-04-05 15:23:43 +00:00
#endif /* CONFIG_SCHEDSTATS */
}
static void ttwu_activate(struct rq *rq, struct task_struct *p, int en_flags)
{
sched: refactor try_to_wake_up() Factor ttwu_activate() and ttwu_woken_up() out of try_to_wake_up(). The factoring out doesn't affect try_to_wake_up() much code-generation-wise. Depending on configuration options, it ends up generating the same object code as before or slightly different one due to different register assignment. This is to help future implementation of try_to_wake_up_local(). Mike Galbraith suggested rename to ttwu_post_activation() from ttwu_woken_up() and comment update in try_to_wake_up(). Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Ingo Molnar <mingo@elte.hu>
2009-12-03 06:08:03 +00:00
activate_task(rq, p, en_flags);
sched: Provide p->on_rq Provide a generic p->on_rq because the p->se.on_rq semantics are unfavourable for lockless wakeups but needed for sched_fair. In particular, p->on_rq is only cleared when we actually dequeue the task in schedule() and not on any random dequeue as done by things like __migrate_task() and __sched_setscheduler(). This also allows us to remove p->se usage from !sched_fair code. Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110405152728.949545047@chello.nl
2011-04-05 15:23:44 +00:00
p->on_rq = 1;
sched: Move wq_worker_waking to the correct site wq_worker_waking_up() needs to match wq_worker_sleeping(), since the latter is only called on deactivate, move the former near activate. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Tejun Heo <tj@kernel.org> Link: http://lkml.kernel.org/n/top-t3m7n70n9frmv4pv2n5fwmov@git.kernel.org Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-13 11:28:56 +00:00
/* if a worker is waking up, notify workqueue */
if (p->flags & PF_WQ_WORKER)
wq_worker_waking_up(p, cpu_of(rq));
sched: refactor try_to_wake_up() Factor ttwu_activate() and ttwu_woken_up() out of try_to_wake_up(). The factoring out doesn't affect try_to_wake_up() much code-generation-wise. Depending on configuration options, it ends up generating the same object code as before or slightly different one due to different register assignment. This is to help future implementation of try_to_wake_up_local(). Mike Galbraith suggested rename to ttwu_post_activation() from ttwu_woken_up() and comment update in try_to_wake_up(). Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Ingo Molnar <mingo@elte.hu>
2009-12-03 06:08:03 +00:00
}
sched: Rename ttwu_post_activation() to ttwu_do_wakeup() The ttwu_post_activation() code does the core wakeup, it sets TASK_RUNNING and performs wakeup-preemption, so give is a more descriptive name. Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110405152729.434609705@chello.nl
2011-04-05 15:23:56 +00:00
/*
* Mark the task runnable and perform wakeup-preemption.
*/
sched: Change the ttwu() success details try_to_wake_up() would only return a success when it would have to place a task on a rq, change that to every time we change p->state to TASK_RUNNING, because that's the real measure of wakeups. This results in that success is always true for the tracepoints. Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110405152728.866866929@chello.nl
2011-04-05 15:23:42 +00:00
static void
sched: Rename ttwu_post_activation() to ttwu_do_wakeup() The ttwu_post_activation() code does the core wakeup, it sets TASK_RUNNING and performs wakeup-preemption, so give is a more descriptive name. Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110405152729.434609705@chello.nl
2011-04-05 15:23:56 +00:00
ttwu_do_wakeup(struct rq *rq, struct task_struct *p, int wake_flags)
sched: refactor try_to_wake_up() Factor ttwu_activate() and ttwu_woken_up() out of try_to_wake_up(). The factoring out doesn't affect try_to_wake_up() much code-generation-wise. Depending on configuration options, it ends up generating the same object code as before or slightly different one due to different register assignment. This is to help future implementation of try_to_wake_up_local(). Mike Galbraith suggested rename to ttwu_post_activation() from ttwu_woken_up() and comment update in try_to_wake_up(). Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Ingo Molnar <mingo@elte.hu>
2009-12-03 06:08:03 +00:00
{
sched: Change the ttwu() success details try_to_wake_up() would only return a success when it would have to place a task on a rq, change that to every time we change p->state to TASK_RUNNING, because that's the real measure of wakeups. This results in that success is always true for the tracepoints. Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110405152728.866866929@chello.nl
2011-04-05 15:23:42 +00:00
trace_sched_wakeup(p, true);
sched: refactor try_to_wake_up() Factor ttwu_activate() and ttwu_woken_up() out of try_to_wake_up(). The factoring out doesn't affect try_to_wake_up() much code-generation-wise. Depending on configuration options, it ends up generating the same object code as before or slightly different one due to different register assignment. This is to help future implementation of try_to_wake_up_local(). Mike Galbraith suggested rename to ttwu_post_activation() from ttwu_woken_up() and comment update in try_to_wake_up(). Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Ingo Molnar <mingo@elte.hu>
2009-12-03 06:08:03 +00:00
check_preempt_curr(rq, p, wake_flags);
p->state = TASK_RUNNING;
#ifdef CONFIG_SMP
if (p->sched_class->task_woken)
p->sched_class->task_woken(rq, p);
sched: Remove unlikely() from ttwu_post_activation The unlikely() used in ttwu_post_activation() tests if the rq->idle_stamp is set. But since this is for a wakeup, and wakeups happen when tasks block on IO, and blocking tasks on IO may put the system into idle, this can actually be a common occurence. Running the annotated branch profiler on an average desktop running firefox, evolution, xchat and distcc, the report shows: correct incorrect % Function File Line ------- --------- - -------- ---- ---- 34884862 146110926 80 ttwu_post_activation sched.c 2309 80% of the time, this unlikely is incorrect. Best not to assume what the result is, and just remove the branch annotation. Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-12-06 22:10:31 +00:00
if (rq->idle_stamp) {
sched: refactor try_to_wake_up() Factor ttwu_activate() and ttwu_woken_up() out of try_to_wake_up(). The factoring out doesn't affect try_to_wake_up() much code-generation-wise. Depending on configuration options, it ends up generating the same object code as before or slightly different one due to different register assignment. This is to help future implementation of try_to_wake_up_local(). Mike Galbraith suggested rename to ttwu_post_activation() from ttwu_woken_up() and comment update in try_to_wake_up(). Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Ingo Molnar <mingo@elte.hu>
2009-12-03 06:08:03 +00:00
u64 delta = rq->clock - rq->idle_stamp;
u64 max = 2*sysctl_sched_migration_cost;
if (delta > max)
rq->avg_idle = max;
else
update_avg(&rq->avg_idle, delta);
rq->idle_stamp = 0;
}
#endif
}
sched: Restructure ttwu() some more Factor our helper functions to make the inner workings of try_to_wake_up() more obvious, this also allows for adding remote queues. Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110405152729.475848012@chello.nl
2011-04-05 15:23:57 +00:00
static void
ttwu_do_activate(struct rq *rq, struct task_struct *p, int wake_flags)
{
#ifdef CONFIG_SMP
if (p->sched_contributes_to_load)
rq->nr_uninterruptible--;
#endif
ttwu_activate(rq, p, ENQUEUE_WAKEUP | ENQUEUE_WAKING);
ttwu_do_wakeup(rq, p, wake_flags);
}
/*
* Called in case the task @p isn't fully descheduled from its runqueue,
* in this case we must do a remote wakeup. Its a 'light' wakeup though,
* since all we need to do is flip p->state to TASK_RUNNING, since
* the task is still ->on_rq.
*/
static int ttwu_remote(struct task_struct *p, int wake_flags)
{
struct rq *rq;
int ret = 0;
rq = __task_rq_lock(p);
if (p->on_rq) {
ttwu_do_wakeup(rq, p, wake_flags);
ret = 1;
}
__task_rq_unlock(rq);
return ret;
}
sched: Move the second half of ttwu() to the remote cpu Now that we've removed the rq->lock requirement from the first part of ttwu() and can compute placement without holding any rq->lock, ensure we execute the second half of ttwu() on the actual cpu we want the task to run on. This avoids having to take rq->lock and doing the task enqueue remotely, saving lots on cacheline transfers. As measured using: http://oss.oracle.com/~mason/sembench.c $ for i in /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor ; do echo performance > $i; done $ echo 4096 32000 64 128 > /proc/sys/kernel/sem $ ./sembench -t 2048 -w 1900 -o 0 unpatched: run time 30 seconds 647278 worker burns per second patched: run time 30 seconds 816715 worker burns per second Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110405152729.515897185@chello.nl
2011-04-05 15:23:58 +00:00
#ifdef CONFIG_SMP
sched: Add irq_{enter,exit}() to scheduler_ipi() Ensure scheduler_ipi() calls irq_{enter,exit} when it does some actual work. Traditionally we never did any actual work from the resched IPI and all magic happened in the return from interrupt path. Now that we do do some work, we need to ensure irq_{enter,exit} are called so that we don't confuse things. This affects things like timekeeping, NO_HZ and RCU, basically everything with a hook in irq_enter/exit. Explicit examples of things going wrong are: sched_clock_cpu() -- has a callback when leaving NO_HZ state to take a new reading from GTOD and TSC. Without this callback, time is stuck in the past. RCU -- needs in_irq() to work in order to avoid some nasty deadlocks Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2011-07-19 22:07:25 +00:00
static void sched_ttwu_do_pending(struct task_struct *list)
sched: Move the second half of ttwu() to the remote cpu Now that we've removed the rq->lock requirement from the first part of ttwu() and can compute placement without holding any rq->lock, ensure we execute the second half of ttwu() on the actual cpu we want the task to run on. This avoids having to take rq->lock and doing the task enqueue remotely, saving lots on cacheline transfers. As measured using: http://oss.oracle.com/~mason/sembench.c $ for i in /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor ; do echo performance > $i; done $ echo 4096 32000 64 128 > /proc/sys/kernel/sem $ ./sembench -t 2048 -w 1900 -o 0 unpatched: run time 30 seconds 647278 worker burns per second patched: run time 30 seconds 816715 worker burns per second Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110405152729.515897185@chello.nl
2011-04-05 15:23:58 +00:00
{
struct rq *rq = this_rq();
raw_spin_lock(&rq->lock);
while (list) {
struct task_struct *p = list;
list = list->wake_entry;
ttwu_do_activate(rq, p, 0);
}
raw_spin_unlock(&rq->lock);
}
sched: Add irq_{enter,exit}() to scheduler_ipi() Ensure scheduler_ipi() calls irq_{enter,exit} when it does some actual work. Traditionally we never did any actual work from the resched IPI and all magic happened in the return from interrupt path. Now that we do do some work, we need to ensure irq_{enter,exit} are called so that we don't confuse things. This affects things like timekeeping, NO_HZ and RCU, basically everything with a hook in irq_enter/exit. Explicit examples of things going wrong are: sched_clock_cpu() -- has a callback when leaving NO_HZ state to take a new reading from GTOD and TSC. Without this callback, time is stuck in the past. RCU -- needs in_irq() to work in order to avoid some nasty deadlocks Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2011-07-19 22:07:25 +00:00
#ifdef CONFIG_HOTPLUG_CPU
static void sched_ttwu_pending(void)
{
struct rq *rq = this_rq();
struct task_struct *list = xchg(&rq->wake_list, NULL);
if (!list)
return;
sched_ttwu_do_pending(list);
}
#endif /* CONFIG_HOTPLUG_CPU */
sched: Move the second half of ttwu() to the remote cpu Now that we've removed the rq->lock requirement from the first part of ttwu() and can compute placement without holding any rq->lock, ensure we execute the second half of ttwu() on the actual cpu we want the task to run on. This avoids having to take rq->lock and doing the task enqueue remotely, saving lots on cacheline transfers. As measured using: http://oss.oracle.com/~mason/sembench.c $ for i in /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor ; do echo performance > $i; done $ echo 4096 32000 64 128 > /proc/sys/kernel/sem $ ./sembench -t 2048 -w 1900 -o 0 unpatched: run time 30 seconds 647278 worker burns per second patched: run time 30 seconds 816715 worker burns per second Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110405152729.515897185@chello.nl
2011-04-05 15:23:58 +00:00
void scheduler_ipi(void)
{
sched: Add irq_{enter,exit}() to scheduler_ipi() Ensure scheduler_ipi() calls irq_{enter,exit} when it does some actual work. Traditionally we never did any actual work from the resched IPI and all magic happened in the return from interrupt path. Now that we do do some work, we need to ensure irq_{enter,exit} are called so that we don't confuse things. This affects things like timekeeping, NO_HZ and RCU, basically everything with a hook in irq_enter/exit. Explicit examples of things going wrong are: sched_clock_cpu() -- has a callback when leaving NO_HZ state to take a new reading from GTOD and TSC. Without this callback, time is stuck in the past. RCU -- needs in_irq() to work in order to avoid some nasty deadlocks Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2011-07-19 22:07:25 +00:00
struct rq *rq = this_rq();
struct task_struct *list = xchg(&rq->wake_list, NULL);
if (!list)
return;
/*
* Not all reschedule IPI handlers call irq_enter/irq_exit, since
* traditionally all their work was done from the interrupt return
* path. Now that we actually do some work, we need to make sure
* we do call them.
*
* Some archs already do call them, luckily irq_enter/exit nest
* properly.
*
* Arguably we should visit all archs and update all handlers,
* however a fair share of IPIs are still resched only so this would
* somewhat pessimize the simple resched case.
*/
irq_enter();
sched_ttwu_do_pending(list);
irq_exit();
sched: Move the second half of ttwu() to the remote cpu Now that we've removed the rq->lock requirement from the first part of ttwu() and can compute placement without holding any rq->lock, ensure we execute the second half of ttwu() on the actual cpu we want the task to run on. This avoids having to take rq->lock and doing the task enqueue remotely, saving lots on cacheline transfers. As measured using: http://oss.oracle.com/~mason/sembench.c $ for i in /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor ; do echo performance > $i; done $ echo 4096 32000 64 128 > /proc/sys/kernel/sem $ ./sembench -t 2048 -w 1900 -o 0 unpatched: run time 30 seconds 647278 worker burns per second patched: run time 30 seconds 816715 worker burns per second Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110405152729.515897185@chello.nl
2011-04-05 15:23:58 +00:00
}
static void ttwu_queue_remote(struct task_struct *p, int cpu)
{
struct rq *rq = cpu_rq(cpu);
struct task_struct *next = rq->wake_list;
for (;;) {
struct task_struct *old = next;
p->wake_entry = next;
next = cmpxchg(&rq->wake_list, old, p);
if (next == old)
break;
}
if (!next)
smp_send_reschedule(cpu);
}
sched: Fix ttwu() for __ARCH_WANT_INTERRUPTS_ON_CTXSW Marc reported that e4a52bcb9 (sched: Remove rq->lock from the first half of ttwu()) broke his ARM-SMP machine. Now ARM is one of the few __ARCH_WANT_INTERRUPTS_ON_CTXSW users, so that exception in the ttwu() code was suspect. Yong found that the interrupt could hit after context_switch() changes current but before it clears p->on_cpu, if that interrupt were to attempt a wake-up of p we would indeed find ourselves spinning in IRQ context. Fix this by reverting to the old behaviour for this situation and perform a full remote wake-up. Cc: Frank Rowand <frank.rowand@am.sony.com> Cc: Yong Zhang <yong.zhang0@gmail.com> Cc: Oleg Nesterov <oleg@redhat.com> Reported-by: Marc Zyngier <Marc.Zyngier@arm.com> Tested-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-05-26 12:21:33 +00:00
#ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW
static int ttwu_activate_remote(struct task_struct *p, int wake_flags)
{
struct rq *rq;
int ret = 0;
rq = __task_rq_lock(p);
if (p->on_cpu) {
ttwu_activate(rq, p, ENQUEUE_WAKEUP);
ttwu_do_wakeup(rq, p, wake_flags);
ret = 1;
}
__task_rq_unlock(rq);
return ret;
}
#endif /* __ARCH_WANT_INTERRUPTS_ON_CTXSW */
#endif /* CONFIG_SMP */
sched: Move the second half of ttwu() to the remote cpu Now that we've removed the rq->lock requirement from the first part of ttwu() and can compute placement without holding any rq->lock, ensure we execute the second half of ttwu() on the actual cpu we want the task to run on. This avoids having to take rq->lock and doing the task enqueue remotely, saving lots on cacheline transfers. As measured using: http://oss.oracle.com/~mason/sembench.c $ for i in /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor ; do echo performance > $i; done $ echo 4096 32000 64 128 > /proc/sys/kernel/sem $ ./sembench -t 2048 -w 1900 -o 0 unpatched: run time 30 seconds 647278 worker burns per second patched: run time 30 seconds 816715 worker burns per second Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110405152729.515897185@chello.nl
2011-04-05 15:23:58 +00:00
sched: Restructure ttwu() some more Factor our helper functions to make the inner workings of try_to_wake_up() more obvious, this also allows for adding remote queues. Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110405152729.475848012@chello.nl
2011-04-05 15:23:57 +00:00
static void ttwu_queue(struct task_struct *p, int cpu)
{
struct rq *rq = cpu_rq(cpu);
SCHED_TTWU_QUEUE is not longer needed since sparc32 now implements IPI Signed-off-by: Daniel Hellstrom <daniel@gaisler.com> Reported-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-20 04:01:10 +00:00
#if defined(CONFIG_SMP)
sched: Move the second half of ttwu() to the remote cpu Now that we've removed the rq->lock requirement from the first part of ttwu() and can compute placement without holding any rq->lock, ensure we execute the second half of ttwu() on the actual cpu we want the task to run on. This avoids having to take rq->lock and doing the task enqueue remotely, saving lots on cacheline transfers. As measured using: http://oss.oracle.com/~mason/sembench.c $ for i in /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor ; do echo performance > $i; done $ echo 4096 32000 64 128 > /proc/sys/kernel/sem $ ./sembench -t 2048 -w 1900 -o 0 unpatched: run time 30 seconds 647278 worker burns per second patched: run time 30 seconds 816715 worker burns per second Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110405152729.515897185@chello.nl
2011-04-05 15:23:58 +00:00
if (sched_feat(TTWU_QUEUE) && cpu != smp_processor_id()) {
sched: Fix cross-cpu clock sync on remote wakeups Markus reported that commit 317f394160e ("sched: Move the second half of ttwu() to the remote cpu") caused some accounting funnies on his AMD Phenom II X4, such as weird 'top' results. It turns out that this is due to non-synced TSC and the queued remote wakeups stopped coupeling the two relevant cpu clocks, which leads to wakeups seeing time jumps, which in turn lead to skewed runtime stats. Add an explicit call to sched_clock_cpu() to couple the per-cpu clocks to restore the normal flow of time. Reported-and-tested-by: Markus Trippelsdorf <markus@trippelsdorf.de> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1306835745.2353.3.camel@twins Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-05-31 10:26:55 +00:00
sched_clock_cpu(cpu); /* sync clocks x-cpu */
sched: Move the second half of ttwu() to the remote cpu Now that we've removed the rq->lock requirement from the first part of ttwu() and can compute placement without holding any rq->lock, ensure we execute the second half of ttwu() on the actual cpu we want the task to run on. This avoids having to take rq->lock and doing the task enqueue remotely, saving lots on cacheline transfers. As measured using: http://oss.oracle.com/~mason/sembench.c $ for i in /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor ; do echo performance > $i; done $ echo 4096 32000 64 128 > /proc/sys/kernel/sem $ ./sembench -t 2048 -w 1900 -o 0 unpatched: run time 30 seconds 647278 worker burns per second patched: run time 30 seconds 816715 worker burns per second Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110405152729.515897185@chello.nl
2011-04-05 15:23:58 +00:00
ttwu_queue_remote(p, cpu);
return;
}
#endif
sched: Restructure ttwu() some more Factor our helper functions to make the inner workings of try_to_wake_up() more obvious, this also allows for adding remote queues. Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110405152729.475848012@chello.nl
2011-04-05 15:23:57 +00:00
raw_spin_lock(&rq->lock);
ttwu_do_activate(rq, p, 0);
raw_spin_unlock(&rq->lock);
sched: refactor try_to_wake_up() Factor ttwu_activate() and ttwu_woken_up() out of try_to_wake_up(). The factoring out doesn't affect try_to_wake_up() much code-generation-wise. Depending on configuration options, it ends up generating the same object code as before or slightly different one due to different register assignment. This is to help future implementation of try_to_wake_up_local(). Mike Galbraith suggested rename to ttwu_post_activation() from ttwu_woken_up() and comment update in try_to_wake_up(). Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Ingo Molnar <mingo@elte.hu>
2009-12-03 06:08:03 +00:00
}
/**
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
* try_to_wake_up - wake up a thread
sched: refactor try_to_wake_up() Factor ttwu_activate() and ttwu_woken_up() out of try_to_wake_up(). The factoring out doesn't affect try_to_wake_up() much code-generation-wise. Depending on configuration options, it ends up generating the same object code as before or slightly different one due to different register assignment. This is to help future implementation of try_to_wake_up_local(). Mike Galbraith suggested rename to ttwu_post_activation() from ttwu_woken_up() and comment update in try_to_wake_up(). Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Ingo Molnar <mingo@elte.hu>
2009-12-03 06:08:03 +00:00
* @p: the thread to be awakened
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
* @state: the mask of task states that can be woken
sched: refactor try_to_wake_up() Factor ttwu_activate() and ttwu_woken_up() out of try_to_wake_up(). The factoring out doesn't affect try_to_wake_up() much code-generation-wise. Depending on configuration options, it ends up generating the same object code as before or slightly different one due to different register assignment. This is to help future implementation of try_to_wake_up_local(). Mike Galbraith suggested rename to ttwu_post_activation() from ttwu_woken_up() and comment update in try_to_wake_up(). Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Ingo Molnar <mingo@elte.hu>
2009-12-03 06:08:03 +00:00
* @wake_flags: wake modifier flags (WF_*)
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
*
* Put it on the run-queue if it's not already there. The "current"
* thread is always on the run-queue (except when the actual
* re-schedule is in progress), and as such you're allowed to do
* the simpler "current->state = TASK_RUNNING" to mark yourself
* runnable without the overhead of this.
*
sched: refactor try_to_wake_up() Factor ttwu_activate() and ttwu_woken_up() out of try_to_wake_up(). The factoring out doesn't affect try_to_wake_up() much code-generation-wise. Depending on configuration options, it ends up generating the same object code as before or slightly different one due to different register assignment. This is to help future implementation of try_to_wake_up_local(). Mike Galbraith suggested rename to ttwu_post_activation() from ttwu_woken_up() and comment update in try_to_wake_up(). Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Ingo Molnar <mingo@elte.hu>
2009-12-03 06:08:03 +00:00
* Returns %true if @p was woken up, %false if it was already running
* or @state didn't match @p's state.
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
*/
sched: Remove rq->lock from the first half of ttwu() Currently ttwu() does two rq->lock acquisitions, once on the task's old rq, holding it over the p->state fiddling and load-balance pass. Then it drops the old rq->lock to acquire the new rq->lock. By having serialized ttwu(), p->sched_class, p->cpus_allowed with p->pi_lock, we can now drop the whole first rq->lock acquisition. The p->pi_lock serializing concurrent ttwu() calls protects p->state, which we will set to TASK_WAKING to bridge possible p->pi_lock to rq->lock gaps and serialize set_task_cpu() calls against task_rq_lock(). The p->pi_lock serialization of p->sched_class allows us to call scheduling class methods without holding the rq->lock, and the serialization of p->cpus_allowed allows us to do the load-balancing bits without races. Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110405152729.354401150@chello.nl
2011-04-05 15:23:54 +00:00
static int
try_to_wake_up(struct task_struct *p, unsigned int state, int wake_flags)
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
{
unsigned long flags;
sched: Restructure ttwu() some more Factor our helper functions to make the inner workings of try_to_wake_up() more obvious, this also allows for adding remote queues. Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110405152729.475848012@chello.nl
2011-04-05 15:23:57 +00:00
int cpu, success = 0;
sched: update shares on wakeup We found that the affine wakeup code needs rather accurate load figures to be effective. The trouble is that updating the load figures is fairly expensive with group scheduling. Therefore ratelimit the updating. Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Cc: Mike Galbraith <efault@gmx.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-27 11:41:35 +00:00
Add memory barrier semantics to wake_up() & co Oleg Nesterov and others have pointed out that on some architectures, the traditional sequence of set_current_state(TASK_INTERRUPTIBLE); if (CONDITION) return; schedule(); is racy wrt another CPU doing CONDITION = 1; wake_up_process(p); because while set_current_state() has a memory barrier separating setting of the TASK_INTERRUPTIBLE state from reading of the CONDITION variable, there is no such memory barrier on the wakeup side. Now, wake_up_process() does actually take a spinlock before it reads and sets the task state on the waking side, and on x86 (and many other architectures) that spinlock is in fact equivalent to a memory barrier, but that is not generally guaranteed. The write that sets CONDITION could move into the critical region protected by the runqueue spinlock. However, adding a smp_wmb() to before the spinlock should now order the writing of CONDITION wrt the lock itself, which in turn is ordered wrt the accesses within the spinlock (which includes the reading of the old state). This should thus close the race (which probably has never been seen in practice, but since smp_wmb() is a no-op on x86, it's not like this will make anything worse either on the most common architecture where the spinlock already gave the required protection). Acked-by: Oleg Nesterov <oleg@tv-sign.ru> Acked-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-24 02:05:03 +00:00
smp_wmb();
sched: Serialize p->cpus_allowed and ttwu() using p->pi_lock Currently p->pi_lock already serializes p->sched_class, also put p->cpus_allowed and try_to_wake_up() under it, this prepares the way to do the first part of ttwu() without holding rq->lock. By having p->sched_class and p->cpus_allowed serialized by p->pi_lock, we prepare the way to call select_task_rq() without holding rq->lock. Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110405152728.990364093@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-05 15:23:45 +00:00
raw_spin_lock_irqsave(&p->pi_lock, flags);
sched: Add TASK_WAKING We're going to want to drop rq->lock in try_to_wake_up() for a longer period of time, however we also want to deal with concurrent waking of the same task, which is currently handled by holding rq->lock. So introduce a new TASK state, namely TASK_WAKING, which indicates someone is already waking the task (other wakers will fail p->state & state). We also keep preemption disabled over the whole ttwu(). Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-09-15 12:43:03 +00:00
if (!(p->state & state))
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
goto out;
sched: Restructure ttwu() some more Factor our helper functions to make the inner workings of try_to_wake_up() more obvious, this also allows for adding remote queues. Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110405152729.475848012@chello.nl
2011-04-05 15:23:57 +00:00
success = 1; /* we're going to change ->state */
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
cpu = task_cpu(p);
sched: Restructure ttwu() some more Factor our helper functions to make the inner workings of try_to_wake_up() more obvious, this also allows for adding remote queues. Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110405152729.475848012@chello.nl
2011-04-05 15:23:57 +00:00
if (p->on_rq && ttwu_remote(p, wake_flags))
goto stat;
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
#ifdef CONFIG_SMP
sched: Add TASK_WAKING We're going to want to drop rq->lock in try_to_wake_up() for a longer period of time, however we also want to deal with concurrent waking of the same task, which is currently handled by holding rq->lock. So introduce a new TASK state, namely TASK_WAKING, which indicates someone is already waking the task (other wakers will fail p->state & state). We also keep preemption disabled over the whole ttwu(). Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-09-15 12:43:03 +00:00
/*
sched: Restructure ttwu() some more Factor our helper functions to make the inner workings of try_to_wake_up() more obvious, this also allows for adding remote queues. Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110405152729.475848012@chello.nl
2011-04-05 15:23:57 +00:00
* If the owning (remote) cpu is still in the middle of schedule() with
* this task as prev, wait until its done referencing the task.
sched: Add TASK_WAKING We're going to want to drop rq->lock in try_to_wake_up() for a longer period of time, however we also want to deal with concurrent waking of the same task, which is currently handled by holding rq->lock. So introduce a new TASK state, namely TASK_WAKING, which indicates someone is already waking the task (other wakers will fail p->state & state). We also keep preemption disabled over the whole ttwu(). Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-09-15 12:43:03 +00:00
*/
sched: Remove rq->lock from the first half of ttwu() Currently ttwu() does two rq->lock acquisitions, once on the task's old rq, holding it over the p->state fiddling and load-balance pass. Then it drops the old rq->lock to acquire the new rq->lock. By having serialized ttwu(), p->sched_class, p->cpus_allowed with p->pi_lock, we can now drop the whole first rq->lock acquisition. The p->pi_lock serializing concurrent ttwu() calls protects p->state, which we will set to TASK_WAKING to bridge possible p->pi_lock to rq->lock gaps and serialize set_task_cpu() calls against task_rq_lock(). The p->pi_lock serialization of p->sched_class allows us to call scheduling class methods without holding the rq->lock, and the serialization of p->cpus_allowed allows us to do the load-balancing bits without races. Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110405152729.354401150@chello.nl
2011-04-05 15:23:54 +00:00
while (p->on_cpu) {
#ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW
/*
sched: Fix ttwu() for __ARCH_WANT_INTERRUPTS_ON_CTXSW Marc reported that e4a52bcb9 (sched: Remove rq->lock from the first half of ttwu()) broke his ARM-SMP machine. Now ARM is one of the few __ARCH_WANT_INTERRUPTS_ON_CTXSW users, so that exception in the ttwu() code was suspect. Yong found that the interrupt could hit after context_switch() changes current but before it clears p->on_cpu, if that interrupt were to attempt a wake-up of p we would indeed find ourselves spinning in IRQ context. Fix this by reverting to the old behaviour for this situation and perform a full remote wake-up. Cc: Frank Rowand <frank.rowand@am.sony.com> Cc: Yong Zhang <yong.zhang0@gmail.com> Cc: Oleg Nesterov <oleg@redhat.com> Reported-by: Marc Zyngier <Marc.Zyngier@arm.com> Tested-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-05-26 12:21:33 +00:00
* In case the architecture enables interrupts in
* context_switch(), we cannot busy wait, since that
* would lead to deadlocks when an interrupt hits and
* tries to wake up @prev. So bail and do a complete
* remote wakeup.
sched: Remove rq->lock from the first half of ttwu() Currently ttwu() does two rq->lock acquisitions, once on the task's old rq, holding it over the p->state fiddling and load-balance pass. Then it drops the old rq->lock to acquire the new rq->lock. By having serialized ttwu(), p->sched_class, p->cpus_allowed with p->pi_lock, we can now drop the whole first rq->lock acquisition. The p->pi_lock serializing concurrent ttwu() calls protects p->state, which we will set to TASK_WAKING to bridge possible p->pi_lock to rq->lock gaps and serialize set_task_cpu() calls against task_rq_lock(). The p->pi_lock serialization of p->sched_class allows us to call scheduling class methods without holding the rq->lock, and the serialization of p->cpus_allowed allows us to do the load-balancing bits without races. Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110405152729.354401150@chello.nl
2011-04-05 15:23:54 +00:00
*/
sched: Fix ttwu() for __ARCH_WANT_INTERRUPTS_ON_CTXSW Marc reported that e4a52bcb9 (sched: Remove rq->lock from the first half of ttwu()) broke his ARM-SMP machine. Now ARM is one of the few __ARCH_WANT_INTERRUPTS_ON_CTXSW users, so that exception in the ttwu() code was suspect. Yong found that the interrupt could hit after context_switch() changes current but before it clears p->on_cpu, if that interrupt were to attempt a wake-up of p we would indeed find ourselves spinning in IRQ context. Fix this by reverting to the old behaviour for this situation and perform a full remote wake-up. Cc: Frank Rowand <frank.rowand@am.sony.com> Cc: Yong Zhang <yong.zhang0@gmail.com> Cc: Oleg Nesterov <oleg@redhat.com> Reported-by: Marc Zyngier <Marc.Zyngier@arm.com> Tested-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-05-26 12:21:33 +00:00
if (ttwu_activate_remote(p, wake_flags))
sched: Restructure ttwu() some more Factor our helper functions to make the inner workings of try_to_wake_up() more obvious, this also allows for adding remote queues. Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110405152729.475848012@chello.nl
2011-04-05 15:23:57 +00:00
goto stat;
sched: Fix ttwu() for __ARCH_WANT_INTERRUPTS_ON_CTXSW Marc reported that e4a52bcb9 (sched: Remove rq->lock from the first half of ttwu()) broke his ARM-SMP machine. Now ARM is one of the few __ARCH_WANT_INTERRUPTS_ON_CTXSW users, so that exception in the ttwu() code was suspect. Yong found that the interrupt could hit after context_switch() changes current but before it clears p->on_cpu, if that interrupt were to attempt a wake-up of p we would indeed find ourselves spinning in IRQ context. Fix this by reverting to the old behaviour for this situation and perform a full remote wake-up. Cc: Frank Rowand <frank.rowand@am.sony.com> Cc: Yong Zhang <yong.zhang0@gmail.com> Cc: Oleg Nesterov <oleg@redhat.com> Reported-by: Marc Zyngier <Marc.Zyngier@arm.com> Tested-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-05-26 12:21:33 +00:00
#else
sched: Remove rq->lock from the first half of ttwu() Currently ttwu() does two rq->lock acquisitions, once on the task's old rq, holding it over the p->state fiddling and load-balance pass. Then it drops the old rq->lock to acquire the new rq->lock. By having serialized ttwu(), p->sched_class, p->cpus_allowed with p->pi_lock, we can now drop the whole first rq->lock acquisition. The p->pi_lock serializing concurrent ttwu() calls protects p->state, which we will set to TASK_WAKING to bridge possible p->pi_lock to rq->lock gaps and serialize set_task_cpu() calls against task_rq_lock(). The p->pi_lock serialization of p->sched_class allows us to call scheduling class methods without holding the rq->lock, and the serialization of p->cpus_allowed allows us to do the load-balancing bits without races. Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110405152729.354401150@chello.nl
2011-04-05 15:23:54 +00:00
cpu_relax();
sched: Fix ttwu() for __ARCH_WANT_INTERRUPTS_ON_CTXSW Marc reported that e4a52bcb9 (sched: Remove rq->lock from the first half of ttwu()) broke his ARM-SMP machine. Now ARM is one of the few __ARCH_WANT_INTERRUPTS_ON_CTXSW users, so that exception in the ttwu() code was suspect. Yong found that the interrupt could hit after context_switch() changes current but before it clears p->on_cpu, if that interrupt were to attempt a wake-up of p we would indeed find ourselves spinning in IRQ context. Fix this by reverting to the old behaviour for this situation and perform a full remote wake-up. Cc: Frank Rowand <frank.rowand@am.sony.com> Cc: Yong Zhang <yong.zhang0@gmail.com> Cc: Oleg Nesterov <oleg@redhat.com> Reported-by: Marc Zyngier <Marc.Zyngier@arm.com> Tested-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-05-26 12:21:33 +00:00
#endif
sched: Add enqueue/dequeue flags In order to reduce the dependency on TASK_WAKING rework the enqueue interface to support a proper flags field. Replace the int wakeup, bool head arguments with an int flags argument and create the following flags: ENQUEUE_WAKEUP - the enqueue is a wakeup of a sleeping task, ENQUEUE_WAKING - the enqueue has relative vruntime due to having sched_class::task_waking() called, ENQUEUE_HEAD - the waking task should be places on the head of the priority queue (where appropriate). For symmetry also convert sched_class::dequeue() to a flags scheme. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-03-24 15:38:48 +00:00
}
sched: Fix race between ttwu() and task_rq_lock() Thomas found that due to ttwu() changing a task's cpu without holding the rq->lock, task_rq_lock() might end up locking the wrong rq. Avoid this by serializing against TASK_WAKING. Reported-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1266241712.15770.420.camel@laptop> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2010-02-15 13:45:54 +00:00
/*
sched: Remove rq->lock from the first half of ttwu() Currently ttwu() does two rq->lock acquisitions, once on the task's old rq, holding it over the p->state fiddling and load-balance pass. Then it drops the old rq->lock to acquire the new rq->lock. By having serialized ttwu(), p->sched_class, p->cpus_allowed with p->pi_lock, we can now drop the whole first rq->lock acquisition. The p->pi_lock serializing concurrent ttwu() calls protects p->state, which we will set to TASK_WAKING to bridge possible p->pi_lock to rq->lock gaps and serialize set_task_cpu() calls against task_rq_lock(). The p->pi_lock serialization of p->sched_class allows us to call scheduling class methods without holding the rq->lock, and the serialization of p->cpus_allowed allows us to do the load-balancing bits without races. Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110405152729.354401150@chello.nl
2011-04-05 15:23:54 +00:00
* Pairs with the smp_wmb() in finish_lock_switch().
sched: Fix race between ttwu() and task_rq_lock() Thomas found that due to ttwu() changing a task's cpu without holding the rq->lock, task_rq_lock() might end up locking the wrong rq. Avoid this by serializing against TASK_WAKING. Reported-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1266241712.15770.420.camel@laptop> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2010-02-15 13:45:54 +00:00
*/
sched: Remove rq->lock from the first half of ttwu() Currently ttwu() does two rq->lock acquisitions, once on the task's old rq, holding it over the p->state fiddling and load-balance pass. Then it drops the old rq->lock to acquire the new rq->lock. By having serialized ttwu(), p->sched_class, p->cpus_allowed with p->pi_lock, we can now drop the whole first rq->lock acquisition. The p->pi_lock serializing concurrent ttwu() calls protects p->state, which we will set to TASK_WAKING to bridge possible p->pi_lock to rq->lock gaps and serialize set_task_cpu() calls against task_rq_lock(). The p->pi_lock serialization of p->sched_class allows us to call scheduling class methods without holding the rq->lock, and the serialization of p->cpus_allowed allows us to do the load-balancing bits without races. Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110405152729.354401150@chello.nl
2011-04-05 15:23:54 +00:00
smp_rmb();
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
sched: Delay task_contributes_to_load() In prepratation of having to call task_contributes_to_load() without holding rq->lock, we need to store the result until we do and can update the rq accounting accordingly. Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110405152729.151523907@chello.nl
2011-04-05 15:23:49 +00:00
p->sched_contributes_to_load = !!task_contributes_to_load(p);
sched: Add TASK_WAKING We're going to want to drop rq->lock in try_to_wake_up() for a longer period of time, however we also want to deal with concurrent waking of the same task, which is currently handled by holding rq->lock. So introduce a new TASK state, namely TASK_WAKING, which indicates someone is already waking the task (other wakers will fail p->state & state). We also keep preemption disabled over the whole ttwu(). Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-09-15 12:43:03 +00:00
p->state = TASK_WAKING;
sched: de-SCHED_OTHER-ize the RT path The current wake-up code path tries to determine if it can optimize the wake-up to "this_cpu" by computing load calculations. The problem is that these calculations are only relevant to SCHED_OTHER tasks where load is king. For RT tasks, priority is king. So the load calculation is completely wasted bandwidth. Therefore, we create a new sched_class interface to help with pre-wakeup routing decisions and move the load calculation as a function of CFS task's class. Signed-off-by: Gregory Haskins <ghaskins@novell.com> Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:09 +00:00
sched: Remove rq->lock from the first half of ttwu() Currently ttwu() does two rq->lock acquisitions, once on the task's old rq, holding it over the p->state fiddling and load-balance pass. Then it drops the old rq->lock to acquire the new rq->lock. By having serialized ttwu(), p->sched_class, p->cpus_allowed with p->pi_lock, we can now drop the whole first rq->lock acquisition. The p->pi_lock serializing concurrent ttwu() calls protects p->state, which we will set to TASK_WAKING to bridge possible p->pi_lock to rq->lock gaps and serialize set_task_cpu() calls against task_rq_lock(). The p->pi_lock serialization of p->sched_class allows us to call scheduling class methods without holding the rq->lock, and the serialization of p->cpus_allowed allows us to do the load-balancing bits without races. Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110405152729.354401150@chello.nl
2011-04-05 15:23:54 +00:00
if (p->sched_class->task_waking)
sched: Remove rq argument to sched_class::task_waking() In preparation of calling this without rq->lock held, remove the dependency on the rq argument. Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110405152729.071474242@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-05 15:23:47 +00:00
p->sched_class->task_waking(p);
sched: Add pre and post wakeup hooks As will be apparent in the next patch, we need a pre wakeup hook for sched_fair task migration, hence rename the post wakeup hook and one pre wakeup. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> LKML-Reference: <20091216170518.114746117@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-16 17:04:40 +00:00
sched: Drop the rq argument to sched_class::select_task_rq() In preparation of calling select_task_rq() without rq->lock held, drop the dependency on the rq argument. Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110405152729.031077745@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-05 15:23:46 +00:00
cpu = select_task_rq(p, SD_BALANCE_WAKE, wake_flags);
sched: Fix schedstat.nr_wakeups_migrate While looking over the code I found that with the ttwu rework the nr_wakeups_migrate test broke since we now switch cpus prior to calling ttwu_stat(), hence the test is always true. Cure this by passing the migration state in wake_flags. Also move the whole test under CONFIG_SMP, its hard to migrate tasks on UP :-) Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/n/tip-pwwxl7gdqs5676f1d4cx6pj7@git.kernel.org Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-05-31 08:49:20 +00:00
if (task_cpu(p) != cpu) {
wake_flags |= WF_MIGRATED;
sched: Remove rq->lock from the first half of ttwu() Currently ttwu() does two rq->lock acquisitions, once on the task's old rq, holding it over the p->state fiddling and load-balance pass. Then it drops the old rq->lock to acquire the new rq->lock. By having serialized ttwu(), p->sched_class, p->cpus_allowed with p->pi_lock, we can now drop the whole first rq->lock acquisition. The p->pi_lock serializing concurrent ttwu() calls protects p->state, which we will set to TASK_WAKING to bridge possible p->pi_lock to rq->lock gaps and serialize set_task_cpu() calls against task_rq_lock(). The p->pi_lock serialization of p->sched_class allows us to call scheduling class methods without holding the rq->lock, and the serialization of p->cpus_allowed allows us to do the load-balancing bits without races. Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110405152729.354401150@chello.nl
2011-04-05 15:23:54 +00:00
set_task_cpu(p, cpu);
sched: Fix schedstat.nr_wakeups_migrate While looking over the code I found that with the ttwu rework the nr_wakeups_migrate test broke since we now switch cpus prior to calling ttwu_stat(), hence the test is always true. Cure this by passing the migration state in wake_flags. Also move the whole test under CONFIG_SMP, its hard to migrate tasks on UP :-) Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/n/tip-pwwxl7gdqs5676f1d4cx6pj7@git.kernel.org Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-05-31 08:49:20 +00:00
}
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
#endif /* CONFIG_SMP */
sched: Restructure ttwu() some more Factor our helper functions to make the inner workings of try_to_wake_up() more obvious, this also allows for adding remote queues. Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110405152729.475848012@chello.nl
2011-04-05 15:23:57 +00:00
ttwu_queue(p, cpu);
stat:
sched: Remove rq argument from ttwu_stat() In order to call ttwu_stat() without holding rq->lock we must remove its rq argument. Since we need to change rq stats, account to the local rq instead of the task rq, this is safe since we have IRQs disabled. Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110405152729.394638826@chello.nl
2011-04-05 15:23:55 +00:00
ttwu_stat(p, cpu, wake_flags);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
out:
sched: Serialize p->cpus_allowed and ttwu() using p->pi_lock Currently p->pi_lock already serializes p->sched_class, also put p->cpus_allowed and try_to_wake_up() under it, this prepares the way to do the first part of ttwu() without holding rq->lock. By having p->sched_class and p->cpus_allowed serialized by p->pi_lock, we prepare the way to call select_task_rq() without holding rq->lock. Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110405152728.990364093@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-05 15:23:45 +00:00
raw_spin_unlock_irqrestore(&p->pi_lock, flags);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
return success;
}
sched: add hooks for workqueue Concurrency managed workqueue needs to know when workers are going to sleep and waking up. Using these two hooks, cmwq keeps track of the current concurrency level and throttles execution of new works if it's too high and wakes up another worker from the sleep hook if it becomes too low. This patch introduces PF_WQ_WORKER to identify workqueue workers and adds the following two hooks. * wq_worker_waking_up(): called when a worker is woken up. * wq_worker_sleeping(): called when a worker is going to sleep and may return a pointer to a local task which should be woken up. The returned task is woken up using try_to_wake_up_local() which is simplified ttwu which is called under rq lock and can only wake up local tasks. Both hooks are currently defined as noop in kernel/workqueue_sched.h. Later cmwq implementation will replace them with proper implementation. These hooks are hard coded as they'll always be enabled. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Ingo Molnar <mingo@elte.hu>
2010-06-08 19:40:37 +00:00
/**
* try_to_wake_up_local - try to wake up a local task with rq lock held
* @p: the thread to be awakened
*
sched: Also serialize ttwu_local() with p->pi_lock Since we now serialize ttwu() using p->pi_lock, we also need to serialize ttwu_local() using that, otherwise, once we drop the rq->lock from ttwu() it can race with ttwu_local(). Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110405152729.192366907@chello.nl
2011-04-05 15:23:50 +00:00
* Put @p on the run-queue if it's not already there. The caller must
sched: add hooks for workqueue Concurrency managed workqueue needs to know when workers are going to sleep and waking up. Using these two hooks, cmwq keeps track of the current concurrency level and throttles execution of new works if it's too high and wakes up another worker from the sleep hook if it becomes too low. This patch introduces PF_WQ_WORKER to identify workqueue workers and adds the following two hooks. * wq_worker_waking_up(): called when a worker is woken up. * wq_worker_sleeping(): called when a worker is going to sleep and may return a pointer to a local task which should be woken up. The returned task is woken up using try_to_wake_up_local() which is simplified ttwu which is called under rq lock and can only wake up local tasks. Both hooks are currently defined as noop in kernel/workqueue_sched.h. Later cmwq implementation will replace them with proper implementation. These hooks are hard coded as they'll always be enabled. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Ingo Molnar <mingo@elte.hu>
2010-06-08 19:40:37 +00:00
* ensure that this_rq() is locked, @p is bound to this_rq() and not
sched: Also serialize ttwu_local() with p->pi_lock Since we now serialize ttwu() using p->pi_lock, we also need to serialize ttwu_local() using that, otherwise, once we drop the rq->lock from ttwu() it can race with ttwu_local(). Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110405152729.192366907@chello.nl
2011-04-05 15:23:50 +00:00
* the current task.
sched: add hooks for workqueue Concurrency managed workqueue needs to know when workers are going to sleep and waking up. Using these two hooks, cmwq keeps track of the current concurrency level and throttles execution of new works if it's too high and wakes up another worker from the sleep hook if it becomes too low. This patch introduces PF_WQ_WORKER to identify workqueue workers and adds the following two hooks. * wq_worker_waking_up(): called when a worker is woken up. * wq_worker_sleeping(): called when a worker is going to sleep and may return a pointer to a local task which should be woken up. The returned task is woken up using try_to_wake_up_local() which is simplified ttwu which is called under rq lock and can only wake up local tasks. Both hooks are currently defined as noop in kernel/workqueue_sched.h. Later cmwq implementation will replace them with proper implementation. These hooks are hard coded as they'll always be enabled. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Ingo Molnar <mingo@elte.hu>
2010-06-08 19:40:37 +00:00
*/
static void try_to_wake_up_local(struct task_struct *p)
{
struct rq *rq = task_rq(p);
BUG_ON(rq != this_rq());
BUG_ON(p == current);
lockdep_assert_held(&rq->lock);
sched: Also serialize ttwu_local() with p->pi_lock Since we now serialize ttwu() using p->pi_lock, we also need to serialize ttwu_local() using that, otherwise, once we drop the rq->lock from ttwu() it can race with ttwu_local(). Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110405152729.192366907@chello.nl
2011-04-05 15:23:50 +00:00
if (!raw_spin_trylock(&p->pi_lock)) {
raw_spin_unlock(&rq->lock);
raw_spin_lock(&p->pi_lock);
raw_spin_lock(&rq->lock);
}
sched: add hooks for workqueue Concurrency managed workqueue needs to know when workers are going to sleep and waking up. Using these two hooks, cmwq keeps track of the current concurrency level and throttles execution of new works if it's too high and wakes up another worker from the sleep hook if it becomes too low. This patch introduces PF_WQ_WORKER to identify workqueue workers and adds the following two hooks. * wq_worker_waking_up(): called when a worker is woken up. * wq_worker_sleeping(): called when a worker is going to sleep and may return a pointer to a local task which should be woken up. The returned task is woken up using try_to_wake_up_local() which is simplified ttwu which is called under rq lock and can only wake up local tasks. Both hooks are currently defined as noop in kernel/workqueue_sched.h. Later cmwq implementation will replace them with proper implementation. These hooks are hard coded as they'll always be enabled. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Ingo Molnar <mingo@elte.hu>
2010-06-08 19:40:37 +00:00
if (!(p->state & TASK_NORMAL))
sched: Also serialize ttwu_local() with p->pi_lock Since we now serialize ttwu() using p->pi_lock, we also need to serialize ttwu_local() using that, otherwise, once we drop the rq->lock from ttwu() it can race with ttwu_local(). Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110405152729.192366907@chello.nl
2011-04-05 15:23:50 +00:00
goto out;
sched: add hooks for workqueue Concurrency managed workqueue needs to know when workers are going to sleep and waking up. Using these two hooks, cmwq keeps track of the current concurrency level and throttles execution of new works if it's too high and wakes up another worker from the sleep hook if it becomes too low. This patch introduces PF_WQ_WORKER to identify workqueue workers and adds the following two hooks. * wq_worker_waking_up(): called when a worker is woken up. * wq_worker_sleeping(): called when a worker is going to sleep and may return a pointer to a local task which should be woken up. The returned task is woken up using try_to_wake_up_local() which is simplified ttwu which is called under rq lock and can only wake up local tasks. Both hooks are currently defined as noop in kernel/workqueue_sched.h. Later cmwq implementation will replace them with proper implementation. These hooks are hard coded as they'll always be enabled. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Ingo Molnar <mingo@elte.hu>
2010-06-08 19:40:37 +00:00
sched: Provide p->on_rq Provide a generic p->on_rq because the p->se.on_rq semantics are unfavourable for lockless wakeups but needed for sched_fair. In particular, p->on_rq is only cleared when we actually dequeue the task in schedule() and not on any random dequeue as done by things like __migrate_task() and __sched_setscheduler(). This also allows us to remove p->se usage from !sched_fair code. Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110405152728.949545047@chello.nl
2011-04-05 15:23:44 +00:00
if (!p->on_rq)
sched: Clean up ttwu() stats Collect all ttwu() stat code into a single function and ensure its always called for an actual wakeup (changing p->state to TASK_RUNNING). Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110405152728.908177058@chello.nl
2011-04-05 15:23:43 +00:00
ttwu_activate(rq, p, ENQUEUE_WAKEUP);
sched: Rename ttwu_post_activation() to ttwu_do_wakeup() The ttwu_post_activation() code does the core wakeup, it sets TASK_RUNNING and performs wakeup-preemption, so give is a more descriptive name. Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110405152729.434609705@chello.nl
2011-04-05 15:23:56 +00:00
ttwu_do_wakeup(rq, p, 0);
sched: Remove rq argument from ttwu_stat() In order to call ttwu_stat() without holding rq->lock we must remove its rq argument. Since we need to change rq stats, account to the local rq instead of the task rq, this is safe since we have IRQs disabled. Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110405152729.394638826@chello.nl
2011-04-05 15:23:55 +00:00
ttwu_stat(p, smp_processor_id(), 0);
sched: Also serialize ttwu_local() with p->pi_lock Since we now serialize ttwu() using p->pi_lock, we also need to serialize ttwu_local() using that, otherwise, once we drop the rq->lock from ttwu() it can race with ttwu_local(). Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110405152729.192366907@chello.nl
2011-04-05 15:23:50 +00:00
out:
raw_spin_unlock(&p->pi_lock);
sched: add hooks for workqueue Concurrency managed workqueue needs to know when workers are going to sleep and waking up. Using these two hooks, cmwq keeps track of the current concurrency level and throttles execution of new works if it's too high and wakes up another worker from the sleep hook if it becomes too low. This patch introduces PF_WQ_WORKER to identify workqueue workers and adds the following two hooks. * wq_worker_waking_up(): called when a worker is woken up. * wq_worker_sleeping(): called when a worker is going to sleep and may return a pointer to a local task which should be woken up. The returned task is woken up using try_to_wake_up_local() which is simplified ttwu which is called under rq lock and can only wake up local tasks. Both hooks are currently defined as noop in kernel/workqueue_sched.h. Later cmwq implementation will replace them with proper implementation. These hooks are hard coded as they'll always be enabled. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Ingo Molnar <mingo@elte.hu>
2010-06-08 19:40:37 +00:00
}
sched: Document memory barriers implied by sleep/wake-up primitives Add a section to the memory barriers document to note the implied memory barriers of sleep primitives (set_current_state() and wrappers) and wake-up primitives (wake_up() and co.). Also extend the in-code comments on the wake_up() functions to note these implied barriers. [ Impact: add documentation ] Signed-off-by: David Howells <dhowells@redhat.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> LKML-Reference: <20090428140138.1192.94723.stgit@warthog.procyon.org.uk> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-28 14:01:38 +00:00
/**
* wake_up_process - Wake up a specific process
* @p: The process to be woken up.
*
* Attempt to wake up the nominated process and move it to the set of runnable
* processes. Returns 1 if the process was woken up, 0 if it was already
* running.
*
* It may be assumed that this function implies a write memory barrier before
* changing the task state if and only if any tasks are woken up.
*/
kernel: remove fastcall in kernel/* [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-08 12:19:53 +00:00
int wake_up_process(struct task_struct *p)
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
{
sched: Use task_contributes_to_load, TASK_ALL and TASK_NORMAL Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
2007-12-06 16:07:07 +00:00
return try_to_wake_up(p, TASK_ALL, 0);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
}
EXPORT_SYMBOL(wake_up_process);
kernel: remove fastcall in kernel/* [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-08 12:19:53 +00:00
int wake_up_state(struct task_struct *p, unsigned int state)
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
{
return try_to_wake_up(p, state, 0);
}
/*
* Perform scheduler related setup for a newly forked process p.
* p is forked by current.
sched: cfs core code apply the CFS core code. this change switches over the scheduler core to CFS's modular design and makes use of kernel/sched_fair/rt/idletask.c to implement Linux's scheduling policies. thanks to Andrew Morton and Thomas Gleixner for lots of detailed review feedback and for fixlets. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
2007-07-09 16:51:59 +00:00
*
* __sched_fork() is basic setup used by init_idle() too:
*/
static void __sched_fork(struct task_struct *p)
{
sched: Provide p->on_rq Provide a generic p->on_rq because the p->se.on_rq semantics are unfavourable for lockless wakeups but needed for sched_fair. In particular, p->on_rq is only cleared when we actually dequeue the task in schedule() and not on any random dequeue as done by things like __migrate_task() and __sched_setscheduler(). This also allows us to remove p->se usage from !sched_fair code. Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110405152728.949545047@chello.nl
2011-04-05 15:23:44 +00:00
p->on_rq = 0;
p->se.on_rq = 0;
sched: cfs core code apply the CFS core code. this change switches over the scheduler core to CFS's modular design and makes use of kernel/sched_fair/rt/idletask.c to implement Linux's scheduling policies. thanks to Andrew Morton and Thomas Gleixner for lots of detailed review feedback and for fixlets. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
2007-07-09 16:51:59 +00:00
p->se.exec_start = 0;
p->se.sum_exec_runtime = 0;
sched: make the scheduler converge to the ideal latency de-HZ-ification of the granularity defaults unearthed a pre-existing property of CFS: while it correctly converges to the granularity goal, it does not prevent run-time fluctuations in the range of [-gran ... 0 ... +gran]. With the increase of the granularity due to the removal of HZ dependencies, this becomes visible in chew-max output (with 5 tasks running): out: 28 . 27. 32 | flu: 0 . 0 | ran: 9 . 13 | per: 37 . 40 out: 27 . 27. 32 | flu: 0 . 0 | ran: 17 . 13 | per: 44 . 40 out: 27 . 27. 32 | flu: 0 . 0 | ran: 9 . 13 | per: 36 . 40 out: 29 . 27. 32 | flu: 2 . 0 | ran: 17 . 13 | per: 46 . 40 out: 28 . 27. 32 | flu: 0 . 0 | ran: 9 . 13 | per: 37 . 40 out: 29 . 27. 32 | flu: 0 . 0 | ran: 18 . 13 | per: 47 . 40 out: 28 . 27. 32 | flu: 0 . 0 | ran: 9 . 13 | per: 37 . 40 average slice is the ideal 13 msecs and the period is picture-perfect 40 msecs. But the 'ran' field fluctuates around 13.33 msecs and there's no mechanism in CFS to keep that from happening: it's a perfectly valid solution that CFS finds. to fix this we add a granularity/preemption rule that knows about the "target latency", which makes tasks that run longer than the ideal latency run a bit less. The simplest approach is to simply decrease the preemption granularity when a task overruns its ideal latency. For this we have to track how much the task executed since its last preemption. ( this adds a new field to task_struct, but we can eliminate that overhead in 2.6.24 by putting all the scheduler timestamps into an anonymous union. ) with this change in place, chew-max output is fluctuation-less all around: out: 28 . 27. 39 | flu: 0 . 2 | ran: 13 . 13 | per: 41 . 40 out: 28 . 27. 39 | flu: 0 . 2 | ran: 13 . 13 | per: 41 . 40 out: 28 . 27. 39 | flu: 0 . 2 | ran: 13 . 13 | per: 41 . 40 out: 28 . 27. 39 | flu: 0 . 2 | ran: 13 . 13 | per: 41 . 40 out: 28 . 27. 39 | flu: 0 . 1 | ran: 13 . 13 | per: 41 . 40 out: 28 . 27. 39 | flu: 0 . 1 | ran: 13 . 13 | per: 41 . 40 this patch has no impact on any fastpath or on any globally observable scheduling property. (unless you have sharp enough eyes to see millisecond-level ruckles in glxgears smoothness :-) Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Mike Galbraith <efault@gmx.de>
2007-08-28 10:53:24 +00:00
p->se.prev_sum_exec_runtime = 0;
perfcounters: add task migrations counter Impact: add new feature, new sw counter Add a counter that counts the number of cross-CPU migrations a task is suffering. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-14 11:34:15 +00:00
p->se.nr_migrations = 0;
sched: Fix switch_from_fair() When a task is taken out of the fair class we must ensure the vruntime is properly normalized because when we put it back in it will assume to be normalized. The case that goes wrong is when changing away from the fair class while sleeping. Sleeping tasks have non-normalized vruntime in order to make sleeper-fairness work. So treat the switch away from fair as a wakeup and preserve the relative vruntime. Also update sysrq-n to call the ->switch_{to,from} methods. Reported-by: Onkalo Samu <samu.p.onkalo@nokia.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-01-17 16:03:27 +00:00
p->se.vruntime = 0;
sched: Provide p->on_rq Provide a generic p->on_rq because the p->se.on_rq semantics are unfavourable for lockless wakeups but needed for sched_fair. In particular, p->on_rq is only cleared when we actually dequeue the task in schedule() and not on any random dequeue as done by things like __migrate_task() and __sched_setscheduler(). This also allows us to remove p->se usage from !sched_fair code. Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110405152728.949545047@chello.nl
2011-04-05 15:23:44 +00:00
INIT_LIST_HEAD(&p->se.group_node);
[PATCH] sched: reduce debug code move the rest of the debugging/instrumentation code to under CONFIG_SCHEDSTATS too. This reduces code size and speeds code up: text data bss dec hex filename 33044 4122 28 37194 914a sched.o.before 32708 4122 28 36858 8ffa sched.o.after Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-08-02 15:41:40 +00:00
#ifdef CONFIG_SCHEDSTATS
sched: Implement group scheduler statistics in one struct Put all statistic fields of sched_entity in one struct, sched_statistics, and embed it into sched_entity. This change allows to memset the sched_statistics to 0 when needed (for instance when forking), avoiding bugs of non initialized fields. Signed-off-by: Lucas De Marchi <lucas.de.marchi@gmail.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1268275065-18542-1-git-send-email-lucas.de.marchi@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-03-11 02:37:45 +00:00
memset(&p->se.statistics, 0, sizeof(p->se.statistics));
[PATCH] sched: reduce debug code move the rest of the debugging/instrumentation code to under CONFIG_SCHEDSTATS too. This reduces code size and speeds code up: text data bss dec hex filename 33044 4122 28 37194 914a sched.o.before 32708 4122 28 36858 8ffa sched.o.after Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-08-02 15:41:40 +00:00
#endif
[PATCH] sched: consolidate sbe sbf Consolidate balance-on-exec with balance-on-fork. This is made easy by the sched-domains RCU patches. As well as the general goodness of code reduction, this allows the runqueues to be unlocked during balance-on-fork. schedstats is a problem. Maybe just have balance-on-event instead of distinguishing fork and exec? Signed-off-by: Nick Piggin <nickpiggin@yahoo.com.au> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-25 21:57:29 +00:00
sched: sched_rt_entity Move the task_struct members specific to rt scheduling together. A future optimization could be to put sched_entity and sched_rt_entity into a union. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> CC: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:27 +00:00
INIT_LIST_HEAD(&p->rt.run_list);
[PATCH] sched: consolidate sbe sbf Consolidate balance-on-exec with balance-on-fork. This is made easy by the sched-domains RCU patches. As well as the general goodness of code reduction, this allows the runqueues to be unlocked during balance-on-fork. schedstats is a problem. Maybe just have balance-on-event instead of distinguishing fork and exec? Signed-off-by: Nick Piggin <nickpiggin@yahoo.com.au> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-25 21:57:29 +00:00
[PATCH] sched: arch preempt notifier mechanism This adds a general mechanism whereby a task can request the scheduler to notify it whenever it is preempted or scheduled back in. This allows the task to swap any special-purpose registers like the fpu or Intel's VT registers. Signed-off-by: Avi Kivity <avi@qumranet.com> [ mingo@elte.hu: fixes, cleanups ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-26 11:40:43 +00:00
#ifdef CONFIG_PREEMPT_NOTIFIERS
INIT_HLIST_HEAD(&p->preempt_notifiers);
#endif
sched: cfs core code apply the CFS core code. this change switches over the scheduler core to CFS's modular design and makes use of kernel/sched_fair/rt/idletask.c to implement Linux's scheduling policies. thanks to Andrew Morton and Thomas Gleixner for lots of detailed review feedback and for fixlets. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
2007-07-09 16:51:59 +00:00
}
/*
* fork()/clone()-time setup:
*/
sched: Remove unused parameters from sched_fork() and wake_up_new_task() sched_fork() and wake_up_new_task() are defined with a parameter 'unsigned long clone_flags', which is unused. This patch removes the parameters. Signed-off-by: Samir Bellabes <sam@synack.fr> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1305130685-1047-1-git-send-email-sam@synack.fr Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-05-11 16:18:05 +00:00
void sched_fork(struct task_struct *p)
sched: cfs core code apply the CFS core code. this change switches over the scheduler core to CFS's modular design and makes use of kernel/sched_fair/rt/idletask.c to implement Linux's scheduling policies. thanks to Andrew Morton and Thomas Gleixner for lots of detailed review feedback and for fixlets. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
2007-07-09 16:51:59 +00:00
{
sched: Add p->pi_lock to task_rq_lock() In order to be able to call set_task_cpu() while either holding p->pi_lock or task_rq(p)->lock we need to hold both locks in order to stabilize task_rq(). This makes task_rq_lock() acquire both locks, and have __task_rq_lock() validate that p->pi_lock is held. This increases the locking overhead for most scheduler syscalls but allows reduction of rq->lock contention for some scheduler hot paths (ttwu). Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110405152729.232781355@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-05 15:23:51 +00:00
unsigned long flags;
sched: cfs core code apply the CFS core code. this change switches over the scheduler core to CFS's modular design and makes use of kernel/sched_fair/rt/idletask.c to implement Linux's scheduling policies. thanks to Andrew Morton and Thomas Gleixner for lots of detailed review feedback and for fixlets. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
2007-07-09 16:51:59 +00:00
int cpu = get_cpu();
__sched_fork(p);
sched: Use TASK_WAKING for fork wakups For later convenience use TASK_WAKING for fresh tasks. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> LKML-Reference: <20091216170517.732561278@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-16 17:04:35 +00:00
/*
sched: Fix TASK_WAKING vs fork deadlock Oleg noticed a few races with the TASK_WAKING usage on fork. - since TASK_WAKING is basically a spinlock, it should be IRQ safe - since we set TASK_WAKING (*) without holding rq->lock it could be there still is a rq->lock holder, thereby not actually providing full serialization. (*) in fact we clear PF_STARTING, which in effect enables TASK_WAKING. Cure the second issue by not setting TASK_WAKING in sched_fork(), but only temporarily in wake_up_new_task() while calling select_task_rq(). Cure the first by holding rq->lock around the select_task_rq() call, this will disable IRQs, this however requires that we push down the rq->lock release into select_task_rq_fair()'s cgroup stuff. Because select_task_rq_fair() still needs to drop the rq->lock we cannot fully get rid of TASK_WAKING. Reported-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-03-24 17:34:10 +00:00
* We mark the process as running here. This guarantees that
sched: Use TASK_WAKING for fork wakups For later convenience use TASK_WAKING for fresh tasks. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> LKML-Reference: <20091216170517.732561278@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-16 17:04:35 +00:00
* nobody will actually run it, and a signal or other external
* event cannot wake it up and insert it on the runqueue either.
*/
sched: Fix TASK_WAKING vs fork deadlock Oleg noticed a few races with the TASK_WAKING usage on fork. - since TASK_WAKING is basically a spinlock, it should be IRQ safe - since we set TASK_WAKING (*) without holding rq->lock it could be there still is a rq->lock holder, thereby not actually providing full serialization. (*) in fact we clear PF_STARTING, which in effect enables TASK_WAKING. Cure the second issue by not setting TASK_WAKING in sched_fork(), but only temporarily in wake_up_new_task() while calling select_task_rq(). Cure the first by holding rq->lock around the select_task_rq() call, this will disable IRQs, this however requires that we push down the rq->lock release into select_task_rq_fair()'s cgroup stuff. Because select_task_rq_fair() still needs to drop the rq->lock we cannot fully get rid of TASK_WAKING. Reported-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-03-24 17:34:10 +00:00
p->state = TASK_RUNNING;
sched: cfs core code apply the CFS core code. this change switches over the scheduler core to CFS's modular design and makes use of kernel/sched_fair/rt/idletask.c to implement Linux's scheduling policies. thanks to Andrew Morton and Thomas Gleixner for lots of detailed review feedback and for fixlets. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
2007-07-09 16:51:59 +00:00
sched: fix broken SCHED_RESET_ON_FORK handling Setting child->prio = current->normal_prio _after_ SCHED_RESET_ON_FORK has been handled for an RT parent gives birth to a deranged mutant child with non-RT policy, but RT prio and sched_class. Move PI leakage protection up, always set priorities and weight, and if the child is leaving RT class, reset rt_priority to the proper value. Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1311779695.8691.2.camel@marge.simson.net Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-27 15:14:55 +00:00
/*
* Make sure we do not leak PI boosting priority to the child.
*/
p->prio = current->normal_prio;
sched: Clean up SCHED_RESET_ON_FORK Make SCHED_RESET_ON_FORK sched_fork() bits a self-contained unlikely code path. Signed-off-by: Mike Galbraith <efault@gmx.de> Acked-by: Lennart Poettering <mzxreary@0pointer.de> Cc: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <1245228361.18329.6.camel@marge.simson.net> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-06-17 08:46:01 +00:00
/*
* Revert to default priority/policy on fork if requested.
*/
if (unlikely(p->sched_reset_on_fork)) {
sched: fix broken SCHED_RESET_ON_FORK handling Setting child->prio = current->normal_prio _after_ SCHED_RESET_ON_FORK has been handled for an RT parent gives birth to a deranged mutant child with non-RT policy, but RT prio and sched_class. Move PI leakage protection up, always set priorities and weight, and if the child is leaving RT class, reset rt_priority to the proper value. Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1311779695.8691.2.camel@marge.simson.net Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-27 15:14:55 +00:00
if (task_has_rt_policy(p)) {
sched: Clean up SCHED_RESET_ON_FORK Make SCHED_RESET_ON_FORK sched_fork() bits a self-contained unlikely code path. Signed-off-by: Mike Galbraith <efault@gmx.de> Acked-by: Lennart Poettering <mzxreary@0pointer.de> Cc: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <1245228361.18329.6.camel@marge.simson.net> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-06-17 08:46:01 +00:00
p->policy = SCHED_NORMAL;
sched: Add SCHED_RESET_ON_FORK functionality for nice < 0 tasks Signed-off-by: Mike Galbraith <efault@gmx.de> Acked-by: Lennart Poettering <mzxreary@0pointer.de> Cc: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <1245228482.27326.1.camel@marge.simson.net> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-06-17 08:48:02 +00:00
p->static_prio = NICE_TO_PRIO(0);
sched: fix broken SCHED_RESET_ON_FORK handling Setting child->prio = current->normal_prio _after_ SCHED_RESET_ON_FORK has been handled for an RT parent gives birth to a deranged mutant child with non-RT policy, but RT prio and sched_class. Move PI leakage protection up, always set priorities and weight, and if the child is leaving RT class, reset rt_priority to the proper value. Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1311779695.8691.2.camel@marge.simson.net Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-27 15:14:55 +00:00
p->rt_priority = 0;
} else if (PRIO_TO_NICE(p->static_prio) < 0)
p->static_prio = NICE_TO_PRIO(0);
p->prio = p->normal_prio = __normal_prio(p);
set_load_weight(p);
sched: Add SCHED_RESET_ON_FORK functionality for nice < 0 tasks Signed-off-by: Mike Galbraith <efault@gmx.de> Acked-by: Lennart Poettering <mzxreary@0pointer.de> Cc: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <1245228482.27326.1.camel@marge.simson.net> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-06-17 08:48:02 +00:00
sched: Clean up SCHED_RESET_ON_FORK Make SCHED_RESET_ON_FORK sched_fork() bits a self-contained unlikely code path. Signed-off-by: Mike Galbraith <efault@gmx.de> Acked-by: Lennart Poettering <mzxreary@0pointer.de> Cc: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <1245228361.18329.6.camel@marge.simson.net> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-06-17 08:46:01 +00:00
/*
* We don't need the reset flag anymore after the fork. It has
* fulfilled its duty:
*/
p->sched_reset_on_fork = 0;
}
sched: Introduce SCHED_RESET_ON_FORK scheduling policy flag This patch introduces a new flag SCHED_RESET_ON_FORK which can be passed to the kernel via sched_setscheduler(), ORed in the policy parameter. If set this will make sure that when the process forks a) the scheduling priority is reset to DEFAULT_PRIO if it was higher and b) the scheduling policy is reset to SCHED_NORMAL if it was either SCHED_FIFO or SCHED_RR. Why have this? Currently, if a process is real-time scheduled this will 'leak' to all its child processes. For security reasons it is often (always?) a good idea to make sure that if a process acquires RT scheduling this is confined to this process and only this process. More specifically this makes the per-process resource limit RLIMIT_RTTIME useful for security purposes, because it makes it impossible to use a fork bomb to circumvent the per-process RLIMIT_RTTIME accounting. This feature is also useful for tools like 'renice' which can then change the nice level of a process without having this spill to all its child processes. Why expose this via sched_setscheduler() and not other syscalls such as prctl() or sched_setparam()? prctl() does not take a pid parameter. Due to that it would be impossible to modify this flag for other processes than the current one. The struct passed to sched_setparam() can unfortunately not be extended without breaking compatibility, since sched_setparam() lacks a size parameter. How to use this from userspace? In your RT program simply replace this: sched_setscheduler(pid, SCHED_FIFO, &param); by this: sched_setscheduler(pid, SCHED_FIFO|SCHED_RESET_ON_FORK, &param); Signed-off-by: Lennart Poettering <lennart@poettering.net> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20090615152714.GA29092@tango.0pointer.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-06-15 15:17:47 +00:00
sched: clean up sched_fork() The adjusting sched_class is a missing part of the already existing "do not leak PI boosting priority to the child" at the sched_fork(). This patch moves the adjusting sched_class from wake_up_new_task() to sched_fork(). this also shrinks the code a bit: text data bss dec hex filename 40111 4018 292 44421 ad85 sched.o.before 40102 4018 292 44412 ad7c sched.o.after Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com> Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-15 15:00:11 +00:00
if (!rt_prio(p->prio))
p->sched_class = &fair_sched_class;
[PATCH] pi-futex: scheduler support for pi Add framework to boost/unboost the priority of RT tasks. This consists of: - caching the 'normal' priority in ->normal_prio - providing a functions to set/get the priority of the task - make sched_setscheduler() aware of boosting The effective_prio() cleanups also fix a priority-calculation bug pointed out by Andrey Gelman, in set_user_nice(). has_rt_policy() fix: Peter Williams <pwil3058@bigpond.net.au> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Cc: Andrey Gelman <agelman@012.net.il> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 09:54:51 +00:00
sched: Sanitize fork() handling Currently we try to do task placement in wake_up_new_task() after we do the load-balance pass in sched_fork(). This yields complicated semantics in that we have to deal with tasks on different RQs and the set_task_cpu() calls in copy_process() and sched_fork() Rename ->task_new() to ->task_fork() and call it from sched_fork() before the balancing, this gives the policy a clear point to place the task. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-11-27 16:32:46 +00:00
if (p->sched_class->task_fork)
p->sched_class->task_fork(p);
sched: silence PROVE_RCU in sched_fork() Because cgroup_fork() is ran before sched_fork() [ from copy_process() ] and the child's pid is not yet visible the child is pinned to its cgroup. Therefore we can silence this warning. A nicer solution would be moving cgroup_fork() to right after dup_task_struct() and exclude PF_STARTING from task_subsys_state(). Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Reviewed-by: Li Zefan <lizf@cn.fujitsu.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2010-06-22 09:44:53 +00:00
/*
* The child is not yet in the pid-hash so no cgroup attach races,
* and the cgroup is pinned to this child due to cgroup_fork()
* is ran before sched_fork().
*
* Silence PROVE_RCU.
*/
sched: Add p->pi_lock to task_rq_lock() In order to be able to call set_task_cpu() while either holding p->pi_lock or task_rq(p)->lock we need to hold both locks in order to stabilize task_rq(). This makes task_rq_lock() acquire both locks, and have __task_rq_lock() validate that p->pi_lock is held. This increases the locking overhead for most scheduler syscalls but allows reduction of rq->lock contention for some scheduler hot paths (ttwu). Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110405152729.232781355@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-05 15:23:51 +00:00
raw_spin_lock_irqsave(&p->pi_lock, flags);
sched: Hook sched_balance_self() into sched_class::select_task_rq() Rather ugly patch to fully place the sched_balance_self() code inside the fair class. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-09-10 11:42:00 +00:00
set_task_cpu(p, cpu);
sched: Add p->pi_lock to task_rq_lock() In order to be able to call set_task_cpu() while either holding p->pi_lock or task_rq(p)->lock we need to hold both locks in order to stabilize task_rq(). This makes task_rq_lock() acquire both locks, and have __task_rq_lock() validate that p->pi_lock is held. This increases the locking overhead for most scheduler syscalls but allows reduction of rq->lock contention for some scheduler hot paths (ttwu). Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110405152729.232781355@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-05 15:23:51 +00:00
raw_spin_unlock_irqrestore(&p->pi_lock, flags);
sched: Hook sched_balance_self() into sched_class::select_task_rq() Rather ugly patch to fully place the sched_balance_self() code inside the fair class. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-09-10 11:42:00 +00:00
[PATCH] per-task-delay-accounting: cpu delay collection via schedstats Make the task-related schedstats functions callable by delay accounting even if schedstats collection isn't turned on. This removes the dependency of delay accounting on schedstats. Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com> Signed-off-by: Shailabh Nagar <nagar@watson.ibm.com> Signed-off-by: Balbir Singh <balbir@in.ibm.com> Cc: Jes Sorensen <jes@sgi.com> Cc: Peter Chubb <peterc@gelato.unsw.edu.au> Cc: Erich Focht <efocht@ess.nec.de> Cc: Levent Serinol <lserinol@gmail.com> Cc: Jay Lan <jlan@engr.sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-14 07:24:38 +00:00
#if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT)
sched: cfs core code apply the CFS core code. this change switches over the scheduler core to CFS's modular design and makes use of kernel/sched_fair/rt/idletask.c to implement Linux's scheduling policies. thanks to Andrew Morton and Thomas Gleixner for lots of detailed review feedback and for fixlets. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
2007-07-09 16:51:59 +00:00
if (likely(sched_info_on()))
[PATCH] per-task-delay-accounting: cpu delay collection via schedstats Make the task-related schedstats functions callable by delay accounting even if schedstats collection isn't turned on. This removes the dependency of delay accounting on schedstats. Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com> Signed-off-by: Shailabh Nagar <nagar@watson.ibm.com> Signed-off-by: Balbir Singh <balbir@in.ibm.com> Cc: Jes Sorensen <jes@sgi.com> Cc: Peter Chubb <peterc@gelato.unsw.edu.au> Cc: Erich Focht <efocht@ess.nec.de> Cc: Levent Serinol <lserinol@gmail.com> Cc: Jay Lan <jlan@engr.sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-14 07:24:38 +00:00
memset(&p->sched_info, 0, sizeof(p->sched_info));
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
#endif
sched: Always provide p->on_cpu Always provide p->on_cpu so that we can determine if its on a cpu without having to lock the rq. Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110405152728.785452014@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-05 15:23:40 +00:00
#if defined(CONFIG_SMP)
p->on_cpu = 0;
[PATCH] sched: cleanup context switch locking Instead of requiring architecture code to interact with the scheduler's locking implementation, provide a couple of defines that can be used by the architecture to request runqueue unlocked context switches, and ask for interrupts to be enabled over the context switch. Also replaces the "switch_lock" used by these architectures with an oncpu flag (note, not a potentially slow bitflag). This eliminates one bus locked memory operation when context switching, and simplifies the task_running function. Signed-off-by: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-25 21:57:23 +00:00
#endif
sched: Isolate preempt counting in its own config option Create a new CONFIG_PREEMPT_COUNT that handles the inc/dec of preempt count offset independently. So that the offset can be updated by preempt_disable() and preempt_enable() even without the need for CONFIG_PREEMPT beeing set. This prepares to make CONFIG_DEBUG_SPINLOCK_SLEEP working with !CONFIG_PREEMPT where it currently doesn't detect code that sleeps inside explicit preemption disabled sections. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
2011-06-07 23:13:27 +00:00
#ifdef CONFIG_PREEMPT_COUNT
[PATCH] sched: cleanup context switch locking Instead of requiring architecture code to interact with the scheduler's locking implementation, provide a couple of defines that can be used by the architecture to request runqueue unlocked context switches, and ask for interrupts to be enabled over the context switch. Also replaces the "switch_lock" used by these architectures with an oncpu flag (note, not a potentially slow bitflag). This eliminates one bus locked memory operation when context switching, and simplifies the task_running function. Signed-off-by: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-25 21:57:23 +00:00
/* Want to start with kernel preemption disabled. */
[PATCH] m68k: introduce task_thread_info new helper - task_thread_info(task). On platforms that have thread_info allocated separately (i.e. in default case) it simply returns task->thread_info. m68k wants (and for good reasons) to embed its thread_info into task_struct. So it will (in later patch) have task_thread_info() of its own. For now we just add a macro for generic case and convert existing instances of its body in core kernel to uses of new macro. Obviously safe - all normal architectures get the same preprocessor output they used to get. Signed-off-by: Al Viro <viro@parcelfarce.linux.theplanet.co.uk> Signed-off-by: Roman Zippel <zippel@linux-m68k.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-14 00:06:55 +00:00
task_thread_info(p)->preempt_count = 1;
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
#endif
sched: Make pushable_tasks CONFIG_SMP dependant As noted by Peter Zijlstra at https://lkml.org/lkml/2010/11/10/391 (while reviewing other stuff, though), tracking pushable tasks only makes sense on SMP systems. Signed-off-by: Dario Faggioli <raistlin@linux.it> Acked-by: Steven Rostedt <rostedt@goodmis.org> Acked-by: Gregory Haskins <ghaskins@novell.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1291143093.2697.298.camel@Palantir> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-30 18:51:33 +00:00
#ifdef CONFIG_SMP
sched: create "pushable_tasks" list to limit pushing to one attempt The RT scheduler employs a "push/pull" design to actively balance tasks within the system (on a per disjoint cpuset basis). When a task is awoken, it is immediately determined if there are any lower priority cpus which should be preempted. This is opposed to the way normal SCHED_OTHER tasks behave, which will wait for a periodic rebalancing operation to occur before spreading out load. When a particular RQ has more than 1 active RT task, it is said to be in an "overloaded" state. Once this occurs, the system enters the active balancing mode, where it will try to push the task away, or persuade a different cpu to pull it over. The system will stay in this state until the system falls back below the <= 1 queued RT task per RQ. However, the current implementation suffers from a limitation in the push logic. Once overloaded, all tasks (other than current) on the RQ are analyzed on every push operation, even if it was previously unpushable (due to affinity, etc). Whats more, the operation stops at the first task that is unpushable and will not look at items lower in the queue. This causes two problems: 1) We can have the same tasks analyzed over and over again during each push, which extends out the fast path in the scheduler for no gain. Consider a RQ that has dozens of tasks that are bound to a core. Each one of those tasks will be encountered and skipped for each push operation while they are queued. 2) There may be lower-priority tasks under the unpushable task that could have been successfully pushed, but will never be considered until either the unpushable task is cleared, or a pull operation succeeds. The net result is a potential latency source for mid priority tasks. This patch aims to rectify these two conditions by introducing a new priority sorted list: "pushable_tasks". A task is added to the list each time a task is activated or preempted. It is removed from the list any time it is deactivated, made current, or fails to push. This works because a task only needs to be attempted to push once. After an initial failure to push, the other cpus will eventually try to pull the task when the conditions are proper. This also solves the problem that we don't completely analyze all tasks due to encountering an unpushable tasks. Now every task will have a push attempted (when appropriate). This reduces latency both by shorting the critical section of the rq->lock for certain workloads, and by making sure the algorithm considers all eligible tasks in the system. [ rostedt: added a couple more BUG_ONs ] Signed-off-by: Gregory Haskins <ghaskins@novell.com> Acked-by: Steven Rostedt <srostedt@redhat.com>
2008-12-29 14:39:53 +00:00
plist_node_init(&p->pushable_tasks, MAX_PRIO);
sched: Make pushable_tasks CONFIG_SMP dependant As noted by Peter Zijlstra at https://lkml.org/lkml/2010/11/10/391 (while reviewing other stuff, though), tracking pushable tasks only makes sense on SMP systems. Signed-off-by: Dario Faggioli <raistlin@linux.it> Acked-by: Steven Rostedt <rostedt@goodmis.org> Acked-by: Gregory Haskins <ghaskins@novell.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1291143093.2697.298.camel@Palantir> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-30 18:51:33 +00:00
#endif
sched: create "pushable_tasks" list to limit pushing to one attempt The RT scheduler employs a "push/pull" design to actively balance tasks within the system (on a per disjoint cpuset basis). When a task is awoken, it is immediately determined if there are any lower priority cpus which should be preempted. This is opposed to the way normal SCHED_OTHER tasks behave, which will wait for a periodic rebalancing operation to occur before spreading out load. When a particular RQ has more than 1 active RT task, it is said to be in an "overloaded" state. Once this occurs, the system enters the active balancing mode, where it will try to push the task away, or persuade a different cpu to pull it over. The system will stay in this state until the system falls back below the <= 1 queued RT task per RQ. However, the current implementation suffers from a limitation in the push logic. Once overloaded, all tasks (other than current) on the RQ are analyzed on every push operation, even if it was previously unpushable (due to affinity, etc). Whats more, the operation stops at the first task that is unpushable and will not look at items lower in the queue. This causes two problems: 1) We can have the same tasks analyzed over and over again during each push, which extends out the fast path in the scheduler for no gain. Consider a RQ that has dozens of tasks that are bound to a core. Each one of those tasks will be encountered and skipped for each push operation while they are queued. 2) There may be lower-priority tasks under the unpushable task that could have been successfully pushed, but will never be considered until either the unpushable task is cleared, or a pull operation succeeds. The net result is a potential latency source for mid priority tasks. This patch aims to rectify these two conditions by introducing a new priority sorted list: "pushable_tasks". A task is added to the list each time a task is activated or preempted. It is removed from the list any time it is deactivated, made current, or fails to push. This works because a task only needs to be attempted to push once. After an initial failure to push, the other cpus will eventually try to pull the task when the conditions are proper. This also solves the problem that we don't completely analyze all tasks due to encountering an unpushable tasks. Now every task will have a push attempted (when appropriate). This reduces latency both by shorting the critical section of the rq->lock for certain workloads, and by making sure the algorithm considers all eligible tasks in the system. [ rostedt: added a couple more BUG_ONs ] Signed-off-by: Gregory Haskins <ghaskins@novell.com> Acked-by: Steven Rostedt <srostedt@redhat.com>
2008-12-29 14:39:53 +00:00
[PATCH] sched: consolidate sbe sbf Consolidate balance-on-exec with balance-on-fork. This is made easy by the sched-domains RCU patches. As well as the general goodness of code reduction, this allows the runqueues to be unlocked during balance-on-fork. schedstats is a problem. Maybe just have balance-on-event instead of distinguishing fork and exec? Signed-off-by: Nick Piggin <nickpiggin@yahoo.com.au> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-25 21:57:29 +00:00
put_cpu();
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
}
/*
* wake_up_new_task - wake up a newly created task for the first time.
*
* This function will do some initial scheduler statistics housekeeping
* that must be done for every newly created context, then puts the task
* on the runqueue and wakes it.
*/
sched: Remove unused parameters from sched_fork() and wake_up_new_task() sched_fork() and wake_up_new_task() are defined with a parameter 'unsigned long clone_flags', which is unused. This patch removes the parameters. Signed-off-by: Samir Bellabes <sam@synack.fr> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1305130685-1047-1-git-send-email-sam@synack.fr Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-05-11 16:18:05 +00:00
void wake_up_new_task(struct task_struct *p)
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
{
unsigned long flags;
sched: cfs core code apply the CFS core code. this change switches over the scheduler core to CFS's modular design and makes use of kernel/sched_fair/rt/idletask.c to implement Linux's scheduling policies. thanks to Andrew Morton and Thomas Gleixner for lots of detailed review feedback and for fixlets. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
2007-07-09 16:51:59 +00:00
struct rq *rq;
sched: Fix fork vs hotplug vs cpuset namespaces There are a number of issues: 1) TASK_WAKING vs cgroup_clone (cpusets) copy_process(): sched_fork() child->state = TASK_WAKING; /* waiting for wake_up_new_task() */ if (current->nsproxy != p->nsproxy) ns_cgroup_clone() cgroup_clone() mutex_lock(inode->i_mutex) mutex_lock(cgroup_mutex) cgroup_attach_task() ss->can_attach() ss->attach() [ -> cpuset_attach() ] cpuset_attach_task() set_cpus_allowed_ptr(); while (child->state == TASK_WAKING) cpu_relax(); will deadlock the system. 2) cgroup_clone (cpusets) vs copy_process So even if the above would work we still have: copy_process(): if (current->nsproxy != p->nsproxy) ns_cgroup_clone() cgroup_clone() mutex_lock(inode->i_mutex) mutex_lock(cgroup_mutex) cgroup_attach_task() ss->can_attach() ss->attach() [ -> cpuset_attach() ] cpuset_attach_task() set_cpus_allowed_ptr(); ... p->cpus_allowed = current->cpus_allowed over-writing the modified cpus_allowed. 3) fork() vs hotplug if we unplug the child's cpu after the sanity check when the child gets attached to the task_list but before wake_up_new_task() shit will meet with fan. Solve all these issues by moving fork cpu selection into wake_up_new_task(). Reported-by: Serge E. Hallyn <serue@us.ibm.com> Tested-by: Serge E. Hallyn <serue@us.ibm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1264106190.4283.1314.camel@laptop> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2010-01-21 20:04:57 +00:00
sched: Drop rq->lock from first part of wake_up_new_task() Since p->pi_lock now protects all things needed to call select_task_rq() avoid the double remote rq->lock acquisition and rely on p->pi_lock. Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110405152729.273362517@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-05 15:23:52 +00:00
raw_spin_lock_irqsave(&p->pi_lock, flags);
sched: Fix fork vs hotplug vs cpuset namespaces There are a number of issues: 1) TASK_WAKING vs cgroup_clone (cpusets) copy_process(): sched_fork() child->state = TASK_WAKING; /* waiting for wake_up_new_task() */ if (current->nsproxy != p->nsproxy) ns_cgroup_clone() cgroup_clone() mutex_lock(inode->i_mutex) mutex_lock(cgroup_mutex) cgroup_attach_task() ss->can_attach() ss->attach() [ -> cpuset_attach() ] cpuset_attach_task() set_cpus_allowed_ptr(); while (child->state == TASK_WAKING) cpu_relax(); will deadlock the system. 2) cgroup_clone (cpusets) vs copy_process So even if the above would work we still have: copy_process(): if (current->nsproxy != p->nsproxy) ns_cgroup_clone() cgroup_clone() mutex_lock(inode->i_mutex) mutex_lock(cgroup_mutex) cgroup_attach_task() ss->can_attach() ss->attach() [ -> cpuset_attach() ] cpuset_attach_task() set_cpus_allowed_ptr(); ... p->cpus_allowed = current->cpus_allowed over-writing the modified cpus_allowed. 3) fork() vs hotplug if we unplug the child's cpu after the sanity check when the child gets attached to the task_list but before wake_up_new_task() shit will meet with fan. Solve all these issues by moving fork cpu selection into wake_up_new_task(). Reported-by: Serge E. Hallyn <serue@us.ibm.com> Tested-by: Serge E. Hallyn <serue@us.ibm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1264106190.4283.1314.camel@laptop> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2010-01-21 20:04:57 +00:00
#ifdef CONFIG_SMP
/*
* Fork balancing, do it here and not earlier because:
* - cpus_allowed can change in the fork path
* - any previously selected cpu might disappear through hotplug
*/
sched: Drop rq->lock from first part of wake_up_new_task() Since p->pi_lock now protects all things needed to call select_task_rq() avoid the double remote rq->lock acquisition and rely on p->pi_lock. Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110405152729.273362517@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-05 15:23:52 +00:00
set_task_cpu(p, select_task_rq(p, SD_BALANCE_FORK, 0));
sched: Fix TASK_WAKING vs fork deadlock Oleg noticed a few races with the TASK_WAKING usage on fork. - since TASK_WAKING is basically a spinlock, it should be IRQ safe - since we set TASK_WAKING (*) without holding rq->lock it could be there still is a rq->lock holder, thereby not actually providing full serialization. (*) in fact we clear PF_STARTING, which in effect enables TASK_WAKING. Cure the second issue by not setting TASK_WAKING in sched_fork(), but only temporarily in wake_up_new_task() while calling select_task_rq(). Cure the first by holding rq->lock around the select_task_rq() call, this will disable IRQs, this however requires that we push down the rq->lock release into select_task_rq_fair()'s cgroup stuff. Because select_task_rq_fair() still needs to drop the rq->lock we cannot fully get rid of TASK_WAKING. Reported-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-03-24 17:34:10 +00:00
#endif
sched: Drop rq->lock from first part of wake_up_new_task() Since p->pi_lock now protects all things needed to call select_task_rq() avoid the double remote rq->lock acquisition and rely on p->pi_lock. Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110405152729.273362517@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-05 15:23:52 +00:00
rq = __task_rq_lock(p);
sched: Sanitize fork() handling Currently we try to do task placement in wake_up_new_task() after we do the load-balance pass in sched_fork(). This yields complicated semantics in that we have to deal with tasks on different RQs and the set_task_cpu() calls in copy_process() and sched_fork() Rename ->task_new() to ->task_fork() and call it from sched_fork() before the balancing, this gives the policy a clear point to place the task. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-11-27 16:32:46 +00:00
activate_task(rq, p, 0);
sched: Provide p->on_rq Provide a generic p->on_rq because the p->se.on_rq semantics are unfavourable for lockless wakeups but needed for sched_fair. In particular, p->on_rq is only cleared when we actually dequeue the task in schedule() and not on any random dequeue as done by things like __migrate_task() and __sched_setscheduler(). This also allows us to remove p->se usage from !sched_fair code. Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110405152728.949545047@chello.nl
2011-04-05 15:23:44 +00:00
p->on_rq = 1;
sched: Change the ttwu() success details try_to_wake_up() would only return a success when it would have to place a task on a rq, change that to every time we change p->state to TASK_RUNNING, because that's the real measure of wakeups. This results in that success is always true for the tracepoints. Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110405152728.866866929@chello.nl
2011-04-05 15:23:42 +00:00
trace_sched_wakeup_new(p, true);
sched: Add WF_FORK Avoid the cache buddies from biasing the time distribution away from fork()ers. Normally the next buddy will be the preferred scheduling target, but this makes fork()s prefer to run the new child, whereas we prefer to run the parent, since that will generate more work. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-09-14 18:02:34 +00:00
check_preempt_curr(rq, p, WF_FORK);
sched: RT-balance, replace hooks with pre/post schedule and wakeup methods To make the main sched.c code more agnostic to the schedule classes. Instead of having specific hooks in the schedule code for the RT class balancing. They are replaced with a pre_schedule, post_schedule and task_wake_up methods. These methods may be used by any of the classes but currently, only the sched_rt class implements them. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:22 +00:00
#ifdef CONFIG_SMP
sched: Add pre and post wakeup hooks As will be apparent in the next patch, we need a pre wakeup hook for sched_fair task migration, hence rename the post wakeup hook and one pre wakeup. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> LKML-Reference: <20091216170518.114746117@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-16 17:04:40 +00:00
if (p->sched_class->task_woken)
p->sched_class->task_woken(rq, p);
sched: RT-balance, replace hooks with pre/post schedule and wakeup methods To make the main sched.c code more agnostic to the schedule classes. Instead of having specific hooks in the schedule code for the RT class balancing. They are replaced with a pre_schedule, post_schedule and task_wake_up methods. These methods may be used by any of the classes but currently, only the sched_rt class implements them. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:22 +00:00
#endif
sched: Add p->pi_lock to task_rq_lock() In order to be able to call set_task_cpu() while either holding p->pi_lock or task_rq(p)->lock we need to hold both locks in order to stabilize task_rq(). This makes task_rq_lock() acquire both locks, and have __task_rq_lock() validate that p->pi_lock is held. This increases the locking overhead for most scheduler syscalls but allows reduction of rq->lock contention for some scheduler hot paths (ttwu). Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110405152729.232781355@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-05 15:23:51 +00:00
task_rq_unlock(rq, p, &flags);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
}
[PATCH] sched: arch preempt notifier mechanism This adds a general mechanism whereby a task can request the scheduler to notify it whenever it is preempted or scheduled back in. This allows the task to swap any special-purpose registers like the fpu or Intel's VT registers. Signed-off-by: Avi Kivity <avi@qumranet.com> [ mingo@elte.hu: fixes, cleanups ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-26 11:40:43 +00:00
#ifdef CONFIG_PREEMPT_NOTIFIERS
/**
sched: fix typos in documentation Fixed typos in function documentation. Signed-off-by: Luis Henriques <henrix@sapo.pt> LKML-Reference: <20090316195809.GA6073@hades.domain.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-16 19:58:09 +00:00
* preempt_notifier_register - tell me when current is being preempted & rescheduled
sched: fix kernel-doc warnings Fix kernel-doc warnings in sched.c: Warning(linux-2623-rc1g4//kernel/sched.c:1685): No description found for parameter 'notifier' Warning(linux-2623-rc1g4//kernel/sched.c:1696): No description found for parameter 'notifier' Warning(linux-2623-rc1g4//kernel/sched.c:1750): No description found for parameter 'prev' Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-31 07:37:50 +00:00
* @notifier: notifier struct to register
[PATCH] sched: arch preempt notifier mechanism This adds a general mechanism whereby a task can request the scheduler to notify it whenever it is preempted or scheduled back in. This allows the task to swap any special-purpose registers like the fpu or Intel's VT registers. Signed-off-by: Avi Kivity <avi@qumranet.com> [ mingo@elte.hu: fixes, cleanups ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-26 11:40:43 +00:00
*/
void preempt_notifier_register(struct preempt_notifier *notifier)
{
hlist_add_head(&notifier->link, &current->preempt_notifiers);
}
EXPORT_SYMBOL_GPL(preempt_notifier_register);
/**
* preempt_notifier_unregister - no longer interested in preemption notifications
sched: fix kernel-doc warnings Fix kernel-doc warnings in sched.c: Warning(linux-2623-rc1g4//kernel/sched.c:1685): No description found for parameter 'notifier' Warning(linux-2623-rc1g4//kernel/sched.c:1696): No description found for parameter 'notifier' Warning(linux-2623-rc1g4//kernel/sched.c:1750): No description found for parameter 'prev' Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-31 07:37:50 +00:00
* @notifier: notifier struct to unregister
[PATCH] sched: arch preempt notifier mechanism This adds a general mechanism whereby a task can request the scheduler to notify it whenever it is preempted or scheduled back in. This allows the task to swap any special-purpose registers like the fpu or Intel's VT registers. Signed-off-by: Avi Kivity <avi@qumranet.com> [ mingo@elte.hu: fixes, cleanups ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-26 11:40:43 +00:00
*
* This is safe to call from within a preemption notifier.
*/
void preempt_notifier_unregister(struct preempt_notifier *notifier)
{
hlist_del(&notifier->link);
}
EXPORT_SYMBOL_GPL(preempt_notifier_unregister);
static void fire_sched_in_preempt_notifiers(struct task_struct *curr)
{
struct preempt_notifier *notifier;
struct hlist_node *node;
hlist_for_each_entry(notifier, node, &curr->preempt_notifiers, link)
notifier->ops->sched_in(notifier, raw_smp_processor_id());
}
static void
fire_sched_out_preempt_notifiers(struct task_struct *curr,
struct task_struct *next)
{
struct preempt_notifier *notifier;
struct hlist_node *node;
hlist_for_each_entry(notifier, node, &curr->preempt_notifiers, link)
notifier->ops->sched_out(notifier, next);
}
sched: add comments for ifdefs in sched.c make sched.c easier to read. Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-30 12:23:45 +00:00
#else /* !CONFIG_PREEMPT_NOTIFIERS */
[PATCH] sched: arch preempt notifier mechanism This adds a general mechanism whereby a task can request the scheduler to notify it whenever it is preempted or scheduled back in. This allows the task to swap any special-purpose registers like the fpu or Intel's VT registers. Signed-off-by: Avi Kivity <avi@qumranet.com> [ mingo@elte.hu: fixes, cleanups ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-26 11:40:43 +00:00
static void fire_sched_in_preempt_notifiers(struct task_struct *curr)
{
}
static void
fire_sched_out_preempt_notifiers(struct task_struct *curr,
struct task_struct *next)
{
}
sched: add comments for ifdefs in sched.c make sched.c easier to read. Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-30 12:23:45 +00:00
#endif /* CONFIG_PREEMPT_NOTIFIERS */
[PATCH] sched: arch preempt notifier mechanism This adds a general mechanism whereby a task can request the scheduler to notify it whenever it is preempted or scheduled back in. This allows the task to swap any special-purpose registers like the fpu or Intel's VT registers. Signed-off-by: Avi Kivity <avi@qumranet.com> [ mingo@elte.hu: fixes, cleanups ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-26 11:40:43 +00:00
[PATCH] sched: cleanup context switch locking Instead of requiring architecture code to interact with the scheduler's locking implementation, provide a couple of defines that can be used by the architecture to request runqueue unlocked context switches, and ask for interrupts to be enabled over the context switch. Also replaces the "switch_lock" used by these architectures with an oncpu flag (note, not a potentially slow bitflag). This eliminates one bus locked memory operation when context switching, and simplifies the task_running function. Signed-off-by: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-25 21:57:23 +00:00
/**
* prepare_task_switch - prepare to switch tasks
* @rq: the runqueue preparing to switch
sched: fix kernel-doc warnings Fix kernel-doc warnings in sched.c: Warning(linux-2623-rc1g4//kernel/sched.c:1685): No description found for parameter 'notifier' Warning(linux-2623-rc1g4//kernel/sched.c:1696): No description found for parameter 'notifier' Warning(linux-2623-rc1g4//kernel/sched.c:1750): No description found for parameter 'prev' Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-31 07:37:50 +00:00
* @prev: the current task that is being switched out
[PATCH] sched: cleanup context switch locking Instead of requiring architecture code to interact with the scheduler's locking implementation, provide a couple of defines that can be used by the architecture to request runqueue unlocked context switches, and ask for interrupts to be enabled over the context switch. Also replaces the "switch_lock" used by these architectures with an oncpu flag (note, not a potentially slow bitflag). This eliminates one bus locked memory operation when context switching, and simplifies the task_running function. Signed-off-by: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-25 21:57:23 +00:00
* @next: the task we are going to switch to.
*
* This is called with the rq lock held and interrupts off. It must
* be paired with a subsequent finish_task_switch after the context
* switch.
*
* prepare_task_switch sets up locking and calls architecture specific
* hooks.
*/
[PATCH] sched: arch preempt notifier mechanism This adds a general mechanism whereby a task can request the scheduler to notify it whenever it is preempted or scheduled back in. This allows the task to swap any special-purpose registers like the fpu or Intel's VT registers. Signed-off-by: Avi Kivity <avi@qumranet.com> [ mingo@elte.hu: fixes, cleanups ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-26 11:40:43 +00:00
static inline void
prepare_task_switch(struct rq *rq, struct task_struct *prev,
struct task_struct *next)
[PATCH] sched: cleanup context switch locking Instead of requiring architecture code to interact with the scheduler's locking implementation, provide a couple of defines that can be used by the architecture to request runqueue unlocked context switches, and ask for interrupts to be enabled over the context switch. Also replaces the "switch_lock" used by these architectures with an oncpu flag (note, not a potentially slow bitflag). This eliminates one bus locked memory operation when context switching, and simplifies the task_running function. Signed-off-by: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-25 21:57:23 +00:00
{
perf: Cure task_oncpu_function_call() races Oleg reported that on architectures with __ARCH_WANT_INTERRUPTS_ON_CTXSW the IPI from task_oncpu_function_call() can land before perf_event_task_sched_in() and cause interesting situations for eg. perf_install_in_context(). This patch reworks the task_oncpu_function_call() interface to give a more usable primitive as well as rework all its users to hopefully be more obvious as well as remove the races. While looking at the code I also found a number of races against perf_event_task_sched_out() which can flip contexts between tasks so plug those too. Reported-and-reviewed-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-02-02 12:19:09 +00:00
sched_info_switch(prev, next);
perf_event_task_sched_out(prev, next);
[PATCH] sched: arch preempt notifier mechanism This adds a general mechanism whereby a task can request the scheduler to notify it whenever it is preempted or scheduled back in. This allows the task to swap any special-purpose registers like the fpu or Intel's VT registers. Signed-off-by: Avi Kivity <avi@qumranet.com> [ mingo@elte.hu: fixes, cleanups ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-26 11:40:43 +00:00
fire_sched_out_preempt_notifiers(prev, next);
[PATCH] sched: cleanup context switch locking Instead of requiring architecture code to interact with the scheduler's locking implementation, provide a couple of defines that can be used by the architecture to request runqueue unlocked context switches, and ask for interrupts to be enabled over the context switch. Also replaces the "switch_lock" used by these architectures with an oncpu flag (note, not a potentially slow bitflag). This eliminates one bus locked memory operation when context switching, and simplifies the task_running function. Signed-off-by: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-25 21:57:23 +00:00
prepare_lock_switch(rq, next);
prepare_arch_switch(next);
perf: Cure task_oncpu_function_call() races Oleg reported that on architectures with __ARCH_WANT_INTERRUPTS_ON_CTXSW the IPI from task_oncpu_function_call() can land before perf_event_task_sched_in() and cause interesting situations for eg. perf_install_in_context(). This patch reworks the task_oncpu_function_call() interface to give a more usable primitive as well as rework all its users to hopefully be more obvious as well as remove the races. While looking at the code I also found a number of races against perf_event_task_sched_out() which can flip contexts between tasks so plug those too. Reported-and-reviewed-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-02-02 12:19:09 +00:00
trace_sched_switch(prev, next);
[PATCH] sched: cleanup context switch locking Instead of requiring architecture code to interact with the scheduler's locking implementation, provide a couple of defines that can be used by the architecture to request runqueue unlocked context switches, and ask for interrupts to be enabled over the context switch. Also replaces the "switch_lock" used by these architectures with an oncpu flag (note, not a potentially slow bitflag). This eliminates one bus locked memory operation when context switching, and simplifies the task_running function. Signed-off-by: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-25 21:57:23 +00:00
}
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
/**
* finish_task_switch - clean up after a task-switch
[kernel-doc] fix various DocBook build problems/warnings Most serious is fixing include/sound/pcm.h, which breaks the DocBook build. The other stuff is just filling in things that cause warnings.
2005-09-07 05:15:17 +00:00
* @rq: runqueue associated with task-switch
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
* @prev: the thread we just switched away from.
*
[PATCH] sched: cleanup context switch locking Instead of requiring architecture code to interact with the scheduler's locking implementation, provide a couple of defines that can be used by the architecture to request runqueue unlocked context switches, and ask for interrupts to be enabled over the context switch. Also replaces the "switch_lock" used by these architectures with an oncpu flag (note, not a potentially slow bitflag). This eliminates one bus locked memory operation when context switching, and simplifies the task_running function. Signed-off-by: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-25 21:57:23 +00:00
* finish_task_switch must be called after the context switch, paired
* with a prepare_task_switch call before the context switch.
* finish_task_switch will reconcile locking set up by prepare_task_switch,
* and do any other architecture-specific cleanup actions.
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
*
* Note that we may have delayed dropping an mm in context_switch(). If
sched: style cleanups style cleanup of various changes that were done recently. no code changed: text data bss dec hex filename 23680 2542 28 26250 668a sched.o.before 23680 2542 28 26250 668a sched.o.after Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-12-05 14:46:09 +00:00
* so, we finish that here outside of the runqueue lock. (Doing it
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
* with the lock held can cause deadlocks; see schedule() for
* details.)
*/
sched: uninline scheduler * save ~300 bytes * activate_idle_task() was moved to avoid a warning bloat-o-meter output: add/remove: 6/0 grow/shrink: 0/16 up/down: 438/-733 (-295) <=== function old new delta __enqueue_entity - 165 +165 finish_task_switch - 110 +110 update_curr_rt - 79 +79 __load_balance_iterator - 32 +32 __task_rq_unlock - 28 +28 find_process_by_pid - 24 +24 do_sched_setscheduler 133 123 -10 sys_sched_rr_get_interval 176 165 -11 sys_sched_getparam 156 145 -11 normalize_rt_tasks 482 470 -12 sched_getaffinity 112 99 -13 sys_sched_getscheduler 86 72 -14 sched_setaffinity 226 212 -14 sched_setscheduler 666 642 -24 load_balance_start_fair 33 9 -24 load_balance_next_fair 33 9 -24 dequeue_task_rt 133 67 -66 put_prev_task_rt 97 28 -69 schedule_tail 133 50 -83 schedule 682 594 -88 enqueue_entity 499 366 -133 task_new_fair 317 180 -137 Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 15:00:13 +00:00
static void finish_task_switch(struct rq *rq, struct task_struct *prev)
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
__releases(rq->lock)
{
struct mm_struct *mm = rq->prev_mm;
[PATCH] kill PF_DEAD flag After the previous change (->flags & PF_DEAD) <=> (->state == EXIT_DEAD), we don't need PF_DEAD any longer. Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-29 09:01:10 +00:00
long prev_state;
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
rq->prev_mm = NULL;
/*
* A task struct has one reference for the use as "current".
[PATCH] introduce TASK_DEAD state I am not sure about this patch, I am asking Ingo to take a decision. task_struct->state == EXIT_DEAD is a very special case, to avoid a confusion it makes sense to introduce a new state, TASK_DEAD, while EXIT_DEAD should live only in ->exit_state as documented in sched.h. Note that this state is not visible to user-space, get_task_state() masks off unsuitable states. Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-29 09:01:11 +00:00
* If a task dies, then it sets TASK_DEAD in tsk->state and calls
[PATCH] kill PF_DEAD flag After the previous change (->flags & PF_DEAD) <=> (->state == EXIT_DEAD), we don't need PF_DEAD any longer. Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-29 09:01:10 +00:00
* schedule one last time. The schedule call will never return, and
* the scheduled task must drop that reference.
[PATCH] introduce TASK_DEAD state I am not sure about this patch, I am asking Ingo to take a decision. task_struct->state == EXIT_DEAD is a very special case, to avoid a confusion it makes sense to introduce a new state, TASK_DEAD, while EXIT_DEAD should live only in ->exit_state as documented in sched.h. Note that this state is not visible to user-space, get_task_state() masks off unsuitable states. Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-29 09:01:11 +00:00
* The test for TASK_DEAD must occur while the runqueue locks are
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
* still held, otherwise prev could be scheduled on another cpu, die
* there before we look at prev->state, and then the reference would
* be dropped twice.
* Manfred Spraul <manfred@colorfullife.com>
*/
[PATCH] kill PF_DEAD flag After the previous change (->flags & PF_DEAD) <=> (->state == EXIT_DEAD), we don't need PF_DEAD any longer. Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-29 09:01:10 +00:00
prev_state = prev->state;
[PATCH] sched: cleanup context switch locking Instead of requiring architecture code to interact with the scheduler's locking implementation, provide a couple of defines that can be used by the architecture to request runqueue unlocked context switches, and ask for interrupts to be enabled over the context switch. Also replaces the "switch_lock" used by these architectures with an oncpu flag (note, not a potentially slow bitflag). This eliminates one bus locked memory operation when context switching, and simplifies the task_running function. Signed-off-by: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-25 21:57:23 +00:00
finish_arch_switch(prev);
sched/perf: Make sure irqs are disabled for perf_event_task_sched_in() perf_event_task_sched_in() expects interrupts to be disabled, but on architectures with __ARCH_WANT_INTERRUPTS_ON_CTXSW defined, this isn't true. If this is defined, disable irqs around the call in finish_task_switch(). Signed-off-by: Jamie Iles <jamie.iles@picochip.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Russell King - ARM Linux <linux@arm.linux.org.uk> LKML-Reference: <1262964453-27370-1-git-send-email-jamie.iles@picochip.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-01-08 15:27:33 +00:00
#ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW
local_irq_disable();
#endif /* __ARCH_WANT_INTERRUPTS_ON_CTXSW */
perf events: Remove arg from perf sched hooks Since we only ever schedule the local cpu, there is no need to pass the cpu number to the perf sched hooks. This micro-optimizes things a bit. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-27 10:51:52 +00:00
perf_event_task_sched_in(current);
sched/perf: Make sure irqs are disabled for perf_event_task_sched_in() perf_event_task_sched_in() expects interrupts to be disabled, but on architectures with __ARCH_WANT_INTERRUPTS_ON_CTXSW defined, this isn't true. If this is defined, disable irqs around the call in finish_task_switch(). Signed-off-by: Jamie Iles <jamie.iles@picochip.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Russell King - ARM Linux <linux@arm.linux.org.uk> LKML-Reference: <1262964453-27370-1-git-send-email-jamie.iles@picochip.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-01-08 15:27:33 +00:00
#ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW
local_irq_enable();
#endif /* __ARCH_WANT_INTERRUPTS_ON_CTXSW */
[PATCH] sched: cleanup context switch locking Instead of requiring architecture code to interact with the scheduler's locking implementation, provide a couple of defines that can be used by the architecture to request runqueue unlocked context switches, and ask for interrupts to be enabled over the context switch. Also replaces the "switch_lock" used by these architectures with an oncpu flag (note, not a potentially slow bitflag). This eliminates one bus locked memory operation when context switching, and simplifies the task_running function. Signed-off-by: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-25 21:57:23 +00:00
finish_lock_switch(rq, prev);
sched: add RT task pushing This patch adds an algorithm to push extra RT tasks off a run queue to other CPU runqueues. When more than one RT task is added to a run queue, this algorithm takes an assertive approach to push the RT tasks that are not running onto other run queues that have lower priority. The way this works is that the highest RT task that is not running is looked at and we examine the runqueues on the CPUS for that tasks affinity mask. We find the runqueue with the lowest prio in the CPU affinity of the picked task, and if it is lower in prio than the picked task, we push the task onto that CPU runqueue. We continue pushing RT tasks off the current runqueue until we don't push any more. The algorithm stops when the next highest RT task can't preempt any other processes on other CPUS. TODO: The algorithm may stop when there are still RT tasks that can be migrated. Specifically, if the highest non running RT task CPU affinity is restricted to CPUs that are running higher priority tasks, there may be a lower priority task queued that has an affinity with a CPU that is running a lower priority task that it could be migrated to. This patch set does not address this issue. Note: checkpatch reveals two over 80 character instances. I'm not sure that breaking them up will help visually, so I left them as is. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:05 +00:00
[PATCH] sched: arch preempt notifier mechanism This adds a general mechanism whereby a task can request the scheduler to notify it whenever it is preempted or scheduled back in. This allows the task to swap any special-purpose registers like the fpu or Intel's VT registers. Signed-off-by: Avi Kivity <avi@qumranet.com> [ mingo@elte.hu: fixes, cleanups ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-26 11:40:43 +00:00
fire_sched_in_preempt_notifiers(current);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
if (mm)
mmdrop(mm);
[PATCH] introduce TASK_DEAD state I am not sure about this patch, I am asking Ingo to take a decision. task_struct->state == EXIT_DEAD is a very special case, to avoid a confusion it makes sense to introduce a new state, TASK_DEAD, while EXIT_DEAD should live only in ->exit_state as documented in sched.h. Note that this state is not visible to user-space, get_task_state() masks off unsuitable states. Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-29 09:01:11 +00:00
if (unlikely(prev_state == TASK_DEAD)) {
[PATCH] kretprobe instance recycled by parent process When kretprobe probes the schedule() function, if the probed process exits then schedule() will never return, so some kretprobe instances will never be recycled. In this patch the parent process will recycle retprobe instances of the probed function and there will be no memory leak of kretprobe instances. Signed-off-by: bibo mao <bibo.mao@intel.com> Cc: Masami Hiramatsu <hiramatu@sdl.hitachi.co.jp> Cc: Prasanna S Panchamukhi <prasanna@in.ibm.com> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-26 09:38:20 +00:00
/*
* Remove function-return probe instances associated with this
* task and put them back on the free list.
sched: style cleanups 4 small style cleanups to sched.c: checkpatch.pl is now happy about the totality of sched.c [ignoring false positives] - yay! ;-) Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-09 16:52:00 +00:00
*/
[PATCH] kretprobe instance recycled by parent process When kretprobe probes the schedule() function, if the probed process exits then schedule() will never return, so some kretprobe instances will never be recycled. In this patch the parent process will recycle retprobe instances of the probed function and there will be no memory leak of kretprobe instances. Signed-off-by: bibo mao <bibo.mao@intel.com> Cc: Masami Hiramatsu <hiramatu@sdl.hitachi.co.jp> Cc: Prasanna S Panchamukhi <prasanna@in.ibm.com> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-26 09:38:20 +00:00
kprobe_flush_task(prev);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
put_task_struct(prev);
[PATCH] kretprobe instance recycled by parent process When kretprobe probes the schedule() function, if the probed process exits then schedule() will never return, so some kretprobe instances will never be recycled. In this patch the parent process will recycle retprobe instances of the probed function and there will be no memory leak of kretprobe instances. Signed-off-by: bibo mao <bibo.mao@intel.com> Cc: Masami Hiramatsu <hiramatu@sdl.hitachi.co.jp> Cc: Prasanna S Panchamukhi <prasanna@in.ibm.com> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-26 09:38:20 +00:00
}
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
}
sched: Enhance the pre/post scheduling logic We currently have an explicit "needs_post" vtable method which returns a stack variable for whether we should later run post-schedule. This leads to an awkward exchange of the variable as it bubbles back up out of the context switch. Peter Zijlstra observed that this information could be stored in the run-queue itself instead of handled on the stack. Therefore, we revert to the method of having context_switch return void, and update an internal rq->post_schedule variable when we require further processing. In addition, we fix a race condition where we try to access current->sched_class without holding the rq->lock. This is technically racy, as the sched-class could change out from under us. Instead, we reference the per-rq post_schedule variable with the runqueue unlocked, but with preemption disabled to see if we need to reacquire the rq->lock. Finally, we clean the code up slightly by removing the #ifdef CONFIG_SMP conditionals from the schedule() call, and implement some inline helper functions instead. This patch passes checkpatch, and rt-migrate. Signed-off-by: Gregory Haskins <ghaskins@novell.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20090729150422.17691.55590.stgit@dev.haskins.net> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-07-29 15:08:47 +00:00
#ifdef CONFIG_SMP
/* assumes rq->lock is held */
static inline void pre_schedule(struct rq *rq, struct task_struct *prev)
{
if (prev->sched_class->pre_schedule)
prev->sched_class->pre_schedule(rq, prev);
}
/* rq->lock is NOT held, but preemption is disabled */
static inline void post_schedule(struct rq *rq)
{
if (rq->post_schedule) {
unsigned long flags;
sched: Convert rq->lock to raw_spinlock Convert locks which cannot be sleeping locks in preempt-rt to raw_spinlocks. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Ingo Molnar <mingo@elte.hu>
2009-11-17 13:28:38 +00:00
raw_spin_lock_irqsave(&rq->lock, flags);
sched: Enhance the pre/post scheduling logic We currently have an explicit "needs_post" vtable method which returns a stack variable for whether we should later run post-schedule. This leads to an awkward exchange of the variable as it bubbles back up out of the context switch. Peter Zijlstra observed that this information could be stored in the run-queue itself instead of handled on the stack. Therefore, we revert to the method of having context_switch return void, and update an internal rq->post_schedule variable when we require further processing. In addition, we fix a race condition where we try to access current->sched_class without holding the rq->lock. This is technically racy, as the sched-class could change out from under us. Instead, we reference the per-rq post_schedule variable with the runqueue unlocked, but with preemption disabled to see if we need to reacquire the rq->lock. Finally, we clean the code up slightly by removing the #ifdef CONFIG_SMP conditionals from the schedule() call, and implement some inline helper functions instead. This patch passes checkpatch, and rt-migrate. Signed-off-by: Gregory Haskins <ghaskins@novell.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20090729150422.17691.55590.stgit@dev.haskins.net> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-07-29 15:08:47 +00:00
if (rq->curr->sched_class->post_schedule)
rq->curr->sched_class->post_schedule(rq);
sched: Convert rq->lock to raw_spinlock Convert locks which cannot be sleeping locks in preempt-rt to raw_spinlocks. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Ingo Molnar <mingo@elte.hu>
2009-11-17 13:28:38 +00:00
raw_spin_unlock_irqrestore(&rq->lock, flags);
sched: Enhance the pre/post scheduling logic We currently have an explicit "needs_post" vtable method which returns a stack variable for whether we should later run post-schedule. This leads to an awkward exchange of the variable as it bubbles back up out of the context switch. Peter Zijlstra observed that this information could be stored in the run-queue itself instead of handled on the stack. Therefore, we revert to the method of having context_switch return void, and update an internal rq->post_schedule variable when we require further processing. In addition, we fix a race condition where we try to access current->sched_class without holding the rq->lock. This is technically racy, as the sched-class could change out from under us. Instead, we reference the per-rq post_schedule variable with the runqueue unlocked, but with preemption disabled to see if we need to reacquire the rq->lock. Finally, we clean the code up slightly by removing the #ifdef CONFIG_SMP conditionals from the schedule() call, and implement some inline helper functions instead. This patch passes checkpatch, and rt-migrate. Signed-off-by: Gregory Haskins <ghaskins@novell.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20090729150422.17691.55590.stgit@dev.haskins.net> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-07-29 15:08:47 +00:00
rq->post_schedule = 0;
}
}
#else
sched: Check for pushing rt tasks after all scheduling The current method for pushing RT tasks after scheduling only happens after a context switch. But we found cases where a task is set up on a run queue to be pushed but the push never happens because the schedule chooses the same task. This bug was found with the help of Gregory Haskins and the use of ftrace (trace_printk). It tooks several days for both of us analyzing the code and the trace output to find this. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20090729042526.205923666@goodmis.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-07-29 04:21:22 +00:00
sched: Enhance the pre/post scheduling logic We currently have an explicit "needs_post" vtable method which returns a stack variable for whether we should later run post-schedule. This leads to an awkward exchange of the variable as it bubbles back up out of the context switch. Peter Zijlstra observed that this information could be stored in the run-queue itself instead of handled on the stack. Therefore, we revert to the method of having context_switch return void, and update an internal rq->post_schedule variable when we require further processing. In addition, we fix a race condition where we try to access current->sched_class without holding the rq->lock. This is technically racy, as the sched-class could change out from under us. Instead, we reference the per-rq post_schedule variable with the runqueue unlocked, but with preemption disabled to see if we need to reacquire the rq->lock. Finally, we clean the code up slightly by removing the #ifdef CONFIG_SMP conditionals from the schedule() call, and implement some inline helper functions instead. This patch passes checkpatch, and rt-migrate. Signed-off-by: Gregory Haskins <ghaskins@novell.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20090729150422.17691.55590.stgit@dev.haskins.net> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-07-29 15:08:47 +00:00
static inline void pre_schedule(struct rq *rq, struct task_struct *p)
{
}
static inline void post_schedule(struct rq *rq)
{
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
}
sched: Enhance the pre/post scheduling logic We currently have an explicit "needs_post" vtable method which returns a stack variable for whether we should later run post-schedule. This leads to an awkward exchange of the variable as it bubbles back up out of the context switch. Peter Zijlstra observed that this information could be stored in the run-queue itself instead of handled on the stack. Therefore, we revert to the method of having context_switch return void, and update an internal rq->post_schedule variable when we require further processing. In addition, we fix a race condition where we try to access current->sched_class without holding the rq->lock. This is technically racy, as the sched-class could change out from under us. Instead, we reference the per-rq post_schedule variable with the runqueue unlocked, but with preemption disabled to see if we need to reacquire the rq->lock. Finally, we clean the code up slightly by removing the #ifdef CONFIG_SMP conditionals from the schedule() call, and implement some inline helper functions instead. This patch passes checkpatch, and rt-migrate. Signed-off-by: Gregory Haskins <ghaskins@novell.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20090729150422.17691.55590.stgit@dev.haskins.net> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-07-29 15:08:47 +00:00
#endif
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
/**
* schedule_tail - first thing a freshly forked thread must call.
* @prev: the thread we just switched away from.
*/
[PATCH] sched: cleanup, remove task_t, convert to struct task_struct cleanup: remove task_t and convert all the uses to struct task_struct. I introduced it for the scheduler anno and it was a mistake. Conversion was mostly scripted, the result was reviewed and all secondary whitespace and style impact (if any) was fixed up by hand. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-03 07:25:41 +00:00
asmlinkage void schedule_tail(struct task_struct *prev)
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
__releases(rq->lock)
{
[PATCH] sched: cleanup, convert sched.c-internal typedefs to struct convert: - runqueue_t to 'struct rq' - prio_array_t to 'struct prio_array' - migration_req_t to 'struct migration_req' I was the one who added these but they are both against the kernel coding style and also were used inconsistently at places. So just get rid of them at once, now that we are flushing the scheduler patch-queue anyway. Conversion was mostly scripted, the result was reviewed and all secondary whitespace and style impact (if any) was fixed up by hand. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-03 07:25:42 +00:00
struct rq *rq = this_rq();
[PATCH] sched: cleanup context switch locking Instead of requiring architecture code to interact with the scheduler's locking implementation, provide a couple of defines that can be used by the architecture to request runqueue unlocked context switches, and ask for interrupts to be enabled over the context switch. Also replaces the "switch_lock" used by these architectures with an oncpu flag (note, not a potentially slow bitflag). This eliminates one bus locked memory operation when context switching, and simplifies the task_running function. Signed-off-by: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-25 21:57:23 +00:00
finish_task_switch(rq, prev);
sched: Check for pushing rt tasks after all scheduling The current method for pushing RT tasks after scheduling only happens after a context switch. But we found cases where a task is set up on a run queue to be pushed but the push never happens because the schedule chooses the same task. This bug was found with the help of Gregory Haskins and the use of ftrace (trace_printk). It tooks several days for both of us analyzing the code and the trace output to find this. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20090729042526.205923666@goodmis.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-07-29 04:21:22 +00:00
sched: Enhance the pre/post scheduling logic We currently have an explicit "needs_post" vtable method which returns a stack variable for whether we should later run post-schedule. This leads to an awkward exchange of the variable as it bubbles back up out of the context switch. Peter Zijlstra observed that this information could be stored in the run-queue itself instead of handled on the stack. Therefore, we revert to the method of having context_switch return void, and update an internal rq->post_schedule variable when we require further processing. In addition, we fix a race condition where we try to access current->sched_class without holding the rq->lock. This is technically racy, as the sched-class could change out from under us. Instead, we reference the per-rq post_schedule variable with the runqueue unlocked, but with preemption disabled to see if we need to reacquire the rq->lock. Finally, we clean the code up slightly by removing the #ifdef CONFIG_SMP conditionals from the schedule() call, and implement some inline helper functions instead. This patch passes checkpatch, and rt-migrate. Signed-off-by: Gregory Haskins <ghaskins@novell.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20090729150422.17691.55590.stgit@dev.haskins.net> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-07-29 15:08:47 +00:00
/*
* FIXME: do we need to worry about rq being invalidated by the
* task_switch?
*/
post_schedule(rq);
[PATCH] sched: cleanup, convert sched.c-internal typedefs to struct convert: - runqueue_t to 'struct rq' - prio_array_t to 'struct prio_array' - migration_req_t to 'struct migration_req' I was the one who added these but they are both against the kernel coding style and also were used inconsistently at places. So just get rid of them at once, now that we are flushing the scheduler patch-queue anyway. Conversion was mostly scripted, the result was reviewed and all secondary whitespace and style impact (if any) was fixed up by hand. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-03 07:25:42 +00:00
[PATCH] sched: cleanup context switch locking Instead of requiring architecture code to interact with the scheduler's locking implementation, provide a couple of defines that can be used by the architecture to request runqueue unlocked context switches, and ask for interrupts to be enabled over the context switch. Also replaces the "switch_lock" used by these architectures with an oncpu flag (note, not a potentially slow bitflag). This eliminates one bus locked memory operation when context switching, and simplifies the task_running function. Signed-off-by: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-25 21:57:23 +00:00
#ifdef __ARCH_WANT_UNLOCKED_CTXSW
/* In this case, finish_task_switch does not reenable preemption */
preempt_enable();
#endif
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
if (current->set_child_tid)
pid namespaces: changes to show virtual ids to user This is the largest patch in the set. Make all (I hope) the places where the pid is shown to or get from user operate on the virtual pids. The idea is: - all in-kernel data structures must store either struct pid itself or the pid's global nr, obtained with pid_nr() call; - when seeking the task from kernel code with the stored id one should use find_task_by_pid() call that works with global pids; - when showing pid's numerical value to the user the virtual one should be used, but however when one shows task's pid outside this task's namespace the global one is to be used; - when getting the pid from userspace one need to consider this as the virtual one and use appropriate task/pid-searching functions. [akpm@linux-foundation.org: build fix] [akpm@linux-foundation.org: nuther build fix] [akpm@linux-foundation.org: yet nuther build fix] [akpm@linux-foundation.org: remove unneeded casts] Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Signed-off-by: Alexey Dobriyan <adobriyan@openvz.org> Cc: Sukadev Bhattiprolu <sukadev@us.ibm.com> Cc: Oleg Nesterov <oleg@tv-sign.ru> Cc: Paul Menage <menage@google.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-19 06:40:14 +00:00
put_user(task_pid_vnr(current), current->set_child_tid);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
}
/*
* context_switch - switch to the new MM and the new
* thread's register state.
*/
sched: cfs core code apply the CFS core code. this change switches over the scheduler core to CFS's modular design and makes use of kernel/sched_fair/rt/idletask.c to implement Linux's scheduling policies. thanks to Andrew Morton and Thomas Gleixner for lots of detailed review feedback and for fixlets. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
2007-07-09 16:51:59 +00:00
static inline void
[PATCH] sched: cleanup, convert sched.c-internal typedefs to struct convert: - runqueue_t to 'struct rq' - prio_array_t to 'struct prio_array' - migration_req_t to 'struct migration_req' I was the one who added these but they are both against the kernel coding style and also were used inconsistently at places. So just get rid of them at once, now that we are flushing the scheduler patch-queue anyway. Conversion was mostly scripted, the result was reviewed and all secondary whitespace and style impact (if any) was fixed up by hand. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-03 07:25:42 +00:00
context_switch(struct rq *rq, struct task_struct *prev,
[PATCH] sched: cleanup, remove task_t, convert to struct task_struct cleanup: remove task_t and convert all the uses to struct task_struct. I introduced it for the scheduler anno and it was a mistake. Conversion was mostly scripted, the result was reviewed and all secondary whitespace and style impact (if any) was fixed up by hand. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-03 07:25:41 +00:00
struct task_struct *next)
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
{
sched: cfs core code apply the CFS core code. this change switches over the scheduler core to CFS's modular design and makes use of kernel/sched_fair/rt/idletask.c to implement Linux's scheduling policies. thanks to Andrew Morton and Thomas Gleixner for lots of detailed review feedback and for fixlets. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
2007-07-09 16:51:59 +00:00
struct mm_struct *mm, *oldmm;
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
[PATCH] sched: arch preempt notifier mechanism This adds a general mechanism whereby a task can request the scheduler to notify it whenever it is preempted or scheduled back in. This allows the task to swap any special-purpose registers like the fpu or Intel's VT registers. Signed-off-by: Avi Kivity <avi@qumranet.com> [ mingo@elte.hu: fixes, cleanups ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-26 11:40:43 +00:00
prepare_task_switch(rq, prev, next);
perf: Cure task_oncpu_function_call() races Oleg reported that on architectures with __ARCH_WANT_INTERRUPTS_ON_CTXSW the IPI from task_oncpu_function_call() can land before perf_event_task_sched_in() and cause interesting situations for eg. perf_install_in_context(). This patch reworks the task_oncpu_function_call() interface to give a more usable primitive as well as rework all its users to hopefully be more obvious as well as remove the races. While looking at the code I also found a number of races against perf_event_task_sched_out() which can flip contexts between tasks so plug those too. Reported-and-reviewed-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-02-02 12:19:09 +00:00
sched: cfs core code apply the CFS core code. this change switches over the scheduler core to CFS's modular design and makes use of kernel/sched_fair/rt/idletask.c to implement Linux's scheduling policies. thanks to Andrew Morton and Thomas Gleixner for lots of detailed review feedback and for fixlets. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
2007-07-09 16:51:59 +00:00
mm = next->mm;
oldmm = prev->active_mm;
[PATCH] i386: paravirt CPU hypercall batching mode The VMI ROM has a mode where hypercalls can be queued and batched. This turns out to be a significant win during context switch, but must be done at a specific point before side effects to CPU state are visible to subsequent instructions. This is similar to the MMU batching hooks already provided. The same hooks could be used by the Xen backend to implement a context switch multicall. To explain a bit more about lazy modes in the paravirt patches, basically, the idea is that only one of lazy CPU or MMU mode can be active at any given time. Lazy MMU mode is similar to this lazy CPU mode, and allows for batching of multiple PTE updates (say, inside a remap loop), but to avoid keeping some kind of state machine about when to flush cpu or mmu updates, we just allow one or the other to be active. Although there is no real reason a more comprehensive scheme could not be implemented, there is also no demonstrated need for this extra complexity. Signed-off-by: Zachary Amsden <zach@vmware.com> Signed-off-by: Andi Kleen <ak@suse.de> Cc: Andi Kleen <ak@suse.de> Cc: Jeremy Fitzhardinge <jeremy@xensource.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Chris Wright <chrisw@sous-sol.org> Signed-off-by: Andrew Morton <akpm@osdl.org>
2007-02-13 12:26:21 +00:00
/*
* For paravirt, this is coupled with an exit in switch_to to
* combine the page table reload and the switch backend into
* one hypercall.
*/
x86/paravirt: finish change from lazy cpu to context switch start/end Impact: fix lazy context switch API Pass the previous and next tasks into the context switch start end calls, so that the called functions can properly access the task state (esp in end_context_switch, in which the next task is not yet completely current). Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
2009-02-18 19:18:57 +00:00
arch_start_context_switch(prev);
[PATCH] i386: paravirt CPU hypercall batching mode The VMI ROM has a mode where hypercalls can be queued and batched. This turns out to be a significant win during context switch, but must be done at a specific point before side effects to CPU state are visible to subsequent instructions. This is similar to the MMU batching hooks already provided. The same hooks could be used by the Xen backend to implement a context switch multicall. To explain a bit more about lazy modes in the paravirt patches, basically, the idea is that only one of lazy CPU or MMU mode can be active at any given time. Lazy MMU mode is similar to this lazy CPU mode, and allows for batching of multiple PTE updates (say, inside a remap loop), but to avoid keeping some kind of state machine about when to flush cpu or mmu updates, we just allow one or the other to be active. Although there is no real reason a more comprehensive scheme could not be implemented, there is also no demonstrated need for this extra complexity. Signed-off-by: Zachary Amsden <zach@vmware.com> Signed-off-by: Andi Kleen <ak@suse.de> Cc: Andi Kleen <ak@suse.de> Cc: Jeremy Fitzhardinge <jeremy@xensource.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Chris Wright <chrisw@sous-sol.org> Signed-off-by: Andrew Morton <akpm@osdl.org>
2007-02-13 12:26:21 +00:00
sched: Remove branch hints within context_switch() With 710390d9 "sched: Optimize branch hint in context_switch()" the branch hint logic within context_switch() got inversed. In fact the hints "if (likely(!mm))" and "if (likely(!prev->mm))" mean that it is likely that the previous and next task are kernel threads. That assumption is certainly counter intuitive, but Tim has shown that at least with his workload this is true. Nevertheless the truth is: it depends on the current workload. So just remove the annotations which also improves readability. Reported-by: Tim Blechmann <tim@klingt.org> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> LKML-Reference: <20100916124225.GA2209@osiris.boeblingen.de.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-09-16 12:42:25 +00:00
if (!mm) {
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
next->active_mm = oldmm;
atomic_inc(&oldmm->mm_count);
enter_lazy_tlb(oldmm, next);
} else
switch_mm(oldmm, mm, next);
sched: Remove branch hints within context_switch() With 710390d9 "sched: Optimize branch hint in context_switch()" the branch hint logic within context_switch() got inversed. In fact the hints "if (likely(!mm))" and "if (likely(!prev->mm))" mean that it is likely that the previous and next task are kernel threads. That assumption is certainly counter intuitive, but Tim has shown that at least with his workload this is true. Nevertheless the truth is: it depends on the current workload. So just remove the annotations which also improves readability. Reported-by: Tim Blechmann <tim@klingt.org> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> LKML-Reference: <20100916124225.GA2209@osiris.boeblingen.de.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-09-16 12:42:25 +00:00
if (!prev->mm) {
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
prev->active_mm = NULL;
rq->prev_mm = oldmm;
}
[PATCH] lockdep: core, fix rq-lock handling on __ARCH_WANT_UNLOCKED_CTXSW On platforms that have __ARCH_WANT_UNLOCKED_CTXSW set and want to implement lock validator support there's a bug in rq->lock handling: in this case we dont 'carry over' the runqueue lock into another task - but still we did a spinlock_release() of it. Fix this by making the spinlock_release() in context_switch() dependent on !__ARCH_WANT_UNLOCKED_CTXSW. (Reported by Ralf Baechle on MIPS, which has __ARCH_WANT_UNLOCKED_CTXSW. This fixes a lockdep-internal BUG message on such platforms.) Signed-off-by: Ingo Molnar <mingo@elte.hu> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-14 07:24:27 +00:00
/*
* Since the runqueue lock will be released by the next
* task (which is an invalid locking op but in the case
* of the scheduler it's an obvious special-case), so we
* do an early lockdep release here:
*/
#ifndef __ARCH_WANT_UNLOCKED_CTXSW
[PATCH] lockdep: prove spinlock rwlock locking correctness Use the lock validator framework to prove spinlock and rwlock locking correctness. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-03 07:24:54 +00:00
spin_release(&rq->lock.dep_map, 1, _THIS_IP_);
[PATCH] lockdep: core, fix rq-lock handling on __ARCH_WANT_UNLOCKED_CTXSW On platforms that have __ARCH_WANT_UNLOCKED_CTXSW set and want to implement lock validator support there's a bug in rq->lock handling: in this case we dont 'carry over' the runqueue lock into another task - but still we did a spinlock_release() of it. Fix this by making the spinlock_release() in context_switch() dependent on !__ARCH_WANT_UNLOCKED_CTXSW. (Reported by Ralf Baechle on MIPS, which has __ARCH_WANT_UNLOCKED_CTXSW. This fixes a lockdep-internal BUG message on such platforms.) Signed-off-by: Ingo Molnar <mingo@elte.hu> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-14 07:24:27 +00:00
#endif
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
/* Here we just switch the register state and the stack. */
switch_to(prev, next, prev);
sched: cfs core code apply the CFS core code. this change switches over the scheduler core to CFS's modular design and makes use of kernel/sched_fair/rt/idletask.c to implement Linux's scheduling policies. thanks to Andrew Morton and Thomas Gleixner for lots of detailed review feedback and for fixlets. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
2007-07-09 16:51:59 +00:00
barrier();
/*
* this_rq must be evaluated again because prev may have moved
* CPUs since it called schedule(), thus the 'rq' on its stack
* frame will be invalid.
*/
finish_task_switch(this_rq(), prev);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
}
/*
* nr_running, nr_uninterruptible and nr_context_switches:
*
* externally visible scheduler statistics: current number of runnable
* threads, current number of uninterruptible-sleeping threads, total
* number of context switches performed since bootup.
*/
unsigned long nr_running(void)
{
unsigned long i, sum = 0;
for_each_online_cpu(i)
sum += cpu_rq(i)->nr_running;
return sum;
sched: Nominate idle load balancer from a semi-idle package. Currently the nomination of idle-load balancer is done by choosing the first idle cpu in the nohz.cpu_mask. This may not be power-efficient, since such an idle cpu could come from a completely idle core/package thereby preventing the whole core/package from being in a low-power state. For eg, consider a quad-core dual package system. The cpu numbering need not be sequential and can something like [0, 2, 4, 6] and [1, 3, 5, 7]. With sched_mc/smt_power_savings and the power-aware IRQ balance, we try to keep as fewer Packages/Cores active. But the current idle load balancer logic goes against this by choosing the first_cpu in the nohz.cpu_mask and not taking the system topology into consideration. Improve the algorithm to nominate the idle load balancer from a semi idle cores/packages thereby increasing the probability of the cores/packages being in deeper sleep states for longer duration. The algorithm is activated only when sched_mc/smt_power_savings != 0. Signed-off-by: Gautham R Shenoy <ego@in.ibm.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20090414045530.7645.12175.stgit@sofia.in.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-14 04:55:30 +00:00
}
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
unsigned long nr_uninterruptible(void)
sched: Nominate idle load balancer from a semi-idle package. Currently the nomination of idle-load balancer is done by choosing the first idle cpu in the nohz.cpu_mask. This may not be power-efficient, since such an idle cpu could come from a completely idle core/package thereby preventing the whole core/package from being in a low-power state. For eg, consider a quad-core dual package system. The cpu numbering need not be sequential and can something like [0, 2, 4, 6] and [1, 3, 5, 7]. With sched_mc/smt_power_savings and the power-aware IRQ balance, we try to keep as fewer Packages/Cores active. But the current idle load balancer logic goes against this by choosing the first_cpu in the nohz.cpu_mask and not taking the system topology into consideration. Improve the algorithm to nominate the idle load balancer from a semi idle cores/packages thereby increasing the probability of the cores/packages being in deeper sleep states for longer duration. The algorithm is activated only when sched_mc/smt_power_savings != 0. Signed-off-by: Gautham R Shenoy <ego@in.ibm.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20090414045530.7645.12175.stgit@sofia.in.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-14 04:55:30 +00:00
{
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
unsigned long i, sum = 0;
sched: Nominate idle load balancer from a semi-idle package. Currently the nomination of idle-load balancer is done by choosing the first idle cpu in the nohz.cpu_mask. This may not be power-efficient, since such an idle cpu could come from a completely idle core/package thereby preventing the whole core/package from being in a low-power state. For eg, consider a quad-core dual package system. The cpu numbering need not be sequential and can something like [0, 2, 4, 6] and [1, 3, 5, 7]. With sched_mc/smt_power_savings and the power-aware IRQ balance, we try to keep as fewer Packages/Cores active. But the current idle load balancer logic goes against this by choosing the first_cpu in the nohz.cpu_mask and not taking the system topology into consideration. Improve the algorithm to nominate the idle load balancer from a semi idle cores/packages thereby increasing the probability of the cores/packages being in deeper sleep states for longer duration. The algorithm is activated only when sched_mc/smt_power_savings != 0. Signed-off-by: Gautham R Shenoy <ego@in.ibm.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20090414045530.7645.12175.stgit@sofia.in.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-14 04:55:30 +00:00
[PATCH] for_each_possible_cpu: fixes for generic part replaces for_each_cpu with for_each_possible_cpu(). Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-28 09:56:37 +00:00
for_each_possible_cpu(i)
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
sum += cpu_rq(i)->nr_uninterruptible;
sched: Nominate idle load balancer from a semi-idle package. Currently the nomination of idle-load balancer is done by choosing the first idle cpu in the nohz.cpu_mask. This may not be power-efficient, since such an idle cpu could come from a completely idle core/package thereby preventing the whole core/package from being in a low-power state. For eg, consider a quad-core dual package system. The cpu numbering need not be sequential and can something like [0, 2, 4, 6] and [1, 3, 5, 7]. With sched_mc/smt_power_savings and the power-aware IRQ balance, we try to keep as fewer Packages/Cores active. But the current idle load balancer logic goes against this by choosing the first_cpu in the nohz.cpu_mask and not taking the system topology into consideration. Improve the algorithm to nominate the idle load balancer from a semi idle cores/packages thereby increasing the probability of the cores/packages being in deeper sleep states for longer duration. The algorithm is activated only when sched_mc/smt_power_savings != 0. Signed-off-by: Gautham R Shenoy <ego@in.ibm.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20090414045530.7645.12175.stgit@sofia.in.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-14 04:55:30 +00:00
/*
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
* Since we read the counters lockless, it might be slightly
* inaccurate. Do not allow it to go below zero though:
sched: Nominate idle load balancer from a semi-idle package. Currently the nomination of idle-load balancer is done by choosing the first idle cpu in the nohz.cpu_mask. This may not be power-efficient, since such an idle cpu could come from a completely idle core/package thereby preventing the whole core/package from being in a low-power state. For eg, consider a quad-core dual package system. The cpu numbering need not be sequential and can something like [0, 2, 4, 6] and [1, 3, 5, 7]. With sched_mc/smt_power_savings and the power-aware IRQ balance, we try to keep as fewer Packages/Cores active. But the current idle load balancer logic goes against this by choosing the first_cpu in the nohz.cpu_mask and not taking the system topology into consideration. Improve the algorithm to nominate the idle load balancer from a semi idle cores/packages thereby increasing the probability of the cores/packages being in deeper sleep states for longer duration. The algorithm is activated only when sched_mc/smt_power_savings != 0. Signed-off-by: Gautham R Shenoy <ego@in.ibm.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20090414045530.7645.12175.stgit@sofia.in.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-14 04:55:30 +00:00
*/
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
if (unlikely((long)sum < 0))
sum = 0;
sched: Nominate idle load balancer from a semi-idle package. Currently the nomination of idle-load balancer is done by choosing the first idle cpu in the nohz.cpu_mask. This may not be power-efficient, since such an idle cpu could come from a completely idle core/package thereby preventing the whole core/package from being in a low-power state. For eg, consider a quad-core dual package system. The cpu numbering need not be sequential and can something like [0, 2, 4, 6] and [1, 3, 5, 7]. With sched_mc/smt_power_savings and the power-aware IRQ balance, we try to keep as fewer Packages/Cores active. But the current idle load balancer logic goes against this by choosing the first_cpu in the nohz.cpu_mask and not taking the system topology into consideration. Improve the algorithm to nominate the idle load balancer from a semi idle cores/packages thereby increasing the probability of the cores/packages being in deeper sleep states for longer duration. The algorithm is activated only when sched_mc/smt_power_savings != 0. Signed-off-by: Gautham R Shenoy <ego@in.ibm.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20090414045530.7645.12175.stgit@sofia.in.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-14 04:55:30 +00:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
return sum;
sched: Nominate idle load balancer from a semi-idle package. Currently the nomination of idle-load balancer is done by choosing the first idle cpu in the nohz.cpu_mask. This may not be power-efficient, since such an idle cpu could come from a completely idle core/package thereby preventing the whole core/package from being in a low-power state. For eg, consider a quad-core dual package system. The cpu numbering need not be sequential and can something like [0, 2, 4, 6] and [1, 3, 5, 7]. With sched_mc/smt_power_savings and the power-aware IRQ balance, we try to keep as fewer Packages/Cores active. But the current idle load balancer logic goes against this by choosing the first_cpu in the nohz.cpu_mask and not taking the system topology into consideration. Improve the algorithm to nominate the idle load balancer from a semi idle cores/packages thereby increasing the probability of the cores/packages being in deeper sleep states for longer duration. The algorithm is activated only when sched_mc/smt_power_savings != 0. Signed-off-by: Gautham R Shenoy <ego@in.ibm.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20090414045530.7645.12175.stgit@sofia.in.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-14 04:55:30 +00:00
}
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
unsigned long long nr_context_switches(void)
sched: dynticks idle load balancing Fix the process idle load balancing in the presence of dynticks. cpus for which ticks are stopped will sleep till the next event wakes it up. Potentially these sleeps can be for large durations and during which today, there is no periodic idle load balancing being done. This patch nominates an owner among the idle cpus, which does the idle load balancing on behalf of the other idle cpus. And once all the cpus are completely idle, then we can stop this idle load balancing too. Checks added in fast path are minimized. Whenever there are busy cpus in the system, there will be an owner(idle cpu) doing the system wide idle load balancing. Open items: 1. Intelligent owner selection (like an idle core in a busy package). 2. Merge with rcu's nohz_cpu_mask? Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-08 07:32:51 +00:00
{
[PATCH] unnecessary long index i in sched Unless we expect to have more than 2G CPUs, there's no reason to have 'i' as a long long here. Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 09:54:31 +00:00
int i;
unsigned long long sum = 0;
sched: dynticks idle load balancing Fix the process idle load balancing in the presence of dynticks. cpus for which ticks are stopped will sleep till the next event wakes it up. Potentially these sleeps can be for large durations and during which today, there is no periodic idle load balancing being done. This patch nominates an owner among the idle cpus, which does the idle load balancing on behalf of the other idle cpus. And once all the cpus are completely idle, then we can stop this idle load balancing too. Checks added in fast path are minimized. Whenever there are busy cpus in the system, there will be an owner(idle cpu) doing the system wide idle load balancing. Open items: 1. Intelligent owner selection (like an idle core in a busy package). 2. Merge with rcu's nohz_cpu_mask? Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-08 07:32:51 +00:00
[PATCH] for_each_possible_cpu: fixes for generic part replaces for_each_cpu with for_each_possible_cpu(). Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-28 09:56:37 +00:00
for_each_possible_cpu(i)
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
sum += cpu_rq(i)->nr_switches;
sched: dynticks idle load balancing Fix the process idle load balancing in the presence of dynticks. cpus for which ticks are stopped will sleep till the next event wakes it up. Potentially these sleeps can be for large durations and during which today, there is no periodic idle load balancing being done. This patch nominates an owner among the idle cpus, which does the idle load balancing on behalf of the other idle cpus. And once all the cpus are completely idle, then we can stop this idle load balancing too. Checks added in fast path are minimized. Whenever there are busy cpus in the system, there will be an owner(idle cpu) doing the system wide idle load balancing. Open items: 1. Intelligent owner selection (like an idle core in a busy package). 2. Merge with rcu's nohz_cpu_mask? Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-08 07:32:51 +00:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
return sum;
}
sched: fix nohz load balancer on cpu offline Christian Borntraeger reports: > After a logical cpu offline, even on a complete idle system, there > is one cpu with full ticks. It turns out that nohz.cpu_mask has the > the offlined cpu still set. > > In select_nohz_load_balancer() we check if the system is completely > idle to turn of load balancing. We compare cpu_online_map with > nohz.cpu_mask. Since cpu_online_map is updated on cpu unplug, > but nohz.cpu_mask is not, the check fails and the scheduler believes > that we need an "idle load balancer" even on a fully idle system. > Since the ilb cpu does not deactivate the timer tick this breaks NOHZ. Fix the select_nohz_load_balancer() to not set the nohz.cpu_mask while a cpu is going offline. Reported-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Tested-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-04 19:59:44 +00:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
unsigned long nr_iowait(void)
{
unsigned long i, sum = 0;
sched: fix nohz load balancer on cpu offline Christian Borntraeger reports: > After a logical cpu offline, even on a complete idle system, there > is one cpu with full ticks. It turns out that nohz.cpu_mask has the > the offlined cpu still set. > > In select_nohz_load_balancer() we check if the system is completely > idle to turn of load balancing. We compare cpu_online_map with > nohz.cpu_mask. Since cpu_online_map is updated on cpu unplug, > but nohz.cpu_mask is not, the check fails and the scheduler believes > that we need an "idle load balancer" even on a fully idle system. > Since the ilb cpu does not deactivate the timer tick this breaks NOHZ. Fix the select_nohz_load_balancer() to not set the nohz.cpu_mask while a cpu is going offline. Reported-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Tested-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-04 19:59:44 +00:00
[PATCH] for_each_possible_cpu: fixes for generic part replaces for_each_cpu with for_each_possible_cpu(). Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-28 09:56:37 +00:00
for_each_possible_cpu(i)
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
sum += atomic_read(&cpu_rq(i)->nr_iowait);
sched: dynticks idle load balancing Fix the process idle load balancing in the presence of dynticks. cpus for which ticks are stopped will sleep till the next event wakes it up. Potentially these sleeps can be for large durations and during which today, there is no periodic idle load balancing being done. This patch nominates an owner among the idle cpus, which does the idle load balancing on behalf of the other idle cpus. And once all the cpus are completely idle, then we can stop this idle load balancing too. Checks added in fast path are minimized. Whenever there are busy cpus in the system, there will be an owner(idle cpu) doing the system wide idle load balancing. Open items: 1. Intelligent owner selection (like an idle core in a busy package). 2. Merge with rcu's nohz_cpu_mask? Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-08 07:32:51 +00:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
return sum;
}
sched: fix nohz load balancer on cpu offline Christian Borntraeger reports: > After a logical cpu offline, even on a complete idle system, there > is one cpu with full ticks. It turns out that nohz.cpu_mask has the > the offlined cpu still set. > > In select_nohz_load_balancer() we check if the system is completely > idle to turn of load balancing. We compare cpu_online_map with > nohz.cpu_mask. Since cpu_online_map is updated on cpu unplug, > but nohz.cpu_mask is not, the check fails and the scheduler believes > that we need an "idle load balancer" even on a fully idle system. > Since the ilb cpu does not deactivate the timer tick this breaks NOHZ. Fix the select_nohz_load_balancer() to not set the nohz.cpu_mask while a cpu is going offline. Reported-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Tested-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-04 19:59:44 +00:00
sched: Cure nr_iowait_cpu() users Commit 0224cf4c5e (sched: Intoduce get_cpu_iowait_time_us()) broke things by not making sure preemption was indeed disabled by the callers of nr_iowait_cpu() which took the iowait value of the current cpu. This resulted in a heap of preempt warnings. Cure this by making nr_iowait_cpu() take a cpu number and fix up the callers to pass in the right number. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Arjan van de Ven <arjan@infradead.org> Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Rafael J. Wysocki <rjw@sisk.pl> Cc: Maxim Levitsky <maximlevitsky@gmail.com> Cc: Len Brown <len.brown@intel.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: Jiri Slaby <jslaby@suse.cz> Cc: linux-pm@lists.linux-foundation.org LKML-Reference: <1277968037.1868.120.camel@laptop> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-07-01 07:07:17 +00:00
unsigned long nr_iowait_cpu(int cpu)
cpuidle: fix the menu governor to boost IO performance Fix the menu idle governor which balances power savings, energy efficiency and performance impact. The reason for a reworked governor is that there have been serious performance issues reported with the existing code on Nehalem server systems. To show this I'm sure Andrew wants to see benchmark results: (benchmark is "fio", "no cstates" is using "idle=poll") no cstates current linux new algorithm 1 disk 107 Mb/s 85 Mb/s 105 Mb/s 2 disks 215 Mb/s 123 Mb/s 209 Mb/s 12 disks 590 Mb/s 320 Mb/s 585 Mb/s In various power benchmark measurements, no degredation was found by our measurement&diagnostics team. Obviously a small percentage more power was used in the "fio" benchmark, due to the much higher performance. While it would be a novel idea to describe the new algorithm in this commit message, I cheaped out and described it in comments in the code instead. [changes since first post: spelling fixes from akpm, review feedback, folded menu-tng into menu.c] Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Cc: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Cc: Len Brown <lenb@kernel.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Yanmin Zhang <yanmin_zhang@linux.intel.com> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-22 00:04:08 +00:00
{
sched: Cure nr_iowait_cpu() users Commit 0224cf4c5e (sched: Intoduce get_cpu_iowait_time_us()) broke things by not making sure preemption was indeed disabled by the callers of nr_iowait_cpu() which took the iowait value of the current cpu. This resulted in a heap of preempt warnings. Cure this by making nr_iowait_cpu() take a cpu number and fix up the callers to pass in the right number. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Arjan van de Ven <arjan@infradead.org> Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Rafael J. Wysocki <rjw@sisk.pl> Cc: Maxim Levitsky <maximlevitsky@gmail.com> Cc: Len Brown <len.brown@intel.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: Jiri Slaby <jslaby@suse.cz> Cc: linux-pm@lists.linux-foundation.org LKML-Reference: <1277968037.1868.120.camel@laptop> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-07-01 07:07:17 +00:00
struct rq *this = cpu_rq(cpu);
cpuidle: fix the menu governor to boost IO performance Fix the menu idle governor which balances power savings, energy efficiency and performance impact. The reason for a reworked governor is that there have been serious performance issues reported with the existing code on Nehalem server systems. To show this I'm sure Andrew wants to see benchmark results: (benchmark is "fio", "no cstates" is using "idle=poll") no cstates current linux new algorithm 1 disk 107 Mb/s 85 Mb/s 105 Mb/s 2 disks 215 Mb/s 123 Mb/s 209 Mb/s 12 disks 590 Mb/s 320 Mb/s 585 Mb/s In various power benchmark measurements, no degredation was found by our measurement&diagnostics team. Obviously a small percentage more power was used in the "fio" benchmark, due to the much higher performance. While it would be a novel idea to describe the new algorithm in this commit message, I cheaped out and described it in comments in the code instead. [changes since first post: spelling fixes from akpm, review feedback, folded menu-tng into menu.c] Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Cc: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Cc: Len Brown <lenb@kernel.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Yanmin Zhang <yanmin_zhang@linux.intel.com> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-22 00:04:08 +00:00
return atomic_read(&this->nr_iowait);
}
sched: dynticks idle load balancing Fix the process idle load balancing in the presence of dynticks. cpus for which ticks are stopped will sleep till the next event wakes it up. Potentially these sleeps can be for large durations and during which today, there is no periodic idle load balancing being done. This patch nominates an owner among the idle cpus, which does the idle load balancing on behalf of the other idle cpus. And once all the cpus are completely idle, then we can stop this idle load balancing too. Checks added in fast path are minimized. Whenever there are busy cpus in the system, there will be an owner(idle cpu) doing the system wide idle load balancing. Open items: 1. Intelligent owner selection (like an idle core in a busy package). 2. Merge with rcu's nohz_cpu_mask? Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-08 07:32:51 +00:00
cpuidle: fix the menu governor to boost IO performance Fix the menu idle governor which balances power savings, energy efficiency and performance impact. The reason for a reworked governor is that there have been serious performance issues reported with the existing code on Nehalem server systems. To show this I'm sure Andrew wants to see benchmark results: (benchmark is "fio", "no cstates" is using "idle=poll") no cstates current linux new algorithm 1 disk 107 Mb/s 85 Mb/s 105 Mb/s 2 disks 215 Mb/s 123 Mb/s 209 Mb/s 12 disks 590 Mb/s 320 Mb/s 585 Mb/s In various power benchmark measurements, no degredation was found by our measurement&diagnostics team. Obviously a small percentage more power was used in the "fio" benchmark, due to the much higher performance. While it would be a novel idea to describe the new algorithm in this commit message, I cheaped out and described it in comments in the code instead. [changes since first post: spelling fixes from akpm, review feedback, folded menu-tng into menu.c] Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Cc: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Cc: Len Brown <lenb@kernel.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Yanmin Zhang <yanmin_zhang@linux.intel.com> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-22 00:04:08 +00:00
unsigned long this_cpu_load(void)
{
struct rq *this = this_rq();
return this->cpu_load[0];
}
sched: Nominate a power-efficient ilb in select_nohz_balancer() The CPU that first goes idle becomes the idle-load-balancer and remains that until either it picks up a task or till all the CPUs of the system goes idle. Optimize this further to allow it to relinquish it's post once all it's siblings in the power-aware sched_domain go idle, thereby allowing the whole package-core to go idle. While relinquising the post, nominate another an idle-load balancer from a semi-idle core/package. Signed-off-by: Gautham R Shenoy <ego@in.ibm.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20090414045535.7645.31641.stgit@sofia.in.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-14 04:55:35 +00:00
sched: dynticks idle load balancing Fix the process idle load balancing in the presence of dynticks. cpus for which ticks are stopped will sleep till the next event wakes it up. Potentially these sleeps can be for large durations and during which today, there is no periodic idle load balancing being done. This patch nominates an owner among the idle cpus, which does the idle load balancing on behalf of the other idle cpus. And once all the cpus are completely idle, then we can stop this idle load balancing too. Checks added in fast path are minimized. Whenever there are busy cpus in the system, there will be an owner(idle cpu) doing the system wide idle load balancing. Open items: 1. Intelligent owner selection (like an idle core in a busy package). 2. Merge with rcu's nohz_cpu_mask? Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-08 07:32:51 +00:00
sched, timers: move calc_load() to scheduler Dimitri Sivanich noticed that xtime_lock is held write locked across calc_load() which iterates over all online CPUs. That can cause long latencies for xtime_lock readers on large SMP systems. The load average calculation is an rough estimate anyway so there is no real need to protect the readers vs. the update. It's not a problem when the avenrun array is updated while a reader copies the values. Instead of iterating over all online CPUs let the scheduler_tick code update the number of active tasks shortly before the avenrun update happens. The avenrun update itself is handled by the CPU which calls do_timer(). [ Impact: reduce xtime_lock write locked section ] Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org>
2009-04-11 08:43:41 +00:00
/* Variables and functions for calc_load */
static atomic_long_t calc_load_tasks;
static unsigned long calc_load_update;
unsigned long avenrun[3];
EXPORT_SYMBOL(avenrun);
sched: dynticks idle load balancing Fix the process idle load balancing in the presence of dynticks. cpus for which ticks are stopped will sleep till the next event wakes it up. Potentially these sleeps can be for large durations and during which today, there is no periodic idle load balancing being done. This patch nominates an owner among the idle cpus, which does the idle load balancing on behalf of the other idle cpus. And once all the cpus are completely idle, then we can stop this idle load balancing too. Checks added in fast path are minimized. Whenever there are busy cpus in the system, there will be an owner(idle cpu) doing the system wide idle load balancing. Open items: 1. Intelligent owner selection (like an idle core in a busy package). 2. Merge with rcu's nohz_cpu_mask? Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-08 07:32:51 +00:00
sched: Cure load average vs NO_HZ woes Chase reported that due to us decrementing calc_load_task prematurely (before the next LOAD_FREQ sample), the load average could be scewed by as much as the number of CPUs in the machine. This patch, based on Chase's patch, cures the problem by keeping the delta of the CPU going into NO_HZ idle separately and folding that in on the next LOAD_FREQ update. This restores the balance and we get strict LOAD_FREQ period samples. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Chase Douglas <chase.douglas@canonical.com> LKML-Reference: <1271934490.1776.343.camel@laptop> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-04-22 19:50:19 +00:00
static long calc_load_fold_active(struct rq *this_rq)
{
long nr_active, delta = 0;
nr_active = this_rq->nr_running;
nr_active += (long) this_rq->nr_uninterruptible;
if (nr_active != this_rq->calc_load_active) {
delta = nr_active - this_rq->calc_load_active;
this_rq->calc_load_active = nr_active;
}
return delta;
}
sched: Cure more NO_HZ load average woes There's a long-running regression that proved difficult to fix and which is hitting certain people and is rather annoying in its effects. Damien reported that after 74f5187ac8 (sched: Cure load average vs NO_HZ woes) his load average is unnaturally high, he also noted that even with that patch reverted the load avgerage numbers are not correct. The problem is that the previous patch only solved half the NO_HZ problem, it addressed the part of going into NO_HZ mode, not of comming out of NO_HZ mode. This patch implements that missing half. When comming out of NO_HZ mode there are two important things to take care of: - Folding the pending idle delta into the global active count. - Correctly aging the averages for the idle-duration. So with this patch the NO_HZ interaction should be complete and behaviour between CONFIG_NO_HZ=[yn] should be equivalent. Furthermore, this patch slightly changes the load average computation by adding a rounding term to the fixed point multiplication. Reported-by: Damien Wyart <damien.wyart@free.fr> Reported-by: Tim McGrath <tmhikaru@gmail.com> Tested-by: Damien Wyart <damien.wyart@free.fr> Tested-by: Orion Poplawski <orion@cora.nwra.com> Tested-by: Kyle McMartin <kyle@mcmartin.ca> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: stable@kernel.org Cc: Chase Douglas <chase.douglas@canonical.com> LKML-Reference: <1291129145.32004.874.camel@laptop> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-30 18:48:45 +00:00
static unsigned long
calc_load(unsigned long load, unsigned long exp, unsigned long active)
{
load *= exp;
load += active * (FIXED_1 - exp);
load += 1UL << (FSHIFT - 1);
return load >> FSHIFT;
}
sched: Cure load average vs NO_HZ woes Chase reported that due to us decrementing calc_load_task prematurely (before the next LOAD_FREQ sample), the load average could be scewed by as much as the number of CPUs in the machine. This patch, based on Chase's patch, cures the problem by keeping the delta of the CPU going into NO_HZ idle separately and folding that in on the next LOAD_FREQ update. This restores the balance and we get strict LOAD_FREQ period samples. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Chase Douglas <chase.douglas@canonical.com> LKML-Reference: <1271934490.1776.343.camel@laptop> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-04-22 19:50:19 +00:00
#ifdef CONFIG_NO_HZ
/*
* For NO_HZ we delay the active fold to the next LOAD_FREQ update.
*
* When making the ILB scale, we should try to pull this in as well.
*/
static atomic_long_t calc_load_tasks_idle;
static void calc_load_account_idle(struct rq *this_rq)
{
long delta;
delta = calc_load_fold_active(this_rq);
if (delta)
atomic_long_add(delta, &calc_load_tasks_idle);
}
static long calc_load_fold_idle(void)
{
long delta = 0;
/*
* Its got a race, we don't care...
*/
if (atomic_long_read(&calc_load_tasks_idle))
delta = atomic_long_xchg(&calc_load_tasks_idle, 0);
return delta;
}
sched: Cure more NO_HZ load average woes There's a long-running regression that proved difficult to fix and which is hitting certain people and is rather annoying in its effects. Damien reported that after 74f5187ac8 (sched: Cure load average vs NO_HZ woes) his load average is unnaturally high, he also noted that even with that patch reverted the load avgerage numbers are not correct. The problem is that the previous patch only solved half the NO_HZ problem, it addressed the part of going into NO_HZ mode, not of comming out of NO_HZ mode. This patch implements that missing half. When comming out of NO_HZ mode there are two important things to take care of: - Folding the pending idle delta into the global active count. - Correctly aging the averages for the idle-duration. So with this patch the NO_HZ interaction should be complete and behaviour between CONFIG_NO_HZ=[yn] should be equivalent. Furthermore, this patch slightly changes the load average computation by adding a rounding term to the fixed point multiplication. Reported-by: Damien Wyart <damien.wyart@free.fr> Reported-by: Tim McGrath <tmhikaru@gmail.com> Tested-by: Damien Wyart <damien.wyart@free.fr> Tested-by: Orion Poplawski <orion@cora.nwra.com> Tested-by: Kyle McMartin <kyle@mcmartin.ca> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: stable@kernel.org Cc: Chase Douglas <chase.douglas@canonical.com> LKML-Reference: <1291129145.32004.874.camel@laptop> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-30 18:48:45 +00:00
/**
* fixed_power_int - compute: x^n, in O(log n) time
*
* @x: base of the power
* @frac_bits: fractional bits of @x
* @n: power to raise @x to.
*
* By exploiting the relation between the definition of the natural power
* function: x^n := x*x*...*x (x multiplied by itself for n times), and
* the binary encoding of numbers used by computers: n := \Sum n_i * 2^i,
* (where: n_i \elem {0, 1}, the binary vector representing n),
* we find: x^n := x^(\Sum n_i * 2^i) := \Prod x^(n_i * 2^i), which is
* of course trivially computable in O(log_2 n), the length of our binary
* vector.
*/
static unsigned long
fixed_power_int(unsigned long x, unsigned int frac_bits, unsigned int n)
{
unsigned long result = 1UL << frac_bits;
if (n) for (;;) {
if (n & 1) {
result *= x;
result += 1UL << (frac_bits - 1);
result >>= frac_bits;
}
n >>= 1;
if (!n)
break;
x *= x;
x += 1UL << (frac_bits - 1);
x >>= frac_bits;
}
return result;
}
/*
* a1 = a0 * e + a * (1 - e)
*
* a2 = a1 * e + a * (1 - e)
* = (a0 * e + a * (1 - e)) * e + a * (1 - e)
* = a0 * e^2 + a * (1 - e) * (1 + e)
*
* a3 = a2 * e + a * (1 - e)
* = (a0 * e^2 + a * (1 - e) * (1 + e)) * e + a * (1 - e)
* = a0 * e^3 + a * (1 - e) * (1 + e + e^2)
*
* ...
*
* an = a0 * e^n + a * (1 - e) * (1 + e + ... + e^n-1) [1]
* = a0 * e^n + a * (1 - e) * (1 - e^n)/(1 - e)
* = a0 * e^n + a * (1 - e^n)
*
* [1] application of the geometric series:
*
* n 1 - x^(n+1)
* S_n := \Sum x^i = -------------
* i=0 1 - x
*/
static unsigned long
calc_load_n(unsigned long load, unsigned long exp,
unsigned long active, unsigned int n)
{
return calc_load(load, fixed_power_int(exp, FSHIFT, n), active);
}
/*
* NO_HZ can leave us missing all per-cpu ticks calling
* calc_load_account_active(), but since an idle CPU folds its delta into
* calc_load_tasks_idle per calc_load_account_idle(), all we need to do is fold
* in the pending idle delta if our idle period crossed a load cycle boundary.
*
* Once we've updated the global active value, we need to apply the exponential
* weights adjusted to the number of cycles missed.
*/
static void calc_global_nohz(unsigned long ticks)
{
long delta, active, n;
if (time_before(jiffies, calc_load_update))
return;
/*
* If we crossed a calc_load_update boundary, make sure to fold
* any pending idle changes, the respective CPUs might have
* missed the tick driven calc_load_account_active() update
* due to NO_HZ.
*/
delta = calc_load_fold_idle();
if (delta)
atomic_long_add(delta, &calc_load_tasks);
/*
* If we were idle for multiple load cycles, apply them.
*/
if (ticks >= LOAD_FREQ) {
n = ticks / LOAD_FREQ;
active = atomic_long_read(&calc_load_tasks);
active = active > 0 ? active * FIXED_1 : 0;
avenrun[0] = calc_load_n(avenrun[0], EXP_1, active, n);
avenrun[1] = calc_load_n(avenrun[1], EXP_5, active, n);
avenrun[2] = calc_load_n(avenrun[2], EXP_15, active, n);
calc_load_update += n * LOAD_FREQ;
}
/*
* Its possible the remainder of the above division also crosses
* a LOAD_FREQ period, the regular check in calc_global_load()
* which comes after this will take care of that.
*
* Consider us being 11 ticks before a cycle completion, and us
* sleeping for 4*LOAD_FREQ + 22 ticks, then the above code will
* age us 4 cycles, and the test in calc_global_load() will
* pick up the final one.
*/
}
sched: Cure load average vs NO_HZ woes Chase reported that due to us decrementing calc_load_task prematurely (before the next LOAD_FREQ sample), the load average could be scewed by as much as the number of CPUs in the machine. This patch, based on Chase's patch, cures the problem by keeping the delta of the CPU going into NO_HZ idle separately and folding that in on the next LOAD_FREQ update. This restores the balance and we get strict LOAD_FREQ period samples. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Chase Douglas <chase.douglas@canonical.com> LKML-Reference: <1271934490.1776.343.camel@laptop> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-04-22 19:50:19 +00:00
#else
static void calc_load_account_idle(struct rq *this_rq)
{
}
static inline long calc_load_fold_idle(void)
{
return 0;
}
sched: Cure more NO_HZ load average woes There's a long-running regression that proved difficult to fix and which is hitting certain people and is rather annoying in its effects. Damien reported that after 74f5187ac8 (sched: Cure load average vs NO_HZ woes) his load average is unnaturally high, he also noted that even with that patch reverted the load avgerage numbers are not correct. The problem is that the previous patch only solved half the NO_HZ problem, it addressed the part of going into NO_HZ mode, not of comming out of NO_HZ mode. This patch implements that missing half. When comming out of NO_HZ mode there are two important things to take care of: - Folding the pending idle delta into the global active count. - Correctly aging the averages for the idle-duration. So with this patch the NO_HZ interaction should be complete and behaviour between CONFIG_NO_HZ=[yn] should be equivalent. Furthermore, this patch slightly changes the load average computation by adding a rounding term to the fixed point multiplication. Reported-by: Damien Wyart <damien.wyart@free.fr> Reported-by: Tim McGrath <tmhikaru@gmail.com> Tested-by: Damien Wyart <damien.wyart@free.fr> Tested-by: Orion Poplawski <orion@cora.nwra.com> Tested-by: Kyle McMartin <kyle@mcmartin.ca> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: stable@kernel.org Cc: Chase Douglas <chase.douglas@canonical.com> LKML-Reference: <1291129145.32004.874.camel@laptop> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-30 18:48:45 +00:00
static void calc_global_nohz(unsigned long ticks)
{
}
sched: Cure load average vs NO_HZ woes Chase reported that due to us decrementing calc_load_task prematurely (before the next LOAD_FREQ sample), the load average could be scewed by as much as the number of CPUs in the machine. This patch, based on Chase's patch, cures the problem by keeping the delta of the CPU going into NO_HZ idle separately and folding that in on the next LOAD_FREQ update. This restores the balance and we get strict LOAD_FREQ period samples. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Chase Douglas <chase.douglas@canonical.com> LKML-Reference: <1271934490.1776.343.camel@laptop> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-04-22 19:50:19 +00:00
#endif
sched, timers: cleanup avenrun users avenrun is an rough estimate so we don't have to worry about consistency of the three avenrun values. Remove the xtime lock dependency and provide a function to scale the values. Cleanup the users. [ Impact: cleanup ] Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org>
2009-05-02 18:08:52 +00:00
/**
* get_avenrun - get the load average array
* @loads: pointer to dest load array
* @offset: offset to add
* @shift: shift count to shift the result left
*
* These values are estimates at best, so no need for locking.
*/
void get_avenrun(unsigned long *loads, unsigned long offset, int shift)
{
loads[0] = (avenrun[0] + offset) << shift;
loads[1] = (avenrun[1] + offset) << shift;
loads[2] = (avenrun[2] + offset) << shift;
sched: dynticks idle load balancing Fix the process idle load balancing in the presence of dynticks. cpus for which ticks are stopped will sleep till the next event wakes it up. Potentially these sleeps can be for large durations and during which today, there is no periodic idle load balancing being done. This patch nominates an owner among the idle cpus, which does the idle load balancing on behalf of the other idle cpus. And once all the cpus are completely idle, then we can stop this idle load balancing too. Checks added in fast path are minimized. Whenever there are busy cpus in the system, there will be an owner(idle cpu) doing the system wide idle load balancing. Open items: 1. Intelligent owner selection (like an idle core in a busy package). 2. Merge with rcu's nohz_cpu_mask? Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-08 07:32:51 +00:00
}
/*
sched, timers: move calc_load() to scheduler Dimitri Sivanich noticed that xtime_lock is held write locked across calc_load() which iterates over all online CPUs. That can cause long latencies for xtime_lock readers on large SMP systems. The load average calculation is an rough estimate anyway so there is no real need to protect the readers vs. the update. It's not a problem when the avenrun array is updated while a reader copies the values. Instead of iterating over all online CPUs let the scheduler_tick code update the number of active tasks shortly before the avenrun update happens. The avenrun update itself is handled by the CPU which calls do_timer(). [ Impact: reduce xtime_lock write locked section ] Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org>
2009-04-11 08:43:41 +00:00
* calc_load - update the avenrun load estimates 10 ticks after the
* CPUs have updated calc_load_tasks.
[PATCH] sched: extract load calculation from rebalance_tick A load calculation is always done in rebalance_tick() in addition to the real load balancing activities that only take place when certain jiffie counts have been reached. Move that processing into a separate function and call it directly from scheduler_tick(). Also extract the time slice handling from scheduler_tick and put it into a separate function. Then we can clean up scheduler_tick significantly. It will no longer have any gotos. Signed-off-by: Christoph Lameter <clameter@sgi.com> Cc: Peter Williams <pwil3058@bigpond.net.au> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Christoph Lameter <clameter@sgi.com> Cc: "Siddha, Suresh B" <suresh.b.siddha@intel.com> Cc: "Chen, Kenneth W" <kenneth.w.chen@intel.com> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 10:20:22 +00:00
*/
sched: Cure more NO_HZ load average woes There's a long-running regression that proved difficult to fix and which is hitting certain people and is rather annoying in its effects. Damien reported that after 74f5187ac8 (sched: Cure load average vs NO_HZ woes) his load average is unnaturally high, he also noted that even with that patch reverted the load avgerage numbers are not correct. The problem is that the previous patch only solved half the NO_HZ problem, it addressed the part of going into NO_HZ mode, not of comming out of NO_HZ mode. This patch implements that missing half. When comming out of NO_HZ mode there are two important things to take care of: - Folding the pending idle delta into the global active count. - Correctly aging the averages for the idle-duration. So with this patch the NO_HZ interaction should be complete and behaviour between CONFIG_NO_HZ=[yn] should be equivalent. Furthermore, this patch slightly changes the load average computation by adding a rounding term to the fixed point multiplication. Reported-by: Damien Wyart <damien.wyart@free.fr> Reported-by: Tim McGrath <tmhikaru@gmail.com> Tested-by: Damien Wyart <damien.wyart@free.fr> Tested-by: Orion Poplawski <orion@cora.nwra.com> Tested-by: Kyle McMartin <kyle@mcmartin.ca> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: stable@kernel.org Cc: Chase Douglas <chase.douglas@canonical.com> LKML-Reference: <1291129145.32004.874.camel@laptop> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-30 18:48:45 +00:00
void calc_global_load(unsigned long ticks)
[PATCH] sched: extract load calculation from rebalance_tick A load calculation is always done in rebalance_tick() in addition to the real load balancing activities that only take place when certain jiffie counts have been reached. Move that processing into a separate function and call it directly from scheduler_tick(). Also extract the time slice handling from scheduler_tick and put it into a separate function. Then we can clean up scheduler_tick significantly. It will no longer have any gotos. Signed-off-by: Christoph Lameter <clameter@sgi.com> Cc: Peter Williams <pwil3058@bigpond.net.au> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Christoph Lameter <clameter@sgi.com> Cc: "Siddha, Suresh B" <suresh.b.siddha@intel.com> Cc: "Chen, Kenneth W" <kenneth.w.chen@intel.com> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 10:20:22 +00:00
{
sched, timers: move calc_load() to scheduler Dimitri Sivanich noticed that xtime_lock is held write locked across calc_load() which iterates over all online CPUs. That can cause long latencies for xtime_lock readers on large SMP systems. The load average calculation is an rough estimate anyway so there is no real need to protect the readers vs. the update. It's not a problem when the avenrun array is updated while a reader copies the values. Instead of iterating over all online CPUs let the scheduler_tick code update the number of active tasks shortly before the avenrun update happens. The avenrun update itself is handled by the CPU which calls do_timer(). [ Impact: reduce xtime_lock write locked section ] Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org>
2009-04-11 08:43:41 +00:00
long active;
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
sched: Cure more NO_HZ load average woes There's a long-running regression that proved difficult to fix and which is hitting certain people and is rather annoying in its effects. Damien reported that after 74f5187ac8 (sched: Cure load average vs NO_HZ woes) his load average is unnaturally high, he also noted that even with that patch reverted the load avgerage numbers are not correct. The problem is that the previous patch only solved half the NO_HZ problem, it addressed the part of going into NO_HZ mode, not of comming out of NO_HZ mode. This patch implements that missing half. When comming out of NO_HZ mode there are two important things to take care of: - Folding the pending idle delta into the global active count. - Correctly aging the averages for the idle-duration. So with this patch the NO_HZ interaction should be complete and behaviour between CONFIG_NO_HZ=[yn] should be equivalent. Furthermore, this patch slightly changes the load average computation by adding a rounding term to the fixed point multiplication. Reported-by: Damien Wyart <damien.wyart@free.fr> Reported-by: Tim McGrath <tmhikaru@gmail.com> Tested-by: Damien Wyart <damien.wyart@free.fr> Tested-by: Orion Poplawski <orion@cora.nwra.com> Tested-by: Kyle McMartin <kyle@mcmartin.ca> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: stable@kernel.org Cc: Chase Douglas <chase.douglas@canonical.com> LKML-Reference: <1291129145.32004.874.camel@laptop> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-30 18:48:45 +00:00
calc_global_nohz(ticks);
if (time_before(jiffies, calc_load_update + 10))
sched, timers: move calc_load() to scheduler Dimitri Sivanich noticed that xtime_lock is held write locked across calc_load() which iterates over all online CPUs. That can cause long latencies for xtime_lock readers on large SMP systems. The load average calculation is an rough estimate anyway so there is no real need to protect the readers vs. the update. It's not a problem when the avenrun array is updated while a reader copies the values. Instead of iterating over all online CPUs let the scheduler_tick code update the number of active tasks shortly before the avenrun update happens. The avenrun update itself is handled by the CPU which calls do_timer(). [ Impact: reduce xtime_lock write locked section ] Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org>
2009-04-11 08:43:41 +00:00
return;
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
sched, timers: move calc_load() to scheduler Dimitri Sivanich noticed that xtime_lock is held write locked across calc_load() which iterates over all online CPUs. That can cause long latencies for xtime_lock readers on large SMP systems. The load average calculation is an rough estimate anyway so there is no real need to protect the readers vs. the update. It's not a problem when the avenrun array is updated while a reader copies the values. Instead of iterating over all online CPUs let the scheduler_tick code update the number of active tasks shortly before the avenrun update happens. The avenrun update itself is handled by the CPU which calls do_timer(). [ Impact: reduce xtime_lock write locked section ] Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org>
2009-04-11 08:43:41 +00:00
active = atomic_long_read(&calc_load_tasks);
active = active > 0 ? active * FIXED_1 : 0;
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
sched, timers: move calc_load() to scheduler Dimitri Sivanich noticed that xtime_lock is held write locked across calc_load() which iterates over all online CPUs. That can cause long latencies for xtime_lock readers on large SMP systems. The load average calculation is an rough estimate anyway so there is no real need to protect the readers vs. the update. It's not a problem when the avenrun array is updated while a reader copies the values. Instead of iterating over all online CPUs let the scheduler_tick code update the number of active tasks shortly before the avenrun update happens. The avenrun update itself is handled by the CPU which calls do_timer(). [ Impact: reduce xtime_lock write locked section ] Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org>
2009-04-11 08:43:41 +00:00
avenrun[0] = calc_load(avenrun[0], EXP_1, active);
avenrun[1] = calc_load(avenrun[1], EXP_5, active);
avenrun[2] = calc_load(avenrun[2], EXP_15, active);
sched: cfs core code apply the CFS core code. this change switches over the scheduler core to CFS's modular design and makes use of kernel/sched_fair/rt/idletask.c to implement Linux's scheduling policies. thanks to Andrew Morton and Thomas Gleixner for lots of detailed review feedback and for fixlets. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
2007-07-09 16:51:59 +00:00
sched, timers: move calc_load() to scheduler Dimitri Sivanich noticed that xtime_lock is held write locked across calc_load() which iterates over all online CPUs. That can cause long latencies for xtime_lock readers on large SMP systems. The load average calculation is an rough estimate anyway so there is no real need to protect the readers vs. the update. It's not a problem when the avenrun array is updated while a reader copies the values. Instead of iterating over all online CPUs let the scheduler_tick code update the number of active tasks shortly before the avenrun update happens. The avenrun update itself is handled by the CPU which calls do_timer(). [ Impact: reduce xtime_lock write locked section ] Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org>
2009-04-11 08:43:41 +00:00
calc_load_update += LOAD_FREQ;
}
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
sched, timers: move calc_load() to scheduler Dimitri Sivanich noticed that xtime_lock is held write locked across calc_load() which iterates over all online CPUs. That can cause long latencies for xtime_lock readers on large SMP systems. The load average calculation is an rough estimate anyway so there is no real need to protect the readers vs. the update. It's not a problem when the avenrun array is updated while a reader copies the values. Instead of iterating over all online CPUs let the scheduler_tick code update the number of active tasks shortly before the avenrun update happens. The avenrun update itself is handled by the CPU which calls do_timer(). [ Impact: reduce xtime_lock write locked section ] Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org>
2009-04-11 08:43:41 +00:00
/*
sched: Cure load average vs NO_HZ woes Chase reported that due to us decrementing calc_load_task prematurely (before the next LOAD_FREQ sample), the load average could be scewed by as much as the number of CPUs in the machine. This patch, based on Chase's patch, cures the problem by keeping the delta of the CPU going into NO_HZ idle separately and folding that in on the next LOAD_FREQ update. This restores the balance and we get strict LOAD_FREQ period samples. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Chase Douglas <chase.douglas@canonical.com> LKML-Reference: <1271934490.1776.343.camel@laptop> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-04-22 19:50:19 +00:00
* Called from update_cpu_load() to periodically update this CPU's
* active count.
sched, timers: move calc_load() to scheduler Dimitri Sivanich noticed that xtime_lock is held write locked across calc_load() which iterates over all online CPUs. That can cause long latencies for xtime_lock readers on large SMP systems. The load average calculation is an rough estimate anyway so there is no real need to protect the readers vs. the update. It's not a problem when the avenrun array is updated while a reader copies the values. Instead of iterating over all online CPUs let the scheduler_tick code update the number of active tasks shortly before the avenrun update happens. The avenrun update itself is handled by the CPU which calls do_timer(). [ Impact: reduce xtime_lock write locked section ] Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org>
2009-04-11 08:43:41 +00:00
*/
static void calc_load_account_active(struct rq *this_rq)
{
sched: Cure load average vs NO_HZ woes Chase reported that due to us decrementing calc_load_task prematurely (before the next LOAD_FREQ sample), the load average could be scewed by as much as the number of CPUs in the machine. This patch, based on Chase's patch, cures the problem by keeping the delta of the CPU going into NO_HZ idle separately and folding that in on the next LOAD_FREQ update. This restores the balance and we get strict LOAD_FREQ period samples. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Chase Douglas <chase.douglas@canonical.com> LKML-Reference: <1271934490.1776.343.camel@laptop> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-04-22 19:50:19 +00:00
long delta;
[PATCH] sched: add option to serialize load balancing Large sched domains can be very expensive to scan. Add an option SD_SERIALIZE to the sched domain flags. If that flag is set then we make sure that no other such domain is being balanced. [akpm@osdl.org: build fix] Signed-off-by: Christoph Lameter <clameter@sgi.com> Cc: Peter Williams <pwil3058@bigpond.net.au> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Christoph Lameter <clameter@sgi.com> Cc: "Siddha, Suresh B" <suresh.b.siddha@intel.com> Cc: "Chen, Kenneth W" <kenneth.w.chen@intel.com> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 10:20:29 +00:00
sched: Cure load average vs NO_HZ woes Chase reported that due to us decrementing calc_load_task prematurely (before the next LOAD_FREQ sample), the load average could be scewed by as much as the number of CPUs in the machine. This patch, based on Chase's patch, cures the problem by keeping the delta of the CPU going into NO_HZ idle separately and folding that in on the next LOAD_FREQ update. This restores the balance and we get strict LOAD_FREQ period samples. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Chase Douglas <chase.douglas@canonical.com> LKML-Reference: <1271934490.1776.343.camel@laptop> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-04-22 19:50:19 +00:00
if (time_before(jiffies, this_rq->calc_load_update))
return;
[PATCH] sched: decrease number of load balances Currently at a particular domain, each cpu in the sched group will do a load balance at the frequency of balance_interval. More the cores and threads, more the cpus will be in each sched group at SMP and NUMA domain. And we endup spending quite a bit of time doing load balancing in those domains. Fix this by making only one cpu(first idle cpu or first cpu in the group if all the cpus are busy) in the sched group do the load balance at that particular sched domain and this load will slowly percolate down to the other cpus with in that group(when they do load balancing at lower domains). Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Cc: Christoph Lameter <clameter@engr.sgi.com> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 10:20:33 +00:00
sched: Cure load average vs NO_HZ woes Chase reported that due to us decrementing calc_load_task prematurely (before the next LOAD_FREQ sample), the load average could be scewed by as much as the number of CPUs in the machine. This patch, based on Chase's patch, cures the problem by keeping the delta of the CPU going into NO_HZ idle separately and folding that in on the next LOAD_FREQ update. This restores the balance and we get strict LOAD_FREQ period samples. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Chase Douglas <chase.douglas@canonical.com> LKML-Reference: <1271934490.1776.343.camel@laptop> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-04-22 19:50:19 +00:00
delta = calc_load_fold_active(this_rq);
delta += calc_load_fold_idle();
if (delta)
sched, timers: move calc_load() to scheduler Dimitri Sivanich noticed that xtime_lock is held write locked across calc_load() which iterates over all online CPUs. That can cause long latencies for xtime_lock readers on large SMP systems. The load average calculation is an rough estimate anyway so there is no real need to protect the readers vs. the update. It's not a problem when the avenrun array is updated while a reader copies the values. Instead of iterating over all online CPUs let the scheduler_tick code update the number of active tasks shortly before the avenrun update happens. The avenrun update itself is handled by the CPU which calls do_timer(). [ Impact: reduce xtime_lock write locked section ] Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org>
2009-04-11 08:43:41 +00:00
atomic_long_add(delta, &calc_load_tasks);
sched: Cure load average vs NO_HZ woes Chase reported that due to us decrementing calc_load_task prematurely (before the next LOAD_FREQ sample), the load average could be scewed by as much as the number of CPUs in the machine. This patch, based on Chase's patch, cures the problem by keeping the delta of the CPU going into NO_HZ idle separately and folding that in on the next LOAD_FREQ update. This restores the balance and we get strict LOAD_FREQ period samples. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Chase Douglas <chase.douglas@canonical.com> LKML-Reference: <1271934490.1776.343.camel@laptop> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-04-22 19:50:19 +00:00
this_rq->calc_load_update += LOAD_FREQ;
sched: dynticks idle load balancing Fix the process idle load balancing in the presence of dynticks. cpus for which ticks are stopped will sleep till the next event wakes it up. Potentially these sleeps can be for large durations and during which today, there is no periodic idle load balancing being done. This patch nominates an owner among the idle cpus, which does the idle load balancing on behalf of the other idle cpus. And once all the cpus are completely idle, then we can stop this idle load balancing too. Checks added in fast path are minimized. Whenever there are busy cpus in the system, there will be an owner(idle cpu) doing the system wide idle load balancing. Open items: 1. Intelligent owner selection (like an idle core in a busy package). 2. Merge with rcu's nohz_cpu_mask? Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-08 07:32:51 +00:00
}
sched: Avoid side-effect of tickless idle on update_cpu_load tickless idle has a negative side effect on update_cpu_load(), which in turn can affect load balancing behavior. update_cpu_load() is supposed to be called every tick, to keep track of various load indicies. With tickless idle, there are no scheduler ticks called on the idle CPUs. Idle CPUs may still do load balancing (with idle_load_balance CPU) using the stale cpu_load. It will also cause problems when all CPUs go idle for a while and become active again. In this case loads would not degrade as expected. This is how rq->nr_load_updates change looks like under different conditions: <cpu_num> <nr_load_updates change> All CPUS idle for 10 seconds (HZ=1000) 0 1621 10 496 11 139 12 875 13 1672 14 12 15 21 1 1472 2 2426 3 1161 4 2108 5 1525 6 701 7 249 8 766 9 1967 One CPU busy rest idle for 10 seconds 0 10003 10 601 11 95 12 966 13 1597 14 114 15 98 1 3457 2 93 3 6679 4 1425 5 1479 6 595 7 193 8 633 9 1687 All CPUs busy for 10 seconds 0 10026 10 10026 11 10026 12 10026 13 10025 14 10025 15 10025 1 10026 2 10026 3 10026 4 10026 5 10026 6 10026 7 10026 8 10026 9 10026 That is update_cpu_load works properly only when all CPUs are busy. If all are idle, all the CPUs get way lower updates. And when few CPUs are busy and rest are idle, only busy and ilb CPU does proper updates and rest of the idle CPUs will do lower updates. The patch keeps track of when a last update was done and fixes up the load avg based on current time. On one of my test system SPECjbb with warehouse 1..numcpus, patch improves throughput numbers by ~1% (average of 6 runs). On another test system (with different domain hierarchy) there is no noticable change in perf. Signed-off-by: Venkatesh Pallipadi <venki@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Thomas Gleixner <tglx@linutronix.de> LKML-Reference: <AANLkTilLtDWQsAUrIxJ6s04WTgmw9GuOODc5AOrYsaR5@mail.gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-05-18 01:14:43 +00:00
/*
* The exact cpuload at various idx values, calculated at every tick would be
* load = (2^idx - 1) / 2^idx * load + 1 / 2^idx * cur_load
*
* If a cpu misses updates for n-1 ticks (as it was idle) and update gets called
* on nth tick when cpu may be busy, then we have:
* load = ((2^idx - 1) / 2^idx)^(n-1) * load
* load = (2^idx - 1) / 2^idx) * load + 1 / 2^idx * cur_load
*
* decay_load_missed() below does efficient calculation of
* load = ((2^idx - 1) / 2^idx)^(n-1) * load
* avoiding 0..n-1 loop doing load = ((2^idx - 1) / 2^idx) * load
*
* The calculation is approximated on a 128 point scale.
* degrade_zero_ticks is the number of ticks after which load at any
* particular idx is approximated to be zero.
* degrade_factor is a precomputed table, a row for each load idx.
* Each column corresponds to degradation factor for a power of two ticks,
* based on 128 point scale.
* Example:
* row 2, col 3 (=12) says that the degradation at load idx 2 after
* 8 ticks is 12/128 (which is an approximation of exact factor 3^8/4^8).
*
* With this power of 2 load factors, we can degrade the load n times
* by looking at 1 bits in n and doing as many mult/shift instead of
* n mult/shifts needed by the exact degradation.
*/
#define DEGRADE_SHIFT 7
static const unsigned char
degrade_zero_ticks[CPU_LOAD_IDX_MAX] = {0, 8, 32, 64, 128};
static const unsigned char
degrade_factor[CPU_LOAD_IDX_MAX][DEGRADE_SHIFT + 1] = {
{0, 0, 0, 0, 0, 0, 0, 0},
{64, 32, 8, 0, 0, 0, 0, 0},
{96, 72, 40, 12, 1, 0, 0},
{112, 98, 75, 43, 15, 1, 0},
{120, 112, 98, 76, 45, 16, 2} };
/*
* Update cpu_load for any missed ticks, due to tickless idle. The backlog
* would be when CPU is idle and so we just decay the old load without
* adding any new load.
*/
static unsigned long
decay_load_missed(unsigned long load, unsigned long missed_updates, int idx)
{
int j = 0;
if (!missed_updates)
return load;
if (missed_updates >= degrade_zero_ticks[idx])
return 0;
if (idx == 1)
return load >> missed_updates;
while (missed_updates) {
if (missed_updates % 2)
load = (load * degrade_factor[idx][j]) >> DEGRADE_SHIFT;
missed_updates >>= 1;
j++;
}
return load;
}
sched: dynticks idle load balancing Fix the process idle load balancing in the presence of dynticks. cpus for which ticks are stopped will sleep till the next event wakes it up. Potentially these sleeps can be for large durations and during which today, there is no periodic idle load balancing being done. This patch nominates an owner among the idle cpus, which does the idle load balancing on behalf of the other idle cpus. And once all the cpus are completely idle, then we can stop this idle load balancing too. Checks added in fast path are minimized. Whenever there are busy cpus in the system, there will be an owner(idle cpu) doing the system wide idle load balancing. Open items: 1. Intelligent owner selection (like an idle core in a busy package). 2. Merge with rcu's nohz_cpu_mask? Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-08 07:32:51 +00:00
/*
sched: cfs core code apply the CFS core code. this change switches over the scheduler core to CFS's modular design and makes use of kernel/sched_fair/rt/idletask.c to implement Linux's scheduling policies. thanks to Andrew Morton and Thomas Gleixner for lots of detailed review feedback and for fixlets. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
2007-07-09 16:51:59 +00:00
* Update rq->cpu_load[] statistics. This function is usually called every
sched: Avoid side-effect of tickless idle on update_cpu_load tickless idle has a negative side effect on update_cpu_load(), which in turn can affect load balancing behavior. update_cpu_load() is supposed to be called every tick, to keep track of various load indicies. With tickless idle, there are no scheduler ticks called on the idle CPUs. Idle CPUs may still do load balancing (with idle_load_balance CPU) using the stale cpu_load. It will also cause problems when all CPUs go idle for a while and become active again. In this case loads would not degrade as expected. This is how rq->nr_load_updates change looks like under different conditions: <cpu_num> <nr_load_updates change> All CPUS idle for 10 seconds (HZ=1000) 0 1621 10 496 11 139 12 875 13 1672 14 12 15 21 1 1472 2 2426 3 1161 4 2108 5 1525 6 701 7 249 8 766 9 1967 One CPU busy rest idle for 10 seconds 0 10003 10 601 11 95 12 966 13 1597 14 114 15 98 1 3457 2 93 3 6679 4 1425 5 1479 6 595 7 193 8 633 9 1687 All CPUs busy for 10 seconds 0 10026 10 10026 11 10026 12 10026 13 10025 14 10025 15 10025 1 10026 2 10026 3 10026 4 10026 5 10026 6 10026 7 10026 8 10026 9 10026 That is update_cpu_load works properly only when all CPUs are busy. If all are idle, all the CPUs get way lower updates. And when few CPUs are busy and rest are idle, only busy and ilb CPU does proper updates and rest of the idle CPUs will do lower updates. The patch keeps track of when a last update was done and fixes up the load avg based on current time. On one of my test system SPECjbb with warehouse 1..numcpus, patch improves throughput numbers by ~1% (average of 6 runs). On another test system (with different domain hierarchy) there is no noticable change in perf. Signed-off-by: Venkatesh Pallipadi <venki@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Thomas Gleixner <tglx@linutronix.de> LKML-Reference: <AANLkTilLtDWQsAUrIxJ6s04WTgmw9GuOODc5AOrYsaR5@mail.gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-05-18 01:14:43 +00:00
* scheduler tick (TICK_NSEC). With tickless idle this will not be called
* every tick. We fix it up based on jiffies.
sched: dynticks idle load balancing Fix the process idle load balancing in the presence of dynticks. cpus for which ticks are stopped will sleep till the next event wakes it up. Potentially these sleeps can be for large durations and during which today, there is no periodic idle load balancing being done. This patch nominates an owner among the idle cpus, which does the idle load balancing on behalf of the other idle cpus. And once all the cpus are completely idle, then we can stop this idle load balancing too. Checks added in fast path are minimized. Whenever there are busy cpus in the system, there will be an owner(idle cpu) doing the system wide idle load balancing. Open items: 1. Intelligent owner selection (like an idle core in a busy package). 2. Merge with rcu's nohz_cpu_mask? Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-08 07:32:51 +00:00
*/
sched: cfs core code apply the CFS core code. this change switches over the scheduler core to CFS's modular design and makes use of kernel/sched_fair/rt/idletask.c to implement Linux's scheduling policies. thanks to Andrew Morton and Thomas Gleixner for lots of detailed review feedback and for fixlets. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
2007-07-09 16:51:59 +00:00
static void update_cpu_load(struct rq *this_rq)
sched: dynticks idle load balancing Fix the process idle load balancing in the presence of dynticks. cpus for which ticks are stopped will sleep till the next event wakes it up. Potentially these sleeps can be for large durations and during which today, there is no periodic idle load balancing being done. This patch nominates an owner among the idle cpus, which does the idle load balancing on behalf of the other idle cpus. And once all the cpus are completely idle, then we can stop this idle load balancing too. Checks added in fast path are minimized. Whenever there are busy cpus in the system, there will be an owner(idle cpu) doing the system wide idle load balancing. Open items: 1. Intelligent owner selection (like an idle core in a busy package). 2. Merge with rcu's nohz_cpu_mask? Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-08 07:32:51 +00:00
{
sched: clean up struct load_stat 'struct load_stat' is redundant now so let's get rid of it. Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Mike Galbraith <efault@gmx.de> Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-15 15:00:06 +00:00
unsigned long this_load = this_rq->load.weight;
sched: Avoid side-effect of tickless idle on update_cpu_load tickless idle has a negative side effect on update_cpu_load(), which in turn can affect load balancing behavior. update_cpu_load() is supposed to be called every tick, to keep track of various load indicies. With tickless idle, there are no scheduler ticks called on the idle CPUs. Idle CPUs may still do load balancing (with idle_load_balance CPU) using the stale cpu_load. It will also cause problems when all CPUs go idle for a while and become active again. In this case loads would not degrade as expected. This is how rq->nr_load_updates change looks like under different conditions: <cpu_num> <nr_load_updates change> All CPUS idle for 10 seconds (HZ=1000) 0 1621 10 496 11 139 12 875 13 1672 14 12 15 21 1 1472 2 2426 3 1161 4 2108 5 1525 6 701 7 249 8 766 9 1967 One CPU busy rest idle for 10 seconds 0 10003 10 601 11 95 12 966 13 1597 14 114 15 98 1 3457 2 93 3 6679 4 1425 5 1479 6 595 7 193 8 633 9 1687 All CPUs busy for 10 seconds 0 10026 10 10026 11 10026 12 10026 13 10025 14 10025 15 10025 1 10026 2 10026 3 10026 4 10026 5 10026 6 10026 7 10026 8 10026 9 10026 That is update_cpu_load works properly only when all CPUs are busy. If all are idle, all the CPUs get way lower updates. And when few CPUs are busy and rest are idle, only busy and ilb CPU does proper updates and rest of the idle CPUs will do lower updates. The patch keeps track of when a last update was done and fixes up the load avg based on current time. On one of my test system SPECjbb with warehouse 1..numcpus, patch improves throughput numbers by ~1% (average of 6 runs). On another test system (with different domain hierarchy) there is no noticable change in perf. Signed-off-by: Venkatesh Pallipadi <venki@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Thomas Gleixner <tglx@linutronix.de> LKML-Reference: <AANLkTilLtDWQsAUrIxJ6s04WTgmw9GuOODc5AOrYsaR5@mail.gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-05-18 01:14:43 +00:00
unsigned long curr_jiffies = jiffies;
unsigned long pending_updates;
sched: cfs core code apply the CFS core code. this change switches over the scheduler core to CFS's modular design and makes use of kernel/sched_fair/rt/idletask.c to implement Linux's scheduling policies. thanks to Andrew Morton and Thomas Gleixner for lots of detailed review feedback and for fixlets. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
2007-07-09 16:51:59 +00:00
int i, scale;
sched: dynticks idle load balancing Fix the process idle load balancing in the presence of dynticks. cpus for which ticks are stopped will sleep till the next event wakes it up. Potentially these sleeps can be for large durations and during which today, there is no periodic idle load balancing being done. This patch nominates an owner among the idle cpus, which does the idle load balancing on behalf of the other idle cpus. And once all the cpus are completely idle, then we can stop this idle load balancing too. Checks added in fast path are minimized. Whenever there are busy cpus in the system, there will be an owner(idle cpu) doing the system wide idle load balancing. Open items: 1. Intelligent owner selection (like an idle core in a busy package). 2. Merge with rcu's nohz_cpu_mask? Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-08 07:32:51 +00:00
sched: cfs core code apply the CFS core code. this change switches over the scheduler core to CFS's modular design and makes use of kernel/sched_fair/rt/idletask.c to implement Linux's scheduling policies. thanks to Andrew Morton and Thomas Gleixner for lots of detailed review feedback and for fixlets. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
2007-07-09 16:51:59 +00:00
this_rq->nr_load_updates++;
sched: dynticks idle load balancing Fix the process idle load balancing in the presence of dynticks. cpus for which ticks are stopped will sleep till the next event wakes it up. Potentially these sleeps can be for large durations and during which today, there is no periodic idle load balancing being done. This patch nominates an owner among the idle cpus, which does the idle load balancing on behalf of the other idle cpus. And once all the cpus are completely idle, then we can stop this idle load balancing too. Checks added in fast path are minimized. Whenever there are busy cpus in the system, there will be an owner(idle cpu) doing the system wide idle load balancing. Open items: 1. Intelligent owner selection (like an idle core in a busy package). 2. Merge with rcu's nohz_cpu_mask? Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-08 07:32:51 +00:00
sched: Avoid side-effect of tickless idle on update_cpu_load tickless idle has a negative side effect on update_cpu_load(), which in turn can affect load balancing behavior. update_cpu_load() is supposed to be called every tick, to keep track of various load indicies. With tickless idle, there are no scheduler ticks called on the idle CPUs. Idle CPUs may still do load balancing (with idle_load_balance CPU) using the stale cpu_load. It will also cause problems when all CPUs go idle for a while and become active again. In this case loads would not degrade as expected. This is how rq->nr_load_updates change looks like under different conditions: <cpu_num> <nr_load_updates change> All CPUS idle for 10 seconds (HZ=1000) 0 1621 10 496 11 139 12 875 13 1672 14 12 15 21 1 1472 2 2426 3 1161 4 2108 5 1525 6 701 7 249 8 766 9 1967 One CPU busy rest idle for 10 seconds 0 10003 10 601 11 95 12 966 13 1597 14 114 15 98 1 3457 2 93 3 6679 4 1425 5 1479 6 595 7 193 8 633 9 1687 All CPUs busy for 10 seconds 0 10026 10 10026 11 10026 12 10026 13 10025 14 10025 15 10025 1 10026 2 10026 3 10026 4 10026 5 10026 6 10026 7 10026 8 10026 9 10026 That is update_cpu_load works properly only when all CPUs are busy. If all are idle, all the CPUs get way lower updates. And when few CPUs are busy and rest are idle, only busy and ilb CPU does proper updates and rest of the idle CPUs will do lower updates. The patch keeps track of when a last update was done and fixes up the load avg based on current time. On one of my test system SPECjbb with warehouse 1..numcpus, patch improves throughput numbers by ~1% (average of 6 runs). On another test system (with different domain hierarchy) there is no noticable change in perf. Signed-off-by: Venkatesh Pallipadi <venki@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Thomas Gleixner <tglx@linutronix.de> LKML-Reference: <AANLkTilLtDWQsAUrIxJ6s04WTgmw9GuOODc5AOrYsaR5@mail.gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-05-18 01:14:43 +00:00
/* Avoid repeated calls on same jiffy, when moving in and out of idle */
if (curr_jiffies == this_rq->last_load_update_tick)
return;
pending_updates = curr_jiffies - this_rq->last_load_update_tick;
this_rq->last_load_update_tick = curr_jiffies;
sched: cfs core code apply the CFS core code. this change switches over the scheduler core to CFS's modular design and makes use of kernel/sched_fair/rt/idletask.c to implement Linux's scheduling policies. thanks to Andrew Morton and Thomas Gleixner for lots of detailed review feedback and for fixlets. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
2007-07-09 16:51:59 +00:00
/* Update our load: */
sched: Avoid side-effect of tickless idle on update_cpu_load tickless idle has a negative side effect on update_cpu_load(), which in turn can affect load balancing behavior. update_cpu_load() is supposed to be called every tick, to keep track of various load indicies. With tickless idle, there are no scheduler ticks called on the idle CPUs. Idle CPUs may still do load balancing (with idle_load_balance CPU) using the stale cpu_load. It will also cause problems when all CPUs go idle for a while and become active again. In this case loads would not degrade as expected. This is how rq->nr_load_updates change looks like under different conditions: <cpu_num> <nr_load_updates change> All CPUS idle for 10 seconds (HZ=1000) 0 1621 10 496 11 139 12 875 13 1672 14 12 15 21 1 1472 2 2426 3 1161 4 2108 5 1525 6 701 7 249 8 766 9 1967 One CPU busy rest idle for 10 seconds 0 10003 10 601 11 95 12 966 13 1597 14 114 15 98 1 3457 2 93 3 6679 4 1425 5 1479 6 595 7 193 8 633 9 1687 All CPUs busy for 10 seconds 0 10026 10 10026 11 10026 12 10026 13 10025 14 10025 15 10025 1 10026 2 10026 3 10026 4 10026 5 10026 6 10026 7 10026 8 10026 9 10026 That is update_cpu_load works properly only when all CPUs are busy. If all are idle, all the CPUs get way lower updates. And when few CPUs are busy and rest are idle, only busy and ilb CPU does proper updates and rest of the idle CPUs will do lower updates. The patch keeps track of when a last update was done and fixes up the load avg based on current time. On one of my test system SPECjbb with warehouse 1..numcpus, patch improves throughput numbers by ~1% (average of 6 runs). On another test system (with different domain hierarchy) there is no noticable change in perf. Signed-off-by: Venkatesh Pallipadi <venki@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Thomas Gleixner <tglx@linutronix.de> LKML-Reference: <AANLkTilLtDWQsAUrIxJ6s04WTgmw9GuOODc5AOrYsaR5@mail.gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-05-18 01:14:43 +00:00
this_rq->cpu_load[0] = this_load; /* Fasttrack for idx 0 */
for (i = 1, scale = 2; i < CPU_LOAD_IDX_MAX; i++, scale += scale) {
sched: cfs core code apply the CFS core code. this change switches over the scheduler core to CFS's modular design and makes use of kernel/sched_fair/rt/idletask.c to implement Linux's scheduling policies. thanks to Andrew Morton and Thomas Gleixner for lots of detailed review feedback and for fixlets. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
2007-07-09 16:51:59 +00:00
unsigned long old_load, new_load;
sched: convert nohz struct to cpumask_var_t. Impact: (future) size reduction for large NR_CPUS. Dynamically allocating cpumasks (when CONFIG_CPUMASK_OFFSTACK) saves space for small nr_cpu_ids but big CONFIG_NR_CPUS. cpumask_var_t is just a struct cpumask for !CONFIG_CPUMASK_OFFSTACK. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-24 16:05:09 +00:00
sched: cfs core code apply the CFS core code. this change switches over the scheduler core to CFS's modular design and makes use of kernel/sched_fair/rt/idletask.c to implement Linux's scheduling policies. thanks to Andrew Morton and Thomas Gleixner for lots of detailed review feedback and for fixlets. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
2007-07-09 16:51:59 +00:00
/* scale is effectively 1 << i now, and >> i divides by scale */
sched: dynticks idle load balancing Fix the process idle load balancing in the presence of dynticks. cpus for which ticks are stopped will sleep till the next event wakes it up. Potentially these sleeps can be for large durations and during which today, there is no periodic idle load balancing being done. This patch nominates an owner among the idle cpus, which does the idle load balancing on behalf of the other idle cpus. And once all the cpus are completely idle, then we can stop this idle load balancing too. Checks added in fast path are minimized. Whenever there are busy cpus in the system, there will be an owner(idle cpu) doing the system wide idle load balancing. Open items: 1. Intelligent owner selection (like an idle core in a busy package). 2. Merge with rcu's nohz_cpu_mask? Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-08 07:32:51 +00:00
sched: cfs core code apply the CFS core code. this change switches over the scheduler core to CFS's modular design and makes use of kernel/sched_fair/rt/idletask.c to implement Linux's scheduling policies. thanks to Andrew Morton and Thomas Gleixner for lots of detailed review feedback and for fixlets. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
2007-07-09 16:51:59 +00:00
old_load = this_rq->cpu_load[i];
sched: Avoid side-effect of tickless idle on update_cpu_load tickless idle has a negative side effect on update_cpu_load(), which in turn can affect load balancing behavior. update_cpu_load() is supposed to be called every tick, to keep track of various load indicies. With tickless idle, there are no scheduler ticks called on the idle CPUs. Idle CPUs may still do load balancing (with idle_load_balance CPU) using the stale cpu_load. It will also cause problems when all CPUs go idle for a while and become active again. In this case loads would not degrade as expected. This is how rq->nr_load_updates change looks like under different conditions: <cpu_num> <nr_load_updates change> All CPUS idle for 10 seconds (HZ=1000) 0 1621 10 496 11 139 12 875 13 1672 14 12 15 21 1 1472 2 2426 3 1161 4 2108 5 1525 6 701 7 249 8 766 9 1967 One CPU busy rest idle for 10 seconds 0 10003 10 601 11 95 12 966 13 1597 14 114 15 98 1 3457 2 93 3 6679 4 1425 5 1479 6 595 7 193 8 633 9 1687 All CPUs busy for 10 seconds 0 10026 10 10026 11 10026 12 10026 13 10025 14 10025 15 10025 1 10026 2 10026 3 10026 4 10026 5 10026 6 10026 7 10026 8 10026 9 10026 That is update_cpu_load works properly only when all CPUs are busy. If all are idle, all the CPUs get way lower updates. And when few CPUs are busy and rest are idle, only busy and ilb CPU does proper updates and rest of the idle CPUs will do lower updates. The patch keeps track of when a last update was done and fixes up the load avg based on current time. On one of my test system SPECjbb with warehouse 1..numcpus, patch improves throughput numbers by ~1% (average of 6 runs). On another test system (with different domain hierarchy) there is no noticable change in perf. Signed-off-by: Venkatesh Pallipadi <venki@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Thomas Gleixner <tglx@linutronix.de> LKML-Reference: <AANLkTilLtDWQsAUrIxJ6s04WTgmw9GuOODc5AOrYsaR5@mail.gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-05-18 01:14:43 +00:00
old_load = decay_load_missed(old_load, pending_updates - 1, i);
sched: cfs core code apply the CFS core code. this change switches over the scheduler core to CFS's modular design and makes use of kernel/sched_fair/rt/idletask.c to implement Linux's scheduling policies. thanks to Andrew Morton and Thomas Gleixner for lots of detailed review feedback and for fixlets. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
2007-07-09 16:51:59 +00:00
new_load = this_load;
sched: remove precise CPU load CPU load calculations are statistical anyway, and there's little benefit from having it calculated on every scheduling event. So remove this code, it gets rid of a divide from the scheduler wakeup and context-switch fastpath. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Mike Galbraith <efault@gmx.de> Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-15 15:00:03 +00:00
/*
* Round up the averaging division if load is increasing. This
* prevents us from getting stuck on 9 if the load is 10, for
* example.
*/
if (new_load > old_load)
sched: Avoid side-effect of tickless idle on update_cpu_load tickless idle has a negative side effect on update_cpu_load(), which in turn can affect load balancing behavior. update_cpu_load() is supposed to be called every tick, to keep track of various load indicies. With tickless idle, there are no scheduler ticks called on the idle CPUs. Idle CPUs may still do load balancing (with idle_load_balance CPU) using the stale cpu_load. It will also cause problems when all CPUs go idle for a while and become active again. In this case loads would not degrade as expected. This is how rq->nr_load_updates change looks like under different conditions: <cpu_num> <nr_load_updates change> All CPUS idle for 10 seconds (HZ=1000) 0 1621 10 496 11 139 12 875 13 1672 14 12 15 21 1 1472 2 2426 3 1161 4 2108 5 1525 6 701 7 249 8 766 9 1967 One CPU busy rest idle for 10 seconds 0 10003 10 601 11 95 12 966 13 1597 14 114 15 98 1 3457 2 93 3 6679 4 1425 5 1479 6 595 7 193 8 633 9 1687 All CPUs busy for 10 seconds 0 10026 10 10026 11 10026 12 10026 13 10025 14 10025 15 10025 1 10026 2 10026 3 10026 4 10026 5 10026 6 10026 7 10026 8 10026 9 10026 That is update_cpu_load works properly only when all CPUs are busy. If all are idle, all the CPUs get way lower updates. And when few CPUs are busy and rest are idle, only busy and ilb CPU does proper updates and rest of the idle CPUs will do lower updates. The patch keeps track of when a last update was done and fixes up the load avg based on current time. On one of my test system SPECjbb with warehouse 1..numcpus, patch improves throughput numbers by ~1% (average of 6 runs). On another test system (with different domain hierarchy) there is no noticable change in perf. Signed-off-by: Venkatesh Pallipadi <venki@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Thomas Gleixner <tglx@linutronix.de> LKML-Reference: <AANLkTilLtDWQsAUrIxJ6s04WTgmw9GuOODc5AOrYsaR5@mail.gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-05-18 01:14:43 +00:00
new_load += scale - 1;
this_rq->cpu_load[i] = (old_load * (scale - 1) + new_load) >> i;
sched: cfs core code apply the CFS core code. this change switches over the scheduler core to CFS's modular design and makes use of kernel/sched_fair/rt/idletask.c to implement Linux's scheduling policies. thanks to Andrew Morton and Thomas Gleixner for lots of detailed review feedback and for fixlets. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
2007-07-09 16:51:59 +00:00
}
sched: Move sched_avg_update() to update_cpu_load() Currently sched_avg_update() (which updates rt_avg stats in the rq) is getting called from scale_rt_power() (in the load balance context) which doesn't take rq->lock. Fix it by moving the sched_avg_update() to more appropriate update_cpu_load() where the CFS load gets updated as well. Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1282596171.2694.3.camel@sbsiddha-MOBL3> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-08-23 20:42:51 +00:00
sched_avg_update(this_rq);
sched: Avoid side-effect of tickless idle on update_cpu_load tickless idle has a negative side effect on update_cpu_load(), which in turn can affect load balancing behavior. update_cpu_load() is supposed to be called every tick, to keep track of various load indicies. With tickless idle, there are no scheduler ticks called on the idle CPUs. Idle CPUs may still do load balancing (with idle_load_balance CPU) using the stale cpu_load. It will also cause problems when all CPUs go idle for a while and become active again. In this case loads would not degrade as expected. This is how rq->nr_load_updates change looks like under different conditions: <cpu_num> <nr_load_updates change> All CPUS idle for 10 seconds (HZ=1000) 0 1621 10 496 11 139 12 875 13 1672 14 12 15 21 1 1472 2 2426 3 1161 4 2108 5 1525 6 701 7 249 8 766 9 1967 One CPU busy rest idle for 10 seconds 0 10003 10 601 11 95 12 966 13 1597 14 114 15 98 1 3457 2 93 3 6679 4 1425 5 1479 6 595 7 193 8 633 9 1687 All CPUs busy for 10 seconds 0 10026 10 10026 11 10026 12 10026 13 10025 14 10025 15 10025 1 10026 2 10026 3 10026 4 10026 5 10026 6 10026 7 10026 8 10026 9 10026 That is update_cpu_load works properly only when all CPUs are busy. If all are idle, all the CPUs get way lower updates. And when few CPUs are busy and rest are idle, only busy and ilb CPU does proper updates and rest of the idle CPUs will do lower updates. The patch keeps track of when a last update was done and fixes up the load avg based on current time. On one of my test system SPECjbb with warehouse 1..numcpus, patch improves throughput numbers by ~1% (average of 6 runs). On another test system (with different domain hierarchy) there is no noticable change in perf. Signed-off-by: Venkatesh Pallipadi <venki@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Thomas Gleixner <tglx@linutronix.de> LKML-Reference: <AANLkTilLtDWQsAUrIxJ6s04WTgmw9GuOODc5AOrYsaR5@mail.gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-05-18 01:14:43 +00:00
}
static void update_cpu_load_active(struct rq *this_rq)
{
update_cpu_load(this_rq);
sched: dynticks idle load balancing Fix the process idle load balancing in the presence of dynticks. cpus for which ticks are stopped will sleep till the next event wakes it up. Potentially these sleeps can be for large durations and during which today, there is no periodic idle load balancing being done. This patch nominates an owner among the idle cpus, which does the idle load balancing on behalf of the other idle cpus. And once all the cpus are completely idle, then we can stop this idle load balancing too. Checks added in fast path are minimized. Whenever there are busy cpus in the system, there will be an owner(idle cpu) doing the system wide idle load balancing. Open items: 1. Intelligent owner selection (like an idle core in a busy package). 2. Merge with rcu's nohz_cpu_mask? Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-08 07:32:51 +00:00
sched: Cure load average vs NO_HZ woes Chase reported that due to us decrementing calc_load_task prematurely (before the next LOAD_FREQ sample), the load average could be scewed by as much as the number of CPUs in the machine. This patch, based on Chase's patch, cures the problem by keeping the delta of the CPU going into NO_HZ idle separately and folding that in on the next LOAD_FREQ update. This restores the balance and we get strict LOAD_FREQ period samples. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Chase Douglas <chase.douglas@canonical.com> LKML-Reference: <1271934490.1776.343.camel@laptop> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-04-22 19:50:19 +00:00
calc_load_account_active(this_rq);
sched: dynticks idle load balancing Fix the process idle load balancing in the presence of dynticks. cpus for which ticks are stopped will sleep till the next event wakes it up. Potentially these sleeps can be for large durations and during which today, there is no periodic idle load balancing being done. This patch nominates an owner among the idle cpus, which does the idle load balancing on behalf of the other idle cpus. And once all the cpus are completely idle, then we can stop this idle load balancing too. Checks added in fast path are minimized. Whenever there are busy cpus in the system, there will be an owner(idle cpu) doing the system wide idle load balancing. Open items: 1. Intelligent owner selection (like an idle core in a busy package). 2. Merge with rcu's nohz_cpu_mask? Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-08 07:32:51 +00:00
}
sched: cfs core code apply the CFS core code. this change switches over the scheduler core to CFS's modular design and makes use of kernel/sched_fair/rt/idletask.c to implement Linux's scheduling policies. thanks to Andrew Morton and Thomas Gleixner for lots of detailed review feedback and for fixlets. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
2007-07-09 16:51:59 +00:00
#ifdef CONFIG_SMP
sched: don't rebalance if attached on NULL domain Impact: fix function graph trace hang / drop pointless softirq on UP While debugging a function graph trace hang on an old PII, I saw that it consumed most of its time on the timer interrupt. And the domain rebalancing softirq was the most concerned. The timer interrupt calls trigger_load_balance() which will decide if it is worth to schedule a rebalancing softirq. In case of builtin UP kernel, no problem arises because there is no domain question. In case of builtin SMP kernel running on an SMP box, still no problem, the softirq will be raised each time we reach the next_balance time. In case of builtin SMP kernel running on a UP box (most distros provide default SMP kernels, whatever the box you have), then the CPU is attached to the NULL sched domain. So a kind of unexpected behaviour happen: trigger_load_balance() -> raises the rebalancing softirq later on softirq: run_rebalance_domains() -> rebalance_domains() where the for_each_domain(cpu, sd) is not taken because of the NULL domain we are attached at. Which means rq->next_balance is never updated. So on the next timer tick, we will enter trigger_load_balance() which will always reschedule() the rebalacing softirq: if (time_after_eq(jiffies, rq->next_balance)) raise_softirq(SCHED_SOFTIRQ); So for each tick, we process this pointless softirq. This patch fixes it by checking if we are attached to the null domain before raising the softirq, another possible fix would be to set the maximal possible JIFFIES value to rq->next_balance if we are attached to the NULL domain. v2: build fix on UP Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <49af242d.1c07d00a.32d5.ffffc019@mx.google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-05 00:27:02 +00:00
sched: dynticks idle load balancing Fix the process idle load balancing in the presence of dynticks. cpus for which ticks are stopped will sleep till the next event wakes it up. Potentially these sleeps can be for large durations and during which today, there is no periodic idle load balancing being done. This patch nominates an owner among the idle cpus, which does the idle load balancing on behalf of the other idle cpus. And once all the cpus are completely idle, then we can stop this idle load balancing too. Checks added in fast path are minimized. Whenever there are busy cpus in the system, there will be an owner(idle cpu) doing the system wide idle load balancing. Open items: 1. Intelligent owner selection (like an idle core in a busy package). 2. Merge with rcu's nohz_cpu_mask? Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-08 07:32:51 +00:00
/*
sched: Fix sched_exec() balancing Since we access ->cpus_allowed without holding rq->lock we need a retry loop to validate the result, this comes for near free when we merge sched_migrate_task() into sched_exec() since that already does the needed check. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> LKML-Reference: <20091216170517.884743662@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-16 17:04:37 +00:00
* sched_exec - execve() is a valuable balancing opportunity, because at
* this point the task has the smallest effective memory and cache footprint.
sched: dynticks idle load balancing Fix the process idle load balancing in the presence of dynticks. cpus for which ticks are stopped will sleep till the next event wakes it up. Potentially these sleeps can be for large durations and during which today, there is no periodic idle load balancing being done. This patch nominates an owner among the idle cpus, which does the idle load balancing on behalf of the other idle cpus. And once all the cpus are completely idle, then we can stop this idle load balancing too. Checks added in fast path are minimized. Whenever there are busy cpus in the system, there will be an owner(idle cpu) doing the system wide idle load balancing. Open items: 1. Intelligent owner selection (like an idle core in a busy package). 2. Merge with rcu's nohz_cpu_mask? Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-08 07:32:51 +00:00
*/
sched: Fix sched_exec() balancing Since we access ->cpus_allowed without holding rq->lock we need a retry loop to validate the result, this comes for near free when we merge sched_migrate_task() into sched_exec() since that already does the needed check. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> LKML-Reference: <20091216170517.884743662@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-16 17:04:37 +00:00
void sched_exec(void)
sched: dynticks idle load balancing Fix the process idle load balancing in the presence of dynticks. cpus for which ticks are stopped will sleep till the next event wakes it up. Potentially these sleeps can be for large durations and during which today, there is no periodic idle load balancing being done. This patch nominates an owner among the idle cpus, which does the idle load balancing on behalf of the other idle cpus. And once all the cpus are completely idle, then we can stop this idle load balancing too. Checks added in fast path are minimized. Whenever there are busy cpus in the system, there will be an owner(idle cpu) doing the system wide idle load balancing. Open items: 1. Intelligent owner selection (like an idle core in a busy package). 2. Merge with rcu's nohz_cpu_mask? Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-08 07:32:51 +00:00
{
sched: Fix sched_exec() balancing Since we access ->cpus_allowed without holding rq->lock we need a retry loop to validate the result, this comes for near free when we merge sched_migrate_task() into sched_exec() since that already does the needed check. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> LKML-Reference: <20091216170517.884743662@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-16 17:04:37 +00:00
struct task_struct *p = current;
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
unsigned long flags;
sched: Fix TASK_WAKING vs fork deadlock Oleg noticed a few races with the TASK_WAKING usage on fork. - since TASK_WAKING is basically a spinlock, it should be IRQ safe - since we set TASK_WAKING (*) without holding rq->lock it could be there still is a rq->lock holder, thereby not actually providing full serialization. (*) in fact we clear PF_STARTING, which in effect enables TASK_WAKING. Cure the second issue by not setting TASK_WAKING in sched_fork(), but only temporarily in wake_up_new_task() while calling select_task_rq(). Cure the first by holding rq->lock around the select_task_rq() call, this will disable IRQs, this however requires that we push down the rq->lock release into select_task_rq_fair()'s cgroup stuff. Because select_task_rq_fair() still needs to drop the rq->lock we cannot fully get rid of TASK_WAKING. Reported-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-03-24 17:34:10 +00:00
int dest_cpu;
sched: dynticks idle load balancing Fix the process idle load balancing in the presence of dynticks. cpus for which ticks are stopped will sleep till the next event wakes it up. Potentially these sleeps can be for large durations and during which today, there is no periodic idle load balancing being done. This patch nominates an owner among the idle cpus, which does the idle load balancing on behalf of the other idle cpus. And once all the cpus are completely idle, then we can stop this idle load balancing too. Checks added in fast path are minimized. Whenever there are busy cpus in the system, there will be an owner(idle cpu) doing the system wide idle load balancing. Open items: 1. Intelligent owner selection (like an idle core in a busy package). 2. Merge with rcu's nohz_cpu_mask? Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-08 07:32:51 +00:00
sched: Drop rq->lock from sched_exec() Since we can now call select_task_rq() and set_task_cpu() with only p->pi_lock held, and sched_exec() load-balancing has always been optimistic, drop all rq->lock usage. Oleg also noted that need_migrate_task() will always be true for current, so don't bother calling that at all. Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110405152729.314204889@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-05 15:23:53 +00:00
raw_spin_lock_irqsave(&p->pi_lock, flags);
sched: Drop the rq argument to sched_class::select_task_rq() In preparation of calling select_task_rq() without rq->lock held, drop the dependency on the rq argument. Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110405152729.031077745@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-05 15:23:46 +00:00
dest_cpu = p->sched_class->select_task_rq(p, SD_BALANCE_EXEC, 0);
sched: Fix TASK_WAKING vs fork deadlock Oleg noticed a few races with the TASK_WAKING usage on fork. - since TASK_WAKING is basically a spinlock, it should be IRQ safe - since we set TASK_WAKING (*) without holding rq->lock it could be there still is a rq->lock holder, thereby not actually providing full serialization. (*) in fact we clear PF_STARTING, which in effect enables TASK_WAKING. Cure the second issue by not setting TASK_WAKING in sched_fork(), but only temporarily in wake_up_new_task() while calling select_task_rq(). Cure the first by holding rq->lock around the select_task_rq() call, this will disable IRQs, this however requires that we push down the rq->lock release into select_task_rq_fair()'s cgroup stuff. Because select_task_rq_fair() still needs to drop the rq->lock we cannot fully get rid of TASK_WAKING. Reported-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-03-24 17:34:10 +00:00
if (dest_cpu == smp_processor_id())
goto unlock;
sched: Fix sched_exec() balancing Since we access ->cpus_allowed without holding rq->lock we need a retry loop to validate the result, this comes for near free when we merge sched_migrate_task() into sched_exec() since that already does the needed check. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> LKML-Reference: <20091216170517.884743662@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-16 17:04:37 +00:00
sched: Drop rq->lock from sched_exec() Since we can now call select_task_rq() and set_task_cpu() with only p->pi_lock held, and sched_exec() load-balancing has always been optimistic, drop all rq->lock usage. Oleg also noted that need_migrate_task() will always be true for current, so don't bother calling that at all. Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110405152729.314204889@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-05 15:23:53 +00:00
if (likely(cpu_active(dest_cpu))) {
sched: replace migration_thread with cpu_stop Currently migration_thread is serving three purposes - migration pusher, context to execute active_load_balance() and forced context switcher for expedited RCU synchronize_sched. All three roles are hardcoded into migration_thread() and determining which job is scheduled is slightly messy. This patch kills migration_thread and replaces all three uses with cpu_stop. The three different roles of migration_thread() are splitted into three separate cpu_stop callbacks - migration_cpu_stop(), active_load_balance_cpu_stop() and synchronize_sched_expedited_cpu_stop() - and each use case now simply asks cpu_stop to execute the callback as necessary. synchronize_sched_expedited() was implemented with private preallocated resources and custom multi-cpu queueing and waiting logic, both of which are provided by cpu_stop. synchronize_sched_expedited_count is made atomic and all other shared resources along with the mutex are dropped. synchronize_sched_expedited() also implemented a check to detect cases where not all the callback got executed on their assigned cpus and fall back to synchronize_sched(). If called with cpu hotplug blocked, cpu_stop already guarantees that and the condition cannot happen; otherwise, stop_machine() would break. However, this patch preserves the paranoid check using a cpumask to record on which cpus the stopper ran so that it can serve as a bisection point if something actually goes wrong theree. Because the internal execution state is no longer visible, rcu_expedited_torture_stats() is removed. This patch also renames cpu_stop threads to from "stopper/%d" to "migration/%d". The names of these threads ultimately don't matter and there's no reason to make unnecessary userland visible changes. With this patch applied, stop_machine() and sched now share the same resources. stop_machine() is faster without wasting any resources and sched migration users are much cleaner. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Dipankar Sarma <dipankar@in.ibm.com> Cc: Josh Triplett <josh@freedesktop.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Dimitri Sivanich <sivanich@sgi.com>
2010-05-06 16:49:21 +00:00
struct migration_arg arg = { p, dest_cpu };
sched: dynticks idle load balancing Fix the process idle load balancing in the presence of dynticks. cpus for which ticks are stopped will sleep till the next event wakes it up. Potentially these sleeps can be for large durations and during which today, there is no periodic idle load balancing being done. This patch nominates an owner among the idle cpus, which does the idle load balancing on behalf of the other idle cpus. And once all the cpus are completely idle, then we can stop this idle load balancing too. Checks added in fast path are minimized. Whenever there are busy cpus in the system, there will be an owner(idle cpu) doing the system wide idle load balancing. Open items: 1. Intelligent owner selection (like an idle core in a busy package). 2. Merge with rcu's nohz_cpu_mask? Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-08 07:32:51 +00:00
sched: Drop rq->lock from sched_exec() Since we can now call select_task_rq() and set_task_cpu() with only p->pi_lock held, and sched_exec() load-balancing has always been optimistic, drop all rq->lock usage. Oleg also noted that need_migrate_task() will always be true for current, so don't bother calling that at all. Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110405152729.314204889@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-05 15:23:53 +00:00
raw_spin_unlock_irqrestore(&p->pi_lock, flags);
stop_one_cpu(task_cpu(p), migration_cpu_stop, &arg);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
return;
}
sched: Fix TASK_WAKING vs fork deadlock Oleg noticed a few races with the TASK_WAKING usage on fork. - since TASK_WAKING is basically a spinlock, it should be IRQ safe - since we set TASK_WAKING (*) without holding rq->lock it could be there still is a rq->lock holder, thereby not actually providing full serialization. (*) in fact we clear PF_STARTING, which in effect enables TASK_WAKING. Cure the second issue by not setting TASK_WAKING in sched_fork(), but only temporarily in wake_up_new_task() while calling select_task_rq(). Cure the first by holding rq->lock around the select_task_rq() call, this will disable IRQs, this however requires that we push down the rq->lock release into select_task_rq_fair()'s cgroup stuff. Because select_task_rq_fair() still needs to drop the rq->lock we cannot fully get rid of TASK_WAKING. Reported-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-03-24 17:34:10 +00:00
unlock:
sched: Drop rq->lock from sched_exec() Since we can now call select_task_rq() and set_task_cpu() with only p->pi_lock held, and sched_exec() load-balancing has always been optimistic, drop all rq->lock usage. Oleg also noted that need_migrate_task() will always be true for current, so don't bother calling that at all. Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110405152729.314204889@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-05 15:23:53 +00:00
raw_spin_unlock_irqrestore(&p->pi_lock, flags);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
}
sched: cfs core code apply the CFS core code. this change switches over the scheduler core to CFS's modular design and makes use of kernel/sched_fair/rt/idletask.c to implement Linux's scheduling policies. thanks to Andrew Morton and Thomas Gleixner for lots of detailed review feedback and for fixlets. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
2007-07-09 16:51:59 +00:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
#endif
DEFINE_PER_CPU(struct kernel_stat, kstat);
EXPORT_PER_CPU_SYMBOL(kstat);
/*
posixtimers, sched: Fix posix clock monotonicity Impact: Regression fix (against clock_gettime() backwarding bug) This patch re-introduces a couple of functions, task_sched_runtime and thread_group_sched_runtime, which was once removed at the time of 2.6.28-rc1. These functions protect the sampling of thread/process clock with rq lock. This rq lock is required not to update rq->clock during the sampling. i.e. The clock_gettime() may return ((accounted runtime before update) + (delta after update)) that is less than what it should be. v2 -> v3: - Rename static helper function __task_delta_exec() to do_task_delta_exec() since -tip tree already has a __task_delta_exec() of different version. v1 -> v2: - Revises comments of function and patch description. - Add note about accuracy of thread group's runtime. Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: stable@kernel.org [2.6.28.x][2.6.29.x] LKML-Reference: <49D1CC93.4080401@jp.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-31 07:56:03 +00:00
* Return any ns on the sched_clock that have not yet been accounted in
timers: fix itimer/many thread hang Overview This patch reworks the handling of POSIX CPU timers, including the ITIMER_PROF, ITIMER_VIRT timers and rlimit handling. It was put together with the help of Roland McGrath, the owner and original writer of this code. The problem we ran into, and the reason for this rework, has to do with using a profiling timer in a process with a large number of threads. It appears that the performance of the old implementation of run_posix_cpu_timers() was at least O(n*3) (where "n" is the number of threads in a process) or worse. Everything is fine with an increasing number of threads until the time taken for that routine to run becomes the same as or greater than the tick time, at which point things degrade rather quickly. This patch fixes bug 9906, "Weird hang with NPTL and SIGPROF." Code Changes This rework corrects the implementation of run_posix_cpu_timers() to make it run in constant time for a particular machine. (Performance may vary between one machine and another depending upon whether the kernel is built as single- or multiprocessor and, in the latter case, depending upon the number of running processors.) To do this, at each tick we now update fields in signal_struct as well as task_struct. The run_posix_cpu_timers() function uses those fields to make its decisions. We define a new structure, "task_cputime," to contain user, system and scheduler times and use these in appropriate places: struct task_cputime { cputime_t utime; cputime_t stime; unsigned long long sum_exec_runtime; }; This is included in the structure "thread_group_cputime," which is a new substructure of signal_struct and which varies for uniprocessor versus multiprocessor kernels. For uniprocessor kernels, it uses "task_cputime" as a simple substructure, while for multiprocessor kernels it is a pointer: struct thread_group_cputime { struct task_cputime totals; }; struct thread_group_cputime { struct task_cputime *totals; }; We also add a new task_cputime substructure directly to signal_struct, to cache the earliest expiration of process-wide timers, and task_cputime also replaces the it_*_expires fields of task_struct (used for earliest expiration of thread timers). The "thread_group_cputime" structure contains process-wide timers that are updated via account_user_time() and friends. In the non-SMP case the structure is a simple aggregator; unfortunately in the SMP case that simplicity was not achievable due to cache-line contention between CPUs (in one measured case performance was actually _worse_ on a 16-cpu system than the same test on a 4-cpu system, due to this contention). For SMP, the thread_group_cputime counters are maintained as a per-cpu structure allocated using alloc_percpu(). The timer functions update only the timer field in the structure corresponding to the running CPU, obtained using per_cpu_ptr(). We define a set of inline functions in sched.h that we use to maintain the thread_group_cputime structure and hide the differences between UP and SMP implementations from the rest of the kernel. The thread_group_cputime_init() function initializes the thread_group_cputime structure for the given task. The thread_group_cputime_alloc() is a no-op for UP; for SMP it calls the out-of-line function thread_group_cputime_alloc_smp() to allocate and fill in the per-cpu structures and fields. The thread_group_cputime_free() function, also a no-op for UP, in SMP frees the per-cpu structures. The thread_group_cputime_clone_thread() function (also a UP no-op) for SMP calls thread_group_cputime_alloc() if the per-cpu structures haven't yet been allocated. The thread_group_cputime() function fills the task_cputime structure it is passed with the contents of the thread_group_cputime fields; in UP it's that simple but in SMP it must also safely check that tsk->signal is non-NULL (if it is it just uses the appropriate fields of task_struct) and, if so, sums the per-cpu values for each online CPU. Finally, the three functions account_group_user_time(), account_group_system_time() and account_group_exec_runtime() are used by timer functions to update the respective fields of the thread_group_cputime structure. Non-SMP operation is trivial and will not be mentioned further. The per-cpu structure is always allocated when a task creates its first new thread, via a call to thread_group_cputime_clone_thread() from copy_signal(). It is freed at process exit via a call to thread_group_cputime_free() from cleanup_signal(). All functions that formerly summed utime/stime/sum_sched_runtime values from from all threads in the thread group now use thread_group_cputime() to snapshot the values in the thread_group_cputime structure or the values in the task structure itself if the per-cpu structure hasn't been allocated. Finally, the code in kernel/posix-cpu-timers.c has changed quite a bit. The run_posix_cpu_timers() function has been split into a fast path and a slow path; the former safely checks whether there are any expired thread timers and, if not, just returns, while the slow path does the heavy lifting. With the dedicated thread group fields, timers are no longer "rebalanced" and the process_timer_rebalance() function and related code has gone away. All summing loops are gone and all code that used them now uses the thread_group_cputime() inline. When process-wide timers are set, the new task_cputime structure in signal_struct is used to cache the earliest expiration; this is checked in the fast path. Performance The fix appears not to add significant overhead to existing operations. It generally performs the same as the current code except in two cases, one in which it performs slightly worse (Case 5 below) and one in which it performs very significantly better (Case 2 below). Overall it's a wash except in those two cases. I've since done somewhat more involved testing on a dual-core Opteron system. Case 1: With no itimer running, for a test with 100,000 threads, the fixed kernel took 1428.5 seconds, 513 seconds more than the unfixed system, all of which was spent in the system. There were twice as many voluntary context switches with the fix as without it. Case 2: With an itimer running at .01 second ticks and 4000 threads (the most an unmodified kernel can handle), the fixed kernel ran the test in eight percent of the time (5.8 seconds as opposed to 70 seconds) and had better tick accuracy (.012 seconds per tick as opposed to .023 seconds per tick). Case 3: A 4000-thread test with an initial timer tick of .01 second and an interval of 10,000 seconds (i.e. a timer that ticks only once) had very nearly the same performance in both cases: 6.3 seconds elapsed for the fixed kernel versus 5.5 seconds for the unfixed kernel. With fewer threads (eight in these tests), the Case 1 test ran in essentially the same time on both the modified and unmodified kernels (5.2 seconds versus 5.8 seconds). The Case 2 test ran in about the same time as well, 5.9 seconds versus 5.4 seconds but again with much better tick accuracy, .013 seconds per tick versus .025 seconds per tick for the unmodified kernel. Since the fix affected the rlimit code, I also tested soft and hard CPU limits. Case 4: With a hard CPU limit of 20 seconds and eight threads (and an itimer running), the modified kernel was very slightly favored in that while it killed the process in 19.997 seconds of CPU time (5.002 seconds of wall time), only .003 seconds of that was system time, the rest was user time. The unmodified kernel killed the process in 20.001 seconds of CPU (5.014 seconds of wall time) of which .016 seconds was system time. Really, though, the results were too close to call. The results were essentially the same with no itimer running. Case 5: With a soft limit of 20 seconds and a hard limit of 2000 seconds (where the hard limit would never be reached) and an itimer running, the modified kernel exhibited worse tick accuracy than the unmodified kernel: .050 seconds/tick versus .028 seconds/tick. Otherwise, performance was almost indistinguishable. With no itimer running this test exhibited virtually identical behavior and times in both cases. In times past I did some limited performance testing. those results are below. On a four-cpu Opteron system without this fix, a sixteen-thread test executed in 3569.991 seconds, of which user was 3568.435s and system was 1.556s. On the same system with the fix, user and elapsed time were about the same, but system time dropped to 0.007 seconds. Performance with eight, four and one thread were comparable. Interestingly, the timer ticks with the fix seemed more accurate: The sixteen-thread test with the fix received 149543 ticks for 0.024 seconds per tick, while the same test without the fix received 58720 for 0.061 seconds per tick. Both cases were configured for an interval of 0.01 seconds. Again, the other tests were comparable. Each thread in this test computed the primes up to 25,000,000. I also did a test with a large number of threads, 100,000 threads, which is impossible without the fix. In this case each thread computed the primes only up to 10,000 (to make the runtime manageable). System time dominated, at 1546.968 seconds out of a total 2176.906 seconds (giving a user time of 629.938s). It received 147651 ticks for 0.015 seconds per tick, still quite accurate. There is obviously no comparable test without the fix. Signed-off-by: Frank Mayhar <fmayhar@google.com> Cc: Roland McGrath <roland@redhat.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-12 16:54:39 +00:00
* @p in case that task is currently running.
posixtimers, sched: Fix posix clock monotonicity Impact: Regression fix (against clock_gettime() backwarding bug) This patch re-introduces a couple of functions, task_sched_runtime and thread_group_sched_runtime, which was once removed at the time of 2.6.28-rc1. These functions protect the sampling of thread/process clock with rq lock. This rq lock is required not to update rq->clock during the sampling. i.e. The clock_gettime() may return ((accounted runtime before update) + (delta after update)) that is less than what it should be. v2 -> v3: - Rename static helper function __task_delta_exec() to do_task_delta_exec() since -tip tree already has a __task_delta_exec() of different version. v1 -> v2: - Revises comments of function and patch description. - Add note about accuracy of thread group's runtime. Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: stable@kernel.org [2.6.28.x][2.6.29.x] LKML-Reference: <49D1CC93.4080401@jp.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-31 07:56:03 +00:00
*
* Called with task_rq_lock() held on @rq.
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
*/
posixtimers, sched: Fix posix clock monotonicity Impact: Regression fix (against clock_gettime() backwarding bug) This patch re-introduces a couple of functions, task_sched_runtime and thread_group_sched_runtime, which was once removed at the time of 2.6.28-rc1. These functions protect the sampling of thread/process clock with rq lock. This rq lock is required not to update rq->clock during the sampling. i.e. The clock_gettime() may return ((accounted runtime before update) + (delta after update)) that is less than what it should be. v2 -> v3: - Rename static helper function __task_delta_exec() to do_task_delta_exec() since -tip tree already has a __task_delta_exec() of different version. v1 -> v2: - Revises comments of function and patch description. - Add note about accuracy of thread group's runtime. Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: stable@kernel.org [2.6.28.x][2.6.29.x] LKML-Reference: <49D1CC93.4080401@jp.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-31 07:56:03 +00:00
static u64 do_task_delta_exec(struct task_struct *p, struct rq *rq)
{
u64 ns = 0;
if (task_current(rq, p)) {
update_rq_clock(rq);
sched: Do not account irq time to current task Scheduler accounts both softirq and interrupt processing times to the currently running task. This means, if the interrupt processing was for some other task in the system, then the current task ends up being penalized as it gets shorter runtime than otherwise. Change sched task accounting to acoount only actual task time from currently running task. Now update_curr(), modifies the delta_exec to depend on rq->clock_task. Note that this change only handles CONFIG_IRQ_TIME_ACCOUNTING case. We can extend this to CONFIG_VIRT_CPU_ACCOUNTING with minimal effort. But, thats for later. This change will impact scheduling behavior in interrupt heavy conditions. Tested on a 4-way system with eth0 handled by CPU 2 and a network heavy task (nc) running on CPU 3 (and no RSS/RFS). With that I have CPU 2 spending 75%+ of its time in irq processing. CPU 3 spending around 35% time running nc task. Now, if I run another CPU intensive task on CPU 2, without this change /proc/<pid>/schedstat shows 100% of time accounted to this task. With this change, it rightly shows less than 25% accounted to this task as remaining time is actually spent on irq processing. Signed-off-by: Venkatesh Pallipadi <venki@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1286237003-12406-7-git-send-email-venki@google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-05 00:03:21 +00:00
ns = rq->clock_task - p->se.exec_start;
posixtimers, sched: Fix posix clock monotonicity Impact: Regression fix (against clock_gettime() backwarding bug) This patch re-introduces a couple of functions, task_sched_runtime and thread_group_sched_runtime, which was once removed at the time of 2.6.28-rc1. These functions protect the sampling of thread/process clock with rq lock. This rq lock is required not to update rq->clock during the sampling. i.e. The clock_gettime() may return ((accounted runtime before update) + (delta after update)) that is less than what it should be. v2 -> v3: - Rename static helper function __task_delta_exec() to do_task_delta_exec() since -tip tree already has a __task_delta_exec() of different version. v1 -> v2: - Revises comments of function and patch description. - Add note about accuracy of thread group's runtime. Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: stable@kernel.org [2.6.28.x][2.6.29.x] LKML-Reference: <49D1CC93.4080401@jp.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-31 07:56:03 +00:00
if ((s64)ns < 0)
ns = 0;
}
return ns;
}
timers: fix itimer/many thread hang, v2 This is the second resubmission of the posix timer rework patch, posted a few days ago. This includes the changes from the previous resubmittion, which addressed Oleg Nesterov's comments, removing the RCU stuff from the patch and un-inlining the thread_group_cputime() function for SMP. In addition, per Ingo Molnar it simplifies the UP code, consolidating much of it with the SMP version and depending on lower-level SMP/UP handling to take care of the differences. It also cleans up some UP compile errors, moves the scheduler stats-related macros into kernel/sched_stats.h, cleans up a merge error in kernel/fork.c and has a few other minor fixes and cleanups as suggested by Oleg and Ingo. Thanks for the review, guys. Signed-off-by: Frank Mayhar <fmayhar@google.com> Cc: Roland McGrath <roland@redhat.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-12 16:54:39 +00:00
unsigned long long task_delta_exec(struct task_struct *p)
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
{
unsigned long flags;
sched: make posix-cpu-timers use CFS's accounting information update the posix-cpu-timers code to use CFS's CPU accounting information. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-09 16:51:58 +00:00
struct rq *rq;
timers: fix itimer/many thread hang, v2 This is the second resubmission of the posix timer rework patch, posted a few days ago. This includes the changes from the previous resubmittion, which addressed Oleg Nesterov's comments, removing the RCU stuff from the patch and un-inlining the thread_group_cputime() function for SMP. In addition, per Ingo Molnar it simplifies the UP code, consolidating much of it with the SMP version and depending on lower-level SMP/UP handling to take care of the differences. It also cleans up some UP compile errors, moves the scheduler stats-related macros into kernel/sched_stats.h, cleans up a merge error in kernel/fork.c and has a few other minor fixes and cleanups as suggested by Oleg and Ingo. Thanks for the review, guys. Signed-off-by: Frank Mayhar <fmayhar@google.com> Cc: Roland McGrath <roland@redhat.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-12 16:54:39 +00:00
u64 ns = 0;
[PATCH] sched: clean up fallout of recent changes Clean up some of the impact of recent (and not so recent) scheduler changes: - turning macros into nice inline functions - sanitizing and unifying variable definitions - whitespace, style consistency, 80-lines, comment correctness, spelling and curly braces police Due to the macro hell and variable placement simplifications there's even 26 bytes of .text saved: text data bss dec hex filename 25510 4153 192 29855 749f sched.o.before 25484 4153 192 29829 7485 sched.o.after [akpm@osdl.org: build fix] Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-03 07:25:40 +00:00
sched: make posix-cpu-timers use CFS's accounting information update the posix-cpu-timers code to use CFS's CPU accounting information. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-09 16:51:58 +00:00
rq = task_rq_lock(p, &flags);
posixtimers, sched: Fix posix clock monotonicity Impact: Regression fix (against clock_gettime() backwarding bug) This patch re-introduces a couple of functions, task_sched_runtime and thread_group_sched_runtime, which was once removed at the time of 2.6.28-rc1. These functions protect the sampling of thread/process clock with rq lock. This rq lock is required not to update rq->clock during the sampling. i.e. The clock_gettime() may return ((accounted runtime before update) + (delta after update)) that is less than what it should be. v2 -> v3: - Rename static helper function __task_delta_exec() to do_task_delta_exec() since -tip tree already has a __task_delta_exec() of different version. v1 -> v2: - Revises comments of function and patch description. - Add note about accuracy of thread group's runtime. Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: stable@kernel.org [2.6.28.x][2.6.29.x] LKML-Reference: <49D1CC93.4080401@jp.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-31 07:56:03 +00:00
ns = do_task_delta_exec(p, rq);
sched: Add p->pi_lock to task_rq_lock() In order to be able to call set_task_cpu() while either holding p->pi_lock or task_rq(p)->lock we need to hold both locks in order to stabilize task_rq(). This makes task_rq_lock() acquire both locks, and have __task_rq_lock() validate that p->pi_lock is held. This increases the locking overhead for most scheduler syscalls but allows reduction of rq->lock contention for some scheduler hot paths (ttwu). Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110405152729.232781355@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-05 15:23:51 +00:00
task_rq_unlock(rq, p, &flags);
timers: fix itimer/many thread hang, fix fix bogus rq dereference: v3 removed the locking but also removed the rq initialization. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-30 06:28:17 +00:00
posixtimers, sched: Fix posix clock monotonicity Impact: Regression fix (against clock_gettime() backwarding bug) This patch re-introduces a couple of functions, task_sched_runtime and thread_group_sched_runtime, which was once removed at the time of 2.6.28-rc1. These functions protect the sampling of thread/process clock with rq lock. This rq lock is required not to update rq->clock during the sampling. i.e. The clock_gettime() may return ((accounted runtime before update) + (delta after update)) that is less than what it should be. v2 -> v3: - Rename static helper function __task_delta_exec() to do_task_delta_exec() since -tip tree already has a __task_delta_exec() of different version. v1 -> v2: - Revises comments of function and patch description. - Add note about accuracy of thread group's runtime. Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: stable@kernel.org [2.6.28.x][2.6.29.x] LKML-Reference: <49D1CC93.4080401@jp.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-31 07:56:03 +00:00
return ns;
}
timers: fix itimer/many thread hang Overview This patch reworks the handling of POSIX CPU timers, including the ITIMER_PROF, ITIMER_VIRT timers and rlimit handling. It was put together with the help of Roland McGrath, the owner and original writer of this code. The problem we ran into, and the reason for this rework, has to do with using a profiling timer in a process with a large number of threads. It appears that the performance of the old implementation of run_posix_cpu_timers() was at least O(n*3) (where "n" is the number of threads in a process) or worse. Everything is fine with an increasing number of threads until the time taken for that routine to run becomes the same as or greater than the tick time, at which point things degrade rather quickly. This patch fixes bug 9906, "Weird hang with NPTL and SIGPROF." Code Changes This rework corrects the implementation of run_posix_cpu_timers() to make it run in constant time for a particular machine. (Performance may vary between one machine and another depending upon whether the kernel is built as single- or multiprocessor and, in the latter case, depending upon the number of running processors.) To do this, at each tick we now update fields in signal_struct as well as task_struct. The run_posix_cpu_timers() function uses those fields to make its decisions. We define a new structure, "task_cputime," to contain user, system and scheduler times and use these in appropriate places: struct task_cputime { cputime_t utime; cputime_t stime; unsigned long long sum_exec_runtime; }; This is included in the structure "thread_group_cputime," which is a new substructure of signal_struct and which varies for uniprocessor versus multiprocessor kernels. For uniprocessor kernels, it uses "task_cputime" as a simple substructure, while for multiprocessor kernels it is a pointer: struct thread_group_cputime { struct task_cputime totals; }; struct thread_group_cputime { struct task_cputime *totals; }; We also add a new task_cputime substructure directly to signal_struct, to cache the earliest expiration of process-wide timers, and task_cputime also replaces the it_*_expires fields of task_struct (used for earliest expiration of thread timers). The "thread_group_cputime" structure contains process-wide timers that are updated via account_user_time() and friends. In the non-SMP case the structure is a simple aggregator; unfortunately in the SMP case that simplicity was not achievable due to cache-line contention between CPUs (in one measured case performance was actually _worse_ on a 16-cpu system than the same test on a 4-cpu system, due to this contention). For SMP, the thread_group_cputime counters are maintained as a per-cpu structure allocated using alloc_percpu(). The timer functions update only the timer field in the structure corresponding to the running CPU, obtained using per_cpu_ptr(). We define a set of inline functions in sched.h that we use to maintain the thread_group_cputime structure and hide the differences between UP and SMP implementations from the rest of the kernel. The thread_group_cputime_init() function initializes the thread_group_cputime structure for the given task. The thread_group_cputime_alloc() is a no-op for UP; for SMP it calls the out-of-line function thread_group_cputime_alloc_smp() to allocate and fill in the per-cpu structures and fields. The thread_group_cputime_free() function, also a no-op for UP, in SMP frees the per-cpu structures. The thread_group_cputime_clone_thread() function (also a UP no-op) for SMP calls thread_group_cputime_alloc() if the per-cpu structures haven't yet been allocated. The thread_group_cputime() function fills the task_cputime structure it is passed with the contents of the thread_group_cputime fields; in UP it's that simple but in SMP it must also safely check that tsk->signal is non-NULL (if it is it just uses the appropriate fields of task_struct) and, if so, sums the per-cpu values for each online CPU. Finally, the three functions account_group_user_time(), account_group_system_time() and account_group_exec_runtime() are used by timer functions to update the respective fields of the thread_group_cputime structure. Non-SMP operation is trivial and will not be mentioned further. The per-cpu structure is always allocated when a task creates its first new thread, via a call to thread_group_cputime_clone_thread() from copy_signal(). It is freed at process exit via a call to thread_group_cputime_free() from cleanup_signal(). All functions that formerly summed utime/stime/sum_sched_runtime values from from all threads in the thread group now use thread_group_cputime() to snapshot the values in the thread_group_cputime structure or the values in the task structure itself if the per-cpu structure hasn't been allocated. Finally, the code in kernel/posix-cpu-timers.c has changed quite a bit. The run_posix_cpu_timers() function has been split into a fast path and a slow path; the former safely checks whether there are any expired thread timers and, if not, just returns, while the slow path does the heavy lifting. With the dedicated thread group fields, timers are no longer "rebalanced" and the process_timer_rebalance() function and related code has gone away. All summing loops are gone and all code that used them now uses the thread_group_cputime() inline. When process-wide timers are set, the new task_cputime structure in signal_struct is used to cache the earliest expiration; this is checked in the fast path. Performance The fix appears not to add significant overhead to existing operations. It generally performs the same as the current code except in two cases, one in which it performs slightly worse (Case 5 below) and one in which it performs very significantly better (Case 2 below). Overall it's a wash except in those two cases. I've since done somewhat more involved testing on a dual-core Opteron system. Case 1: With no itimer running, for a test with 100,000 threads, the fixed kernel took 1428.5 seconds, 513 seconds more than the unfixed system, all of which was spent in the system. There were twice as many voluntary context switches with the fix as without it. Case 2: With an itimer running at .01 second ticks and 4000 threads (the most an unmodified kernel can handle), the fixed kernel ran the test in eight percent of the time (5.8 seconds as opposed to 70 seconds) and had better tick accuracy (.012 seconds per tick as opposed to .023 seconds per tick). Case 3: A 4000-thread test with an initial timer tick of .01 second and an interval of 10,000 seconds (i.e. a timer that ticks only once) had very nearly the same performance in both cases: 6.3 seconds elapsed for the fixed kernel versus 5.5 seconds for the unfixed kernel. With fewer threads (eight in these tests), the Case 1 test ran in essentially the same time on both the modified and unmodified kernels (5.2 seconds versus 5.8 seconds). The Case 2 test ran in about the same time as well, 5.9 seconds versus 5.4 seconds but again with much better tick accuracy, .013 seconds per tick versus .025 seconds per tick for the unmodified kernel. Since the fix affected the rlimit code, I also tested soft and hard CPU limits. Case 4: With a hard CPU limit of 20 seconds and eight threads (and an itimer running), the modified kernel was very slightly favored in that while it killed the process in 19.997 seconds of CPU time (5.002 seconds of wall time), only .003 seconds of that was system time, the rest was user time. The unmodified kernel killed the process in 20.001 seconds of CPU (5.014 seconds of wall time) of which .016 seconds was system time. Really, though, the results were too close to call. The results were essentially the same with no itimer running. Case 5: With a soft limit of 20 seconds and a hard limit of 2000 seconds (where the hard limit would never be reached) and an itimer running, the modified kernel exhibited worse tick accuracy than the unmodified kernel: .050 seconds/tick versus .028 seconds/tick. Otherwise, performance was almost indistinguishable. With no itimer running this test exhibited virtually identical behavior and times in both cases. In times past I did some limited performance testing. those results are below. On a four-cpu Opteron system without this fix, a sixteen-thread test executed in 3569.991 seconds, of which user was 3568.435s and system was 1.556s. On the same system with the fix, user and elapsed time were about the same, but system time dropped to 0.007 seconds. Performance with eight, four and one thread were comparable. Interestingly, the timer ticks with the fix seemed more accurate: The sixteen-thread test with the fix received 149543 ticks for 0.024 seconds per tick, while the same test without the fix received 58720 for 0.061 seconds per tick. Both cases were configured for an interval of 0.01 seconds. Again, the other tests were comparable. Each thread in this test computed the primes up to 25,000,000. I also did a test with a large number of threads, 100,000 threads, which is impossible without the fix. In this case each thread computed the primes only up to 10,000 (to make the runtime manageable). System time dominated, at 1546.968 seconds out of a total 2176.906 seconds (giving a user time of 629.938s). It received 147651 ticks for 0.015 seconds per tick, still quite accurate. There is obviously no comparable test without the fix. Signed-off-by: Frank Mayhar <fmayhar@google.com> Cc: Roland McGrath <roland@redhat.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-12 16:54:39 +00:00
posixtimers, sched: Fix posix clock monotonicity Impact: Regression fix (against clock_gettime() backwarding bug) This patch re-introduces a couple of functions, task_sched_runtime and thread_group_sched_runtime, which was once removed at the time of 2.6.28-rc1. These functions protect the sampling of thread/process clock with rq lock. This rq lock is required not to update rq->clock during the sampling. i.e. The clock_gettime() may return ((accounted runtime before update) + (delta after update)) that is less than what it should be. v2 -> v3: - Rename static helper function __task_delta_exec() to do_task_delta_exec() since -tip tree already has a __task_delta_exec() of different version. v1 -> v2: - Revises comments of function and patch description. - Add note about accuracy of thread group's runtime. Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: stable@kernel.org [2.6.28.x][2.6.29.x] LKML-Reference: <49D1CC93.4080401@jp.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-31 07:56:03 +00:00
/*
* Return accounted runtime for the task.
* In case the task is currently running, return the runtime plus current's
* pending runtime that have not been accounted yet.
*/
unsigned long long task_sched_runtime(struct task_struct *p)
{
unsigned long flags;
struct rq *rq;
u64 ns = 0;
rq = task_rq_lock(p, &flags);
ns = p->se.sum_exec_runtime + do_task_delta_exec(p, rq);
sched: Add p->pi_lock to task_rq_lock() In order to be able to call set_task_cpu() while either holding p->pi_lock or task_rq(p)->lock we need to hold both locks in order to stabilize task_rq(). This makes task_rq_lock() acquire both locks, and have __task_rq_lock() validate that p->pi_lock is held. This increases the locking overhead for most scheduler syscalls but allows reduction of rq->lock contention for some scheduler hot paths (ttwu). Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110405152729.232781355@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-05 15:23:51 +00:00
task_rq_unlock(rq, p, &flags);
posixtimers, sched: Fix posix clock monotonicity Impact: Regression fix (against clock_gettime() backwarding bug) This patch re-introduces a couple of functions, task_sched_runtime and thread_group_sched_runtime, which was once removed at the time of 2.6.28-rc1. These functions protect the sampling of thread/process clock with rq lock. This rq lock is required not to update rq->clock during the sampling. i.e. The clock_gettime() may return ((accounted runtime before update) + (delta after update)) that is less than what it should be. v2 -> v3: - Rename static helper function __task_delta_exec() to do_task_delta_exec() since -tip tree already has a __task_delta_exec() of different version. v1 -> v2: - Revises comments of function and patch description. - Add note about accuracy of thread group's runtime. Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: stable@kernel.org [2.6.28.x][2.6.29.x] LKML-Reference: <49D1CC93.4080401@jp.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-31 07:56:03 +00:00
return ns;
}
[PATCH] sched: clean up fallout of recent changes Clean up some of the impact of recent (and not so recent) scheduler changes: - turning macros into nice inline functions - sanitizing and unifying variable definitions - whitespace, style consistency, 80-lines, comment correctness, spelling and curly braces police Due to the macro hell and variable placement simplifications there's even 26 bytes of .text saved: text data bss dec hex filename 25510 4153 192 29855 749f sched.o.before 25484 4153 192 29829 7485 sched.o.after [akpm@osdl.org: build fix] Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-03 07:25:40 +00:00
posixtimers, sched: Fix posix clock monotonicity Impact: Regression fix (against clock_gettime() backwarding bug) This patch re-introduces a couple of functions, task_sched_runtime and thread_group_sched_runtime, which was once removed at the time of 2.6.28-rc1. These functions protect the sampling of thread/process clock with rq lock. This rq lock is required not to update rq->clock during the sampling. i.e. The clock_gettime() may return ((accounted runtime before update) + (delta after update)) that is less than what it should be. v2 -> v3: - Rename static helper function __task_delta_exec() to do_task_delta_exec() since -tip tree already has a __task_delta_exec() of different version. v1 -> v2: - Revises comments of function and patch description. - Add note about accuracy of thread group's runtime. Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: stable@kernel.org [2.6.28.x][2.6.29.x] LKML-Reference: <49D1CC93.4080401@jp.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-31 07:56:03 +00:00
/*
* Return sum_exec_runtime for the thread group.
* In case the task is currently running, return the sum plus current's
* pending runtime that have not been accounted yet.
*
* Note that the thread group might have other running tasks as well,
* so the return value not includes other pending runtime that other
* running tasks might have.
*/
unsigned long long thread_group_sched_runtime(struct task_struct *p)
{
struct task_cputime totals;
unsigned long flags;
struct rq *rq;
u64 ns;
rq = task_rq_lock(p, &flags);
thread_group_cputime(p, &totals);
ns = totals.sum_exec_runtime + do_task_delta_exec(p, rq);
sched: Add p->pi_lock to task_rq_lock() In order to be able to call set_task_cpu() while either holding p->pi_lock or task_rq(p)->lock we need to hold both locks in order to stabilize task_rq(). This makes task_rq_lock() acquire both locks, and have __task_rq_lock() validate that p->pi_lock is held. This increases the locking overhead for most scheduler syscalls but allows reduction of rq->lock contention for some scheduler hot paths (ttwu). Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110405152729.232781355@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-05 15:23:51 +00:00
task_rq_unlock(rq, p, &flags);
[PATCH] sched: clean up fallout of recent changes Clean up some of the impact of recent (and not so recent) scheduler changes: - turning macros into nice inline functions - sanitizing and unifying variable definitions - whitespace, style consistency, 80-lines, comment correctness, spelling and curly braces police Due to the macro hell and variable placement simplifications there's even 26 bytes of .text saved: text data bss dec hex filename 25510 4153 192 29855 749f sched.o.before 25484 4153 192 29829 7485 sched.o.after [akpm@osdl.org: build fix] Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-03 07:25:40 +00:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
return ns;
}
/*
* Account user cpu time to a process.
* @p: the process that the cpu time gets accounted to
* @cputime: the cpu time spent in user space since the last update
[PATCH] fix scaled & unscaled cputime accounting The utimescaled / stimescaled fields in the task structure and the global cpustat should be set on all architectures. On s390 the calls to account_user_time_scaled and account_system_time_scaled never have been added. In addition system time that is accounted as guest time to the user time of a process is accounted to the scaled system time instead of the scaled user time. To fix the bugs and to prevent future forgetfulness this patch merges account_system_time_scaled into account_system_time and account_user_time_scaled into account_user_time. Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Jeremy Fitzhardinge <jeremy@xensource.com> Cc: Chris Wright <chrisw@sous-sol.org> Cc: Michael Neuling <mikey@neuling.org> Acked-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2008-12-31 14:11:37 +00:00
* @cputime_scaled: cputime scaled by cpu frequency
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
*/
[PATCH] fix scaled & unscaled cputime accounting The utimescaled / stimescaled fields in the task structure and the global cpustat should be set on all architectures. On s390 the calls to account_user_time_scaled and account_system_time_scaled never have been added. In addition system time that is accounted as guest time to the user time of a process is accounted to the scaled system time instead of the scaled user time. To fix the bugs and to prevent future forgetfulness this patch merges account_system_time_scaled into account_system_time and account_user_time_scaled into account_user_time. Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Jeremy Fitzhardinge <jeremy@xensource.com> Cc: Chris Wright <chrisw@sous-sol.org> Cc: Michael Neuling <mikey@neuling.org> Acked-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2008-12-31 14:11:37 +00:00
void account_user_time(struct task_struct *p, cputime_t cputime,
cputime_t cputime_scaled)
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
{
struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat;
cputime64_t tmp;
[PATCH] fix scaled & unscaled cputime accounting The utimescaled / stimescaled fields in the task structure and the global cpustat should be set on all architectures. On s390 the calls to account_user_time_scaled and account_system_time_scaled never have been added. In addition system time that is accounted as guest time to the user time of a process is accounted to the scaled system time instead of the scaled user time. To fix the bugs and to prevent future forgetfulness this patch merges account_system_time_scaled into account_system_time and account_user_time_scaled into account_user_time. Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Jeremy Fitzhardinge <jeremy@xensource.com> Cc: Chris Wright <chrisw@sous-sol.org> Cc: Michael Neuling <mikey@neuling.org> Acked-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2008-12-31 14:11:37 +00:00
/* Add user time to process. */
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
p->utime = cputime_add(p->utime, cputime);
[PATCH] fix scaled & unscaled cputime accounting The utimescaled / stimescaled fields in the task structure and the global cpustat should be set on all architectures. On s390 the calls to account_user_time_scaled and account_system_time_scaled never have been added. In addition system time that is accounted as guest time to the user time of a process is accounted to the scaled system time instead of the scaled user time. To fix the bugs and to prevent future forgetfulness this patch merges account_system_time_scaled into account_system_time and account_user_time_scaled into account_user_time. Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Jeremy Fitzhardinge <jeremy@xensource.com> Cc: Chris Wright <chrisw@sous-sol.org> Cc: Michael Neuling <mikey@neuling.org> Acked-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2008-12-31 14:11:37 +00:00
p->utimescaled = cputime_add(p->utimescaled, cputime_scaled);
timers: fix itimer/many thread hang Overview This patch reworks the handling of POSIX CPU timers, including the ITIMER_PROF, ITIMER_VIRT timers and rlimit handling. It was put together with the help of Roland McGrath, the owner and original writer of this code. The problem we ran into, and the reason for this rework, has to do with using a profiling timer in a process with a large number of threads. It appears that the performance of the old implementation of run_posix_cpu_timers() was at least O(n*3) (where "n" is the number of threads in a process) or worse. Everything is fine with an increasing number of threads until the time taken for that routine to run becomes the same as or greater than the tick time, at which point things degrade rather quickly. This patch fixes bug 9906, "Weird hang with NPTL and SIGPROF." Code Changes This rework corrects the implementation of run_posix_cpu_timers() to make it run in constant time for a particular machine. (Performance may vary between one machine and another depending upon whether the kernel is built as single- or multiprocessor and, in the latter case, depending upon the number of running processors.) To do this, at each tick we now update fields in signal_struct as well as task_struct. The run_posix_cpu_timers() function uses those fields to make its decisions. We define a new structure, "task_cputime," to contain user, system and scheduler times and use these in appropriate places: struct task_cputime { cputime_t utime; cputime_t stime; unsigned long long sum_exec_runtime; }; This is included in the structure "thread_group_cputime," which is a new substructure of signal_struct and which varies for uniprocessor versus multiprocessor kernels. For uniprocessor kernels, it uses "task_cputime" as a simple substructure, while for multiprocessor kernels it is a pointer: struct thread_group_cputime { struct task_cputime totals; }; struct thread_group_cputime { struct task_cputime *totals; }; We also add a new task_cputime substructure directly to signal_struct, to cache the earliest expiration of process-wide timers, and task_cputime also replaces the it_*_expires fields of task_struct (used for earliest expiration of thread timers). The "thread_group_cputime" structure contains process-wide timers that are updated via account_user_time() and friends. In the non-SMP case the structure is a simple aggregator; unfortunately in the SMP case that simplicity was not achievable due to cache-line contention between CPUs (in one measured case performance was actually _worse_ on a 16-cpu system than the same test on a 4-cpu system, due to this contention). For SMP, the thread_group_cputime counters are maintained as a per-cpu structure allocated using alloc_percpu(). The timer functions update only the timer field in the structure corresponding to the running CPU, obtained using per_cpu_ptr(). We define a set of inline functions in sched.h that we use to maintain the thread_group_cputime structure and hide the differences between UP and SMP implementations from the rest of the kernel. The thread_group_cputime_init() function initializes the thread_group_cputime structure for the given task. The thread_group_cputime_alloc() is a no-op for UP; for SMP it calls the out-of-line function thread_group_cputime_alloc_smp() to allocate and fill in the per-cpu structures and fields. The thread_group_cputime_free() function, also a no-op for UP, in SMP frees the per-cpu structures. The thread_group_cputime_clone_thread() function (also a UP no-op) for SMP calls thread_group_cputime_alloc() if the per-cpu structures haven't yet been allocated. The thread_group_cputime() function fills the task_cputime structure it is passed with the contents of the thread_group_cputime fields; in UP it's that simple but in SMP it must also safely check that tsk->signal is non-NULL (if it is it just uses the appropriate fields of task_struct) and, if so, sums the per-cpu values for each online CPU. Finally, the three functions account_group_user_time(), account_group_system_time() and account_group_exec_runtime() are used by timer functions to update the respective fields of the thread_group_cputime structure. Non-SMP operation is trivial and will not be mentioned further. The per-cpu structure is always allocated when a task creates its first new thread, via a call to thread_group_cputime_clone_thread() from copy_signal(). It is freed at process exit via a call to thread_group_cputime_free() from cleanup_signal(). All functions that formerly summed utime/stime/sum_sched_runtime values from from all threads in the thread group now use thread_group_cputime() to snapshot the values in the thread_group_cputime structure or the values in the task structure itself if the per-cpu structure hasn't been allocated. Finally, the code in kernel/posix-cpu-timers.c has changed quite a bit. The run_posix_cpu_timers() function has been split into a fast path and a slow path; the former safely checks whether there are any expired thread timers and, if not, just returns, while the slow path does the heavy lifting. With the dedicated thread group fields, timers are no longer "rebalanced" and the process_timer_rebalance() function and related code has gone away. All summing loops are gone and all code that used them now uses the thread_group_cputime() inline. When process-wide timers are set, the new task_cputime structure in signal_struct is used to cache the earliest expiration; this is checked in the fast path. Performance The fix appears not to add significant overhead to existing operations. It generally performs the same as the current code except in two cases, one in which it performs slightly worse (Case 5 below) and one in which it performs very significantly better (Case 2 below). Overall it's a wash except in those two cases. I've since done somewhat more involved testing on a dual-core Opteron system. Case 1: With no itimer running, for a test with 100,000 threads, the fixed kernel took 1428.5 seconds, 513 seconds more than the unfixed system, all of which was spent in the system. There were twice as many voluntary context switches with the fix as without it. Case 2: With an itimer running at .01 second ticks and 4000 threads (the most an unmodified kernel can handle), the fixed kernel ran the test in eight percent of the time (5.8 seconds as opposed to 70 seconds) and had better tick accuracy (.012 seconds per tick as opposed to .023 seconds per tick). Case 3: A 4000-thread test with an initial timer tick of .01 second and an interval of 10,000 seconds (i.e. a timer that ticks only once) had very nearly the same performance in both cases: 6.3 seconds elapsed for the fixed kernel versus 5.5 seconds for the unfixed kernel. With fewer threads (eight in these tests), the Case 1 test ran in essentially the same time on both the modified and unmodified kernels (5.2 seconds versus 5.8 seconds). The Case 2 test ran in about the same time as well, 5.9 seconds versus 5.4 seconds but again with much better tick accuracy, .013 seconds per tick versus .025 seconds per tick for the unmodified kernel. Since the fix affected the rlimit code, I also tested soft and hard CPU limits. Case 4: With a hard CPU limit of 20 seconds and eight threads (and an itimer running), the modified kernel was very slightly favored in that while it killed the process in 19.997 seconds of CPU time (5.002 seconds of wall time), only .003 seconds of that was system time, the rest was user time. The unmodified kernel killed the process in 20.001 seconds of CPU (5.014 seconds of wall time) of which .016 seconds was system time. Really, though, the results were too close to call. The results were essentially the same with no itimer running. Case 5: With a soft limit of 20 seconds and a hard limit of 2000 seconds (where the hard limit would never be reached) and an itimer running, the modified kernel exhibited worse tick accuracy than the unmodified kernel: .050 seconds/tick versus .028 seconds/tick. Otherwise, performance was almost indistinguishable. With no itimer running this test exhibited virtually identical behavior and times in both cases. In times past I did some limited performance testing. those results are below. On a four-cpu Opteron system without this fix, a sixteen-thread test executed in 3569.991 seconds, of which user was 3568.435s and system was 1.556s. On the same system with the fix, user and elapsed time were about the same, but system time dropped to 0.007 seconds. Performance with eight, four and one thread were comparable. Interestingly, the timer ticks with the fix seemed more accurate: The sixteen-thread test with the fix received 149543 ticks for 0.024 seconds per tick, while the same test without the fix received 58720 for 0.061 seconds per tick. Both cases were configured for an interval of 0.01 seconds. Again, the other tests were comparable. Each thread in this test computed the primes up to 25,000,000. I also did a test with a large number of threads, 100,000 threads, which is impossible without the fix. In this case each thread computed the primes only up to 10,000 (to make the runtime manageable). System time dominated, at 1546.968 seconds out of a total 2176.906 seconds (giving a user time of 629.938s). It received 147651 ticks for 0.015 seconds per tick, still quite accurate. There is obviously no comparable test without the fix. Signed-off-by: Frank Mayhar <fmayhar@google.com> Cc: Roland McGrath <roland@redhat.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-12 16:54:39 +00:00
account_group_user_time(p, cputime);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
/* Add user time to cpustat. */
tmp = cputime_to_cputime64(cputime);
if (TASK_NICE(p) > 0)
cpustat->nice = cputime64_add(cpustat->nice, tmp);
else
cpustat->user = cputime64_add(cpustat->user, tmp);
cpuacct: add per-cgroup utime/stime statistics Add per-cgroup cpuacct controller statistics like the system and user time consumed by the group of tasks. Changelog: v7 - Changed the name of the statistic from utime to user and from stime to system so that in future we could easily add other statistics like irq, softirq, steal times etc easily. v6 - Fixed a bug in the error path of cpuacct_create() (pointed by Li Zefan). v5 - In cpuacct_stats_show(), use cputime64_to_clock_t() since we are operating on a 64bit variable here. v4 - Remove comments in cpuacct_update_stats() which explained why rcu_read_lock() was needed (as per Peter Zijlstra's review comments). - Don't say that percpu_counter_read() is broken in Documentation/cpuacct.txt as per KAMEZAWA Hiroyuki's review comments. v3 - Fix a small race in the cpuacct hierarchy walk. v2 - stime and utime now exported in clock_t units instead of msecs. - Addressed the code review comments from Balbir and Li Zefan. - Moved to -tip tree. v1 - Moved the stime/utime accounting to cpuacct controller. Earlier versions - http://lkml.org/lkml/2009/2/25/129 Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com> Signed-off-by: Balaji Rao <balajirrao@gmail.com> Cc: Dhaval Giani <dhaval@linux.vnet.ibm.com> Cc: Paul Menage <menage@google.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Reviewed-by: Li Zefan <lizf@cn.fujitsu.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com> Tested-by: Balbir Singh <balbir@linux.vnet.ibm.com> LKML-Reference: <20090331043222.GA4093@in.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-31 04:32:22 +00:00
cpuacct_update_stats(p, CPUACCT_STAT_USER, cputime);
accounting: account for user time when updating memory integrals Adapt acct_update_integrals() to include user time when calculating the time difference. The units of acct_rss_mem1 and acct_vm_mem1 are also changed from pages-jiffies to pages-usecs to avoid calling jiffies_to_usecs() in xacct_add_tsk() which might overflow. Signed-off-by: Jonathan Lim <jlim@sgi.com> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-25 08:48:40 +00:00
/* Account for user time used */
acct_update_integrals(p);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
}
sched: guest CPU accounting: maintain stats in account_system_time() modify account_system_time() to add cputime to cpustat->guest if we are running a VCPU. We add this cputime to cpustat->user instead of cpustat->system because this part of KVM code is in fact user code although it is executed in the kernel. We duplicate VCPU time between guest and user to allow an unmodified "top(1)" to display correct value. A modified "top(1)" is able to display good cpu user time and cpu guest time by subtracting cpu guest time from cpu user time. Update "gtime" in task_struct accordingly. Signed-off-by: Laurent Vivier <Laurent.Vivier@bull.net> Acked-by: Avi Kivity <avi@qumranet.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 15:00:19 +00:00
/*
* Account guest cpu time to a process.
* @p: the process that the cpu time gets accounted to
* @cputime: the cpu time spent in virtual machine since the last update
[PATCH] fix scaled & unscaled cputime accounting The utimescaled / stimescaled fields in the task structure and the global cpustat should be set on all architectures. On s390 the calls to account_user_time_scaled and account_system_time_scaled never have been added. In addition system time that is accounted as guest time to the user time of a process is accounted to the scaled system time instead of the scaled user time. To fix the bugs and to prevent future forgetfulness this patch merges account_system_time_scaled into account_system_time and account_user_time_scaled into account_user_time. Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Jeremy Fitzhardinge <jeremy@xensource.com> Cc: Chris Wright <chrisw@sous-sol.org> Cc: Michael Neuling <mikey@neuling.org> Acked-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2008-12-31 14:11:37 +00:00
* @cputime_scaled: cputime scaled by cpu frequency
sched: guest CPU accounting: maintain stats in account_system_time() modify account_system_time() to add cputime to cpustat->guest if we are running a VCPU. We add this cputime to cpustat->user instead of cpustat->system because this part of KVM code is in fact user code although it is executed in the kernel. We duplicate VCPU time between guest and user to allow an unmodified "top(1)" to display correct value. A modified "top(1)" is able to display good cpu user time and cpu guest time by subtracting cpu guest time from cpu user time. Update "gtime" in task_struct accordingly. Signed-off-by: Laurent Vivier <Laurent.Vivier@bull.net> Acked-by: Avi Kivity <avi@qumranet.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 15:00:19 +00:00
*/
[PATCH] fix scaled & unscaled cputime accounting The utimescaled / stimescaled fields in the task structure and the global cpustat should be set on all architectures. On s390 the calls to account_user_time_scaled and account_system_time_scaled never have been added. In addition system time that is accounted as guest time to the user time of a process is accounted to the scaled system time instead of the scaled user time. To fix the bugs and to prevent future forgetfulness this patch merges account_system_time_scaled into account_system_time and account_user_time_scaled into account_user_time. Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Jeremy Fitzhardinge <jeremy@xensource.com> Cc: Chris Wright <chrisw@sous-sol.org> Cc: Michael Neuling <mikey@neuling.org> Acked-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2008-12-31 14:11:37 +00:00
static void account_guest_time(struct task_struct *p, cputime_t cputime,
cputime_t cputime_scaled)
sched: guest CPU accounting: maintain stats in account_system_time() modify account_system_time() to add cputime to cpustat->guest if we are running a VCPU. We add this cputime to cpustat->user instead of cpustat->system because this part of KVM code is in fact user code although it is executed in the kernel. We duplicate VCPU time between guest and user to allow an unmodified "top(1)" to display correct value. A modified "top(1)" is able to display good cpu user time and cpu guest time by subtracting cpu guest time from cpu user time. Update "gtime" in task_struct accordingly. Signed-off-by: Laurent Vivier <Laurent.Vivier@bull.net> Acked-by: Avi Kivity <avi@qumranet.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 15:00:19 +00:00
{
cputime64_t tmp;
struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat;
tmp = cputime_to_cputime64(cputime);
[PATCH] fix scaled & unscaled cputime accounting The utimescaled / stimescaled fields in the task structure and the global cpustat should be set on all architectures. On s390 the calls to account_user_time_scaled and account_system_time_scaled never have been added. In addition system time that is accounted as guest time to the user time of a process is accounted to the scaled system time instead of the scaled user time. To fix the bugs and to prevent future forgetfulness this patch merges account_system_time_scaled into account_system_time and account_user_time_scaled into account_user_time. Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Jeremy Fitzhardinge <jeremy@xensource.com> Cc: Chris Wright <chrisw@sous-sol.org> Cc: Michael Neuling <mikey@neuling.org> Acked-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2008-12-31 14:11:37 +00:00
/* Add guest time to process. */
sched: guest CPU accounting: maintain stats in account_system_time() modify account_system_time() to add cputime to cpustat->guest if we are running a VCPU. We add this cputime to cpustat->user instead of cpustat->system because this part of KVM code is in fact user code although it is executed in the kernel. We duplicate VCPU time between guest and user to allow an unmodified "top(1)" to display correct value. A modified "top(1)" is able to display good cpu user time and cpu guest time by subtracting cpu guest time from cpu user time. Update "gtime" in task_struct accordingly. Signed-off-by: Laurent Vivier <Laurent.Vivier@bull.net> Acked-by: Avi Kivity <avi@qumranet.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 15:00:19 +00:00
p->utime = cputime_add(p->utime, cputime);
[PATCH] fix scaled & unscaled cputime accounting The utimescaled / stimescaled fields in the task structure and the global cpustat should be set on all architectures. On s390 the calls to account_user_time_scaled and account_system_time_scaled never have been added. In addition system time that is accounted as guest time to the user time of a process is accounted to the scaled system time instead of the scaled user time. To fix the bugs and to prevent future forgetfulness this patch merges account_system_time_scaled into account_system_time and account_user_time_scaled into account_user_time. Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Jeremy Fitzhardinge <jeremy@xensource.com> Cc: Chris Wright <chrisw@sous-sol.org> Cc: Michael Neuling <mikey@neuling.org> Acked-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2008-12-31 14:11:37 +00:00
p->utimescaled = cputime_add(p->utimescaled, cputime_scaled);
timers: fix itimer/many thread hang Overview This patch reworks the handling of POSIX CPU timers, including the ITIMER_PROF, ITIMER_VIRT timers and rlimit handling. It was put together with the help of Roland McGrath, the owner and original writer of this code. The problem we ran into, and the reason for this rework, has to do with using a profiling timer in a process with a large number of threads. It appears that the performance of the old implementation of run_posix_cpu_timers() was at least O(n*3) (where "n" is the number of threads in a process) or worse. Everything is fine with an increasing number of threads until the time taken for that routine to run becomes the same as or greater than the tick time, at which point things degrade rather quickly. This patch fixes bug 9906, "Weird hang with NPTL and SIGPROF." Code Changes This rework corrects the implementation of run_posix_cpu_timers() to make it run in constant time for a particular machine. (Performance may vary between one machine and another depending upon whether the kernel is built as single- or multiprocessor and, in the latter case, depending upon the number of running processors.) To do this, at each tick we now update fields in signal_struct as well as task_struct. The run_posix_cpu_timers() function uses those fields to make its decisions. We define a new structure, "task_cputime," to contain user, system and scheduler times and use these in appropriate places: struct task_cputime { cputime_t utime; cputime_t stime; unsigned long long sum_exec_runtime; }; This is included in the structure "thread_group_cputime," which is a new substructure of signal_struct and which varies for uniprocessor versus multiprocessor kernels. For uniprocessor kernels, it uses "task_cputime" as a simple substructure, while for multiprocessor kernels it is a pointer: struct thread_group_cputime { struct task_cputime totals; }; struct thread_group_cputime { struct task_cputime *totals; }; We also add a new task_cputime substructure directly to signal_struct, to cache the earliest expiration of process-wide timers, and task_cputime also replaces the it_*_expires fields of task_struct (used for earliest expiration of thread timers). The "thread_group_cputime" structure contains process-wide timers that are updated via account_user_time() and friends. In the non-SMP case the structure is a simple aggregator; unfortunately in the SMP case that simplicity was not achievable due to cache-line contention between CPUs (in one measured case performance was actually _worse_ on a 16-cpu system than the same test on a 4-cpu system, due to this contention). For SMP, the thread_group_cputime counters are maintained as a per-cpu structure allocated using alloc_percpu(). The timer functions update only the timer field in the structure corresponding to the running CPU, obtained using per_cpu_ptr(). We define a set of inline functions in sched.h that we use to maintain the thread_group_cputime structure and hide the differences between UP and SMP implementations from the rest of the kernel. The thread_group_cputime_init() function initializes the thread_group_cputime structure for the given task. The thread_group_cputime_alloc() is a no-op for UP; for SMP it calls the out-of-line function thread_group_cputime_alloc_smp() to allocate and fill in the per-cpu structures and fields. The thread_group_cputime_free() function, also a no-op for UP, in SMP frees the per-cpu structures. The thread_group_cputime_clone_thread() function (also a UP no-op) for SMP calls thread_group_cputime_alloc() if the per-cpu structures haven't yet been allocated. The thread_group_cputime() function fills the task_cputime structure it is passed with the contents of the thread_group_cputime fields; in UP it's that simple but in SMP it must also safely check that tsk->signal is non-NULL (if it is it just uses the appropriate fields of task_struct) and, if so, sums the per-cpu values for each online CPU. Finally, the three functions account_group_user_time(), account_group_system_time() and account_group_exec_runtime() are used by timer functions to update the respective fields of the thread_group_cputime structure. Non-SMP operation is trivial and will not be mentioned further. The per-cpu structure is always allocated when a task creates its first new thread, via a call to thread_group_cputime_clone_thread() from copy_signal(). It is freed at process exit via a call to thread_group_cputime_free() from cleanup_signal(). All functions that formerly summed utime/stime/sum_sched_runtime values from from all threads in the thread group now use thread_group_cputime() to snapshot the values in the thread_group_cputime structure or the values in the task structure itself if the per-cpu structure hasn't been allocated. Finally, the code in kernel/posix-cpu-timers.c has changed quite a bit. The run_posix_cpu_timers() function has been split into a fast path and a slow path; the former safely checks whether there are any expired thread timers and, if not, just returns, while the slow path does the heavy lifting. With the dedicated thread group fields, timers are no longer "rebalanced" and the process_timer_rebalance() function and related code has gone away. All summing loops are gone and all code that used them now uses the thread_group_cputime() inline. When process-wide timers are set, the new task_cputime structure in signal_struct is used to cache the earliest expiration; this is checked in the fast path. Performance The fix appears not to add significant overhead to existing operations. It generally performs the same as the current code except in two cases, one in which it performs slightly worse (Case 5 below) and one in which it performs very significantly better (Case 2 below). Overall it's a wash except in those two cases. I've since done somewhat more involved testing on a dual-core Opteron system. Case 1: With no itimer running, for a test with 100,000 threads, the fixed kernel took 1428.5 seconds, 513 seconds more than the unfixed system, all of which was spent in the system. There were twice as many voluntary context switches with the fix as without it. Case 2: With an itimer running at .01 second ticks and 4000 threads (the most an unmodified kernel can handle), the fixed kernel ran the test in eight percent of the time (5.8 seconds as opposed to 70 seconds) and had better tick accuracy (.012 seconds per tick as opposed to .023 seconds per tick). Case 3: A 4000-thread test with an initial timer tick of .01 second and an interval of 10,000 seconds (i.e. a timer that ticks only once) had very nearly the same performance in both cases: 6.3 seconds elapsed for the fixed kernel versus 5.5 seconds for the unfixed kernel. With fewer threads (eight in these tests), the Case 1 test ran in essentially the same time on both the modified and unmodified kernels (5.2 seconds versus 5.8 seconds). The Case 2 test ran in about the same time as well, 5.9 seconds versus 5.4 seconds but again with much better tick accuracy, .013 seconds per tick versus .025 seconds per tick for the unmodified kernel. Since the fix affected the rlimit code, I also tested soft and hard CPU limits. Case 4: With a hard CPU limit of 20 seconds and eight threads (and an itimer running), the modified kernel was very slightly favored in that while it killed the process in 19.997 seconds of CPU time (5.002 seconds of wall time), only .003 seconds of that was system time, the rest was user time. The unmodified kernel killed the process in 20.001 seconds of CPU (5.014 seconds of wall time) of which .016 seconds was system time. Really, though, the results were too close to call. The results were essentially the same with no itimer running. Case 5: With a soft limit of 20 seconds and a hard limit of 2000 seconds (where the hard limit would never be reached) and an itimer running, the modified kernel exhibited worse tick accuracy than the unmodified kernel: .050 seconds/tick versus .028 seconds/tick. Otherwise, performance was almost indistinguishable. With no itimer running this test exhibited virtually identical behavior and times in both cases. In times past I did some limited performance testing. those results are below. On a four-cpu Opteron system without this fix, a sixteen-thread test executed in 3569.991 seconds, of which user was 3568.435s and system was 1.556s. On the same system with the fix, user and elapsed time were about the same, but system time dropped to 0.007 seconds. Performance with eight, four and one thread were comparable. Interestingly, the timer ticks with the fix seemed more accurate: The sixteen-thread test with the fix received 149543 ticks for 0.024 seconds per tick, while the same test without the fix received 58720 for 0.061 seconds per tick. Both cases were configured for an interval of 0.01 seconds. Again, the other tests were comparable. Each thread in this test computed the primes up to 25,000,000. I also did a test with a large number of threads, 100,000 threads, which is impossible without the fix. In this case each thread computed the primes only up to 10,000 (to make the runtime manageable). System time dominated, at 1546.968 seconds out of a total 2176.906 seconds (giving a user time of 629.938s). It received 147651 ticks for 0.015 seconds per tick, still quite accurate. There is obviously no comparable test without the fix. Signed-off-by: Frank Mayhar <fmayhar@google.com> Cc: Roland McGrath <roland@redhat.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-12 16:54:39 +00:00
account_group_user_time(p, cputime);
sched: guest CPU accounting: maintain stats in account_system_time() modify account_system_time() to add cputime to cpustat->guest if we are running a VCPU. We add this cputime to cpustat->user instead of cpustat->system because this part of KVM code is in fact user code although it is executed in the kernel. We duplicate VCPU time between guest and user to allow an unmodified "top(1)" to display correct value. A modified "top(1)" is able to display good cpu user time and cpu guest time by subtracting cpu guest time from cpu user time. Update "gtime" in task_struct accordingly. Signed-off-by: Laurent Vivier <Laurent.Vivier@bull.net> Acked-by: Avi Kivity <avi@qumranet.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 15:00:19 +00:00
p->gtime = cputime_add(p->gtime, cputime);
[PATCH] fix scaled & unscaled cputime accounting The utimescaled / stimescaled fields in the task structure and the global cpustat should be set on all architectures. On s390 the calls to account_user_time_scaled and account_system_time_scaled never have been added. In addition system time that is accounted as guest time to the user time of a process is accounted to the scaled system time instead of the scaled user time. To fix the bugs and to prevent future forgetfulness this patch merges account_system_time_scaled into account_system_time and account_user_time_scaled into account_user_time. Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Jeremy Fitzhardinge <jeremy@xensource.com> Cc: Chris Wright <chrisw@sous-sol.org> Cc: Michael Neuling <mikey@neuling.org> Acked-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2008-12-31 14:11:37 +00:00
/* Add guest time to cpustat. */
sched, cpuacct: Fix niced guest time accounting CPU time of a guest is always accounted in 'user' time without concern for the nice value of its counterpart process although the guest is scheduled under the nice value. This patch fixes the defect and accounts cpu time of a niced guest in 'nice' time as same as a niced process. And also the patch adds 'guest_nice' to cpuacct. The value provides niced guest cpu time which is like 'nice' to 'user'. The original discussions can be found here: http://www.mail-archive.com/kvm@vger.kernel.org/msg23982.html http://www.mail-archive.com/kvm@vger.kernel.org/msg23860.html Signed-off-by: Ryota Ozaki <ozaki.ryota@gmail.com> Acked-by: Avi Kivity <avi@redhat.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1256314810-7897-1-git-send-email-ozaki.ryota@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-10-23 16:20:10 +00:00
if (TASK_NICE(p) > 0) {
cpustat->nice = cputime64_add(cpustat->nice, tmp);
cpustat->guest_nice = cputime64_add(cpustat->guest_nice, tmp);
} else {
cpustat->user = cputime64_add(cpustat->user, tmp);
cpustat->guest = cputime64_add(cpustat->guest, tmp);
}
sched: guest CPU accounting: maintain stats in account_system_time() modify account_system_time() to add cputime to cpustat->guest if we are running a VCPU. We add this cputime to cpustat->user instead of cpustat->system because this part of KVM code is in fact user code although it is executed in the kernel. We duplicate VCPU time between guest and user to allow an unmodified "top(1)" to display correct value. A modified "top(1)" is able to display good cpu user time and cpu guest time by subtracting cpu guest time from cpu user time. Update "gtime" in task_struct accordingly. Signed-off-by: Laurent Vivier <Laurent.Vivier@bull.net> Acked-by: Avi Kivity <avi@qumranet.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 15:00:19 +00:00
}
sched: Refactor account_system_time separating id-update Refactor account_system_time, to separate out the logic of identifying the update needed and code that does actual update. This is used by following patch for IRQ_TIME_ACCOUNTING, which has different identification logic and same update logic. Tested-by: Shaun Ruffell <sruffell@digium.com> Signed-off-by: Venkatesh Pallipadi <venki@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1292980144-28796-4-git-send-email-venki@google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-12-22 01:09:02 +00:00
/*
* Account system cpu time to a process and desired cpustat field
* @p: the process that the cpu time gets accounted to
* @cputime: the cpu time spent in kernel space since the last update
* @cputime_scaled: cputime scaled by cpu frequency
* @target_cputime64: pointer to cpustat field that has to be updated
*/
static inline
void __account_system_time(struct task_struct *p, cputime_t cputime,
cputime_t cputime_scaled, cputime64_t *target_cputime64)
{
cputime64_t tmp = cputime_to_cputime64(cputime);
/* Add system time to process. */
p->stime = cputime_add(p->stime, cputime);
p->stimescaled = cputime_add(p->stimescaled, cputime_scaled);
account_group_system_time(p, cputime);
/* Add system time to cpustat. */
*target_cputime64 = cputime64_add(*target_cputime64, tmp);
cpuacct_update_stats(p, CPUACCT_STAT_SYSTEM, cputime);
/* Account for system time used */
acct_update_integrals(p);
}
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
/*
* Account system cpu time to a process.
* @p: the process that the cpu time gets accounted to
* @hardirq_offset: the offset to subtract from hardirq_count()
* @cputime: the cpu time spent in kernel space since the last update
[PATCH] fix scaled & unscaled cputime accounting The utimescaled / stimescaled fields in the task structure and the global cpustat should be set on all architectures. On s390 the calls to account_user_time_scaled and account_system_time_scaled never have been added. In addition system time that is accounted as guest time to the user time of a process is accounted to the scaled system time instead of the scaled user time. To fix the bugs and to prevent future forgetfulness this patch merges account_system_time_scaled into account_system_time and account_user_time_scaled into account_user_time. Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Jeremy Fitzhardinge <jeremy@xensource.com> Cc: Chris Wright <chrisw@sous-sol.org> Cc: Michael Neuling <mikey@neuling.org> Acked-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2008-12-31 14:11:37 +00:00
* @cputime_scaled: cputime scaled by cpu frequency
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
*/
void account_system_time(struct task_struct *p, int hardirq_offset,
[PATCH] fix scaled & unscaled cputime accounting The utimescaled / stimescaled fields in the task structure and the global cpustat should be set on all architectures. On s390 the calls to account_user_time_scaled and account_system_time_scaled never have been added. In addition system time that is accounted as guest time to the user time of a process is accounted to the scaled system time instead of the scaled user time. To fix the bugs and to prevent future forgetfulness this patch merges account_system_time_scaled into account_system_time and account_user_time_scaled into account_user_time. Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Jeremy Fitzhardinge <jeremy@xensource.com> Cc: Chris Wright <chrisw@sous-sol.org> Cc: Michael Neuling <mikey@neuling.org> Acked-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2008-12-31 14:11:37 +00:00
cputime_t cputime, cputime_t cputime_scaled)
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
{
struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat;
sched: Refactor account_system_time separating id-update Refactor account_system_time, to separate out the logic of identifying the update needed and code that does actual update. This is used by following patch for IRQ_TIME_ACCOUNTING, which has different identification logic and same update logic. Tested-by: Shaun Ruffell <sruffell@digium.com> Signed-off-by: Venkatesh Pallipadi <venki@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1292980144-28796-4-git-send-email-venki@google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-12-22 01:09:02 +00:00
cputime64_t *target_cputime64;
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
sched: add statics, don't return void expressions Noticed by sparse: kernel/sched.c:760:20: warning: symbol 'sched_feat_names' was not declared. Should it be static? kernel/sched.c:767:5: warning: symbol 'sched_feat_open' was not declared. Should it be static? kernel/sched_fair.c:845:3: warning: returning void-valued expression kernel/sched.c:4386:3: warning: returning void-valued expression Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-25 01:17:55 +00:00
if ((p->flags & PF_VCPU) && (irq_count() - hardirq_offset == 0)) {
[PATCH] fix scaled & unscaled cputime accounting The utimescaled / stimescaled fields in the task structure and the global cpustat should be set on all architectures. On s390 the calls to account_user_time_scaled and account_system_time_scaled never have been added. In addition system time that is accounted as guest time to the user time of a process is accounted to the scaled system time instead of the scaled user time. To fix the bugs and to prevent future forgetfulness this patch merges account_system_time_scaled into account_system_time and account_user_time_scaled into account_user_time. Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Jeremy Fitzhardinge <jeremy@xensource.com> Cc: Chris Wright <chrisw@sous-sol.org> Cc: Michael Neuling <mikey@neuling.org> Acked-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2008-12-31 14:11:37 +00:00
account_guest_time(p, cputime, cputime_scaled);
sched: add statics, don't return void expressions Noticed by sparse: kernel/sched.c:760:20: warning: symbol 'sched_feat_names' was not declared. Should it be static? kernel/sched.c:767:5: warning: symbol 'sched_feat_open' was not declared. Should it be static? kernel/sched_fair.c:845:3: warning: returning void-valued expression kernel/sched.c:4386:3: warning: returning void-valued expression Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-25 01:17:55 +00:00
return;
}
sched: guest CPU accounting: maintain stats in account_system_time() modify account_system_time() to add cputime to cpustat->guest if we are running a VCPU. We add this cputime to cpustat->user instead of cpustat->system because this part of KVM code is in fact user code although it is executed in the kernel. We duplicate VCPU time between guest and user to allow an unmodified "top(1)" to display correct value. A modified "top(1)" is able to display good cpu user time and cpu guest time by subtracting cpu guest time from cpu user time. Update "gtime" in task_struct accordingly. Signed-off-by: Laurent Vivier <Laurent.Vivier@bull.net> Acked-by: Avi Kivity <avi@qumranet.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 15:00:19 +00:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
if (hardirq_count() - hardirq_offset)
sched: Refactor account_system_time separating id-update Refactor account_system_time, to separate out the logic of identifying the update needed and code that does actual update. This is used by following patch for IRQ_TIME_ACCOUNTING, which has different identification logic and same update logic. Tested-by: Shaun Ruffell <sruffell@digium.com> Signed-off-by: Venkatesh Pallipadi <venki@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1292980144-28796-4-git-send-email-venki@google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-12-22 01:09:02 +00:00
target_cputime64 = &cpustat->irq;
sched: Fix softirq time accounting Peter Zijlstra found a bug in the way softirq time is accounted in VIRT_CPU_ACCOUNTING on this thread: http://lkml.indiana.edu/hypermail//linux/kernel/1009.2/01366.html The problem is, softirq processing uses local_bh_disable internally. There is no way, later in the flow, to differentiate between whether softirq is being processed or is it just that bh has been disabled. So, a hardirq when bh is disabled results in time being wrongly accounted as softirq. Looking at the code a bit more, the problem exists in !VIRT_CPU_ACCOUNTING as well. As account_system_time() in normal tick based accouting also uses softirq_count, which will be set even when not in softirq with bh disabled. Peter also suggested solution of using 2*SOFTIRQ_OFFSET as irq count for local_bh_{disable,enable} and using just SOFTIRQ_OFFSET while softirq processing. The patch below does that and adds API in_serving_softirq() which returns whether we are currently processing softirq or not. Also changes one of the usages of softirq_count in net/sched/cls_cgroup.c to in_serving_softirq. Looks like many usages of in_softirq really want in_serving_softirq. Those changes can be made individually on a case by case basis. Signed-off-by: Venkatesh Pallipadi <venki@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1286237003-12406-2-git-send-email-venki@google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-05 00:03:16 +00:00
else if (in_serving_softirq())
sched: Refactor account_system_time separating id-update Refactor account_system_time, to separate out the logic of identifying the update needed and code that does actual update. This is used by following patch for IRQ_TIME_ACCOUNTING, which has different identification logic and same update logic. Tested-by: Shaun Ruffell <sruffell@digium.com> Signed-off-by: Venkatesh Pallipadi <venki@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1292980144-28796-4-git-send-email-venki@google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-12-22 01:09:02 +00:00
target_cputime64 = &cpustat->softirq;
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
else
sched: Refactor account_system_time separating id-update Refactor account_system_time, to separate out the logic of identifying the update needed and code that does actual update. This is used by following patch for IRQ_TIME_ACCOUNTING, which has different identification logic and same update logic. Tested-by: Shaun Ruffell <sruffell@digium.com> Signed-off-by: Venkatesh Pallipadi <venki@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1292980144-28796-4-git-send-email-venki@google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-12-22 01:09:02 +00:00
target_cputime64 = &cpustat->system;
cpuacct: add per-cgroup utime/stime statistics Add per-cgroup cpuacct controller statistics like the system and user time consumed by the group of tasks. Changelog: v7 - Changed the name of the statistic from utime to user and from stime to system so that in future we could easily add other statistics like irq, softirq, steal times etc easily. v6 - Fixed a bug in the error path of cpuacct_create() (pointed by Li Zefan). v5 - In cpuacct_stats_show(), use cputime64_to_clock_t() since we are operating on a 64bit variable here. v4 - Remove comments in cpuacct_update_stats() which explained why rcu_read_lock() was needed (as per Peter Zijlstra's review comments). - Don't say that percpu_counter_read() is broken in Documentation/cpuacct.txt as per KAMEZAWA Hiroyuki's review comments. v3 - Fix a small race in the cpuacct hierarchy walk. v2 - stime and utime now exported in clock_t units instead of msecs. - Addressed the code review comments from Balbir and Li Zefan. - Moved to -tip tree. v1 - Moved the stime/utime accounting to cpuacct controller. Earlier versions - http://lkml.org/lkml/2009/2/25/129 Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com> Signed-off-by: Balaji Rao <balajirrao@gmail.com> Cc: Dhaval Giani <dhaval@linux.vnet.ibm.com> Cc: Paul Menage <menage@google.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Reviewed-by: Li Zefan <lizf@cn.fujitsu.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com> Tested-by: Balbir Singh <balbir@linux.vnet.ibm.com> LKML-Reference: <20090331043222.GA4093@in.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-31 04:32:22 +00:00
sched: Refactor account_system_time separating id-update Refactor account_system_time, to separate out the logic of identifying the update needed and code that does actual update. This is used by following patch for IRQ_TIME_ACCOUNTING, which has different identification logic and same update logic. Tested-by: Shaun Ruffell <sruffell@digium.com> Signed-off-by: Venkatesh Pallipadi <venki@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1292980144-28796-4-git-send-email-venki@google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-12-22 01:09:02 +00:00
__account_system_time(p, cputime, cputime_scaled, target_cputime64);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
}
Add scaled time to taskstats based process accounting This adds items to the taststats struct to account for user and system time based on scaling the CPU frequency and instruction issue rates. Adds account_(user|system)_time_scaled callbacks which architectures can use to account for time using this mechanism. Signed-off-by: Michael Neuling <mikey@neuling.org> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Jay Lan <jlan@engr.sgi.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-18 10:06:34 +00:00
/*
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
* Account for involuntary wait time.
sched: Clean up the IRQ_TIME_ACCOUNTING code Fix this warning: lkml.org/lkml/2011/1/30/124 kernel/sched.c:3719: warning: 'irqtime_account_idle_ticks' defined but not used kernel/sched.c:3720: warning: 'irqtime_account_process_tick' defined but not used In a cleaner way than: 7e9498705e81: sched: Add #ifdef around irq time accounting functions This patch will not have any functional impact. Signed-off-by: Venkatesh Pallipadi <venki@google.com> Cc: heiko.carstens@de.ibm.com Cc: a.p.zijlstra@chello.nl LKML-Reference: <1298675596-10992-1-git-send-email-venki@google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-02-25 23:13:16 +00:00
* @cputime: the cpu time spent in involuntary wait
Add scaled time to taskstats based process accounting This adds items to the taststats struct to account for user and system time based on scaling the CPU frequency and instruction issue rates. Adds account_(user|system)_time_scaled callbacks which architectures can use to account for time using this mechanism. Signed-off-by: Michael Neuling <mikey@neuling.org> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Jay Lan <jlan@engr.sgi.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-18 10:06:34 +00:00
*/
[PATCH] idle cputime accounting The cpu time spent by the idle process actually doing something is currently accounted as idle time. This is plain wrong, the architectures that support VIRT_CPU_ACCOUNTING=y can do better: distinguish between the time spent doing nothing and the time spent by idle doing work. The first is accounted with account_idle_time and the second with account_system_time. The architectures that use the account_xxx_time interface directly and not the account_xxx_ticks interface now need to do the check for the idle process in their arch code. In particular to improve the system vs true idle time accounting the arch code needs to measure the true idle time instead of just testing for the idle process. To improve the tick based accounting as well we would need an architecture primitive that can tell us if the pt_regs of the interrupted context points to the magic instruction that halts the cpu. In addition idle time is no more added to the stime of the idle process. This field now contains the system time of the idle process as it should be. On systems without VIRT_CPU_ACCOUNTING this will always be zero as every tick that occurs while idle is running will be accounted as idle time. This patch contains the necessary common code changes to be able to distinguish idle system time and true idle time. The architectures with support for VIRT_CPU_ACCOUNTING need some changes to exploit this. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2008-12-31 14:11:38 +00:00
void account_steal_time(cputime_t cputime)
Add scaled time to taskstats based process accounting This adds items to the taststats struct to account for user and system time based on scaling the CPU frequency and instruction issue rates. Adds account_(user|system)_time_scaled callbacks which architectures can use to account for time using this mechanism. Signed-off-by: Michael Neuling <mikey@neuling.org> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Jay Lan <jlan@engr.sgi.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-18 10:06:34 +00:00
{
[PATCH] idle cputime accounting The cpu time spent by the idle process actually doing something is currently accounted as idle time. This is plain wrong, the architectures that support VIRT_CPU_ACCOUNTING=y can do better: distinguish between the time spent doing nothing and the time spent by idle doing work. The first is accounted with account_idle_time and the second with account_system_time. The architectures that use the account_xxx_time interface directly and not the account_xxx_ticks interface now need to do the check for the idle process in their arch code. In particular to improve the system vs true idle time accounting the arch code needs to measure the true idle time instead of just testing for the idle process. To improve the tick based accounting as well we would need an architecture primitive that can tell us if the pt_regs of the interrupted context points to the magic instruction that halts the cpu. In addition idle time is no more added to the stime of the idle process. This field now contains the system time of the idle process as it should be. On systems without VIRT_CPU_ACCOUNTING this will always be zero as every tick that occurs while idle is running will be accounted as idle time. This patch contains the necessary common code changes to be able to distinguish idle system time and true idle time. The architectures with support for VIRT_CPU_ACCOUNTING need some changes to exploit this. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2008-12-31 14:11:38 +00:00
struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat;
cputime64_t cputime64 = cputime_to_cputime64(cputime);
cpustat->steal = cputime64_add(cpustat->steal, cputime64);
Add scaled time to taskstats based process accounting This adds items to the taststats struct to account for user and system time based on scaling the CPU frequency and instruction issue rates. Adds account_(user|system)_time_scaled callbacks which architectures can use to account for time using this mechanism. Signed-off-by: Michael Neuling <mikey@neuling.org> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Jay Lan <jlan@engr.sgi.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-18 10:06:34 +00:00
}
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
/*
[PATCH] idle cputime accounting The cpu time spent by the idle process actually doing something is currently accounted as idle time. This is plain wrong, the architectures that support VIRT_CPU_ACCOUNTING=y can do better: distinguish between the time spent doing nothing and the time spent by idle doing work. The first is accounted with account_idle_time and the second with account_system_time. The architectures that use the account_xxx_time interface directly and not the account_xxx_ticks interface now need to do the check for the idle process in their arch code. In particular to improve the system vs true idle time accounting the arch code needs to measure the true idle time instead of just testing for the idle process. To improve the tick based accounting as well we would need an architecture primitive that can tell us if the pt_regs of the interrupted context points to the magic instruction that halts the cpu. In addition idle time is no more added to the stime of the idle process. This field now contains the system time of the idle process as it should be. On systems without VIRT_CPU_ACCOUNTING this will always be zero as every tick that occurs while idle is running will be accounted as idle time. This patch contains the necessary common code changes to be able to distinguish idle system time and true idle time. The architectures with support for VIRT_CPU_ACCOUNTING need some changes to exploit this. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2008-12-31 14:11:38 +00:00
* Account for idle time.
* @cputime: the cpu time spent in idle wait
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
*/
[PATCH] idle cputime accounting The cpu time spent by the idle process actually doing something is currently accounted as idle time. This is plain wrong, the architectures that support VIRT_CPU_ACCOUNTING=y can do better: distinguish between the time spent doing nothing and the time spent by idle doing work. The first is accounted with account_idle_time and the second with account_system_time. The architectures that use the account_xxx_time interface directly and not the account_xxx_ticks interface now need to do the check for the idle process in their arch code. In particular to improve the system vs true idle time accounting the arch code needs to measure the true idle time instead of just testing for the idle process. To improve the tick based accounting as well we would need an architecture primitive that can tell us if the pt_regs of the interrupted context points to the magic instruction that halts the cpu. In addition idle time is no more added to the stime of the idle process. This field now contains the system time of the idle process as it should be. On systems without VIRT_CPU_ACCOUNTING this will always be zero as every tick that occurs while idle is running will be accounted as idle time. This patch contains the necessary common code changes to be able to distinguish idle system time and true idle time. The architectures with support for VIRT_CPU_ACCOUNTING need some changes to exploit this. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2008-12-31 14:11:38 +00:00
void account_idle_time(cputime_t cputime)
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
{
struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat;
[PATCH] idle cputime accounting The cpu time spent by the idle process actually doing something is currently accounted as idle time. This is plain wrong, the architectures that support VIRT_CPU_ACCOUNTING=y can do better: distinguish between the time spent doing nothing and the time spent by idle doing work. The first is accounted with account_idle_time and the second with account_system_time. The architectures that use the account_xxx_time interface directly and not the account_xxx_ticks interface now need to do the check for the idle process in their arch code. In particular to improve the system vs true idle time accounting the arch code needs to measure the true idle time instead of just testing for the idle process. To improve the tick based accounting as well we would need an architecture primitive that can tell us if the pt_regs of the interrupted context points to the magic instruction that halts the cpu. In addition idle time is no more added to the stime of the idle process. This field now contains the system time of the idle process as it should be. On systems without VIRT_CPU_ACCOUNTING this will always be zero as every tick that occurs while idle is running will be accounted as idle time. This patch contains the necessary common code changes to be able to distinguish idle system time and true idle time. The architectures with support for VIRT_CPU_ACCOUNTING need some changes to exploit this. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2008-12-31 14:11:38 +00:00
cputime64_t cputime64 = cputime_to_cputime64(cputime);
[PATCH] sched: cleanup, convert sched.c-internal typedefs to struct convert: - runqueue_t to 'struct rq' - prio_array_t to 'struct prio_array' - migration_req_t to 'struct migration_req' I was the one who added these but they are both against the kernel coding style and also were used inconsistently at places. So just get rid of them at once, now that we are flushing the scheduler patch-queue anyway. Conversion was mostly scripted, the result was reviewed and all secondary whitespace and style impact (if any) was fixed up by hand. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-03 07:25:42 +00:00
struct rq *rq = this_rq();
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
[PATCH] idle cputime accounting The cpu time spent by the idle process actually doing something is currently accounted as idle time. This is plain wrong, the architectures that support VIRT_CPU_ACCOUNTING=y can do better: distinguish between the time spent doing nothing and the time spent by idle doing work. The first is accounted with account_idle_time and the second with account_system_time. The architectures that use the account_xxx_time interface directly and not the account_xxx_ticks interface now need to do the check for the idle process in their arch code. In particular to improve the system vs true idle time accounting the arch code needs to measure the true idle time instead of just testing for the idle process. To improve the tick based accounting as well we would need an architecture primitive that can tell us if the pt_regs of the interrupted context points to the magic instruction that halts the cpu. In addition idle time is no more added to the stime of the idle process. This field now contains the system time of the idle process as it should be. On systems without VIRT_CPU_ACCOUNTING this will always be zero as every tick that occurs while idle is running will be accounted as idle time. This patch contains the necessary common code changes to be able to distinguish idle system time and true idle time. The architectures with support for VIRT_CPU_ACCOUNTING need some changes to exploit this. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2008-12-31 14:11:38 +00:00
if (atomic_read(&rq->nr_iowait) > 0)
cpustat->iowait = cputime64_add(cpustat->iowait, cputime64);
else
cpustat->idle = cputime64_add(cpustat->idle, cputime64);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
}
KVM guest: Steal time accounting This patch accounts steal time time in account_process_tick. If one or more tick is considered stolen in the current accounting cycle, user/system accounting is skipped. Idle is fine, since the hypervisor does not report steal time if the guest is halted. Accounting steal time from the core scheduler give us the advantage of direct acess to the runqueue data. In a later opportunity, it can be used to tweak cpu power and make the scheduler aware of the time it lost. [avi: <asm/paravirt.h> doesn't exist on many archs] Signed-off-by: Glauber Costa <glommer@redhat.com> Acked-by: Rik van Riel <riel@redhat.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Tested-by: Eric B Munson <emunson@mgebm.net> CC: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> CC: Anthony Liguori <aliguori@us.ibm.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-07-11 19:28:17 +00:00
static __always_inline bool steal_account_process_tick(void)
{
#ifdef CONFIG_PARAVIRT
if (static_branch(&paravirt_steal_enabled)) {
u64 steal, st = 0;
steal = paravirt_steal_clock(smp_processor_id());
steal -= this_rq()->prev_steal_time;
st = steal_ticks(steal);
this_rq()->prev_steal_time += st * TICK_NSEC;
account_steal_time(st);
return st;
}
#endif
return false;
}
[PATCH] idle cputime accounting The cpu time spent by the idle process actually doing something is currently accounted as idle time. This is plain wrong, the architectures that support VIRT_CPU_ACCOUNTING=y can do better: distinguish between the time spent doing nothing and the time spent by idle doing work. The first is accounted with account_idle_time and the second with account_system_time. The architectures that use the account_xxx_time interface directly and not the account_xxx_ticks interface now need to do the check for the idle process in their arch code. In particular to improve the system vs true idle time accounting the arch code needs to measure the true idle time instead of just testing for the idle process. To improve the tick based accounting as well we would need an architecture primitive that can tell us if the pt_regs of the interrupted context points to the magic instruction that halts the cpu. In addition idle time is no more added to the stime of the idle process. This field now contains the system time of the idle process as it should be. On systems without VIRT_CPU_ACCOUNTING this will always be zero as every tick that occurs while idle is running will be accounted as idle time. This patch contains the necessary common code changes to be able to distinguish idle system time and true idle time. The architectures with support for VIRT_CPU_ACCOUNTING need some changes to exploit this. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2008-12-31 14:11:38 +00:00
#ifndef CONFIG_VIRT_CPU_ACCOUNTING
sched: Export ns irqtimes through /proc/stat CONFIG_IRQ_TIME_ACCOUNTING adds ns granularity irq time on each CPU. This info is already used in scheduler to do proper task chargeback (earlier patches). This patch retro-fits this ns granularity hardirq and softirq information to /proc/stat irq and softirq fields. The update is still done on timer tick, where we look at accumulated ns hardirq/softirq time and account the tick to user/system/irq/hardirq/guest accordingly. No new interface added. Earlier versions looked at adding this as new fields in some /proc files. This one seems to be the best in terms of impact to existing apps, even though it has somewhat more kernel code than earlier versions. Tested-by: Shaun Ruffell <sruffell@digium.com> Signed-off-by: Venkatesh Pallipadi <venki@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1292980144-28796-5-git-send-email-venki@google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-12-22 01:09:03 +00:00
#ifdef CONFIG_IRQ_TIME_ACCOUNTING
/*
* Account a tick to a process and cpustat
* @p: the process that the cpu time gets accounted to
* @user_tick: is the tick from userspace
* @rq: the pointer to rq
*
* Tick demultiplexing follows the order
* - pending hardirq update
* - pending softirq update
* - user_time
* - idle_time
* - system time
* - check for guest_time
* - else account as system_time
*
* Check for hardirq is done both for system and user time as there is
* no timer going off while we are on hardirq and hence we may never get an
* opportunity to update it solely in system time.
* p->stime and friends are only updated on system time and not on irq
* softirq as those do not count in task exec_runtime any more.
*/
static void irqtime_account_process_tick(struct task_struct *p, int user_tick,
struct rq *rq)
{
cputime_t one_jiffy_scaled = cputime_to_scaled(cputime_one_jiffy);
cputime64_t tmp = cputime_to_cputime64(cputime_one_jiffy);
struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat;
KVM guest: Steal time accounting This patch accounts steal time time in account_process_tick. If one or more tick is considered stolen in the current accounting cycle, user/system accounting is skipped. Idle is fine, since the hypervisor does not report steal time if the guest is halted. Accounting steal time from the core scheduler give us the advantage of direct acess to the runqueue data. In a later opportunity, it can be used to tweak cpu power and make the scheduler aware of the time it lost. [avi: <asm/paravirt.h> doesn't exist on many archs] Signed-off-by: Glauber Costa <glommer@redhat.com> Acked-by: Rik van Riel <riel@redhat.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Tested-by: Eric B Munson <emunson@mgebm.net> CC: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> CC: Anthony Liguori <aliguori@us.ibm.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-07-11 19:28:17 +00:00
if (steal_account_process_tick())
return;
sched: Export ns irqtimes through /proc/stat CONFIG_IRQ_TIME_ACCOUNTING adds ns granularity irq time on each CPU. This info is already used in scheduler to do proper task chargeback (earlier patches). This patch retro-fits this ns granularity hardirq and softirq information to /proc/stat irq and softirq fields. The update is still done on timer tick, where we look at accumulated ns hardirq/softirq time and account the tick to user/system/irq/hardirq/guest accordingly. No new interface added. Earlier versions looked at adding this as new fields in some /proc files. This one seems to be the best in terms of impact to existing apps, even though it has somewhat more kernel code than earlier versions. Tested-by: Shaun Ruffell <sruffell@digium.com> Signed-off-by: Venkatesh Pallipadi <venki@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1292980144-28796-5-git-send-email-venki@google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-12-22 01:09:03 +00:00
if (irqtime_account_hi_update()) {
cpustat->irq = cputime64_add(cpustat->irq, tmp);
} else if (irqtime_account_si_update()) {
cpustat->softirq = cputime64_add(cpustat->softirq, tmp);
softirqs: Account ksoftirqd time as cpustat softirq softirq time in ksoftirqd context is not accounted in ns granularity per cpu softirq stats, as we want that to be a part of ksoftirqd exec_runtime. Accounting them as softirq on /proc/stat separately. Tested-by: Shaun Ruffell <sruffell@digium.com> Signed-off-by: Venkatesh Pallipadi <venki@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1292980144-28796-6-git-send-email-venki@google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-12-22 01:09:04 +00:00
} else if (this_cpu_ksoftirqd() == p) {
/*
* ksoftirqd time do not get accounted in cpu_softirq_time.
* So, we have to handle it separately here.
* Also, p->stime needs to be updated for ksoftirqd.
*/
__account_system_time(p, cputime_one_jiffy, one_jiffy_scaled,
&cpustat->softirq);
sched: Export ns irqtimes through /proc/stat CONFIG_IRQ_TIME_ACCOUNTING adds ns granularity irq time on each CPU. This info is already used in scheduler to do proper task chargeback (earlier patches). This patch retro-fits this ns granularity hardirq and softirq information to /proc/stat irq and softirq fields. The update is still done on timer tick, where we look at accumulated ns hardirq/softirq time and account the tick to user/system/irq/hardirq/guest accordingly. No new interface added. Earlier versions looked at adding this as new fields in some /proc files. This one seems to be the best in terms of impact to existing apps, even though it has somewhat more kernel code than earlier versions. Tested-by: Shaun Ruffell <sruffell@digium.com> Signed-off-by: Venkatesh Pallipadi <venki@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1292980144-28796-5-git-send-email-venki@google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-12-22 01:09:03 +00:00
} else if (user_tick) {
account_user_time(p, cputime_one_jiffy, one_jiffy_scaled);
} else if (p == rq->idle) {
account_idle_time(cputime_one_jiffy);
} else if (p->flags & PF_VCPU) { /* System time or guest time */
account_guest_time(p, cputime_one_jiffy, one_jiffy_scaled);
} else {
__account_system_time(p, cputime_one_jiffy, one_jiffy_scaled,
&cpustat->system);
}
}
static void irqtime_account_idle_ticks(int ticks)
{
int i;
struct rq *rq = this_rq();
for (i = 0; i < ticks; i++)
irqtime_account_process_tick(current, 0, rq);
}
sched: Clean up the IRQ_TIME_ACCOUNTING code Fix this warning: lkml.org/lkml/2011/1/30/124 kernel/sched.c:3719: warning: 'irqtime_account_idle_ticks' defined but not used kernel/sched.c:3720: warning: 'irqtime_account_process_tick' defined but not used In a cleaner way than: 7e9498705e81: sched: Add #ifdef around irq time accounting functions This patch will not have any functional impact. Signed-off-by: Venkatesh Pallipadi <venki@google.com> Cc: heiko.carstens@de.ibm.com Cc: a.p.zijlstra@chello.nl LKML-Reference: <1298675596-10992-1-git-send-email-venki@google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-02-25 23:13:16 +00:00
#else /* CONFIG_IRQ_TIME_ACCOUNTING */
sched: Export ns irqtimes through /proc/stat CONFIG_IRQ_TIME_ACCOUNTING adds ns granularity irq time on each CPU. This info is already used in scheduler to do proper task chargeback (earlier patches). This patch retro-fits this ns granularity hardirq and softirq information to /proc/stat irq and softirq fields. The update is still done on timer tick, where we look at accumulated ns hardirq/softirq time and account the tick to user/system/irq/hardirq/guest accordingly. No new interface added. Earlier versions looked at adding this as new fields in some /proc files. This one seems to be the best in terms of impact to existing apps, even though it has somewhat more kernel code than earlier versions. Tested-by: Shaun Ruffell <sruffell@digium.com> Signed-off-by: Venkatesh Pallipadi <venki@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1292980144-28796-5-git-send-email-venki@google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-12-22 01:09:03 +00:00
static void irqtime_account_idle_ticks(int ticks) {}
static void irqtime_account_process_tick(struct task_struct *p, int user_tick,
struct rq *rq) {}
sched: Clean up the IRQ_TIME_ACCOUNTING code Fix this warning: lkml.org/lkml/2011/1/30/124 kernel/sched.c:3719: warning: 'irqtime_account_idle_ticks' defined but not used kernel/sched.c:3720: warning: 'irqtime_account_process_tick' defined but not used In a cleaner way than: 7e9498705e81: sched: Add #ifdef around irq time accounting functions This patch will not have any functional impact. Signed-off-by: Venkatesh Pallipadi <venki@google.com> Cc: heiko.carstens@de.ibm.com Cc: a.p.zijlstra@chello.nl LKML-Reference: <1298675596-10992-1-git-send-email-venki@google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-02-25 23:13:16 +00:00
#endif /* CONFIG_IRQ_TIME_ACCOUNTING */
[PATCH] idle cputime accounting The cpu time spent by the idle process actually doing something is currently accounted as idle time. This is plain wrong, the architectures that support VIRT_CPU_ACCOUNTING=y can do better: distinguish between the time spent doing nothing and the time spent by idle doing work. The first is accounted with account_idle_time and the second with account_system_time. The architectures that use the account_xxx_time interface directly and not the account_xxx_ticks interface now need to do the check for the idle process in their arch code. In particular to improve the system vs true idle time accounting the arch code needs to measure the true idle time instead of just testing for the idle process. To improve the tick based accounting as well we would need an architecture primitive that can tell us if the pt_regs of the interrupted context points to the magic instruction that halts the cpu. In addition idle time is no more added to the stime of the idle process. This field now contains the system time of the idle process as it should be. On systems without VIRT_CPU_ACCOUNTING this will always be zero as every tick that occurs while idle is running will be accounted as idle time. This patch contains the necessary common code changes to be able to distinguish idle system time and true idle time. The architectures with support for VIRT_CPU_ACCOUNTING need some changes to exploit this. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2008-12-31 14:11:38 +00:00
/*
* Account a single tick of cpu time.
* @p: the process that the cpu time gets accounted to
* @user_tick: indicates if the tick is a user or a system tick
*/
void account_process_tick(struct task_struct *p, int user_tick)
{
cputime: Optimize jiffies_to_cputime(1) For powerpc with CONFIG_VIRT_CPU_ACCOUNTING jiffies_to_cputime(1) is not compile time constant and run time calculations are quite expensive. To optimize we use precomputed value. For all other architectures is is preprocessor definition. Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Thomas Gleixner <tglx@linutronix.de> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> LKML-Reference: <1248862529-6063-5-git-send-email-sgruszka@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-07-29 10:15:29 +00:00
cputime_t one_jiffy_scaled = cputime_to_scaled(cputime_one_jiffy);
[PATCH] idle cputime accounting The cpu time spent by the idle process actually doing something is currently accounted as idle time. This is plain wrong, the architectures that support VIRT_CPU_ACCOUNTING=y can do better: distinguish between the time spent doing nothing and the time spent by idle doing work. The first is accounted with account_idle_time and the second with account_system_time. The architectures that use the account_xxx_time interface directly and not the account_xxx_ticks interface now need to do the check for the idle process in their arch code. In particular to improve the system vs true idle time accounting the arch code needs to measure the true idle time instead of just testing for the idle process. To improve the tick based accounting as well we would need an architecture primitive that can tell us if the pt_regs of the interrupted context points to the magic instruction that halts the cpu. In addition idle time is no more added to the stime of the idle process. This field now contains the system time of the idle process as it should be. On systems without VIRT_CPU_ACCOUNTING this will always be zero as every tick that occurs while idle is running will be accounted as idle time. This patch contains the necessary common code changes to be able to distinguish idle system time and true idle time. The architectures with support for VIRT_CPU_ACCOUNTING need some changes to exploit this. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2008-12-31 14:11:38 +00:00
struct rq *rq = this_rq();
sched: Export ns irqtimes through /proc/stat CONFIG_IRQ_TIME_ACCOUNTING adds ns granularity irq time on each CPU. This info is already used in scheduler to do proper task chargeback (earlier patches). This patch retro-fits this ns granularity hardirq and softirq information to /proc/stat irq and softirq fields. The update is still done on timer tick, where we look at accumulated ns hardirq/softirq time and account the tick to user/system/irq/hardirq/guest accordingly. No new interface added. Earlier versions looked at adding this as new fields in some /proc files. This one seems to be the best in terms of impact to existing apps, even though it has somewhat more kernel code than earlier versions. Tested-by: Shaun Ruffell <sruffell@digium.com> Signed-off-by: Venkatesh Pallipadi <venki@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1292980144-28796-5-git-send-email-venki@google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-12-22 01:09:03 +00:00
if (sched_clock_irqtime) {
irqtime_account_process_tick(p, user_tick, rq);
return;
}
KVM guest: Steal time accounting This patch accounts steal time time in account_process_tick. If one or more tick is considered stolen in the current accounting cycle, user/system accounting is skipped. Idle is fine, since the hypervisor does not report steal time if the guest is halted. Accounting steal time from the core scheduler give us the advantage of direct acess to the runqueue data. In a later opportunity, it can be used to tweak cpu power and make the scheduler aware of the time it lost. [avi: <asm/paravirt.h> doesn't exist on many archs] Signed-off-by: Glauber Costa <glommer@redhat.com> Acked-by: Rik van Riel <riel@redhat.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Tested-by: Eric B Munson <emunson@mgebm.net> CC: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> CC: Anthony Liguori <aliguori@us.ibm.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-07-11 19:28:17 +00:00
if (steal_account_process_tick())
return;
[PATCH] idle cputime accounting The cpu time spent by the idle process actually doing something is currently accounted as idle time. This is plain wrong, the architectures that support VIRT_CPU_ACCOUNTING=y can do better: distinguish between the time spent doing nothing and the time spent by idle doing work. The first is accounted with account_idle_time and the second with account_system_time. The architectures that use the account_xxx_time interface directly and not the account_xxx_ticks interface now need to do the check for the idle process in their arch code. In particular to improve the system vs true idle time accounting the arch code needs to measure the true idle time instead of just testing for the idle process. To improve the tick based accounting as well we would need an architecture primitive that can tell us if the pt_regs of the interrupted context points to the magic instruction that halts the cpu. In addition idle time is no more added to the stime of the idle process. This field now contains the system time of the idle process as it should be. On systems without VIRT_CPU_ACCOUNTING this will always be zero as every tick that occurs while idle is running will be accounted as idle time. This patch contains the necessary common code changes to be able to distinguish idle system time and true idle time. The architectures with support for VIRT_CPU_ACCOUNTING need some changes to exploit this. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2008-12-31 14:11:38 +00:00
if (user_tick)
cputime: Optimize jiffies_to_cputime(1) For powerpc with CONFIG_VIRT_CPU_ACCOUNTING jiffies_to_cputime(1) is not compile time constant and run time calculations are quite expensive. To optimize we use precomputed value. For all other architectures is is preprocessor definition. Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Thomas Gleixner <tglx@linutronix.de> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> LKML-Reference: <1248862529-6063-5-git-send-email-sgruszka@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-07-29 10:15:29 +00:00
account_user_time(p, cputime_one_jiffy, one_jiffy_scaled);
sched: account system time properly Andrew Gallatin reported that IRQ and SOFTIRQ times were sometime not reported correctly on recent kernels, and even bisected to commit 457533a7d3402d1d91fbc125c8bd1bd16dcd3cd4 ([PATCH] fix scaled & unscaled cputime accounting) as the first bad commit. Further analysis pointed that commit 79741dd35713ff4f6fd0eafd59fa94e8a4ba922d ([PATCH] idle cputime accounting) was the real cause of the problem. account_process_tick() was not taking into account timer IRQ interrupting the idle task servicing a hard or soft irq. On mostly idle cpu, irqs were thus not accounted and top or mpstat could tell user/admin that cpu was 100 % idle, 0.00 % irq, 0.00 % softirq, while it was not. [ Impact: fix occasionally incorrect CPU statistics in top/mpstat ] Reported-by: Andrew Gallatin <gallatin@myri.com> Re-reported-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Eric Dumazet <dada1@cosmosbay.com> Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: rick.jones2@hp.com Cc: brice@myri.com Cc: Paul Mackerras <paulus@samba.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> LKML-Reference: <49F84BC1.7080602@cosmosbay.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-29 12:44:49 +00:00
else if ((p != rq->idle) || (irq_count() != HARDIRQ_OFFSET))
cputime: Optimize jiffies_to_cputime(1) For powerpc with CONFIG_VIRT_CPU_ACCOUNTING jiffies_to_cputime(1) is not compile time constant and run time calculations are quite expensive. To optimize we use precomputed value. For all other architectures is is preprocessor definition. Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Thomas Gleixner <tglx@linutronix.de> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> LKML-Reference: <1248862529-6063-5-git-send-email-sgruszka@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-07-29 10:15:29 +00:00
account_system_time(p, HARDIRQ_OFFSET, cputime_one_jiffy,
[PATCH] idle cputime accounting The cpu time spent by the idle process actually doing something is currently accounted as idle time. This is plain wrong, the architectures that support VIRT_CPU_ACCOUNTING=y can do better: distinguish between the time spent doing nothing and the time spent by idle doing work. The first is accounted with account_idle_time and the second with account_system_time. The architectures that use the account_xxx_time interface directly and not the account_xxx_ticks interface now need to do the check for the idle process in their arch code. In particular to improve the system vs true idle time accounting the arch code needs to measure the true idle time instead of just testing for the idle process. To improve the tick based accounting as well we would need an architecture primitive that can tell us if the pt_regs of the interrupted context points to the magic instruction that halts the cpu. In addition idle time is no more added to the stime of the idle process. This field now contains the system time of the idle process as it should be. On systems without VIRT_CPU_ACCOUNTING this will always be zero as every tick that occurs while idle is running will be accounted as idle time. This patch contains the necessary common code changes to be able to distinguish idle system time and true idle time. The architectures with support for VIRT_CPU_ACCOUNTING need some changes to exploit this. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2008-12-31 14:11:38 +00:00
one_jiffy_scaled);
else
cputime: Optimize jiffies_to_cputime(1) For powerpc with CONFIG_VIRT_CPU_ACCOUNTING jiffies_to_cputime(1) is not compile time constant and run time calculations are quite expensive. To optimize we use precomputed value. For all other architectures is is preprocessor definition. Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Thomas Gleixner <tglx@linutronix.de> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> LKML-Reference: <1248862529-6063-5-git-send-email-sgruszka@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-07-29 10:15:29 +00:00
account_idle_time(cputime_one_jiffy);
[PATCH] idle cputime accounting The cpu time spent by the idle process actually doing something is currently accounted as idle time. This is plain wrong, the architectures that support VIRT_CPU_ACCOUNTING=y can do better: distinguish between the time spent doing nothing and the time spent by idle doing work. The first is accounted with account_idle_time and the second with account_system_time. The architectures that use the account_xxx_time interface directly and not the account_xxx_ticks interface now need to do the check for the idle process in their arch code. In particular to improve the system vs true idle time accounting the arch code needs to measure the true idle time instead of just testing for the idle process. To improve the tick based accounting as well we would need an architecture primitive that can tell us if the pt_regs of the interrupted context points to the magic instruction that halts the cpu. In addition idle time is no more added to the stime of the idle process. This field now contains the system time of the idle process as it should be. On systems without VIRT_CPU_ACCOUNTING this will always be zero as every tick that occurs while idle is running will be accounted as idle time. This patch contains the necessary common code changes to be able to distinguish idle system time and true idle time. The architectures with support for VIRT_CPU_ACCOUNTING need some changes to exploit this. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2008-12-31 14:11:38 +00:00
}
/*
* Account multiple ticks of steal time.
* @p: the process from which the cpu time has been stolen
* @ticks: number of stolen ticks
*/
void account_steal_ticks(unsigned long ticks)
{
account_steal_time(jiffies_to_cputime(ticks));
}
/*
* Account multiple ticks of idle time.
* @ticks: number of stolen ticks
*/
void account_idle_ticks(unsigned long ticks)
{
sched: Export ns irqtimes through /proc/stat CONFIG_IRQ_TIME_ACCOUNTING adds ns granularity irq time on each CPU. This info is already used in scheduler to do proper task chargeback (earlier patches). This patch retro-fits this ns granularity hardirq and softirq information to /proc/stat irq and softirq fields. The update is still done on timer tick, where we look at accumulated ns hardirq/softirq time and account the tick to user/system/irq/hardirq/guest accordingly. No new interface added. Earlier versions looked at adding this as new fields in some /proc files. This one seems to be the best in terms of impact to existing apps, even though it has somewhat more kernel code than earlier versions. Tested-by: Shaun Ruffell <sruffell@digium.com> Signed-off-by: Venkatesh Pallipadi <venki@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1292980144-28796-5-git-send-email-venki@google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-12-22 01:09:03 +00:00
if (sched_clock_irqtime) {
irqtime_account_idle_ticks(ticks);
return;
}
[PATCH] idle cputime accounting The cpu time spent by the idle process actually doing something is currently accounted as idle time. This is plain wrong, the architectures that support VIRT_CPU_ACCOUNTING=y can do better: distinguish between the time spent doing nothing and the time spent by idle doing work. The first is accounted with account_idle_time and the second with account_system_time. The architectures that use the account_xxx_time interface directly and not the account_xxx_ticks interface now need to do the check for the idle process in their arch code. In particular to improve the system vs true idle time accounting the arch code needs to measure the true idle time instead of just testing for the idle process. To improve the tick based accounting as well we would need an architecture primitive that can tell us if the pt_regs of the interrupted context points to the magic instruction that halts the cpu. In addition idle time is no more added to the stime of the idle process. This field now contains the system time of the idle process as it should be. On systems without VIRT_CPU_ACCOUNTING this will always be zero as every tick that occurs while idle is running will be accounted as idle time. This patch contains the necessary common code changes to be able to distinguish idle system time and true idle time. The architectures with support for VIRT_CPU_ACCOUNTING need some changes to exploit this. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2008-12-31 14:11:38 +00:00
account_idle_time(jiffies_to_cputime(ticks));
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
}
[PATCH] idle cputime accounting The cpu time spent by the idle process actually doing something is currently accounted as idle time. This is plain wrong, the architectures that support VIRT_CPU_ACCOUNTING=y can do better: distinguish between the time spent doing nothing and the time spent by idle doing work. The first is accounted with account_idle_time and the second with account_system_time. The architectures that use the account_xxx_time interface directly and not the account_xxx_ticks interface now need to do the check for the idle process in their arch code. In particular to improve the system vs true idle time accounting the arch code needs to measure the true idle time instead of just testing for the idle process. To improve the tick based accounting as well we would need an architecture primitive that can tell us if the pt_regs of the interrupted context points to the magic instruction that halts the cpu. In addition idle time is no more added to the stime of the idle process. This field now contains the system time of the idle process as it should be. On systems without VIRT_CPU_ACCOUNTING this will always be zero as every tick that occurs while idle is running will be accounted as idle time. This patch contains the necessary common code changes to be able to distinguish idle system time and true idle time. The architectures with support for VIRT_CPU_ACCOUNTING need some changes to exploit this. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2008-12-31 14:11:38 +00:00
#endif
sched: fix process time monotonicity Spencer reported a problem where utime and stime were going negative despite the fixes in commit b27f03d4bdc145a09fb7b0c0e004b29f1ee555fa. The suspected reason for the problem is that signal_struct maintains it's own utime and stime (of exited tasks), these are not updated using the new task_utime() routine, hence sig->utime can go backwards and cause the same problem to occur (sig->utime, adds tsk->utime and not task_utime()). This patch fixes the problem TODO: using max(task->prev_utime, derived utime) works for now, but a more generic solution is to implement cputime_max() and use the cputime_gt() function for comparison. Reported-by: spencer@bluehost.com Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-05 16:12:23 +00:00
/*
* Use precise platform statistics if available:
*/
#ifdef CONFIG_VIRT_CPU_ACCOUNTING
sched: Introduce task_times() to replace task_{u,s}time() pair Functions task_{u,s}time() are called in pair in almost all cases. However task_stime() is implemented to call task_utime() from its inside, so such paired calls run task_utime() twice. It means we do heavy divisions (div_u64 + do_div) twice to get utime and stime which can be obtained at same time by one set of divisions. This patch introduces a function task_times(*tsk, *utime, *stime) to retrieve utime and stime at once in better, optimized way. Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Stanislaw Gruszka <sgruszka@redhat.com> Cc: Spencer Candland <spencer@bluehost.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Americo Wang <xiyou.wangcong@gmail.com> LKML-Reference: <4B0E16AE.906@jp.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-11-26 05:48:30 +00:00
void task_times(struct task_struct *p, cputime_t *ut, cputime_t *st)
sched: fix process time monotonicity Spencer reported a problem where utime and stime were going negative despite the fixes in commit b27f03d4bdc145a09fb7b0c0e004b29f1ee555fa. The suspected reason for the problem is that signal_struct maintains it's own utime and stime (of exited tasks), these are not updated using the new task_utime() routine, hence sig->utime can go backwards and cause the same problem to occur (sig->utime, adds tsk->utime and not task_utime()). This patch fixes the problem TODO: using max(task->prev_utime, derived utime) works for now, but a more generic solution is to implement cputime_max() and use the cputime_gt() function for comparison. Reported-by: spencer@bluehost.com Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-05 16:12:23 +00:00
{
sched, cputime: Cleanups related to task_times() - Remove if({u,s}t)s because no one call it with NULL now. - Use cputime_{add,sub}(). - Add ifndef-endif for prev_{u,s}time since they are used only when !VIRT_CPU_ACCOUNTING. Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Spencer Candland <spencer@bluehost.com> Cc: Americo Wang <xiyou.wangcong@gmail.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Stanislaw Gruszka <sgruszka@redhat.com> LKML-Reference: <4B1624C7.7040302@jp.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-02 08:26:47 +00:00
*ut = p->utime;
*st = p->stime;
sched: fix process time monotonicity Spencer reported a problem where utime and stime were going negative despite the fixes in commit b27f03d4bdc145a09fb7b0c0e004b29f1ee555fa. The suspected reason for the problem is that signal_struct maintains it's own utime and stime (of exited tasks), these are not updated using the new task_utime() routine, hence sig->utime can go backwards and cause the same problem to occur (sig->utime, adds tsk->utime and not task_utime()). This patch fixes the problem TODO: using max(task->prev_utime, derived utime) works for now, but a more generic solution is to implement cputime_max() and use the cputime_gt() function for comparison. Reported-by: spencer@bluehost.com Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-05 16:12:23 +00:00
}
sched, cputime: Introduce thread_group_times() This is a real fix for problem of utime/stime values decreasing described in the thread: http://lkml.org/lkml/2009/11/3/522 Now cputime is accounted in the following way: - {u,s}time in task_struct are increased every time when the thread is interrupted by a tick (timer interrupt). - When a thread exits, its {u,s}time are added to signal->{u,s}time, after adjusted by task_times(). - When all threads in a thread_group exits, accumulated {u,s}time (and also c{u,s}time) in signal struct are added to c{u,s}time in signal struct of the group's parent. So {u,s}time in task struct are "raw" tick count, while {u,s}time and c{u,s}time in signal struct are "adjusted" values. And accounted values are used by: - task_times(), to get cputime of a thread: This function returns adjusted values that originates from raw {u,s}time and scaled by sum_exec_runtime that accounted by CFS. - thread_group_cputime(), to get cputime of a thread group: This function returns sum of all {u,s}time of living threads in the group, plus {u,s}time in the signal struct that is sum of adjusted cputimes of all exited threads belonged to the group. The problem is the return value of thread_group_cputime(), because it is mixed sum of "raw" value and "adjusted" value: group's {u,s}time = foreach(thread){{u,s}time} + exited({u,s}time) This misbehavior can break {u,s}time monotonicity. Assume that if there is a thread that have raw values greater than adjusted values (e.g. interrupted by 1000Hz ticks 50 times but only runs 45ms) and if it exits, cputime will decrease (e.g. -5ms). To fix this, we could do: group's {u,s}time = foreach(t){task_times(t)} + exited({u,s}time) But task_times() contains hard divisions, so applying it for every thread should be avoided. This patch fixes the above problem in the following way: - Modify thread's exit (= __exit_signal()) not to use task_times(). It means {u,s}time in signal struct accumulates raw values instead of adjusted values. As the result it makes thread_group_cputime() to return pure sum of "raw" values. - Introduce a new function thread_group_times(*task, *utime, *stime) that converts "raw" values of thread_group_cputime() to "adjusted" values, in same calculation procedure as task_times(). - Modify group's exit (= wait_task_zombie()) to use this introduced thread_group_times(). It make c{u,s}time in signal struct to have adjusted values like before this patch. - Replace some thread_group_cputime() by thread_group_times(). This replacements are only applied where conveys the "adjusted" cputime to users, and where already uses task_times() near by it. (i.e. sys_times(), getrusage(), and /proc/<PID>/stat.) This patch have a positive side effect: - Before this patch, if a group contains many short-life threads (e.g. runs 0.9ms and not interrupted by ticks), the group's cputime could be invisible since thread's cputime was accumulated after adjusted: imagine adjustment function as adj(ticks, runtime), {adj(0, 0.9) + adj(0, 0.9) + ....} = {0 + 0 + ....} = 0. After this patch it will not happen because the adjustment is applied after accumulated. v2: - remove if()s, put new variables into signal_struct. Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Spencer Candland <spencer@bluehost.com> Cc: Americo Wang <xiyou.wangcong@gmail.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Stanislaw Gruszka <sgruszka@redhat.com> LKML-Reference: <4B162517.8040909@jp.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-02 08:28:07 +00:00
void thread_group_times(struct task_struct *p, cputime_t *ut, cputime_t *st)
sched: fix process time monotonicity Spencer reported a problem where utime and stime were going negative despite the fixes in commit b27f03d4bdc145a09fb7b0c0e004b29f1ee555fa. The suspected reason for the problem is that signal_struct maintains it's own utime and stime (of exited tasks), these are not updated using the new task_utime() routine, hence sig->utime can go backwards and cause the same problem to occur (sig->utime, adds tsk->utime and not task_utime()). This patch fixes the problem TODO: using max(task->prev_utime, derived utime) works for now, but a more generic solution is to implement cputime_max() and use the cputime_gt() function for comparison. Reported-by: spencer@bluehost.com Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-05 16:12:23 +00:00
{
sched, cputime: Introduce thread_group_times() This is a real fix for problem of utime/stime values decreasing described in the thread: http://lkml.org/lkml/2009/11/3/522 Now cputime is accounted in the following way: - {u,s}time in task_struct are increased every time when the thread is interrupted by a tick (timer interrupt). - When a thread exits, its {u,s}time are added to signal->{u,s}time, after adjusted by task_times(). - When all threads in a thread_group exits, accumulated {u,s}time (and also c{u,s}time) in signal struct are added to c{u,s}time in signal struct of the group's parent. So {u,s}time in task struct are "raw" tick count, while {u,s}time and c{u,s}time in signal struct are "adjusted" values. And accounted values are used by: - task_times(), to get cputime of a thread: This function returns adjusted values that originates from raw {u,s}time and scaled by sum_exec_runtime that accounted by CFS. - thread_group_cputime(), to get cputime of a thread group: This function returns sum of all {u,s}time of living threads in the group, plus {u,s}time in the signal struct that is sum of adjusted cputimes of all exited threads belonged to the group. The problem is the return value of thread_group_cputime(), because it is mixed sum of "raw" value and "adjusted" value: group's {u,s}time = foreach(thread){{u,s}time} + exited({u,s}time) This misbehavior can break {u,s}time monotonicity. Assume that if there is a thread that have raw values greater than adjusted values (e.g. interrupted by 1000Hz ticks 50 times but only runs 45ms) and if it exits, cputime will decrease (e.g. -5ms). To fix this, we could do: group's {u,s}time = foreach(t){task_times(t)} + exited({u,s}time) But task_times() contains hard divisions, so applying it for every thread should be avoided. This patch fixes the above problem in the following way: - Modify thread's exit (= __exit_signal()) not to use task_times(). It means {u,s}time in signal struct accumulates raw values instead of adjusted values. As the result it makes thread_group_cputime() to return pure sum of "raw" values. - Introduce a new function thread_group_times(*task, *utime, *stime) that converts "raw" values of thread_group_cputime() to "adjusted" values, in same calculation procedure as task_times(). - Modify group's exit (= wait_task_zombie()) to use this introduced thread_group_times(). It make c{u,s}time in signal struct to have adjusted values like before this patch. - Replace some thread_group_cputime() by thread_group_times(). This replacements are only applied where conveys the "adjusted" cputime to users, and where already uses task_times() near by it. (i.e. sys_times(), getrusage(), and /proc/<PID>/stat.) This patch have a positive side effect: - Before this patch, if a group contains many short-life threads (e.g. runs 0.9ms and not interrupted by ticks), the group's cputime could be invisible since thread's cputime was accumulated after adjusted: imagine adjustment function as adj(ticks, runtime), {adj(0, 0.9) + adj(0, 0.9) + ....} = {0 + 0 + ....} = 0. After this patch it will not happen because the adjustment is applied after accumulated. v2: - remove if()s, put new variables into signal_struct. Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Spencer Candland <spencer@bluehost.com> Cc: Americo Wang <xiyou.wangcong@gmail.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Stanislaw Gruszka <sgruszka@redhat.com> LKML-Reference: <4B162517.8040909@jp.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-02 08:28:07 +00:00
struct task_cputime cputime;
thread_group_cputime(p, &cputime);
*ut = cputime.utime;
*st = cputime.stime;
sched: fix process time monotonicity Spencer reported a problem where utime and stime were going negative despite the fixes in commit b27f03d4bdc145a09fb7b0c0e004b29f1ee555fa. The suspected reason for the problem is that signal_struct maintains it's own utime and stime (of exited tasks), these are not updated using the new task_utime() routine, hence sig->utime can go backwards and cause the same problem to occur (sig->utime, adds tsk->utime and not task_utime()). This patch fixes the problem TODO: using max(task->prev_utime, derived utime) works for now, but a more generic solution is to implement cputime_max() and use the cputime_gt() function for comparison. Reported-by: spencer@bluehost.com Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-05 16:12:23 +00:00
}
#else
sched: Fix granularity of task_u/stime() Originally task_s/utime() were designed to return clock_t but later changed to return cputime_t by following commit: commit efe567fc8281661524ffa75477a7c4ca9b466c63 Author: Christian Borntraeger <borntraeger@de.ibm.com> Date: Thu Aug 23 15:18:02 2007 +0200 It only changed the type of return value, but not the implementation. As the result the granularity of task_s/utime() is still that of clock_t, not that of cputime_t. So using task_s/utime() in __exit_signal() makes values accumulated to the signal struct to be rounded and coarse grained. This patch removes casts to clock_t in task_u/stime(), to keep granularity of cputime_t over the calculation. v2: Use div_u64() to avoid error "undefined reference to `__udivdi3`" on some 32bit systems. Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: xiyou.wangcong@gmail.com Cc: Spencer Candland <spencer@bluehost.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Stanislaw Gruszka <sgruszka@redhat.com> LKML-Reference: <4AFB9029.9000208@jp.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-11-12 04:33:45 +00:00
#ifndef nsecs_to_cputime
sched, time: Define nsecs_to_jiffies() Use of msecs_to_jiffies() for nsecs_to_cputime() have some problems: - The type of msecs_to_jiffies()'s argument is unsigned int, so it cannot convert msecs greater than UINT_MAX = about 49.7 days. - msecs_to_jiffies() returns MAX_JIFFY_OFFSET if MSB of argument is set, assuming that input was negative value. So it cannot convert msecs greater than INT_MAX = about 24.8 days too. This patch defines a new function nsecs_to_jiffies() that can deal greater values, and that can deal all incoming values as unsigned. Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Stanislaw Gruszka <sgruszka@redhat.com> Cc: Spencer Candland <spencer@bluehost.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Amrico Wang <xiyou.wangcong@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: John Stultz <johnstul@linux.vnet.ibm.com> LKML-Reference: <4B0E16E7.5070307@jp.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-11-26 05:49:27 +00:00
# define nsecs_to_cputime(__nsecs) nsecs_to_jiffies(__nsecs)
sched: Fix granularity of task_u/stime() Originally task_s/utime() were designed to return clock_t but later changed to return cputime_t by following commit: commit efe567fc8281661524ffa75477a7c4ca9b466c63 Author: Christian Borntraeger <borntraeger@de.ibm.com> Date: Thu Aug 23 15:18:02 2007 +0200 It only changed the type of return value, but not the implementation. As the result the granularity of task_s/utime() is still that of clock_t, not that of cputime_t. So using task_s/utime() in __exit_signal() makes values accumulated to the signal struct to be rounded and coarse grained. This patch removes casts to clock_t in task_u/stime(), to keep granularity of cputime_t over the calculation. v2: Use div_u64() to avoid error "undefined reference to `__udivdi3`" on some 32bit systems. Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: xiyou.wangcong@gmail.com Cc: Spencer Candland <spencer@bluehost.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Stanislaw Gruszka <sgruszka@redhat.com> LKML-Reference: <4AFB9029.9000208@jp.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-11-12 04:33:45 +00:00
#endif
sched: Introduce task_times() to replace task_{u,s}time() pair Functions task_{u,s}time() are called in pair in almost all cases. However task_stime() is implemented to call task_utime() from its inside, so such paired calls run task_utime() twice. It means we do heavy divisions (div_u64 + do_div) twice to get utime and stime which can be obtained at same time by one set of divisions. This patch introduces a function task_times(*tsk, *utime, *stime) to retrieve utime and stime at once in better, optimized way. Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Stanislaw Gruszka <sgruszka@redhat.com> Cc: Spencer Candland <spencer@bluehost.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Americo Wang <xiyou.wangcong@gmail.com> LKML-Reference: <4B0E16AE.906@jp.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-11-26 05:48:30 +00:00
void task_times(struct task_struct *p, cputime_t *ut, cputime_t *st)
sched: fix process time monotonicity Spencer reported a problem where utime and stime were going negative despite the fixes in commit b27f03d4bdc145a09fb7b0c0e004b29f1ee555fa. The suspected reason for the problem is that signal_struct maintains it's own utime and stime (of exited tasks), these are not updated using the new task_utime() routine, hence sig->utime can go backwards and cause the same problem to occur (sig->utime, adds tsk->utime and not task_utime()). This patch fixes the problem TODO: using max(task->prev_utime, derived utime) works for now, but a more generic solution is to implement cputime_max() and use the cputime_gt() function for comparison. Reported-by: spencer@bluehost.com Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-05 16:12:23 +00:00
{
sched, cputime: Cleanups related to task_times() - Remove if({u,s}t)s because no one call it with NULL now. - Use cputime_{add,sub}(). - Add ifndef-endif for prev_{u,s}time since they are used only when !VIRT_CPU_ACCOUNTING. Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Spencer Candland <spencer@bluehost.com> Cc: Americo Wang <xiyou.wangcong@gmail.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Stanislaw Gruszka <sgruszka@redhat.com> LKML-Reference: <4B1624C7.7040302@jp.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-02 08:26:47 +00:00
cputime_t rtime, utime = p->utime, total = cputime_add(utime, p->stime);
sched: fix process time monotonicity Spencer reported a problem where utime and stime were going negative despite the fixes in commit b27f03d4bdc145a09fb7b0c0e004b29f1ee555fa. The suspected reason for the problem is that signal_struct maintains it's own utime and stime (of exited tasks), these are not updated using the new task_utime() routine, hence sig->utime can go backwards and cause the same problem to occur (sig->utime, adds tsk->utime and not task_utime()). This patch fixes the problem TODO: using max(task->prev_utime, derived utime) works for now, but a more generic solution is to implement cputime_max() and use the cputime_gt() function for comparison. Reported-by: spencer@bluehost.com Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-05 16:12:23 +00:00
/*
* Use CFS's precise accounting:
*/
sched: Introduce task_times() to replace task_{u,s}time() pair Functions task_{u,s}time() are called in pair in almost all cases. However task_stime() is implemented to call task_utime() from its inside, so such paired calls run task_utime() twice. It means we do heavy divisions (div_u64 + do_div) twice to get utime and stime which can be obtained at same time by one set of divisions. This patch introduces a function task_times(*tsk, *utime, *stime) to retrieve utime and stime at once in better, optimized way. Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Stanislaw Gruszka <sgruszka@redhat.com> Cc: Spencer Candland <spencer@bluehost.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Americo Wang <xiyou.wangcong@gmail.com> LKML-Reference: <4B0E16AE.906@jp.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-11-26 05:48:30 +00:00
rtime = nsecs_to_cputime(p->se.sum_exec_runtime);
sched: fix process time monotonicity Spencer reported a problem where utime and stime were going negative despite the fixes in commit b27f03d4bdc145a09fb7b0c0e004b29f1ee555fa. The suspected reason for the problem is that signal_struct maintains it's own utime and stime (of exited tasks), these are not updated using the new task_utime() routine, hence sig->utime can go backwards and cause the same problem to occur (sig->utime, adds tsk->utime and not task_utime()). This patch fixes the problem TODO: using max(task->prev_utime, derived utime) works for now, but a more generic solution is to implement cputime_max() and use the cputime_gt() function for comparison. Reported-by: spencer@bluehost.com Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-05 16:12:23 +00:00
if (total) {
sched: Fix user time incorrectly accounted as system time on 32-bit We have 32-bit variable overflow possibility when multiply in task_times() and thread_group_times() functions. When the overflow happens then the scaled utime value becomes erroneously small and the scaled stime becomes i erroneously big. Reported here: https://bugzilla.redhat.com/show_bug.cgi?id=633037 https://bugzilla.kernel.org/show_bug.cgi?id=16559 Reported-by: Michael Chapman <redhat-bugzilla@very.puzzling.org> Reported-by: Ciriaco Garcia de Celis <sysman@etherpilot.com> Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Cc: <stable@kernel.org> # 2.6.32.19+ (partially) and 2.6.33+ LKML-Reference: <20100914143513.GB8415@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-09-14 14:35:14 +00:00
u64 temp = rtime;
sched: Introduce task_times() to replace task_{u,s}time() pair Functions task_{u,s}time() are called in pair in almost all cases. However task_stime() is implemented to call task_utime() from its inside, so such paired calls run task_utime() twice. It means we do heavy divisions (div_u64 + do_div) twice to get utime and stime which can be obtained at same time by one set of divisions. This patch introduces a function task_times(*tsk, *utime, *stime) to retrieve utime and stime at once in better, optimized way. Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Stanislaw Gruszka <sgruszka@redhat.com> Cc: Spencer Candland <spencer@bluehost.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Americo Wang <xiyou.wangcong@gmail.com> LKML-Reference: <4B0E16AE.906@jp.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-11-26 05:48:30 +00:00
sched: Fix user time incorrectly accounted as system time on 32-bit We have 32-bit variable overflow possibility when multiply in task_times() and thread_group_times() functions. When the overflow happens then the scaled utime value becomes erroneously small and the scaled stime becomes i erroneously big. Reported here: https://bugzilla.redhat.com/show_bug.cgi?id=633037 https://bugzilla.kernel.org/show_bug.cgi?id=16559 Reported-by: Michael Chapman <redhat-bugzilla@very.puzzling.org> Reported-by: Ciriaco Garcia de Celis <sysman@etherpilot.com> Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Cc: <stable@kernel.org> # 2.6.32.19+ (partially) and 2.6.33+ LKML-Reference: <20100914143513.GB8415@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-09-14 14:35:14 +00:00
temp *= utime;
sched: fix process time monotonicity Spencer reported a problem where utime and stime were going negative despite the fixes in commit b27f03d4bdc145a09fb7b0c0e004b29f1ee555fa. The suspected reason for the problem is that signal_struct maintains it's own utime and stime (of exited tasks), these are not updated using the new task_utime() routine, hence sig->utime can go backwards and cause the same problem to occur (sig->utime, adds tsk->utime and not task_utime()). This patch fixes the problem TODO: using max(task->prev_utime, derived utime) works for now, but a more generic solution is to implement cputime_max() and use the cputime_gt() function for comparison. Reported-by: spencer@bluehost.com Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-05 16:12:23 +00:00
do_div(temp, total);
sched: Introduce task_times() to replace task_{u,s}time() pair Functions task_{u,s}time() are called in pair in almost all cases. However task_stime() is implemented to call task_utime() from its inside, so such paired calls run task_utime() twice. It means we do heavy divisions (div_u64 + do_div) twice to get utime and stime which can be obtained at same time by one set of divisions. This patch introduces a function task_times(*tsk, *utime, *stime) to retrieve utime and stime at once in better, optimized way. Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Stanislaw Gruszka <sgruszka@redhat.com> Cc: Spencer Candland <spencer@bluehost.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Americo Wang <xiyou.wangcong@gmail.com> LKML-Reference: <4B0E16AE.906@jp.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-11-26 05:48:30 +00:00
utime = (cputime_t)temp;
} else
utime = rtime;
sched: fix process time monotonicity Spencer reported a problem where utime and stime were going negative despite the fixes in commit b27f03d4bdc145a09fb7b0c0e004b29f1ee555fa. The suspected reason for the problem is that signal_struct maintains it's own utime and stime (of exited tasks), these are not updated using the new task_utime() routine, hence sig->utime can go backwards and cause the same problem to occur (sig->utime, adds tsk->utime and not task_utime()). This patch fixes the problem TODO: using max(task->prev_utime, derived utime) works for now, but a more generic solution is to implement cputime_max() and use the cputime_gt() function for comparison. Reported-by: spencer@bluehost.com Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-05 16:12:23 +00:00
sched: Introduce task_times() to replace task_{u,s}time() pair Functions task_{u,s}time() are called in pair in almost all cases. However task_stime() is implemented to call task_utime() from its inside, so such paired calls run task_utime() twice. It means we do heavy divisions (div_u64 + do_div) twice to get utime and stime which can be obtained at same time by one set of divisions. This patch introduces a function task_times(*tsk, *utime, *stime) to retrieve utime and stime at once in better, optimized way. Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Stanislaw Gruszka <sgruszka@redhat.com> Cc: Spencer Candland <spencer@bluehost.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Americo Wang <xiyou.wangcong@gmail.com> LKML-Reference: <4B0E16AE.906@jp.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-11-26 05:48:30 +00:00
/*
* Compare with previous values, to keep monotonicity:
*/
sched: Fix granularity of task_u/stime() Originally task_s/utime() were designed to return clock_t but later changed to return cputime_t by following commit: commit efe567fc8281661524ffa75477a7c4ca9b466c63 Author: Christian Borntraeger <borntraeger@de.ibm.com> Date: Thu Aug 23 15:18:02 2007 +0200 It only changed the type of return value, but not the implementation. As the result the granularity of task_s/utime() is still that of clock_t, not that of cputime_t. So using task_s/utime() in __exit_signal() makes values accumulated to the signal struct to be rounded and coarse grained. This patch removes casts to clock_t in task_u/stime(), to keep granularity of cputime_t over the calculation. v2: Use div_u64() to avoid error "undefined reference to `__udivdi3`" on some 32bit systems. Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: xiyou.wangcong@gmail.com Cc: Spencer Candland <spencer@bluehost.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Stanislaw Gruszka <sgruszka@redhat.com> LKML-Reference: <4AFB9029.9000208@jp.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-11-12 04:33:45 +00:00
p->prev_utime = max(p->prev_utime, utime);
sched, cputime: Cleanups related to task_times() - Remove if({u,s}t)s because no one call it with NULL now. - Use cputime_{add,sub}(). - Add ifndef-endif for prev_{u,s}time since they are used only when !VIRT_CPU_ACCOUNTING. Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Spencer Candland <spencer@bluehost.com> Cc: Americo Wang <xiyou.wangcong@gmail.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Stanislaw Gruszka <sgruszka@redhat.com> LKML-Reference: <4B1624C7.7040302@jp.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-02 08:26:47 +00:00
p->prev_stime = max(p->prev_stime, cputime_sub(rtime, p->prev_utime));
sched: fix process time monotonicity Spencer reported a problem where utime and stime were going negative despite the fixes in commit b27f03d4bdc145a09fb7b0c0e004b29f1ee555fa. The suspected reason for the problem is that signal_struct maintains it's own utime and stime (of exited tasks), these are not updated using the new task_utime() routine, hence sig->utime can go backwards and cause the same problem to occur (sig->utime, adds tsk->utime and not task_utime()). This patch fixes the problem TODO: using max(task->prev_utime, derived utime) works for now, but a more generic solution is to implement cputime_max() and use the cputime_gt() function for comparison. Reported-by: spencer@bluehost.com Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-05 16:12:23 +00:00
sched, cputime: Cleanups related to task_times() - Remove if({u,s}t)s because no one call it with NULL now. - Use cputime_{add,sub}(). - Add ifndef-endif for prev_{u,s}time since they are used only when !VIRT_CPU_ACCOUNTING. Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Spencer Candland <spencer@bluehost.com> Cc: Americo Wang <xiyou.wangcong@gmail.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Stanislaw Gruszka <sgruszka@redhat.com> LKML-Reference: <4B1624C7.7040302@jp.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-02 08:26:47 +00:00
*ut = p->prev_utime;
*st = p->prev_stime;
sched: fix process time monotonicity Spencer reported a problem where utime and stime were going negative despite the fixes in commit b27f03d4bdc145a09fb7b0c0e004b29f1ee555fa. The suspected reason for the problem is that signal_struct maintains it's own utime and stime (of exited tasks), these are not updated using the new task_utime() routine, hence sig->utime can go backwards and cause the same problem to occur (sig->utime, adds tsk->utime and not task_utime()). This patch fixes the problem TODO: using max(task->prev_utime, derived utime) works for now, but a more generic solution is to implement cputime_max() and use the cputime_gt() function for comparison. Reported-by: spencer@bluehost.com Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-05 16:12:23 +00:00
}
sched, cputime: Introduce thread_group_times() This is a real fix for problem of utime/stime values decreasing described in the thread: http://lkml.org/lkml/2009/11/3/522 Now cputime is accounted in the following way: - {u,s}time in task_struct are increased every time when the thread is interrupted by a tick (timer interrupt). - When a thread exits, its {u,s}time are added to signal->{u,s}time, after adjusted by task_times(). - When all threads in a thread_group exits, accumulated {u,s}time (and also c{u,s}time) in signal struct are added to c{u,s}time in signal struct of the group's parent. So {u,s}time in task struct are "raw" tick count, while {u,s}time and c{u,s}time in signal struct are "adjusted" values. And accounted values are used by: - task_times(), to get cputime of a thread: This function returns adjusted values that originates from raw {u,s}time and scaled by sum_exec_runtime that accounted by CFS. - thread_group_cputime(), to get cputime of a thread group: This function returns sum of all {u,s}time of living threads in the group, plus {u,s}time in the signal struct that is sum of adjusted cputimes of all exited threads belonged to the group. The problem is the return value of thread_group_cputime(), because it is mixed sum of "raw" value and "adjusted" value: group's {u,s}time = foreach(thread){{u,s}time} + exited({u,s}time) This misbehavior can break {u,s}time monotonicity. Assume that if there is a thread that have raw values greater than adjusted values (e.g. interrupted by 1000Hz ticks 50 times but only runs 45ms) and if it exits, cputime will decrease (e.g. -5ms). To fix this, we could do: group's {u,s}time = foreach(t){task_times(t)} + exited({u,s}time) But task_times() contains hard divisions, so applying it for every thread should be avoided. This patch fixes the above problem in the following way: - Modify thread's exit (= __exit_signal()) not to use task_times(). It means {u,s}time in signal struct accumulates raw values instead of adjusted values. As the result it makes thread_group_cputime() to return pure sum of "raw" values. - Introduce a new function thread_group_times(*task, *utime, *stime) that converts "raw" values of thread_group_cputime() to "adjusted" values, in same calculation procedure as task_times(). - Modify group's exit (= wait_task_zombie()) to use this introduced thread_group_times(). It make c{u,s}time in signal struct to have adjusted values like before this patch. - Replace some thread_group_cputime() by thread_group_times(). This replacements are only applied where conveys the "adjusted" cputime to users, and where already uses task_times() near by it. (i.e. sys_times(), getrusage(), and /proc/<PID>/stat.) This patch have a positive side effect: - Before this patch, if a group contains many short-life threads (e.g. runs 0.9ms and not interrupted by ticks), the group's cputime could be invisible since thread's cputime was accumulated after adjusted: imagine adjustment function as adj(ticks, runtime), {adj(0, 0.9) + adj(0, 0.9) + ....} = {0 + 0 + ....} = 0. After this patch it will not happen because the adjustment is applied after accumulated. v2: - remove if()s, put new variables into signal_struct. Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Spencer Candland <spencer@bluehost.com> Cc: Americo Wang <xiyou.wangcong@gmail.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Stanislaw Gruszka <sgruszka@redhat.com> LKML-Reference: <4B162517.8040909@jp.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-02 08:28:07 +00:00
/*
* Must be called with siglock held.
*/
void thread_group_times(struct task_struct *p, cputime_t *ut, cputime_t *st)
sched: fix process time monotonicity Spencer reported a problem where utime and stime were going negative despite the fixes in commit b27f03d4bdc145a09fb7b0c0e004b29f1ee555fa. The suspected reason for the problem is that signal_struct maintains it's own utime and stime (of exited tasks), these are not updated using the new task_utime() routine, hence sig->utime can go backwards and cause the same problem to occur (sig->utime, adds tsk->utime and not task_utime()). This patch fixes the problem TODO: using max(task->prev_utime, derived utime) works for now, but a more generic solution is to implement cputime_max() and use the cputime_gt() function for comparison. Reported-by: spencer@bluehost.com Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-05 16:12:23 +00:00
{
sched, cputime: Introduce thread_group_times() This is a real fix for problem of utime/stime values decreasing described in the thread: http://lkml.org/lkml/2009/11/3/522 Now cputime is accounted in the following way: - {u,s}time in task_struct are increased every time when the thread is interrupted by a tick (timer interrupt). - When a thread exits, its {u,s}time are added to signal->{u,s}time, after adjusted by task_times(). - When all threads in a thread_group exits, accumulated {u,s}time (and also c{u,s}time) in signal struct are added to c{u,s}time in signal struct of the group's parent. So {u,s}time in task struct are "raw" tick count, while {u,s}time and c{u,s}time in signal struct are "adjusted" values. And accounted values are used by: - task_times(), to get cputime of a thread: This function returns adjusted values that originates from raw {u,s}time and scaled by sum_exec_runtime that accounted by CFS. - thread_group_cputime(), to get cputime of a thread group: This function returns sum of all {u,s}time of living threads in the group, plus {u,s}time in the signal struct that is sum of adjusted cputimes of all exited threads belonged to the group. The problem is the return value of thread_group_cputime(), because it is mixed sum of "raw" value and "adjusted" value: group's {u,s}time = foreach(thread){{u,s}time} + exited({u,s}time) This misbehavior can break {u,s}time monotonicity. Assume that if there is a thread that have raw values greater than adjusted values (e.g. interrupted by 1000Hz ticks 50 times but only runs 45ms) and if it exits, cputime will decrease (e.g. -5ms). To fix this, we could do: group's {u,s}time = foreach(t){task_times(t)} + exited({u,s}time) But task_times() contains hard divisions, so applying it for every thread should be avoided. This patch fixes the above problem in the following way: - Modify thread's exit (= __exit_signal()) not to use task_times(). It means {u,s}time in signal struct accumulates raw values instead of adjusted values. As the result it makes thread_group_cputime() to return pure sum of "raw" values. - Introduce a new function thread_group_times(*task, *utime, *stime) that converts "raw" values of thread_group_cputime() to "adjusted" values, in same calculation procedure as task_times(). - Modify group's exit (= wait_task_zombie()) to use this introduced thread_group_times(). It make c{u,s}time in signal struct to have adjusted values like before this patch. - Replace some thread_group_cputime() by thread_group_times(). This replacements are only applied where conveys the "adjusted" cputime to users, and where already uses task_times() near by it. (i.e. sys_times(), getrusage(), and /proc/<PID>/stat.) This patch have a positive side effect: - Before this patch, if a group contains many short-life threads (e.g. runs 0.9ms and not interrupted by ticks), the group's cputime could be invisible since thread's cputime was accumulated after adjusted: imagine adjustment function as adj(ticks, runtime), {adj(0, 0.9) + adj(0, 0.9) + ....} = {0 + 0 + ....} = 0. After this patch it will not happen because the adjustment is applied after accumulated. v2: - remove if()s, put new variables into signal_struct. Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Spencer Candland <spencer@bluehost.com> Cc: Americo Wang <xiyou.wangcong@gmail.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Stanislaw Gruszka <sgruszka@redhat.com> LKML-Reference: <4B162517.8040909@jp.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-02 08:28:07 +00:00
struct signal_struct *sig = p->signal;
struct task_cputime cputime;
cputime_t rtime, utime, total;
sched: fix process time monotonicity Spencer reported a problem where utime and stime were going negative despite the fixes in commit b27f03d4bdc145a09fb7b0c0e004b29f1ee555fa. The suspected reason for the problem is that signal_struct maintains it's own utime and stime (of exited tasks), these are not updated using the new task_utime() routine, hence sig->utime can go backwards and cause the same problem to occur (sig->utime, adds tsk->utime and not task_utime()). This patch fixes the problem TODO: using max(task->prev_utime, derived utime) works for now, but a more generic solution is to implement cputime_max() and use the cputime_gt() function for comparison. Reported-by: spencer@bluehost.com Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-05 16:12:23 +00:00
sched, cputime: Introduce thread_group_times() This is a real fix for problem of utime/stime values decreasing described in the thread: http://lkml.org/lkml/2009/11/3/522 Now cputime is accounted in the following way: - {u,s}time in task_struct are increased every time when the thread is interrupted by a tick (timer interrupt). - When a thread exits, its {u,s}time are added to signal->{u,s}time, after adjusted by task_times(). - When all threads in a thread_group exits, accumulated {u,s}time (and also c{u,s}time) in signal struct are added to c{u,s}time in signal struct of the group's parent. So {u,s}time in task struct are "raw" tick count, while {u,s}time and c{u,s}time in signal struct are "adjusted" values. And accounted values are used by: - task_times(), to get cputime of a thread: This function returns adjusted values that originates from raw {u,s}time and scaled by sum_exec_runtime that accounted by CFS. - thread_group_cputime(), to get cputime of a thread group: This function returns sum of all {u,s}time of living threads in the group, plus {u,s}time in the signal struct that is sum of adjusted cputimes of all exited threads belonged to the group. The problem is the return value of thread_group_cputime(), because it is mixed sum of "raw" value and "adjusted" value: group's {u,s}time = foreach(thread){{u,s}time} + exited({u,s}time) This misbehavior can break {u,s}time monotonicity. Assume that if there is a thread that have raw values greater than adjusted values (e.g. interrupted by 1000Hz ticks 50 times but only runs 45ms) and if it exits, cputime will decrease (e.g. -5ms). To fix this, we could do: group's {u,s}time = foreach(t){task_times(t)} + exited({u,s}time) But task_times() contains hard divisions, so applying it for every thread should be avoided. This patch fixes the above problem in the following way: - Modify thread's exit (= __exit_signal()) not to use task_times(). It means {u,s}time in signal struct accumulates raw values instead of adjusted values. As the result it makes thread_group_cputime() to return pure sum of "raw" values. - Introduce a new function thread_group_times(*task, *utime, *stime) that converts "raw" values of thread_group_cputime() to "adjusted" values, in same calculation procedure as task_times(). - Modify group's exit (= wait_task_zombie()) to use this introduced thread_group_times(). It make c{u,s}time in signal struct to have adjusted values like before this patch. - Replace some thread_group_cputime() by thread_group_times(). This replacements are only applied where conveys the "adjusted" cputime to users, and where already uses task_times() near by it. (i.e. sys_times(), getrusage(), and /proc/<PID>/stat.) This patch have a positive side effect: - Before this patch, if a group contains many short-life threads (e.g. runs 0.9ms and not interrupted by ticks), the group's cputime could be invisible since thread's cputime was accumulated after adjusted: imagine adjustment function as adj(ticks, runtime), {adj(0, 0.9) + adj(0, 0.9) + ....} = {0 + 0 + ....} = 0. After this patch it will not happen because the adjustment is applied after accumulated. v2: - remove if()s, put new variables into signal_struct. Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Spencer Candland <spencer@bluehost.com> Cc: Americo Wang <xiyou.wangcong@gmail.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Stanislaw Gruszka <sgruszka@redhat.com> LKML-Reference: <4B162517.8040909@jp.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-02 08:28:07 +00:00
thread_group_cputime(p, &cputime);
sched: fix process time monotonicity Spencer reported a problem where utime and stime were going negative despite the fixes in commit b27f03d4bdc145a09fb7b0c0e004b29f1ee555fa. The suspected reason for the problem is that signal_struct maintains it's own utime and stime (of exited tasks), these are not updated using the new task_utime() routine, hence sig->utime can go backwards and cause the same problem to occur (sig->utime, adds tsk->utime and not task_utime()). This patch fixes the problem TODO: using max(task->prev_utime, derived utime) works for now, but a more generic solution is to implement cputime_max() and use the cputime_gt() function for comparison. Reported-by: spencer@bluehost.com Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-05 16:12:23 +00:00
sched, cputime: Introduce thread_group_times() This is a real fix for problem of utime/stime values decreasing described in the thread: http://lkml.org/lkml/2009/11/3/522 Now cputime is accounted in the following way: - {u,s}time in task_struct are increased every time when the thread is interrupted by a tick (timer interrupt). - When a thread exits, its {u,s}time are added to signal->{u,s}time, after adjusted by task_times(). - When all threads in a thread_group exits, accumulated {u,s}time (and also c{u,s}time) in signal struct are added to c{u,s}time in signal struct of the group's parent. So {u,s}time in task struct are "raw" tick count, while {u,s}time and c{u,s}time in signal struct are "adjusted" values. And accounted values are used by: - task_times(), to get cputime of a thread: This function returns adjusted values that originates from raw {u,s}time and scaled by sum_exec_runtime that accounted by CFS. - thread_group_cputime(), to get cputime of a thread group: This function returns sum of all {u,s}time of living threads in the group, plus {u,s}time in the signal struct that is sum of adjusted cputimes of all exited threads belonged to the group. The problem is the return value of thread_group_cputime(), because it is mixed sum of "raw" value and "adjusted" value: group's {u,s}time = foreach(thread){{u,s}time} + exited({u,s}time) This misbehavior can break {u,s}time monotonicity. Assume that if there is a thread that have raw values greater than adjusted values (e.g. interrupted by 1000Hz ticks 50 times but only runs 45ms) and if it exits, cputime will decrease (e.g. -5ms). To fix this, we could do: group's {u,s}time = foreach(t){task_times(t)} + exited({u,s}time) But task_times() contains hard divisions, so applying it for every thread should be avoided. This patch fixes the above problem in the following way: - Modify thread's exit (= __exit_signal()) not to use task_times(). It means {u,s}time in signal struct accumulates raw values instead of adjusted values. As the result it makes thread_group_cputime() to return pure sum of "raw" values. - Introduce a new function thread_group_times(*task, *utime, *stime) that converts "raw" values of thread_group_cputime() to "adjusted" values, in same calculation procedure as task_times(). - Modify group's exit (= wait_task_zombie()) to use this introduced thread_group_times(). It make c{u,s}time in signal struct to have adjusted values like before this patch. - Replace some thread_group_cputime() by thread_group_times(). This replacements are only applied where conveys the "adjusted" cputime to users, and where already uses task_times() near by it. (i.e. sys_times(), getrusage(), and /proc/<PID>/stat.) This patch have a positive side effect: - Before this patch, if a group contains many short-life threads (e.g. runs 0.9ms and not interrupted by ticks), the group's cputime could be invisible since thread's cputime was accumulated after adjusted: imagine adjustment function as adj(ticks, runtime), {adj(0, 0.9) + adj(0, 0.9) + ....} = {0 + 0 + ....} = 0. After this patch it will not happen because the adjustment is applied after accumulated. v2: - remove if()s, put new variables into signal_struct. Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Spencer Candland <spencer@bluehost.com> Cc: Americo Wang <xiyou.wangcong@gmail.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Stanislaw Gruszka <sgruszka@redhat.com> LKML-Reference: <4B162517.8040909@jp.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-02 08:28:07 +00:00
total = cputime_add(cputime.utime, cputime.stime);
rtime = nsecs_to_cputime(cputime.sum_exec_runtime);
sched: fix process time monotonicity Spencer reported a problem where utime and stime were going negative despite the fixes in commit b27f03d4bdc145a09fb7b0c0e004b29f1ee555fa. The suspected reason for the problem is that signal_struct maintains it's own utime and stime (of exited tasks), these are not updated using the new task_utime() routine, hence sig->utime can go backwards and cause the same problem to occur (sig->utime, adds tsk->utime and not task_utime()). This patch fixes the problem TODO: using max(task->prev_utime, derived utime) works for now, but a more generic solution is to implement cputime_max() and use the cputime_gt() function for comparison. Reported-by: spencer@bluehost.com Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-05 16:12:23 +00:00
sched, cputime: Introduce thread_group_times() This is a real fix for problem of utime/stime values decreasing described in the thread: http://lkml.org/lkml/2009/11/3/522 Now cputime is accounted in the following way: - {u,s}time in task_struct are increased every time when the thread is interrupted by a tick (timer interrupt). - When a thread exits, its {u,s}time are added to signal->{u,s}time, after adjusted by task_times(). - When all threads in a thread_group exits, accumulated {u,s}time (and also c{u,s}time) in signal struct are added to c{u,s}time in signal struct of the group's parent. So {u,s}time in task struct are "raw" tick count, while {u,s}time and c{u,s}time in signal struct are "adjusted" values. And accounted values are used by: - task_times(), to get cputime of a thread: This function returns adjusted values that originates from raw {u,s}time and scaled by sum_exec_runtime that accounted by CFS. - thread_group_cputime(), to get cputime of a thread group: This function returns sum of all {u,s}time of living threads in the group, plus {u,s}time in the signal struct that is sum of adjusted cputimes of all exited threads belonged to the group. The problem is the return value of thread_group_cputime(), because it is mixed sum of "raw" value and "adjusted" value: group's {u,s}time = foreach(thread){{u,s}time} + exited({u,s}time) This misbehavior can break {u,s}time monotonicity. Assume that if there is a thread that have raw values greater than adjusted values (e.g. interrupted by 1000Hz ticks 50 times but only runs 45ms) and if it exits, cputime will decrease (e.g. -5ms). To fix this, we could do: group's {u,s}time = foreach(t){task_times(t)} + exited({u,s}time) But task_times() contains hard divisions, so applying it for every thread should be avoided. This patch fixes the above problem in the following way: - Modify thread's exit (= __exit_signal()) not to use task_times(). It means {u,s}time in signal struct accumulates raw values instead of adjusted values. As the result it makes thread_group_cputime() to return pure sum of "raw" values. - Introduce a new function thread_group_times(*task, *utime, *stime) that converts "raw" values of thread_group_cputime() to "adjusted" values, in same calculation procedure as task_times(). - Modify group's exit (= wait_task_zombie()) to use this introduced thread_group_times(). It make c{u,s}time in signal struct to have adjusted values like before this patch. - Replace some thread_group_cputime() by thread_group_times(). This replacements are only applied where conveys the "adjusted" cputime to users, and where already uses task_times() near by it. (i.e. sys_times(), getrusage(), and /proc/<PID>/stat.) This patch have a positive side effect: - Before this patch, if a group contains many short-life threads (e.g. runs 0.9ms and not interrupted by ticks), the group's cputime could be invisible since thread's cputime was accumulated after adjusted: imagine adjustment function as adj(ticks, runtime), {adj(0, 0.9) + adj(0, 0.9) + ....} = {0 + 0 + ....} = 0. After this patch it will not happen because the adjustment is applied after accumulated. v2: - remove if()s, put new variables into signal_struct. Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Spencer Candland <spencer@bluehost.com> Cc: Americo Wang <xiyou.wangcong@gmail.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Stanislaw Gruszka <sgruszka@redhat.com> LKML-Reference: <4B162517.8040909@jp.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-02 08:28:07 +00:00
if (total) {
sched: Fix user time incorrectly accounted as system time on 32-bit We have 32-bit variable overflow possibility when multiply in task_times() and thread_group_times() functions. When the overflow happens then the scaled utime value becomes erroneously small and the scaled stime becomes i erroneously big. Reported here: https://bugzilla.redhat.com/show_bug.cgi?id=633037 https://bugzilla.kernel.org/show_bug.cgi?id=16559 Reported-by: Michael Chapman <redhat-bugzilla@very.puzzling.org> Reported-by: Ciriaco Garcia de Celis <sysman@etherpilot.com> Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Cc: <stable@kernel.org> # 2.6.32.19+ (partially) and 2.6.33+ LKML-Reference: <20100914143513.GB8415@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-09-14 14:35:14 +00:00
u64 temp = rtime;
sched: fix process time monotonicity Spencer reported a problem where utime and stime were going negative despite the fixes in commit b27f03d4bdc145a09fb7b0c0e004b29f1ee555fa. The suspected reason for the problem is that signal_struct maintains it's own utime and stime (of exited tasks), these are not updated using the new task_utime() routine, hence sig->utime can go backwards and cause the same problem to occur (sig->utime, adds tsk->utime and not task_utime()). This patch fixes the problem TODO: using max(task->prev_utime, derived utime) works for now, but a more generic solution is to implement cputime_max() and use the cputime_gt() function for comparison. Reported-by: spencer@bluehost.com Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-05 16:12:23 +00:00
sched: Fix user time incorrectly accounted as system time on 32-bit We have 32-bit variable overflow possibility when multiply in task_times() and thread_group_times() functions. When the overflow happens then the scaled utime value becomes erroneously small and the scaled stime becomes i erroneously big. Reported here: https://bugzilla.redhat.com/show_bug.cgi?id=633037 https://bugzilla.kernel.org/show_bug.cgi?id=16559 Reported-by: Michael Chapman <redhat-bugzilla@very.puzzling.org> Reported-by: Ciriaco Garcia de Celis <sysman@etherpilot.com> Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Cc: <stable@kernel.org> # 2.6.32.19+ (partially) and 2.6.33+ LKML-Reference: <20100914143513.GB8415@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-09-14 14:35:14 +00:00
temp *= cputime.utime;
sched, cputime: Introduce thread_group_times() This is a real fix for problem of utime/stime values decreasing described in the thread: http://lkml.org/lkml/2009/11/3/522 Now cputime is accounted in the following way: - {u,s}time in task_struct are increased every time when the thread is interrupted by a tick (timer interrupt). - When a thread exits, its {u,s}time are added to signal->{u,s}time, after adjusted by task_times(). - When all threads in a thread_group exits, accumulated {u,s}time (and also c{u,s}time) in signal struct are added to c{u,s}time in signal struct of the group's parent. So {u,s}time in task struct are "raw" tick count, while {u,s}time and c{u,s}time in signal struct are "adjusted" values. And accounted values are used by: - task_times(), to get cputime of a thread: This function returns adjusted values that originates from raw {u,s}time and scaled by sum_exec_runtime that accounted by CFS. - thread_group_cputime(), to get cputime of a thread group: This function returns sum of all {u,s}time of living threads in the group, plus {u,s}time in the signal struct that is sum of adjusted cputimes of all exited threads belonged to the group. The problem is the return value of thread_group_cputime(), because it is mixed sum of "raw" value and "adjusted" value: group's {u,s}time = foreach(thread){{u,s}time} + exited({u,s}time) This misbehavior can break {u,s}time monotonicity. Assume that if there is a thread that have raw values greater than adjusted values (e.g. interrupted by 1000Hz ticks 50 times but only runs 45ms) and if it exits, cputime will decrease (e.g. -5ms). To fix this, we could do: group's {u,s}time = foreach(t){task_times(t)} + exited({u,s}time) But task_times() contains hard divisions, so applying it for every thread should be avoided. This patch fixes the above problem in the following way: - Modify thread's exit (= __exit_signal()) not to use task_times(). It means {u,s}time in signal struct accumulates raw values instead of adjusted values. As the result it makes thread_group_cputime() to return pure sum of "raw" values. - Introduce a new function thread_group_times(*task, *utime, *stime) that converts "raw" values of thread_group_cputime() to "adjusted" values, in same calculation procedure as task_times(). - Modify group's exit (= wait_task_zombie()) to use this introduced thread_group_times(). It make c{u,s}time in signal struct to have adjusted values like before this patch. - Replace some thread_group_cputime() by thread_group_times(). This replacements are only applied where conveys the "adjusted" cputime to users, and where already uses task_times() near by it. (i.e. sys_times(), getrusage(), and /proc/<PID>/stat.) This patch have a positive side effect: - Before this patch, if a group contains many short-life threads (e.g. runs 0.9ms and not interrupted by ticks), the group's cputime could be invisible since thread's cputime was accumulated after adjusted: imagine adjustment function as adj(ticks, runtime), {adj(0, 0.9) + adj(0, 0.9) + ....} = {0 + 0 + ....} = 0. After this patch it will not happen because the adjustment is applied after accumulated. v2: - remove if()s, put new variables into signal_struct. Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Spencer Candland <spencer@bluehost.com> Cc: Americo Wang <xiyou.wangcong@gmail.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Stanislaw Gruszka <sgruszka@redhat.com> LKML-Reference: <4B162517.8040909@jp.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-02 08:28:07 +00:00
do_div(temp, total);
utime = (cputime_t)temp;
} else
utime = rtime;
sig->prev_utime = max(sig->prev_utime, utime);
sig->prev_stime = max(sig->prev_stime,
cputime_sub(rtime, sig->prev_utime));
*ut = sig->prev_utime;
*st = sig->prev_stime;
sched: fix process time monotonicity Spencer reported a problem where utime and stime were going negative despite the fixes in commit b27f03d4bdc145a09fb7b0c0e004b29f1ee555fa. The suspected reason for the problem is that signal_struct maintains it's own utime and stime (of exited tasks), these are not updated using the new task_utime() routine, hence sig->utime can go backwards and cause the same problem to occur (sig->utime, adds tsk->utime and not task_utime()). This patch fixes the problem TODO: using max(task->prev_utime, derived utime) works for now, but a more generic solution is to implement cputime_max() and use the cputime_gt() function for comparison. Reported-by: spencer@bluehost.com Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-05 16:12:23 +00:00
}
#endif
[PATCH] sched: extract load calculation from rebalance_tick A load calculation is always done in rebalance_tick() in addition to the real load balancing activities that only take place when certain jiffie counts have been reached. Move that processing into a separate function and call it directly from scheduler_tick(). Also extract the time slice handling from scheduler_tick and put it into a separate function. Then we can clean up scheduler_tick significantly. It will no longer have any gotos. Signed-off-by: Christoph Lameter <clameter@sgi.com> Cc: Peter Williams <pwil3058@bigpond.net.au> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Christoph Lameter <clameter@sgi.com> Cc: "Siddha, Suresh B" <suresh.b.siddha@intel.com> Cc: "Chen, Kenneth W" <kenneth.w.chen@intel.com> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 10:20:22 +00:00
/*
* This function gets called by the timer code, with HZ frequency.
* We call it with interrupts disabled.
*/
void scheduler_tick(void)
{
int cpu = smp_processor_id();
struct rq *rq = cpu_rq(cpu);
sched: cfs core code apply the CFS core code. this change switches over the scheduler core to CFS's modular design and makes use of kernel/sched_fair/rt/idletask.c to implement Linux's scheduling policies. thanks to Andrew Morton and Thomas Gleixner for lots of detailed review feedback and for fixlets. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
2007-07-09 16:51:59 +00:00
struct task_struct *curr = rq->curr;
sched: add optional support for CONFIG_HAVE_UNSTABLE_SCHED_CLOCK this replaces the rq->clock stuff (and possibly cpu_clock()). - architectures that have an 'imperfect' hardware clock can set CONFIG_HAVE_UNSTABLE_SCHED_CLOCK - the 'jiffie' window might be superfulous when we update tick_gtod before the __update_sched_clock() call in sched_clock_tick() - cpu_clock() might be implemented as: sched_clock_cpu(smp_processor_id()) if the accuracy proves good enough - how far can TSC drift in a single jiffie when considering the filtering and idle hooks? [ mingo@elte.hu: various fixes and cleanups ] Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-05-03 16:29:28 +00:00
sched_clock_tick();
sched: cfs core code apply the CFS core code. this change switches over the scheduler core to CFS's modular design and makes use of kernel/sched_fair/rt/idletask.c to implement Linux's scheduling policies. thanks to Andrew Morton and Thomas Gleixner for lots of detailed review feedback and for fixlets. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
2007-07-09 16:51:59 +00:00
sched: Convert rq->lock to raw_spinlock Convert locks which cannot be sleeping locks in preempt-rt to raw_spinlocks. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Ingo Molnar <mingo@elte.hu>
2009-11-17 13:28:38 +00:00
raw_spin_lock(&rq->lock);
sched: add optional support for CONFIG_HAVE_UNSTABLE_SCHED_CLOCK this replaces the rq->clock stuff (and possibly cpu_clock()). - architectures that have an 'imperfect' hardware clock can set CONFIG_HAVE_UNSTABLE_SCHED_CLOCK - the 'jiffie' window might be superfulous when we update tick_gtod before the __update_sched_clock() call in sched_clock_tick() - cpu_clock() might be implemented as: sched_clock_cpu(smp_processor_id()) if the accuracy proves good enough - how far can TSC drift in a single jiffie when considering the filtering and idle hooks? [ mingo@elte.hu: various fixes and cleanups ] Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-05-03 16:29:28 +00:00
update_rq_clock(rq);
sched: Avoid side-effect of tickless idle on update_cpu_load tickless idle has a negative side effect on update_cpu_load(), which in turn can affect load balancing behavior. update_cpu_load() is supposed to be called every tick, to keep track of various load indicies. With tickless idle, there are no scheduler ticks called on the idle CPUs. Idle CPUs may still do load balancing (with idle_load_balance CPU) using the stale cpu_load. It will also cause problems when all CPUs go idle for a while and become active again. In this case loads would not degrade as expected. This is how rq->nr_load_updates change looks like under different conditions: <cpu_num> <nr_load_updates change> All CPUS idle for 10 seconds (HZ=1000) 0 1621 10 496 11 139 12 875 13 1672 14 12 15 21 1 1472 2 2426 3 1161 4 2108 5 1525 6 701 7 249 8 766 9 1967 One CPU busy rest idle for 10 seconds 0 10003 10 601 11 95 12 966 13 1597 14 114 15 98 1 3457 2 93 3 6679 4 1425 5 1479 6 595 7 193 8 633 9 1687 All CPUs busy for 10 seconds 0 10026 10 10026 11 10026 12 10026 13 10025 14 10025 15 10025 1 10026 2 10026 3 10026 4 10026 5 10026 6 10026 7 10026 8 10026 9 10026 That is update_cpu_load works properly only when all CPUs are busy. If all are idle, all the CPUs get way lower updates. And when few CPUs are busy and rest are idle, only busy and ilb CPU does proper updates and rest of the idle CPUs will do lower updates. The patch keeps track of when a last update was done and fixes up the load avg based on current time. On one of my test system SPECjbb with warehouse 1..numcpus, patch improves throughput numbers by ~1% (average of 6 runs). On another test system (with different domain hierarchy) there is no noticable change in perf. Signed-off-by: Venkatesh Pallipadi <venki@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Thomas Gleixner <tglx@linutronix.de> LKML-Reference: <AANLkTilLtDWQsAUrIxJ6s04WTgmw9GuOODc5AOrYsaR5@mail.gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-05-18 01:14:43 +00:00
update_cpu_load_active(rq);
sched: rt time limit Very simple time limit on the realtime scheduling classes. Allow the rq's realtime class to consume sched_rt_ratio of every sched_rt_period slice. If the class exceeds this quota the fair class will preempt the realtime class. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:29 +00:00
curr->sched_class->task_tick(rq, curr, 0);
sched: Convert rq->lock to raw_spinlock Convert locks which cannot be sleeping locks in preempt-rt to raw_spinlocks. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Ingo Molnar <mingo@elte.hu>
2009-11-17 13:28:38 +00:00
raw_spin_unlock(&rq->lock);
[PATCH] sched: extract load calculation from rebalance_tick A load calculation is always done in rebalance_tick() in addition to the real load balancing activities that only take place when certain jiffie counts have been reached. Move that processing into a separate function and call it directly from scheduler_tick(). Also extract the time slice handling from scheduler_tick and put it into a separate function. Then we can clean up scheduler_tick significantly. It will no longer have any gotos. Signed-off-by: Christoph Lameter <clameter@sgi.com> Cc: Peter Williams <pwil3058@bigpond.net.au> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Christoph Lameter <clameter@sgi.com> Cc: "Siddha, Suresh B" <suresh.b.siddha@intel.com> Cc: "Chen, Kenneth W" <kenneth.w.chen@intel.com> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 10:20:22 +00:00
perf: Undo the per cpu-context timer stuff Revert the timer per cpu-context timers because of unfortunate nohz interaction. Fixing that would have been somewhat ugly, so go back to driving things from the regular tick. Provide a jiffies interval feature for people who want slower rotations. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Stephane Eranian <eranian@google.com> Cc: Robert Richter <robert.richter@amd.com> Cc: Yinghai Lu <yinghai@kernel.org> LKML-Reference: <20100917093009.519845633@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-09-17 09:28:50 +00:00
perf_event_task_tick();
perf_counter: Fix dynamic irq_period logging We call perf_adjust_freq() from perf_counter_task_tick() which is is called under the rq->lock causing lock recursion. However, it's no longer required to be called under the rq->lock, so remove it from under it. Also, fix up some related comments. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Paul Mackerras <paulus@samba.org> Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: John Kacur <jkacur@redhat.com> LKML-Reference: <20090523163012.476197912@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-05-23 16:28:55 +00:00
[PATCH] sched: move idle status calculation into rebalance_tick() Perform the idle state determination in rebalance_tick. If we separate balancing from sched_tick then we also need to determine the idle state in rebalance_tick. V2->V3 Remove useless idlle != 0 check. Checking nr_running seems to be sufficient. Thanks Suresh. Signed-off-by: Christoph Lameter <clameter@sgi.com> Cc: Peter Williams <pwil3058@bigpond.net.au> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Christoph Lameter <clameter@sgi.com> Cc: "Siddha, Suresh B" <suresh.b.siddha@intel.com> Cc: "Chen, Kenneth W" <kenneth.w.chen@intel.com> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 10:20:23 +00:00
#ifdef CONFIG_SMP
sched: cfs core code apply the CFS core code. this change switches over the scheduler core to CFS's modular design and makes use of kernel/sched_fair/rt/idletask.c to implement Linux's scheduling policies. thanks to Andrew Morton and Thomas Gleixner for lots of detailed review feedback and for fixlets. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
2007-07-09 16:51:59 +00:00
rq->idle_at_tick = idle_cpu(cpu);
trigger_load_balance(rq, cpu);
[PATCH] sched: move idle status calculation into rebalance_tick() Perform the idle state determination in rebalance_tick. If we separate balancing from sched_tick then we also need to determine the idle state in rebalance_tick. V2->V3 Remove useless idlle != 0 check. Checking nr_running seems to be sufficient. Thanks Suresh. Signed-off-by: Christoph Lameter <clameter@sgi.com> Cc: Peter Williams <pwil3058@bigpond.net.au> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Christoph Lameter <clameter@sgi.com> Cc: "Siddha, Suresh B" <suresh.b.siddha@intel.com> Cc: "Chen, Kenneth W" <kenneth.w.chen@intel.com> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 10:20:23 +00:00
#endif
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
}
tracing, sched: mark get_parent_ip() notrace Impact: remove overly redundant tracing entries When tracer is "function" or "function_graph", way too much "get_parent_ip" entries are recorded in ring_buffer. Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> Acked-by: Frederic Weisbecker <fweisbec@gmail.com> Acked-by: Steven Rostedt <srostedt@redhat.com> LKML-Reference: <49D458B1.5000703@cn.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-02 06:18:25 +00:00
notrace unsigned long get_parent_ip(unsigned long addr)
ftrace: trace preempt off critical timings Add preempt off timings. A lot of kernel core code is taken from the RT patch latency trace that was written by Ingo Molnar. This adds "preemptoff" and "preemptirqsoff" to /debugfs/tracing/available_tracers Now instead of just tracing irqs off, preemption off can be selected to be recorded. When this is selected, it shares the same files as irqs off timings. One can either trace preemption off, irqs off, or one or the other off. By echoing "preemptoff" into /debugfs/tracing/current_tracer, recording of preempt off only is performed. "irqsoff" will only record the time irqs are disabled, but "preemptirqsoff" will take the total time irqs or preemption are disabled. Runtime switching of these options is now supported by simpling echoing in the appropriate trace name into /debugfs/tracing/current_tracer. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-12 19:20:42 +00:00
{
if (in_lock_functions(addr)) {
addr = CALLER_ADDR2;
if (in_lock_functions(addr))
addr = CALLER_ADDR3;
}
return addr;
}
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
trace, lockdep: manual preempt count adding for local_bh_disable Impact: fix to preempt trace triggering lockdep check_flag failure In local_bh_disable, the use of add_preempt_count causes the preempt tracer to start recording the time preemption is off. But because it already modified the preempt_count to show softirqs disabled, and before it called the lockdep code to handle this, it causes a state that lockdep can not handle. The preempt tracer will reset the ring buffer on start of a trace, and the ring buffer reset code does a spin_lock_irqsave. This calls into lockdep and lockdep will fail when it detects the invalid state of having softirqs disabled but the internal current->softirqs_enabled is still set. The fix is to manually add the SOFTIRQ_OFFSET to preempt count and call the preempt tracer code outside the lockdep critical area. Thanks to Peter Zijlstra for suggesting this solution. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-23 00:01:40 +00:00
#if defined(CONFIG_PREEMPT) && (defined(CONFIG_DEBUG_PREEMPT) || \
defined(CONFIG_PREEMPT_TRACER))
kprobes: refuse kprobe insertion on add/sub_preempt_counter() Kprobes makes use of preempt_disable(),preempt_enable_noresched() and these functions inturn call add/sub_preempt_count(). So we need to refuse user from inserting probe in to these functions. This patch disallows user from probing add/sub_preempt_count(). Signed-off-by: Srinivasa DS <srinivasa@in.ibm.com> Acked-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-23 23:24:04 +00:00
void __kprobes add_preempt_count(int val)
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
{
ftrace: trace preempt off critical timings Add preempt off timings. A lot of kernel core code is taken from the RT patch latency trace that was written by Ingo Molnar. This adds "preemptoff" and "preemptirqsoff" to /debugfs/tracing/available_tracers Now instead of just tracing irqs off, preemption off can be selected to be recorded. When this is selected, it shares the same files as irqs off timings. One can either trace preemption off, irqs off, or one or the other off. By echoing "preemptoff" into /debugfs/tracing/current_tracer, recording of preempt off only is performed. "irqsoff" will only record the time irqs are disabled, but "preemptirqsoff" will take the total time irqs or preemption are disabled. Runtime switching of these options is now supported by simpling echoing in the appropriate trace name into /debugfs/tracing/current_tracer. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-12 19:20:42 +00:00
#ifdef CONFIG_DEBUG_PREEMPT
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
/*
* Underflow?
*/
[PATCH] lockdep: better lock debugging Generic lock debugging: - generalized lock debugging framework. For example, a bug in one lock subsystem turns off debugging in all lock subsystems. - got rid of the caller address passing (__IP__/__IP_DECL__/etc.) from the mutex/rtmutex debugging code: it caused way too much prototype hackery, and lockdep will give the same information anyway. - ability to do silent tests - check lock freeing in vfree too. - more finegrained debugging options, to allow distributions to turn off more expensive debugging features. There's no separate 'held mutexes' list anymore - but there's a 'held locks' stack within lockdep, which unifies deadlock detection across all lock classes. (this is independent of the lockdep validation stuff - lockdep first checks whether we are holding a lock already) Here are the current debugging options: CONFIG_DEBUG_MUTEXES=y CONFIG_DEBUG_LOCK_ALLOC=y which do: config DEBUG_MUTEXES bool "Mutex debugging, basic checks" config DEBUG_LOCK_ALLOC bool "Detect incorrect freeing of live mutexes" Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-03 07:24:33 +00:00
if (DEBUG_LOCKS_WARN_ON((preempt_count() < 0)))
return;
ftrace: trace preempt off critical timings Add preempt off timings. A lot of kernel core code is taken from the RT patch latency trace that was written by Ingo Molnar. This adds "preemptoff" and "preemptirqsoff" to /debugfs/tracing/available_tracers Now instead of just tracing irqs off, preemption off can be selected to be recorded. When this is selected, it shares the same files as irqs off timings. One can either trace preemption off, irqs off, or one or the other off. By echoing "preemptoff" into /debugfs/tracing/current_tracer, recording of preempt off only is performed. "irqsoff" will only record the time irqs are disabled, but "preemptirqsoff" will take the total time irqs or preemption are disabled. Runtime switching of these options is now supported by simpling echoing in the appropriate trace name into /debugfs/tracing/current_tracer. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-12 19:20:42 +00:00
#endif
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
preempt_count() += val;
ftrace: trace preempt off critical timings Add preempt off timings. A lot of kernel core code is taken from the RT patch latency trace that was written by Ingo Molnar. This adds "preemptoff" and "preemptirqsoff" to /debugfs/tracing/available_tracers Now instead of just tracing irqs off, preemption off can be selected to be recorded. When this is selected, it shares the same files as irqs off timings. One can either trace preemption off, irqs off, or one or the other off. By echoing "preemptoff" into /debugfs/tracing/current_tracer, recording of preempt off only is performed. "irqsoff" will only record the time irqs are disabled, but "preemptirqsoff" will take the total time irqs or preemption are disabled. Runtime switching of these options is now supported by simpling echoing in the appropriate trace name into /debugfs/tracing/current_tracer. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-12 19:20:42 +00:00
#ifdef CONFIG_DEBUG_PREEMPT
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
/*
* Spinlock count overflowing soon?
*/
[PATCH] kernel/sched.c: whitespace cleanups [akpm@osdl.org: additional cleanups] Signed-off-by: Miguel Ojeda Sandonis <maxextreme@gmail.com> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 10:20:38 +00:00
DEBUG_LOCKS_WARN_ON((preempt_count() & PREEMPT_MASK) >=
PREEMPT_MASK - 10);
ftrace: trace preempt off critical timings Add preempt off timings. A lot of kernel core code is taken from the RT patch latency trace that was written by Ingo Molnar. This adds "preemptoff" and "preemptirqsoff" to /debugfs/tracing/available_tracers Now instead of just tracing irqs off, preemption off can be selected to be recorded. When this is selected, it shares the same files as irqs off timings. One can either trace preemption off, irqs off, or one or the other off. By echoing "preemptoff" into /debugfs/tracing/current_tracer, recording of preempt off only is performed. "irqsoff" will only record the time irqs are disabled, but "preemptirqsoff" will take the total time irqs or preemption are disabled. Runtime switching of these options is now supported by simpling echoing in the appropriate trace name into /debugfs/tracing/current_tracer. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-12 19:20:42 +00:00
#endif
if (preempt_count() == val)
trace_preempt_off(CALLER_ADDR0, get_parent_ip(CALLER_ADDR1));
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
}
EXPORT_SYMBOL(add_preempt_count);
kprobes: refuse kprobe insertion on add/sub_preempt_counter() Kprobes makes use of preempt_disable(),preempt_enable_noresched() and these functions inturn call add/sub_preempt_count(). So we need to refuse user from inserting probe in to these functions. This patch disallows user from probing add/sub_preempt_count(). Signed-off-by: Srinivasa DS <srinivasa@in.ibm.com> Acked-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-23 23:24:04 +00:00
void __kprobes sub_preempt_count(int val)
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
{
ftrace: trace preempt off critical timings Add preempt off timings. A lot of kernel core code is taken from the RT patch latency trace that was written by Ingo Molnar. This adds "preemptoff" and "preemptirqsoff" to /debugfs/tracing/available_tracers Now instead of just tracing irqs off, preemption off can be selected to be recorded. When this is selected, it shares the same files as irqs off timings. One can either trace preemption off, irqs off, or one or the other off. By echoing "preemptoff" into /debugfs/tracing/current_tracer, recording of preempt off only is performed. "irqsoff" will only record the time irqs are disabled, but "preemptirqsoff" will take the total time irqs or preemption are disabled. Runtime switching of these options is now supported by simpling echoing in the appropriate trace name into /debugfs/tracing/current_tracer. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-12 19:20:42 +00:00
#ifdef CONFIG_DEBUG_PREEMPT
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
/*
* Underflow?
*/
Revert "sched: improve preempt debugging" This reverts commit 7317d7b87edb41a9135e30be1ec3f7ef817c53dd. This has been reported (and bisected) by Alexey Zaytsev and Kamalesh Babulal to produce annoying warnings during bootup on both x86 and powerpc. kernel_locked() is not a valid test in IRQ context (we update the BKL's ->lock_depth and the preempt count separately and non-atomicalyy), so we cannot put it into the generic preempt debugging checks which can run in IRQ contexts too. Reported-and-bisected-by: Alexey Zaytsev <alexey.zaytsev@gmail.com> Reported-and-bisected-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-12 12:00:50 +00:00
if (DEBUG_LOCKS_WARN_ON(val > preempt_count()))
[PATCH] lockdep: better lock debugging Generic lock debugging: - generalized lock debugging framework. For example, a bug in one lock subsystem turns off debugging in all lock subsystems. - got rid of the caller address passing (__IP__/__IP_DECL__/etc.) from the mutex/rtmutex debugging code: it caused way too much prototype hackery, and lockdep will give the same information anyway. - ability to do silent tests - check lock freeing in vfree too. - more finegrained debugging options, to allow distributions to turn off more expensive debugging features. There's no separate 'held mutexes' list anymore - but there's a 'held locks' stack within lockdep, which unifies deadlock detection across all lock classes. (this is independent of the lockdep validation stuff - lockdep first checks whether we are holding a lock already) Here are the current debugging options: CONFIG_DEBUG_MUTEXES=y CONFIG_DEBUG_LOCK_ALLOC=y which do: config DEBUG_MUTEXES bool "Mutex debugging, basic checks" config DEBUG_LOCK_ALLOC bool "Detect incorrect freeing of live mutexes" Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-03 07:24:33 +00:00
return;
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
/*
* Is the spinlock portion underflowing?
*/
[PATCH] lockdep: better lock debugging Generic lock debugging: - generalized lock debugging framework. For example, a bug in one lock subsystem turns off debugging in all lock subsystems. - got rid of the caller address passing (__IP__/__IP_DECL__/etc.) from the mutex/rtmutex debugging code: it caused way too much prototype hackery, and lockdep will give the same information anyway. - ability to do silent tests - check lock freeing in vfree too. - more finegrained debugging options, to allow distributions to turn off more expensive debugging features. There's no separate 'held mutexes' list anymore - but there's a 'held locks' stack within lockdep, which unifies deadlock detection across all lock classes. (this is independent of the lockdep validation stuff - lockdep first checks whether we are holding a lock already) Here are the current debugging options: CONFIG_DEBUG_MUTEXES=y CONFIG_DEBUG_LOCK_ALLOC=y which do: config DEBUG_MUTEXES bool "Mutex debugging, basic checks" config DEBUG_LOCK_ALLOC bool "Detect incorrect freeing of live mutexes" Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-03 07:24:33 +00:00
if (DEBUG_LOCKS_WARN_ON((val < PREEMPT_MASK) &&
!(preempt_count() & PREEMPT_MASK)))
return;
ftrace: trace preempt off critical timings Add preempt off timings. A lot of kernel core code is taken from the RT patch latency trace that was written by Ingo Molnar. This adds "preemptoff" and "preemptirqsoff" to /debugfs/tracing/available_tracers Now instead of just tracing irqs off, preemption off can be selected to be recorded. When this is selected, it shares the same files as irqs off timings. One can either trace preemption off, irqs off, or one or the other off. By echoing "preemptoff" into /debugfs/tracing/current_tracer, recording of preempt off only is performed. "irqsoff" will only record the time irqs are disabled, but "preemptirqsoff" will take the total time irqs or preemption are disabled. Runtime switching of these options is now supported by simpling echoing in the appropriate trace name into /debugfs/tracing/current_tracer. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-12 19:20:42 +00:00
#endif
[PATCH] lockdep: better lock debugging Generic lock debugging: - generalized lock debugging framework. For example, a bug in one lock subsystem turns off debugging in all lock subsystems. - got rid of the caller address passing (__IP__/__IP_DECL__/etc.) from the mutex/rtmutex debugging code: it caused way too much prototype hackery, and lockdep will give the same information anyway. - ability to do silent tests - check lock freeing in vfree too. - more finegrained debugging options, to allow distributions to turn off more expensive debugging features. There's no separate 'held mutexes' list anymore - but there's a 'held locks' stack within lockdep, which unifies deadlock detection across all lock classes. (this is independent of the lockdep validation stuff - lockdep first checks whether we are holding a lock already) Here are the current debugging options: CONFIG_DEBUG_MUTEXES=y CONFIG_DEBUG_LOCK_ALLOC=y which do: config DEBUG_MUTEXES bool "Mutex debugging, basic checks" config DEBUG_LOCK_ALLOC bool "Detect incorrect freeing of live mutexes" Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-03 07:24:33 +00:00
ftrace: trace preempt off critical timings Add preempt off timings. A lot of kernel core code is taken from the RT patch latency trace that was written by Ingo Molnar. This adds "preemptoff" and "preemptirqsoff" to /debugfs/tracing/available_tracers Now instead of just tracing irqs off, preemption off can be selected to be recorded. When this is selected, it shares the same files as irqs off timings. One can either trace preemption off, irqs off, or one or the other off. By echoing "preemptoff" into /debugfs/tracing/current_tracer, recording of preempt off only is performed. "irqsoff" will only record the time irqs are disabled, but "preemptirqsoff" will take the total time irqs or preemption are disabled. Runtime switching of these options is now supported by simpling echoing in the appropriate trace name into /debugfs/tracing/current_tracer. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-12 19:20:42 +00:00
if (preempt_count() == val)
trace_preempt_on(CALLER_ADDR0, get_parent_ip(CALLER_ADDR1));
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
preempt_count() -= val;
}
EXPORT_SYMBOL(sub_preempt_count);
#endif
/*
sched: cfs core code apply the CFS core code. this change switches over the scheduler core to CFS's modular design and makes use of kernel/sched_fair/rt/idletask.c to implement Linux's scheduling policies. thanks to Andrew Morton and Thomas Gleixner for lots of detailed review feedback and for fixlets. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
2007-07-09 16:51:59 +00:00
* Print scheduling while atomic bug:
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
*/
sched: cfs core code apply the CFS core code. this change switches over the scheduler core to CFS's modular design and makes use of kernel/sched_fair/rt/idletask.c to implement Linux's scheduling policies. thanks to Andrew Morton and Thomas Gleixner for lots of detailed review feedback and for fixlets. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
2007-07-09 16:51:59 +00:00
static noinline void __schedule_bug(struct task_struct *prev)
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
{
sched: use show_regs() to improve __schedule_bug() output A full register dump along with stack backtrace would make the "scheduling while atomic" message more helpful. Use show_regs() instead of dump_stack() for this. We already know we're atomic in here (that is why this function was called) so show_regs()'s atomicity expectations are guaranteed. Also, modify the output of the "BUG: scheduling while atomic:" header a bit to keep task->comm and task->pid together and preempt_count() after them. Signed-off-by: Satyam Sharma <satyam@infradead.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-24 16:23:50 +00:00
struct pt_regs *regs = get_irq_regs();
sched: Restore printk sanity Revert the braindead pr_* crap. (Commit 663997d "sched: Use pr_fmt() and pr_<level>()") It's dumb and causes stupid "sched: " strings all over the place. Signed-off-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Mike Galbraith <efault@gmx.de> Cc: Joe Perches <joe@perches.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> LKML-Reference: <1261315437.4314.6.camel@laptop> [ i dont mind the pr_*() patterns that much - but Peter dislikes them with a vengence. ] [ - v2: remove spurious diffstat from changelog :-/ ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-20 13:23:57 +00:00
printk(KERN_ERR "BUG: scheduling while atomic: %s/%d/0x%08x\n",
prev->comm, prev->pid, preempt_count());
sched: use show_regs() to improve __schedule_bug() output A full register dump along with stack backtrace would make the "scheduling while atomic" message more helpful. Use show_regs() instead of dump_stack() for this. We already know we're atomic in here (that is why this function was called) so show_regs()'s atomicity expectations are guaranteed. Also, modify the output of the "BUG: scheduling while atomic:" header a bit to keep task->comm and task->pid together and preempt_count() after them. Signed-off-by: Satyam Sharma <satyam@infradead.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-24 16:23:50 +00:00
sched: cfs core code apply the CFS core code. this change switches over the scheduler core to CFS's modular design and makes use of kernel/sched_fair/rt/idletask.c to implement Linux's scheduling policies. thanks to Andrew Morton and Thomas Gleixner for lots of detailed review feedback and for fixlets. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
2007-07-09 16:51:59 +00:00
debug_show_held_locks(prev);
sched: print module list in the "scheduling while atomic" warning For the normal WARN_ON() etc we added a print-the-modules-list already, which is very useful to figure out candidates for certain types of bugs. This patch adds the same print to the "scheduling while atomic" BUG warning, for the same reason: when we get here it's very useful to see which modules are loaded, to narrow down the candidate code list. Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Cc: mingo@elte.hu Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-23 16:05:58 +00:00
print_modules();
sched: cfs core code apply the CFS core code. this change switches over the scheduler core to CFS's modular design and makes use of kernel/sched_fair/rt/idletask.c to implement Linux's scheduling policies. thanks to Andrew Morton and Thomas Gleixner for lots of detailed review feedback and for fixlets. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
2007-07-09 16:51:59 +00:00
if (irqs_disabled())
print_irqtrace_events(prev);
sched: use show_regs() to improve __schedule_bug() output A full register dump along with stack backtrace would make the "scheduling while atomic" message more helpful. Use show_regs() instead of dump_stack() for this. We already know we're atomic in here (that is why this function was called) so show_regs()'s atomicity expectations are guaranteed. Also, modify the output of the "BUG: scheduling while atomic:" header a bit to keep task->comm and task->pid together and preempt_count() after them. Signed-off-by: Satyam Sharma <satyam@infradead.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-24 16:23:50 +00:00
if (regs)
show_regs(regs);
else
dump_stack();
sched: cfs core code apply the CFS core code. this change switches over the scheduler core to CFS's modular design and makes use of kernel/sched_fair/rt/idletask.c to implement Linux's scheduling policies. thanks to Andrew Morton and Thomas Gleixner for lots of detailed review feedback and for fixlets. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
2007-07-09 16:51:59 +00:00
}
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
sched: cfs core code apply the CFS core code. this change switches over the scheduler core to CFS's modular design and makes use of kernel/sched_fair/rt/idletask.c to implement Linux's scheduling policies. thanks to Andrew Morton and Thomas Gleixner for lots of detailed review feedback and for fixlets. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
2007-07-09 16:51:59 +00:00
/*
* Various schedule()-time debugging checks and statistics:
*/
static inline void schedule_debug(struct task_struct *prev)
{
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
/*
sched: style cleanups style cleanup of various changes that were done recently. no code changed: text data bss dec hex filename 23680 2542 28 26250 668a sched.o.before 23680 2542 28 26250 668a sched.o.after Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-12-05 14:46:09 +00:00
* Test if we are atomic. Since do_exit() needs to call into
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
* schedule() atomically, we ignore that path for now.
* Otherwise, whine if we are scheduling when we should not be.
*/
sched: unite unlikely pairs in rt_policy() and schedule_debug() Removes obfuscation and may improve assembly. Signed-off-by: Roel Kluin <roel.kluin@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-05-13 21:44:11 +00:00
if (unlikely(in_atomic_preempt_off() && !prev->exit_state))
sched: cfs core code apply the CFS core code. this change switches over the scheduler core to CFS's modular design and makes use of kernel/sched_fair/rt/idletask.c to implement Linux's scheduling policies. thanks to Andrew Morton and Thomas Gleixner for lots of detailed review feedback and for fixlets. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
2007-07-09 16:51:59 +00:00
__schedule_bug(prev);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
profile_hit(SCHED_PROFILING, __builtin_return_address(0));
sched: clean up schedstats, cnt -> count rename all 'cnt' fields and variables to the less yucky 'count' name. yuckage noticed by Andrew Morton. no change in code, other than the /proc/sched_debug bkl_count string got a bit larger: text data bss dec hex filename 38236 3506 24 41766 a326 sched.o.before 38240 3506 24 41770 a32a sched.o.after Signed-off-by: Ingo Molnar <mingo@elte.hu> Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-15 15:00:12 +00:00
schedstat_inc(this_rq(), sched_count);
sched: cfs core code apply the CFS core code. this change switches over the scheduler core to CFS's modular design and makes use of kernel/sched_fair/rt/idletask.c to implement Linux's scheduling policies. thanks to Andrew Morton and Thomas Gleixner for lots of detailed review feedback and for fixlets. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
2007-07-09 16:51:59 +00:00
}
sched: Discard some old bits WAKEUP_RUNNING was an experiment, not sure why that ever ended up being merged... Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-11-30 12:00:37 +00:00
static void put_prev_task(struct rq *rq, struct task_struct *prev)
sched: add avg_overlap decay Impact: more precise avg_overlap metric - better load-balancing avg_overlap is used to measure the runtime overlap of the waker and wakee. However, when a process changes behaviour, eg a pipe becomes un-congested and we don't need to go to sleep after a wakeup for a while, the avg_overlap value grows stale. When running we use the avg runtime between preemption as a measure for avg_overlap since the amount of runtime can be correlated to cache footprint. The longer we run, the less likely we'll be wanting to be migrated to another CPU. Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1236709131.25234.576.camel@laptop> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-10 18:08:11 +00:00
{
sched, rt: Update rq clock when unthrottling of an otherwise idle CPU If an RT task is awakened while it's rt_rq is throttled, the time between wakeup/enqueue and unthrottle/selection may be accounted as rt_time if the CPU is idle. Set rq->skip_clock_update negative upon throttle release to tell put_prev_task() that we need a clock update. Reported-by: Thomas Giesel <skoe@directbox.com> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1304059010.7472.1.camel@marge.simson.net Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-29 06:36:50 +00:00
if (prev->on_rq || rq->skip_clock_update < 0)
sched: Cleanup/optimize clock updates Now that we no longer depend on the clock being updated prior to enqueueing on migratory wakeup, we can clean up a bit, placing calls to update_rq_clock() exactly where they are needed, ie on enqueue, dequeue and schedule events. In the case of a freshly enqueued task immediately preempting, we can skip the update during preemption, as the clock was just updated by the enqueue event. We also save an unneeded call during a migratory wakeup by not updating the previous runqueue, where update_curr() won't be invoked. Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1268301199.6785.32.camel@marge.simson.net> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-03-11 16:16:20 +00:00
update_rq_clock(rq);
sched: Discard some old bits WAKEUP_RUNNING was an experiment, not sure why that ever ended up being merged... Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-11-30 12:00:37 +00:00
prev->sched_class->put_prev_task(rq, prev);
sched: add avg_overlap decay Impact: more precise avg_overlap metric - better load-balancing avg_overlap is used to measure the runtime overlap of the waker and wakee. However, when a process changes behaviour, eg a pipe becomes un-congested and we don't need to go to sleep after a wakeup for a while, the avg_overlap value grows stale. When running we use the avg runtime between preemption as a measure for avg_overlap since the amount of runtime can be correlated to cache footprint. The longer we run, the less likely we'll be wanting to be migrated to another CPU. Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1236709131.25234.576.camel@laptop> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-10 18:08:11 +00:00
}
sched: cfs core code apply the CFS core code. this change switches over the scheduler core to CFS's modular design and makes use of kernel/sched_fair/rt/idletask.c to implement Linux's scheduling policies. thanks to Andrew Morton and Thomas Gleixner for lots of detailed review feedback and for fixlets. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
2007-07-09 16:51:59 +00:00
/*
* Pick up the highest-prio task:
*/
static inline struct task_struct *
sched: kill unused parameter of pick_next_task() Impact: micro-optimization Parameter "prev" is not used really. Signed-off-by: Wang Chen <wangchen@cn.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-02 05:55:26 +00:00
pick_next_task(struct rq *rq)
sched: cfs core code apply the CFS core code. this change switches over the scheduler core to CFS's modular design and makes use of kernel/sched_fair/rt/idletask.c to implement Linux's scheduling policies. thanks to Andrew Morton and Thomas Gleixner for lots of detailed review feedback and for fixlets. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
2007-07-09 16:51:59 +00:00
{
sched: mark scheduling classes as const mark scheduling classes as const. The speeds up the code a bit and shrinks it: text data bss dec hex filename 40027 4018 292 44337 ad31 sched.o.before 40190 3842 292 44324 ad24 sched.o.after Signed-off-by: Ingo Molnar <mingo@elte.hu> Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-15 15:00:12 +00:00
const struct sched_class *class;
sched: cfs core code apply the CFS core code. this change switches over the scheduler core to CFS's modular design and makes use of kernel/sched_fair/rt/idletask.c to implement Linux's scheduling policies. thanks to Andrew Morton and Thomas Gleixner for lots of detailed review feedback and for fixlets. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
2007-07-09 16:51:59 +00:00
struct task_struct *p;
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
/*
sched: cfs core code apply the CFS core code. this change switches over the scheduler core to CFS's modular design and makes use of kernel/sched_fair/rt/idletask.c to implement Linux's scheduling policies. thanks to Andrew Morton and Thomas Gleixner for lots of detailed review feedback and for fixlets. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
2007-07-09 16:51:59 +00:00
* Optimization: we know that if all tasks are in
* the fair class we can call that function directly:
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
*/
sched: Implement hierarchical task accounting for SCHED_OTHER Introduce hierarchical task accounting for the group scheduling case in CFS, as well as promoting the responsibility for maintaining rq->nr_running to the scheduling classes. The primary motivation for this is that with scheduling classes supporting bandwidth throttling it is possible for entities participating in throttled sub-trees to not have root visible changes in rq->nr_running across activate and de-activate operations. This in turn leads to incorrect idle and weight-per-task load balance decisions. This also allows us to make a small fixlet to the fastpath in pick_next_task() under group scheduling. Note: this issue also exists with the existing sched_rt throttling mechanism. This patch does not address that. Signed-off-by: Paul Turner <pjt@google.com> Reviewed-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110721184756.878333391@google.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-21 16:43:27 +00:00
if (likely(rq->nr_running == rq->cfs.h_nr_running)) {
sched: remove the 'u64 now' parameter from ->pick_next_task() remove the 'u64 now' parameter from ->pick_next_task(). ( identity transformation that causes no change in functionality. ) Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-08-09 09:16:48 +00:00
p = fair_sched_class.pick_next_task(rq);
sched: cfs core code apply the CFS core code. this change switches over the scheduler core to CFS's modular design and makes use of kernel/sched_fair/rt/idletask.c to implement Linux's scheduling policies. thanks to Andrew Morton and Thomas Gleixner for lots of detailed review feedback and for fixlets. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
2007-07-09 16:51:59 +00:00
if (likely(p))
return p;
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
}
sched: Create special class for stop/migrate work In order to separate the stop/migrate work thread from the SCHED_FIFO implementation, create a special class for it that is of higher priority than SCHED_FIFO itself. This currently solves a problem where cpu-hotplug consumes so much cpu-time that the SCHED_FIFO class gets throttled, but has the bandwidth replenishment timer pending on the now dead cpu. It is also required for when we add the planned deadline scheduling class above SCHED_FIFO, as the stop/migrate thread still needs to transcent those tasks. Tested-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1285165776.2275.1022.camel@laptop> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-09-22 11:53:15 +00:00
for_each_class(class) {
sched: remove the 'u64 now' parameter from ->pick_next_task() remove the 'u64 now' parameter from ->pick_next_task(). ( identity transformation that causes no change in functionality. ) Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-08-09 09:16:48 +00:00
p = class->pick_next_task(rq);
sched: cfs core code apply the CFS core code. this change switches over the scheduler core to CFS's modular design and makes use of kernel/sched_fair/rt/idletask.c to implement Linux's scheduling policies. thanks to Andrew Morton and Thomas Gleixner for lots of detailed review feedback and for fixlets. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
2007-07-09 16:51:59 +00:00
if (p)
return p;
}
sched: Create special class for stop/migrate work In order to separate the stop/migrate work thread from the SCHED_FIFO implementation, create a special class for it that is of higher priority than SCHED_FIFO itself. This currently solves a problem where cpu-hotplug consumes so much cpu-time that the SCHED_FIFO class gets throttled, but has the bandwidth replenishment timer pending on the now dead cpu. It is also required for when we add the planned deadline scheduling class above SCHED_FIFO, as the stop/migrate thread still needs to transcent those tasks. Tested-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1285165776.2275.1022.camel@laptop> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-09-22 11:53:15 +00:00
BUG(); /* the idle class will always have a runnable task */
sched: cfs core code apply the CFS core code. this change switches over the scheduler core to CFS's modular design and makes use of kernel/sched_fair/rt/idletask.c to implement Linux's scheduling policies. thanks to Andrew Morton and Thomas Gleixner for lots of detailed review feedback and for fixlets. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
2007-07-09 16:51:59 +00:00
}
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
sched: cfs core code apply the CFS core code. this change switches over the scheduler core to CFS's modular design and makes use of kernel/sched_fair/rt/idletask.c to implement Linux's scheduling policies. thanks to Andrew Morton and Thomas Gleixner for lots of detailed review feedback and for fixlets. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
2007-07-09 16:51:59 +00:00
/*
* schedule() is the main scheduler function.
*/
sched: remove extra call overhead for schedule() Lai Jiangshan's patch reminded me that I promised Nick to remove that extra call overhead in schedule(). Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20090313112300.927414207@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-13 11:21:26 +00:00
asmlinkage void __sched schedule(void)
sched: cfs core code apply the CFS core code. this change switches over the scheduler core to CFS's modular design and makes use of kernel/sched_fair/rt/idletask.c to implement Linux's scheduling policies. thanks to Andrew Morton and Thomas Gleixner for lots of detailed review feedback and for fixlets. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
2007-07-09 16:51:59 +00:00
{
struct task_struct *prev, *next;
sched: fix signedness warnings in sched.c Unsigned long values are always assigned to switch_count, make it unsigned long. kernel/sched.c:3897:15: warning: incorrect type in assignment (different signedness) kernel/sched.c:3897:15: expected long *switch_count kernel/sched.c:3897:15: got unsigned long *<noident> kernel/sched.c:3921:16: warning: incorrect type in assignment (different signedness) kernel/sched.c:3921:16: expected long *switch_count kernel/sched.c:3921:16: got unsigned long *<noident> Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-15 17:56:36 +00:00
unsigned long *switch_count;
sched: cfs core code apply the CFS core code. this change switches over the scheduler core to CFS's modular design and makes use of kernel/sched_fair/rt/idletask.c to implement Linux's scheduling policies. thanks to Andrew Morton and Thomas Gleixner for lots of detailed review feedback and for fixlets. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
2007-07-09 16:51:59 +00:00
struct rq *rq;
sched, x86: clean up hrtick implementation random uvesafb failures were reported against Gentoo: http://bugs.gentoo.org/show_bug.cgi?id=222799 and Mihai Moldovan bisected it back to: > 8f4d37ec073c17e2d4aa8851df5837d798606d6f is first bad commit > commit 8f4d37ec073c17e2d4aa8851df5837d798606d6f > Author: Peter Zijlstra <a.p.zijlstra@chello.nl> > Date: Fri Jan 25 21:08:29 2008 +0100 > > sched: high-res preemption tick Linus suspected it to be hrtick + vm86 interaction and observed: > Btw, Peter, Ingo: I think that commit is doing bad things. They aren't > _incorrect_ per se, but they are definitely bad. > > Why? > > Using random _TIF_WORK_MASK flags is really impolite for doing > "scheduling" work. There's a reason that arch/x86/kernel/entry_32.S > special-cases the _TIF_NEED_RESCHED flag: we don't want to exit out of > vm86 mode unnecessarily. > > See the "work_notifysig_v86" label, and how it does that > "save_v86_state()" thing etc etc. Right, I never liked having to fiddle with those TIF flags. Initially I needed it because the hrtimer base lock could not nest in the rq lock. That however is fixed these days. Currently the only reason left to fiddle with the TIF flags is remote wakeups. We cannot program a remote cpu's hrtimer. I've been thinking about using the new and improved IPI function call stuff to implement hrtimer_start_on(). However that does require that smp_call_function_single(.wait=0) works from interrupt context - /me looks at the latest series from Jens - Yes that does seem to be supported, good. Here's a stab at cleaning this stuff up ... Mihai reported test success as well. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Tested-by: Mihai Moldovan <ionic@ionic.de> Cc: Michal Januszewski <spock@gentoo.org> Cc: Antonino Daplas <adaplas@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-18 16:01:23 +00:00
int cpu;
sched: cfs core code apply the CFS core code. this change switches over the scheduler core to CFS's modular design and makes use of kernel/sched_fair/rt/idletask.c to implement Linux's scheduling policies. thanks to Andrew Morton and Thomas Gleixner for lots of detailed review feedback and for fixlets. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
2007-07-09 16:51:59 +00:00
sched: remove extra call overhead for schedule() Lai Jiangshan's patch reminded me that I promised Nick to remove that extra call overhead in schedule(). Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20090313112300.927414207@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-13 11:21:26 +00:00
need_resched:
preempt_disable();
sched: cfs core code apply the CFS core code. this change switches over the scheduler core to CFS's modular design and makes use of kernel/sched_fair/rt/idletask.c to implement Linux's scheduling policies. thanks to Andrew Morton and Thomas Gleixner for lots of detailed review feedback and for fixlets. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
2007-07-09 16:51:59 +00:00
cpu = smp_processor_id();
rq = cpu_rq(cpu);
rcu: refactor RCU's context-switch handling The addition of preemptible RCU to treercu resulted in a bit of confusion and inefficiency surrounding the handling of context switches for RCU-sched and for RCU-preempt. For RCU-sched, a context switch is a quiescent state, pure and simple, just like it always has been. For RCU-preempt, a context switch is in no way a quiescent state, but special handling is required when a task blocks in an RCU read-side critical section. However, the callout from the scheduler and the outer loop in ksoftirqd still calls something named rcu_sched_qs(), whose name is no longer accurate. Furthermore, when rcu_check_callbacks() notes an RCU-sched quiescent state, it ends up unnecessarily (though harmlessly, aside from the performance hit) enqueuing the current task if it happens to be running in an RCU-preempt read-side critical section. This not only increases the maximum latency of scheduler_tick(), it also needlessly increases the overhead of the next outermost rcu_read_unlock() invocation. This patch addresses this situation by separating the notion of RCU's context-switch handling from that of RCU-sched's quiescent states. The context-switch handling is covered by rcu_note_context_switch() in general and by rcu_preempt_note_context_switch() for preemptible RCU. This permits rcu_sched_qs() to handle quiescent states and only quiescent states. It also reduces the maximum latency of scheduler_tick(), though probably by much less than a microsecond. Finally, it means that tasks within preemptible-RCU read-side critical sections avoid incurring the overhead of queuing unless there really is a context switch. Suggested-by: Lai Jiangshan <laijs@cn.fujitsu.com> Acked-by: Lai Jiangshan <laijs@cn.fujitsu.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Peter Zijlstra <peterz@infradead.org>
2010-04-02 00:37:01 +00:00
rcu_note_context_switch(cpu);
sched: cfs core code apply the CFS core code. this change switches over the scheduler core to CFS's modular design and makes use of kernel/sched_fair/rt/idletask.c to implement Linux's scheduling policies. thanks to Andrew Morton and Thomas Gleixner for lots of detailed review feedback and for fixlets. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
2007-07-09 16:51:59 +00:00
prev = rq->curr;
schedule_debug(prev);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
sched, x86: clean up hrtick implementation random uvesafb failures were reported against Gentoo: http://bugs.gentoo.org/show_bug.cgi?id=222799 and Mihai Moldovan bisected it back to: > 8f4d37ec073c17e2d4aa8851df5837d798606d6f is first bad commit > commit 8f4d37ec073c17e2d4aa8851df5837d798606d6f > Author: Peter Zijlstra <a.p.zijlstra@chello.nl> > Date: Fri Jan 25 21:08:29 2008 +0100 > > sched: high-res preemption tick Linus suspected it to be hrtick + vm86 interaction and observed: > Btw, Peter, Ingo: I think that commit is doing bad things. They aren't > _incorrect_ per se, but they are definitely bad. > > Why? > > Using random _TIF_WORK_MASK flags is really impolite for doing > "scheduling" work. There's a reason that arch/x86/kernel/entry_32.S > special-cases the _TIF_NEED_RESCHED flag: we don't want to exit out of > vm86 mode unnecessarily. > > See the "work_notifysig_v86" label, and how it does that > "save_v86_state()" thing etc etc. Right, I never liked having to fiddle with those TIF flags. Initially I needed it because the hrtimer base lock could not nest in the rq lock. That however is fixed these days. Currently the only reason left to fiddle with the TIF flags is remote wakeups. We cannot program a remote cpu's hrtimer. I've been thinking about using the new and improved IPI function call stuff to implement hrtimer_start_on(). However that does require that smp_call_function_single(.wait=0) works from interrupt context - /me looks at the latest series from Jens - Yes that does seem to be supported, good. Here's a stab at cleaning this stuff up ... Mihai reported test success as well. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Tested-by: Mihai Moldovan <ionic@ionic.de> Cc: Michal Januszewski <spock@gentoo.org> Cc: Antonino Daplas <adaplas@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-18 16:01:23 +00:00
if (sched_feat(HRTICK))
sched: make !hrtick faster it is safe to ignore timers and flags when the feature is disabled. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-12 19:20:55 +00:00
hrtick_clear(rq);
sched: high-res preemption tick Use HR-timers (when available) to deliver an accurate preemption tick. The regular scheduler tick that runs at 1/HZ can be too coarse when nice level are used. The fairness system will still keep the cpu utilisation 'fair' by then delaying the task that got an excessive amount of CPU time but try to minimize this by delivering preemption points spot-on. The average frequency of this extra interrupt is sched_latency / nr_latency. Which need not be higher than 1/HZ, its just that the distribution within the sched_latency period is important. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:29 +00:00
sched: Convert rq->lock to raw_spinlock Convert locks which cannot be sleeping locks in preempt-rt to raw_spinlocks. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Ingo Molnar <mingo@elte.hu>
2009-11-17 13:28:38 +00:00
raw_spin_lock_irq(&rq->lock);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
sched: Simplify the reacquire_kernel_lock() logic - Contrary to what 6d558c3a says, there is no need to reload prev = rq->curr after the context switch. You always schedule back to where you came from, prev must be equal to current even if cpu/rq was changed. - This also means reacquire_kernel_lock() can use prev instead of current. - No need to reassign switch_count if reacquire_kernel_lock() reports need_resched(), we can just move the initial assignment down, under the "need_resched_nonpreemptible:" label. - Try to update the comment after context_switch(). Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20100519125711.GA30199@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-05-19 12:57:11 +00:00
switch_count = &prev->nivcsw;
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
if (prev->state && !(preempt_count() & PREEMPT_ACTIVE)) {
sched: add hooks for workqueue Concurrency managed workqueue needs to know when workers are going to sleep and waking up. Using these two hooks, cmwq keeps track of the current concurrency level and throttles execution of new works if it's too high and wakes up another worker from the sleep hook if it becomes too low. This patch introduces PF_WQ_WORKER to identify workqueue workers and adds the following two hooks. * wq_worker_waking_up(): called when a worker is woken up. * wq_worker_sleeping(): called when a worker is going to sleep and may return a pointer to a local task which should be woken up. The returned task is woken up using try_to_wake_up_local() which is simplified ttwu which is called under rq lock and can only wake up local tasks. Both hooks are currently defined as noop in kernel/workqueue_sched.h. Later cmwq implementation will replace them with proper implementation. These hooks are hard coded as they'll always be enabled. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Ingo Molnar <mingo@elte.hu>
2010-06-08 19:40:37 +00:00
if (unlikely(signal_pending_state(prev->state, prev))) {
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
prev->state = TASK_RUNNING;
sched: add hooks for workqueue Concurrency managed workqueue needs to know when workers are going to sleep and waking up. Using these two hooks, cmwq keeps track of the current concurrency level and throttles execution of new works if it's too high and wakes up another worker from the sleep hook if it becomes too low. This patch introduces PF_WQ_WORKER to identify workqueue workers and adds the following two hooks. * wq_worker_waking_up(): called when a worker is woken up. * wq_worker_sleeping(): called when a worker is going to sleep and may return a pointer to a local task which should be woken up. The returned task is woken up using try_to_wake_up_local() which is simplified ttwu which is called under rq lock and can only wake up local tasks. Both hooks are currently defined as noop in kernel/workqueue_sched.h. Later cmwq implementation will replace them with proper implementation. These hooks are hard coded as they'll always be enabled. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Ingo Molnar <mingo@elte.hu>
2010-06-08 19:40:37 +00:00
} else {
sched: Also serialize ttwu_local() with p->pi_lock Since we now serialize ttwu() using p->pi_lock, we also need to serialize ttwu_local() using that, otherwise, once we drop the rq->lock from ttwu() it can race with ttwu_local(). Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110405152729.192366907@chello.nl
2011-04-05 15:23:50 +00:00
deactivate_task(rq, prev, DEQUEUE_SLEEP);
prev->on_rq = 0;
sched: add hooks for workqueue Concurrency managed workqueue needs to know when workers are going to sleep and waking up. Using these two hooks, cmwq keeps track of the current concurrency level and throttles execution of new works if it's too high and wakes up another worker from the sleep hook if it becomes too low. This patch introduces PF_WQ_WORKER to identify workqueue workers and adds the following two hooks. * wq_worker_waking_up(): called when a worker is woken up. * wq_worker_sleeping(): called when a worker is going to sleep and may return a pointer to a local task which should be woken up. The returned task is woken up using try_to_wake_up_local() which is simplified ttwu which is called under rq lock and can only wake up local tasks. Both hooks are currently defined as noop in kernel/workqueue_sched.h. Later cmwq implementation will replace them with proper implementation. These hooks are hard coded as they'll always be enabled. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Ingo Molnar <mingo@elte.hu>
2010-06-08 19:40:37 +00:00
/*
sched: Also serialize ttwu_local() with p->pi_lock Since we now serialize ttwu() using p->pi_lock, we also need to serialize ttwu_local() using that, otherwise, once we drop the rq->lock from ttwu() it can race with ttwu_local(). Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110405152729.192366907@chello.nl
2011-04-05 15:23:50 +00:00
* If a worker went to sleep, notify and ask workqueue
* whether it wants to wake up a task to maintain
* concurrency.
sched: add hooks for workqueue Concurrency managed workqueue needs to know when workers are going to sleep and waking up. Using these two hooks, cmwq keeps track of the current concurrency level and throttles execution of new works if it's too high and wakes up another worker from the sleep hook if it becomes too low. This patch introduces PF_WQ_WORKER to identify workqueue workers and adds the following two hooks. * wq_worker_waking_up(): called when a worker is woken up. * wq_worker_sleeping(): called when a worker is going to sleep and may return a pointer to a local task which should be woken up. The returned task is woken up using try_to_wake_up_local() which is simplified ttwu which is called under rq lock and can only wake up local tasks. Both hooks are currently defined as noop in kernel/workqueue_sched.h. Later cmwq implementation will replace them with proper implementation. These hooks are hard coded as they'll always be enabled. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Ingo Molnar <mingo@elte.hu>
2010-06-08 19:40:37 +00:00
*/
if (prev->flags & PF_WQ_WORKER) {
struct task_struct *to_wakeup;
to_wakeup = wq_worker_sleeping(prev, cpu);
if (to_wakeup)
try_to_wake_up_local(to_wakeup);
}
sched: Provide p->on_rq Provide a generic p->on_rq because the p->se.on_rq semantics are unfavourable for lockless wakeups but needed for sched_fair. In particular, p->on_rq is only cleared when we actually dequeue the task in schedule() and not on any random dequeue as done by things like __migrate_task() and __sched_setscheduler(). This also allows us to remove p->se usage from !sched_fair code. Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110405152728.949545047@chello.nl
2011-04-05 15:23:44 +00:00
block: don't flush plugged IO on forced preemtion scheduling We really only want to unplug the pending IO when the process actually goes to sleep. So move the test for flushing the plug up to the place where we actually deactivate the task - where we have properly checked for preemption and for the process really sleeping. Acked-by: Jens Axboe <jaxboe@fusionio.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-04-13 15:08:20 +00:00
/*
sched: Also serialize ttwu_local() with p->pi_lock Since we now serialize ttwu() using p->pi_lock, we also need to serialize ttwu_local() using that, otherwise, once we drop the rq->lock from ttwu() it can race with ttwu_local(). Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110405152729.192366907@chello.nl
2011-04-05 15:23:50 +00:00
* If we are going to sleep and we have plugged IO
* queued, make sure to submit it to avoid deadlocks.
block: don't flush plugged IO on forced preemtion scheduling We really only want to unplug the pending IO when the process actually goes to sleep. So move the test for flushing the plug up to the place where we actually deactivate the task - where we have properly checked for preemption and for the process really sleeping. Acked-by: Jens Axboe <jaxboe@fusionio.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-04-13 15:08:20 +00:00
*/
if (blk_needs_flush_plug(prev)) {
raw_spin_unlock(&rq->lock);
block: let io_schedule() flush the plug inline Linus correctly observes that the most important dispatch cases are now done from kblockd, this isn't ideal for latency reasons. The original reason for switching dispatches out-of-line was to avoid too deep a stack, so by _only_ letting the "accidental" flush directly in schedule() be guarded by offload to kblockd, we should be able to get the best of both worlds. So add a blk_schedule_flush_plug() that offloads to kblockd, and only use that from the schedule() path. Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2011-04-16 11:27:55 +00:00
blk_schedule_flush_plug(prev);
block: don't flush plugged IO on forced preemtion scheduling We really only want to unplug the pending IO when the process actually goes to sleep. So move the test for flushing the plug up to the place where we actually deactivate the task - where we have properly checked for preemption and for the process really sleeping. Acked-by: Jens Axboe <jaxboe@fusionio.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-04-13 15:08:20 +00:00
raw_spin_lock(&rq->lock);
}
sched: add hooks for workqueue Concurrency managed workqueue needs to know when workers are going to sleep and waking up. Using these two hooks, cmwq keeps track of the current concurrency level and throttles execution of new works if it's too high and wakes up another worker from the sleep hook if it becomes too low. This patch introduces PF_WQ_WORKER to identify workqueue workers and adds the following two hooks. * wq_worker_waking_up(): called when a worker is woken up. * wq_worker_sleeping(): called when a worker is going to sleep and may return a pointer to a local task which should be woken up. The returned task is woken up using try_to_wake_up_local() which is simplified ttwu which is called under rq lock and can only wake up local tasks. Both hooks are currently defined as noop in kernel/workqueue_sched.h. Later cmwq implementation will replace them with proper implementation. These hooks are hard coded as they'll always be enabled. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Ingo Molnar <mingo@elte.hu>
2010-06-08 19:40:37 +00:00
}
sched: cfs core code apply the CFS core code. this change switches over the scheduler core to CFS's modular design and makes use of kernel/sched_fair/rt/idletask.c to implement Linux's scheduling policies. thanks to Andrew Morton and Thomas Gleixner for lots of detailed review feedback and for fixlets. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
2007-07-09 16:51:59 +00:00
switch_count = &prev->nvcsw;
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
}
sched: Enhance the pre/post scheduling logic We currently have an explicit "needs_post" vtable method which returns a stack variable for whether we should later run post-schedule. This leads to an awkward exchange of the variable as it bubbles back up out of the context switch. Peter Zijlstra observed that this information could be stored in the run-queue itself instead of handled on the stack. Therefore, we revert to the method of having context_switch return void, and update an internal rq->post_schedule variable when we require further processing. In addition, we fix a race condition where we try to access current->sched_class without holding the rq->lock. This is technically racy, as the sched-class could change out from under us. Instead, we reference the per-rq post_schedule variable with the runqueue unlocked, but with preemption disabled to see if we need to reacquire the rq->lock. Finally, we clean the code up slightly by removing the #ifdef CONFIG_SMP conditionals from the schedule() call, and implement some inline helper functions instead. This patch passes checkpatch, and rt-migrate. Signed-off-by: Gregory Haskins <ghaskins@novell.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20090729150422.17691.55590.stgit@dev.haskins.net> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-07-29 15:08:47 +00:00
pre_schedule(rq, prev);
sched: pull RT tasks from overloaded runqueues This patch adds the algorithm to pull tasks from RT overloaded runqueues. When a pull RT is initiated, all overloaded runqueues are examined for a RT task that is higher in prio than the highest prio task queued on the target runqueue. If another runqueue holds a RT task that is of higher prio than the highest prio task on the target runqueue is found it is pulled to the target runqueue. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:07 +00:00
sched: cfs core code apply the CFS core code. this change switches over the scheduler core to CFS's modular design and makes use of kernel/sched_fair/rt/idletask.c to implement Linux's scheduling policies. thanks to Andrew Morton and Thomas Gleixner for lots of detailed review feedback and for fixlets. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
2007-07-09 16:51:59 +00:00
if (unlikely(!rq->nr_running))
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
idle_balance(cpu, rq);
sched: add avg_overlap decay Impact: more precise avg_overlap metric - better load-balancing avg_overlap is used to measure the runtime overlap of the waker and wakee. However, when a process changes behaviour, eg a pipe becomes un-congested and we don't need to go to sleep after a wakeup for a while, the avg_overlap value grows stale. When running we use the avg runtime between preemption as a measure for avg_overlap since the amount of runtime can be correlated to cache footprint. The longer we run, the less likely we'll be wanting to be migrated to another CPU. Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1236709131.25234.576.camel@laptop> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-10 18:08:11 +00:00
put_prev_task(rq, prev);
sched: kill unused parameter of pick_next_task() Impact: micro-optimization Parameter "prev" is not used really. Signed-off-by: Wang Chen <wangchen@cn.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-02 05:55:26 +00:00
next = pick_next_task(rq);
Sched: fix skip_clock_update optimization idle_balance() drops/retakes rq->lock, leaving the previous task vulnerable to set_tsk_need_resched(). Clear it after we return from balancing instead, and in setup_thread_stack() as well, so no successfully descheduled or never scheduled task has it set. Need resched confused the skip_clock_update logic, which assumes that the next call to update_rq_clock() will come nearly immediately after being set. Make the optimization robust against the waking a sleeper before it sucessfully deschedules case by checking that the current task has not been dequeued before setting the flag, since it is that useless clock update we're trying to save, and clear unconditionally in schedule() proper instead of conditionally in put_prev_task(). Signed-off-by: Mike Galbraith <efault@gmx.de> Reported-by: Bjoern B. Brandenburg <bbb.lst@gmail.com> Tested-by: Yong Zhang <yong.zhang0@gmail.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: stable@kernel.org LKML-Reference: <1291802742.1417.9.camel@marge.simson.net> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-12-08 10:05:42 +00:00
clear_tsk_need_resched(prev);
rq->skip_clock_update = 0;
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
if (likely(prev != next)) {
rq->nr_switches++;
rq->curr = next;
++*switch_count;
sched: cfs core code apply the CFS core code. this change switches over the scheduler core to CFS's modular design and makes use of kernel/sched_fair/rt/idletask.c to implement Linux's scheduling policies. thanks to Andrew Morton and Thomas Gleixner for lots of detailed review feedback and for fixlets. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
2007-07-09 16:51:59 +00:00
context_switch(rq, prev, next); /* unlocks the rq */
sched: high-res preemption tick Use HR-timers (when available) to deliver an accurate preemption tick. The regular scheduler tick that runs at 1/HZ can be too coarse when nice level are used. The fairness system will still keep the cpu utilisation 'fair' by then delaying the task that got an excessive amount of CPU time but try to minimize this by delivering preemption points spot-on. The average frequency of this extra interrupt is sched_latency / nr_latency. Which need not be higher than 1/HZ, its just that the distribution within the sched_latency period is important. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:29 +00:00
/*
sched: Simplify the reacquire_kernel_lock() logic - Contrary to what 6d558c3a says, there is no need to reload prev = rq->curr after the context switch. You always schedule back to where you came from, prev must be equal to current even if cpu/rq was changed. - This also means reacquire_kernel_lock() can use prev instead of current. - No need to reassign switch_count if reacquire_kernel_lock() reports need_resched(), we can just move the initial assignment down, under the "need_resched_nonpreemptible:" label. - Try to update the comment after context_switch(). Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20100519125711.GA30199@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-05-19 12:57:11 +00:00
* The context switch have flipped the stack from under us
* and restored the local variables which were saved when
* this task called schedule() in the past. prev == current
* is still correct, but it can be moved to another cpu/rq.
sched: high-res preemption tick Use HR-timers (when available) to deliver an accurate preemption tick. The regular scheduler tick that runs at 1/HZ can be too coarse when nice level are used. The fairness system will still keep the cpu utilisation 'fair' by then delaying the task that got an excessive amount of CPU time but try to minimize this by delivering preemption points spot-on. The average frequency of this extra interrupt is sched_latency / nr_latency. Which need not be higher than 1/HZ, its just that the distribution within the sched_latency period is important. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:29 +00:00
*/
cpu = smp_processor_id();
rq = cpu_rq(cpu);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
} else
sched: Convert rq->lock to raw_spinlock Convert locks which cannot be sleeping locks in preempt-rt to raw_spinlocks. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Ingo Molnar <mingo@elte.hu>
2009-11-17 13:28:38 +00:00
raw_spin_unlock_irq(&rq->lock);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
sched: Enhance the pre/post scheduling logic We currently have an explicit "needs_post" vtable method which returns a stack variable for whether we should later run post-schedule. This leads to an awkward exchange of the variable as it bubbles back up out of the context switch. Peter Zijlstra observed that this information could be stored in the run-queue itself instead of handled on the stack. Therefore, we revert to the method of having context_switch return void, and update an internal rq->post_schedule variable when we require further processing. In addition, we fix a race condition where we try to access current->sched_class without holding the rq->lock. This is technically racy, as the sched-class could change out from under us. Instead, we reference the per-rq post_schedule variable with the runqueue unlocked, but with preemption disabled to see if we need to reacquire the rq->lock. Finally, we clean the code up slightly by removing the #ifdef CONFIG_SMP conditionals from the schedule() call, and implement some inline helper functions instead. This patch passes checkpatch, and rt-migrate. Signed-off-by: Gregory Haskins <ghaskins@novell.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20090729150422.17691.55590.stgit@dev.haskins.net> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-07-29 15:08:47 +00:00
post_schedule(rq);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
preempt_enable_no_resched();
sched: remove extra call overhead for schedule() Lai Jiangshan's patch reminded me that I promised Nick to remove that extra call overhead in schedule(). Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20090313112300.927414207@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-13 11:21:26 +00:00
if (need_resched())
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
goto need_resched;
}
EXPORT_SYMBOL(schedule);
mutex: Fix missing conditions to build mutex_spin_on_owner() We don't need to build mutex_spin_on_owner() if we have CONFIG_DEBUG_MUTEXES or CONFIG_HAVE_DEFAULT_NO_SPIN_MUTEXES as it won't be used under such configs. Use CONFIG_MUTEX_SPIN_ON_OWNER as it gathers all the necessary checks before building it. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Acked-by: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <1259783357-8542-2-git-send-regression-fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Cc: Peter Zijlstra <peterz@infradead.org>
2009-12-02 19:49:17 +00:00
#ifdef CONFIG_MUTEX_SPIN_ON_OWNER
mutex: implement adaptive spinning Change mutex contention behaviour such that it will sometimes busy wait on acquisition - moving its behaviour closer to that of spinlocks. This concept got ported to mainline from the -rt tree, where it was originally implemented for rtmutexes by Steven Rostedt, based on work by Gregory Haskins. Testing with Ingo's test-mutex application (http://lkml.org/lkml/2006/1/8/50) gave a 345% boost for VFS scalability on my testbox: # ./test-mutex-shm V 16 10 | grep "^avg ops" avg ops/sec: 296604 # ./test-mutex-shm V 16 10 | grep "^avg ops" avg ops/sec: 85870 The key criteria for the busy wait is that the lock owner has to be running on a (different) cpu. The idea is that as long as the owner is running, there is a fair chance it'll release the lock soon, and thus we'll be better off spinning instead of blocking/scheduling. Since regular mutexes (as opposed to rtmutexes) do not atomically track the owner, we add the owner in a non-atomic fashion and deal with the races in the slowpath. Furthermore, to ease the testing of the performance impact of this new code, there is means to disable this behaviour runtime (without having to reboot the system), when scheduler debugging is enabled (CONFIG_SCHED_DEBUG=y), by issuing the following command: # echo NO_OWNER_SPIN > /debug/sched_features This command re-enables spinning again (this is also the default): # echo OWNER_SPIN > /debug/sched_features Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-12 13:01:47 +00:00
mutex: Use p->on_cpu for the adaptive spin Since we now have p->on_cpu unconditionally available, use it to re-implement mutex_spin_on_owner. Requested-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110405152728.826338173@chello.nl
2011-04-05 15:23:41 +00:00
static inline bool owner_running(struct mutex *lock, struct task_struct *owner)
{
if (lock->owner != owner)
sched: Simplify mutex_spin_on_owner() It does not make sense to rcu_read_lock/unlock() in every loop iteration while spinning on the mutex. Move the rcu protection outside the loop. Also simplify the return path to always check for lock->owner == NULL which meets the requirements of both owner changed and need_resched() caused loop exits. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/alpine.LFD.2.02.1106101458350.11814@ionos Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-06-10 13:08:55 +00:00
return false;
mutex: implement adaptive spinning Change mutex contention behaviour such that it will sometimes busy wait on acquisition - moving its behaviour closer to that of spinlocks. This concept got ported to mainline from the -rt tree, where it was originally implemented for rtmutexes by Steven Rostedt, based on work by Gregory Haskins. Testing with Ingo's test-mutex application (http://lkml.org/lkml/2006/1/8/50) gave a 345% boost for VFS scalability on my testbox: # ./test-mutex-shm V 16 10 | grep "^avg ops" avg ops/sec: 296604 # ./test-mutex-shm V 16 10 | grep "^avg ops" avg ops/sec: 85870 The key criteria for the busy wait is that the lock owner has to be running on a (different) cpu. The idea is that as long as the owner is running, there is a fair chance it'll release the lock soon, and thus we'll be better off spinning instead of blocking/scheduling. Since regular mutexes (as opposed to rtmutexes) do not atomically track the owner, we add the owner in a non-atomic fashion and deal with the races in the slowpath. Furthermore, to ease the testing of the performance impact of this new code, there is means to disable this behaviour runtime (without having to reboot the system), when scheduler debugging is enabled (CONFIG_SCHED_DEBUG=y), by issuing the following command: # echo NO_OWNER_SPIN > /debug/sched_features This command re-enables spinning again (this is also the default): # echo OWNER_SPIN > /debug/sched_features Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-12 13:01:47 +00:00
/*
mutex: Use p->on_cpu for the adaptive spin Since we now have p->on_cpu unconditionally available, use it to re-implement mutex_spin_on_owner. Requested-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110405152728.826338173@chello.nl
2011-04-05 15:23:41 +00:00
* Ensure we emit the owner->on_cpu, dereference _after_ checking
* lock->owner still matches owner, if that fails, owner might
* point to free()d memory, if it still matches, the rcu_read_lock()
* ensures the memory stays valid.
mutex: implement adaptive spinning Change mutex contention behaviour such that it will sometimes busy wait on acquisition - moving its behaviour closer to that of spinlocks. This concept got ported to mainline from the -rt tree, where it was originally implemented for rtmutexes by Steven Rostedt, based on work by Gregory Haskins. Testing with Ingo's test-mutex application (http://lkml.org/lkml/2006/1/8/50) gave a 345% boost for VFS scalability on my testbox: # ./test-mutex-shm V 16 10 | grep "^avg ops" avg ops/sec: 296604 # ./test-mutex-shm V 16 10 | grep "^avg ops" avg ops/sec: 85870 The key criteria for the busy wait is that the lock owner has to be running on a (different) cpu. The idea is that as long as the owner is running, there is a fair chance it'll release the lock soon, and thus we'll be better off spinning instead of blocking/scheduling. Since regular mutexes (as opposed to rtmutexes) do not atomically track the owner, we add the owner in a non-atomic fashion and deal with the races in the slowpath. Furthermore, to ease the testing of the performance impact of this new code, there is means to disable this behaviour runtime (without having to reboot the system), when scheduler debugging is enabled (CONFIG_SCHED_DEBUG=y), by issuing the following command: # echo NO_OWNER_SPIN > /debug/sched_features This command re-enables spinning again (this is also the default): # echo OWNER_SPIN > /debug/sched_features Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-12 13:01:47 +00:00
*/
mutex: Use p->on_cpu for the adaptive spin Since we now have p->on_cpu unconditionally available, use it to re-implement mutex_spin_on_owner. Requested-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110405152728.826338173@chello.nl
2011-04-05 15:23:41 +00:00
barrier();
mutex: implement adaptive spinning Change mutex contention behaviour such that it will sometimes busy wait on acquisition - moving its behaviour closer to that of spinlocks. This concept got ported to mainline from the -rt tree, where it was originally implemented for rtmutexes by Steven Rostedt, based on work by Gregory Haskins. Testing with Ingo's test-mutex application (http://lkml.org/lkml/2006/1/8/50) gave a 345% boost for VFS scalability on my testbox: # ./test-mutex-shm V 16 10 | grep "^avg ops" avg ops/sec: 296604 # ./test-mutex-shm V 16 10 | grep "^avg ops" avg ops/sec: 85870 The key criteria for the busy wait is that the lock owner has to be running on a (different) cpu. The idea is that as long as the owner is running, there is a fair chance it'll release the lock soon, and thus we'll be better off spinning instead of blocking/scheduling. Since regular mutexes (as opposed to rtmutexes) do not atomically track the owner, we add the owner in a non-atomic fashion and deal with the races in the slowpath. Furthermore, to ease the testing of the performance impact of this new code, there is means to disable this behaviour runtime (without having to reboot the system), when scheduler debugging is enabled (CONFIG_SCHED_DEBUG=y), by issuing the following command: # echo NO_OWNER_SPIN > /debug/sched_features This command re-enables spinning again (this is also the default): # echo OWNER_SPIN > /debug/sched_features Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-12 13:01:47 +00:00
sched: Simplify mutex_spin_on_owner() It does not make sense to rcu_read_lock/unlock() in every loop iteration while spinning on the mutex. Move the rcu protection outside the loop. Also simplify the return path to always check for lock->owner == NULL which meets the requirements of both owner changed and need_resched() caused loop exits. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/alpine.LFD.2.02.1106101458350.11814@ionos Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-06-10 13:08:55 +00:00
return owner->on_cpu;
mutex: Use p->on_cpu for the adaptive spin Since we now have p->on_cpu unconditionally available, use it to re-implement mutex_spin_on_owner. Requested-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110405152728.826338173@chello.nl
2011-04-05 15:23:41 +00:00
}
mutex: implement adaptive spinning Change mutex contention behaviour such that it will sometimes busy wait on acquisition - moving its behaviour closer to that of spinlocks. This concept got ported to mainline from the -rt tree, where it was originally implemented for rtmutexes by Steven Rostedt, based on work by Gregory Haskins. Testing with Ingo's test-mutex application (http://lkml.org/lkml/2006/1/8/50) gave a 345% boost for VFS scalability on my testbox: # ./test-mutex-shm V 16 10 | grep "^avg ops" avg ops/sec: 296604 # ./test-mutex-shm V 16 10 | grep "^avg ops" avg ops/sec: 85870 The key criteria for the busy wait is that the lock owner has to be running on a (different) cpu. The idea is that as long as the owner is running, there is a fair chance it'll release the lock soon, and thus we'll be better off spinning instead of blocking/scheduling. Since regular mutexes (as opposed to rtmutexes) do not atomically track the owner, we add the owner in a non-atomic fashion and deal with the races in the slowpath. Furthermore, to ease the testing of the performance impact of this new code, there is means to disable this behaviour runtime (without having to reboot the system), when scheduler debugging is enabled (CONFIG_SCHED_DEBUG=y), by issuing the following command: # echo NO_OWNER_SPIN > /debug/sched_features This command re-enables spinning again (this is also the default): # echo OWNER_SPIN > /debug/sched_features Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-12 13:01:47 +00:00
mutex: Use p->on_cpu for the adaptive spin Since we now have p->on_cpu unconditionally available, use it to re-implement mutex_spin_on_owner. Requested-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110405152728.826338173@chello.nl
2011-04-05 15:23:41 +00:00
/*
* Look out! "owner" is an entirely speculative pointer
* access and not reliable.
*/
int mutex_spin_on_owner(struct mutex *lock, struct task_struct *owner)
{
if (!sched_feat(OWNER_SPIN))
return 0;
mutex: implement adaptive spinning Change mutex contention behaviour such that it will sometimes busy wait on acquisition - moving its behaviour closer to that of spinlocks. This concept got ported to mainline from the -rt tree, where it was originally implemented for rtmutexes by Steven Rostedt, based on work by Gregory Haskins. Testing with Ingo's test-mutex application (http://lkml.org/lkml/2006/1/8/50) gave a 345% boost for VFS scalability on my testbox: # ./test-mutex-shm V 16 10 | grep "^avg ops" avg ops/sec: 296604 # ./test-mutex-shm V 16 10 | grep "^avg ops" avg ops/sec: 85870 The key criteria for the busy wait is that the lock owner has to be running on a (different) cpu. The idea is that as long as the owner is running, there is a fair chance it'll release the lock soon, and thus we'll be better off spinning instead of blocking/scheduling. Since regular mutexes (as opposed to rtmutexes) do not atomically track the owner, we add the owner in a non-atomic fashion and deal with the races in the slowpath. Furthermore, to ease the testing of the performance impact of this new code, there is means to disable this behaviour runtime (without having to reboot the system), when scheduler debugging is enabled (CONFIG_SCHED_DEBUG=y), by issuing the following command: # echo NO_OWNER_SPIN > /debug/sched_features This command re-enables spinning again (this is also the default): # echo OWNER_SPIN > /debug/sched_features Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-12 13:01:47 +00:00
sched: Simplify mutex_spin_on_owner() It does not make sense to rcu_read_lock/unlock() in every loop iteration while spinning on the mutex. Move the rcu protection outside the loop. Also simplify the return path to always check for lock->owner == NULL which meets the requirements of both owner changed and need_resched() caused loop exits. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/alpine.LFD.2.02.1106101458350.11814@ionos Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-06-10 13:08:55 +00:00
rcu_read_lock();
mutex: Use p->on_cpu for the adaptive spin Since we now have p->on_cpu unconditionally available, use it to re-implement mutex_spin_on_owner. Requested-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110405152728.826338173@chello.nl
2011-04-05 15:23:41 +00:00
while (owner_running(lock, owner)) {
if (need_resched())
sched: Simplify mutex_spin_on_owner() It does not make sense to rcu_read_lock/unlock() in every loop iteration while spinning on the mutex. Move the rcu protection outside the loop. Also simplify the return path to always check for lock->owner == NULL which meets the requirements of both owner changed and need_resched() caused loop exits. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/alpine.LFD.2.02.1106101458350.11814@ionos Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-06-10 13:08:55 +00:00
break;
mutex: implement adaptive spinning Change mutex contention behaviour such that it will sometimes busy wait on acquisition - moving its behaviour closer to that of spinlocks. This concept got ported to mainline from the -rt tree, where it was originally implemented for rtmutexes by Steven Rostedt, based on work by Gregory Haskins. Testing with Ingo's test-mutex application (http://lkml.org/lkml/2006/1/8/50) gave a 345% boost for VFS scalability on my testbox: # ./test-mutex-shm V 16 10 | grep "^avg ops" avg ops/sec: 296604 # ./test-mutex-shm V 16 10 | grep "^avg ops" avg ops/sec: 85870 The key criteria for the busy wait is that the lock owner has to be running on a (different) cpu. The idea is that as long as the owner is running, there is a fair chance it'll release the lock soon, and thus we'll be better off spinning instead of blocking/scheduling. Since regular mutexes (as opposed to rtmutexes) do not atomically track the owner, we add the owner in a non-atomic fashion and deal with the races in the slowpath. Furthermore, to ease the testing of the performance impact of this new code, there is means to disable this behaviour runtime (without having to reboot the system), when scheduler debugging is enabled (CONFIG_SCHED_DEBUG=y), by issuing the following command: # echo NO_OWNER_SPIN > /debug/sched_features This command re-enables spinning again (this is also the default): # echo OWNER_SPIN > /debug/sched_features Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-12 13:01:47 +00:00
mutexes, sched: Introduce arch_mutex_cpu_relax() The spinning mutex implementation uses cpu_relax() in busy loops as a compiler barrier. Depending on the architecture, cpu_relax() may do more than needed in this specific mutex spin loops. On System z we also give up the time slice of the virtual cpu in cpu_relax(), which prevents effective spinning on the mutex. This patch replaces cpu_relax() in the spinning mutex code with arch_mutex_cpu_relax(), which can be defined by each architecture that selects HAVE_ARCH_MUTEX_CPU_RELAX. The default is still cpu_relax(), so this patch should not affect other architectures than System z for now. Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1290437256.7455.4.camel@thinkpad> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-22 14:47:36 +00:00
arch_mutex_cpu_relax();
mutex: implement adaptive spinning Change mutex contention behaviour such that it will sometimes busy wait on acquisition - moving its behaviour closer to that of spinlocks. This concept got ported to mainline from the -rt tree, where it was originally implemented for rtmutexes by Steven Rostedt, based on work by Gregory Haskins. Testing with Ingo's test-mutex application (http://lkml.org/lkml/2006/1/8/50) gave a 345% boost for VFS scalability on my testbox: # ./test-mutex-shm V 16 10 | grep "^avg ops" avg ops/sec: 296604 # ./test-mutex-shm V 16 10 | grep "^avg ops" avg ops/sec: 85870 The key criteria for the busy wait is that the lock owner has to be running on a (different) cpu. The idea is that as long as the owner is running, there is a fair chance it'll release the lock soon, and thus we'll be better off spinning instead of blocking/scheduling. Since regular mutexes (as opposed to rtmutexes) do not atomically track the owner, we add the owner in a non-atomic fashion and deal with the races in the slowpath. Furthermore, to ease the testing of the performance impact of this new code, there is means to disable this behaviour runtime (without having to reboot the system), when scheduler debugging is enabled (CONFIG_SCHED_DEBUG=y), by issuing the following command: # echo NO_OWNER_SPIN > /debug/sched_features This command re-enables spinning again (this is also the default): # echo OWNER_SPIN > /debug/sched_features Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-12 13:01:47 +00:00
}
sched: Simplify mutex_spin_on_owner() It does not make sense to rcu_read_lock/unlock() in every loop iteration while spinning on the mutex. Move the rcu protection outside the loop. Also simplify the return path to always check for lock->owner == NULL which meets the requirements of both owner changed and need_resched() caused loop exits. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/alpine.LFD.2.02.1106101458350.11814@ionos Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-06-10 13:08:55 +00:00
rcu_read_unlock();
mutex: Don't spin when the owner CPU is offline or other weird cases Due to recent load-balancer changes that delay the task migration to the next wakeup, the adaptive mutex spinning ends up in a live lock when the owner's CPU gets offlined because the cpu_online() check lives before the owner running check. This patch changes mutex_spin_on_owner() to return 0 (don't spin) in any case where we aren't sure about the owner struct validity or CPU number, and if the said CPU is offline. There is no point going back & re-evaluate spinning in corner cases like that, let's just go to sleep. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1271212509.13059.135.camel@pasglop> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-04-16 21:20:00 +00:00
mutex: Use p->on_cpu for the adaptive spin Since we now have p->on_cpu unconditionally available, use it to re-implement mutex_spin_on_owner. Requested-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110405152728.826338173@chello.nl
2011-04-05 15:23:41 +00:00
/*
sched: Simplify mutex_spin_on_owner() It does not make sense to rcu_read_lock/unlock() in every loop iteration while spinning on the mutex. Move the rcu protection outside the loop. Also simplify the return path to always check for lock->owner == NULL which meets the requirements of both owner changed and need_resched() caused loop exits. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/alpine.LFD.2.02.1106101458350.11814@ionos Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-06-10 13:08:55 +00:00
* We break out the loop above on need_resched() and when the
* owner changed, which is a sign for heavy contention. Return
* success only when lock->owner is NULL.
mutex: Use p->on_cpu for the adaptive spin Since we now have p->on_cpu unconditionally available, use it to re-implement mutex_spin_on_owner. Requested-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110405152728.826338173@chello.nl
2011-04-05 15:23:41 +00:00
*/
sched: Simplify mutex_spin_on_owner() It does not make sense to rcu_read_lock/unlock() in every loop iteration while spinning on the mutex. Move the rcu protection outside the loop. Also simplify the return path to always check for lock->owner == NULL which meets the requirements of both owner changed and need_resched() caused loop exits. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/alpine.LFD.2.02.1106101458350.11814@ionos Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-06-10 13:08:55 +00:00
return lock->owner == NULL;
mutex: implement adaptive spinning Change mutex contention behaviour such that it will sometimes busy wait on acquisition - moving its behaviour closer to that of spinlocks. This concept got ported to mainline from the -rt tree, where it was originally implemented for rtmutexes by Steven Rostedt, based on work by Gregory Haskins. Testing with Ingo's test-mutex application (http://lkml.org/lkml/2006/1/8/50) gave a 345% boost for VFS scalability on my testbox: # ./test-mutex-shm V 16 10 | grep "^avg ops" avg ops/sec: 296604 # ./test-mutex-shm V 16 10 | grep "^avg ops" avg ops/sec: 85870 The key criteria for the busy wait is that the lock owner has to be running on a (different) cpu. The idea is that as long as the owner is running, there is a fair chance it'll release the lock soon, and thus we'll be better off spinning instead of blocking/scheduling. Since regular mutexes (as opposed to rtmutexes) do not atomically track the owner, we add the owner in a non-atomic fashion and deal with the races in the slowpath. Furthermore, to ease the testing of the performance impact of this new code, there is means to disable this behaviour runtime (without having to reboot the system), when scheduler debugging is enabled (CONFIG_SCHED_DEBUG=y), by issuing the following command: # echo NO_OWNER_SPIN > /debug/sched_features This command re-enables spinning again (this is also the default): # echo OWNER_SPIN > /debug/sched_features Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-12 13:01:47 +00:00
}
#endif
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
#ifdef CONFIG_PREEMPT
/*
[PATCH] small kernel/sched.c cleanup - constify and optimize stat_nam (thanks to Michael Tokarev!) - spelling and comment fixes Signed-off-by: Andreas Mohr <andi@lisas.de> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-10 11:43:52 +00:00
* this is the entry point to schedule() from in-kernel preemption
sched: style cleanups style cleanup of various changes that were done recently. no code changed: text data bss dec hex filename 23680 2542 28 26250 668a sched.o.before 23680 2542 28 26250 668a sched.o.after Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-12-05 14:46:09 +00:00
* off of preempt_enable. Kernel preemptions off return from interrupt
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
* occur there and call schedule directly.
*/
tracing/sched: Make preempt_schedule() notrace The function tracer code uses ftrace_preempt_disable() to disable preemption instead of normal preempt_disable(). But there's a slight race condition that may cause it to lose a preemption check. This was made to keep the function tracer from recursing on itself by disabling preemption then having the enable call the function tracer again, causing infinite recursion. The bug was assumed to happen if the call was just in schedule, but this is incorrect. The bug is caused by preempt_schedule() which is called by preempt_enable(). The calling of preempt_enable() when NEED_RESCHED was set would call preempt_schedule() which would call the function tracer again. By making the preempt_schedule() and add_preempt_count() notrace then this will prevent the inifinite recursion. This is because the add_preempt_count() would stop the preempt_enable() in the function tracer from calling preempt_schedule() again. The sub_preempt_count() is also made notrace just to keep it symmetric. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-06-03 01:52:29 +00:00
asmlinkage void __sched notrace preempt_schedule(void)
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
{
struct thread_info *ti = current_thread_info();
sched: remove the !PREEMPT_BKL code remove the !PREEMPT_BKL code. this removes 160 lines of legacy code. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:33 +00:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
/*
* If there is a non-zero preempt_count or interrupts are disabled,
sched: style cleanups style cleanup of various changes that were done recently. no code changed: text data bss dec hex filename 23680 2542 28 26250 668a sched.o.before 23680 2542 28 26250 668a sched.o.after Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-12-05 14:46:09 +00:00
* we do not want to preempt the current task. Just return..
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
*/
[PATCH] sched: likely profiling This likely profiling is pretty fun. I found a few possible problems in sched.c. This patch may be not measurable, but when I did measure long ago, nooping (un)likely cost a couple of % on scheduler heavy benchmarks, so it all adds up. Tweak some branch hints: - the 2nd 64 bits in the bitmask is likely to be populated, because it contains the first 28 bits (nearly 3/4) of the normal priorities. (ratio of 669669:691 ~= 1000:1). - it isn't unlikely that context switching switches to another process. it might be very rapidly switching to and from the idle process (ratio of 475815:419004 and 471330:423544). Let the branch predictor decide. - preempt_enable seems to be very often called in a nested preempt_disable or with interrupts disabled (ratio of 3567760:87965 ~= 40:1) Signed-off-by: Nick Piggin <npiggin@suse.de> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: Daniel Walker <dwalker@mvista.com> Cc: Hua Zhong <hzhong@gmail.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-11 08:21:52 +00:00
if (likely(ti->preempt_count || irqs_disabled()))
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
return;
sched: cleanup: remove unnecessary gotos Replace loops implemented with gotos with real loops. Replace err = ...; goto x; x: return err; with return ...; No functional changes. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 15:00:14 +00:00
do {
tracing/sched: Make preempt_schedule() notrace The function tracer code uses ftrace_preempt_disable() to disable preemption instead of normal preempt_disable(). But there's a slight race condition that may cause it to lose a preemption check. This was made to keep the function tracer from recursing on itself by disabling preemption then having the enable call the function tracer again, causing infinite recursion. The bug was assumed to happen if the call was just in schedule, but this is incorrect. The bug is caused by preempt_schedule() which is called by preempt_enable(). The calling of preempt_enable() when NEED_RESCHED was set would call preempt_schedule() which would call the function tracer again. By making the preempt_schedule() and add_preempt_count() notrace then this will prevent the inifinite recursion. This is because the add_preempt_count() would stop the preempt_enable() in the function tracer from calling preempt_schedule() again. The sub_preempt_count() is also made notrace just to keep it symmetric. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-06-03 01:52:29 +00:00
add_preempt_count_notrace(PREEMPT_ACTIVE);
sched: cleanup: remove unnecessary gotos Replace loops implemented with gotos with real loops. Replace err = ...; goto x; x: return err; with return ...; No functional changes. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 15:00:14 +00:00
schedule();
tracing/sched: Make preempt_schedule() notrace The function tracer code uses ftrace_preempt_disable() to disable preemption instead of normal preempt_disable(). But there's a slight race condition that may cause it to lose a preemption check. This was made to keep the function tracer from recursing on itself by disabling preemption then having the enable call the function tracer again, causing infinite recursion. The bug was assumed to happen if the call was just in schedule, but this is incorrect. The bug is caused by preempt_schedule() which is called by preempt_enable(). The calling of preempt_enable() when NEED_RESCHED was set would call preempt_schedule() which would call the function tracer again. By making the preempt_schedule() and add_preempt_count() notrace then this will prevent the inifinite recursion. This is because the add_preempt_count() would stop the preempt_enable() in the function tracer from calling preempt_schedule() again. The sub_preempt_count() is also made notrace just to keep it symmetric. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-06-03 01:52:29 +00:00
sub_preempt_count_notrace(PREEMPT_ACTIVE);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
sched: cleanup: remove unnecessary gotos Replace loops implemented with gotos with real loops. Replace err = ...; goto x; x: return err; with return ...; No functional changes. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 15:00:14 +00:00
/*
* Check again in case we missed a preemption opportunity
* between schedule and now.
*/
barrier();
sched: TIF_NEED_RESCHED -> need_reshed() cleanup Impact: cleanup Use test_tsk_need_resched(), set_tsk_need_resched(), need_resched() instead of using TIF_NEED_RESCHED. Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <49B10BA4.9070209@cn.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-06 11:40:20 +00:00
} while (need_resched());
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
}
EXPORT_SYMBOL(preempt_schedule);
/*
[PATCH] small kernel/sched.c cleanup - constify and optimize stat_nam (thanks to Michael Tokarev!) - spelling and comment fixes Signed-off-by: Andreas Mohr <andi@lisas.de> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-10 11:43:52 +00:00
* this is the entry point to schedule() from kernel preemption
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
* off of irq context.
* Note, that this is called and return with irqs disabled. This will
* protect us against recursive calling from irq.
*/
asmlinkage void __sched preempt_schedule_irq(void)
{
struct thread_info *ti = current_thread_info();
sched: remove the !PREEMPT_BKL code remove the !PREEMPT_BKL code. this removes 160 lines of legacy code. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:33 +00:00
[PATCH] small kernel/sched.c cleanup - constify and optimize stat_nam (thanks to Michael Tokarev!) - spelling and comment fixes Signed-off-by: Andreas Mohr <andi@lisas.de> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-10 11:43:52 +00:00
/* Catch callers which need to be fixed */
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
BUG_ON(ti->preempt_count || !irqs_disabled());
sched: cleanup: remove unnecessary gotos Replace loops implemented with gotos with real loops. Replace err = ...; goto x; x: return err; with return ...; No functional changes. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 15:00:14 +00:00
do {
add_preempt_count(PREEMPT_ACTIVE);
local_irq_enable();
schedule();
local_irq_disable();
sub_preempt_count(PREEMPT_ACTIVE);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
sched: cleanup: remove unnecessary gotos Replace loops implemented with gotos with real loops. Replace err = ...; goto x; x: return err; with return ...; No functional changes. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 15:00:14 +00:00
/*
* Check again in case we missed a preemption opportunity
* between schedule and now.
*/
barrier();
sched: TIF_NEED_RESCHED -> need_reshed() cleanup Impact: cleanup Use test_tsk_need_resched(), set_tsk_need_resched(), need_resched() instead of using TIF_NEED_RESCHED. Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <49B10BA4.9070209@cn.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-06 11:40:20 +00:00
} while (need_resched());
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
}
#endif /* CONFIG_PREEMPT */
sched: Fix sync wakeups again The sync argument rename to introduce WF_* broke stuff by missing a local alias for an argument in __wake_up_common, fix it by using the more descriptive wake_flags name. This restores WF_SYNC propagation, which fixes wake_affine() behaviour, which fixes pipe-test. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-09-15 17:14:42 +00:00
int default_wake_function(wait_queue_t *curr, unsigned mode, int wake_flags,
[PATCH] sched cleanups whitespace cleanups. Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-10 07:26:11 +00:00
void *key)
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
{
sched: Fix sync wakeups again The sync argument rename to introduce WF_* broke stuff by missing a local alias for an argument in __wake_up_common, fix it by using the more descriptive wake_flags name. This restores WF_SYNC propagation, which fixes wake_affine() behaviour, which fixes pipe-test. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-09-15 17:14:42 +00:00
return try_to_wake_up(curr->private, mode, wake_flags);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
}
EXPORT_SYMBOL(default_wake_function);
/*
sched: style cleanups style cleanup of various changes that were done recently. no code changed: text data bss dec hex filename 23680 2542 28 26250 668a sched.o.before 23680 2542 28 26250 668a sched.o.after Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-12-05 14:46:09 +00:00
* The core wakeup function. Non-exclusive wakeups (nr_exclusive == 0) just
* wake everything up. If it's an exclusive wakeup (nr_exclusive == small +ve
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
* number) then we wake all the non-exclusive tasks and one exclusive task.
*
* There are circumstances in which we can try to wake a task which has already
sched: style cleanups style cleanup of various changes that were done recently. no code changed: text data bss dec hex filename 23680 2542 28 26250 668a sched.o.before 23680 2542 28 26250 668a sched.o.after Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-12-05 14:46:09 +00:00
* started to run but is not in state TASK_RUNNING. try_to_wake_up() returns
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
* zero in this (rare) case, and we handle it by continuing to scan the queue.
*/
wait: don't use __wake_up_common() '777c6c5 wait: prevent exclusive waiter starvation' made __wake_up_common() global to be used from abort_exclusive_wait(). It was needed to do a wake-up with the waitqueue lock held while passing down a key to the wake-up function. Since '4ede816 epoll keyed wakeups: add __wake_up_locked_key() and __wake_up_sync_key()' there is an appropriate wrapper for this case: __wake_up_locked_key(). Use it here and make __wake_up_common() private to the scheduler again. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1239720785-19661-1-git-send-email-hannes@cmpxchg.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-14 14:53:05 +00:00
static void __wake_up_common(wait_queue_head_t *q, unsigned int mode,
sched: Fix sync wakeups again The sync argument rename to introduce WF_* broke stuff by missing a local alias for an argument in __wake_up_common, fix it by using the more descriptive wake_flags name. This restores WF_SYNC propagation, which fixes wake_affine() behaviour, which fixes pipe-test. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-09-15 17:14:42 +00:00
int nr_exclusive, int wake_flags, void *key)
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
{
sched: use list_for_each_entry_safe() in __wake_up_common() Use list_for_each_entry_safe() instead of list_for_each_safe() in __wake_up_common() Signed-off-by: Matthias Kaehlcke <matthias.kaehlcke@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Mike Galbraith <efault@gmx.de> Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-15 15:00:02 +00:00
wait_queue_t *curr, *next;
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
sched: use list_for_each_entry_safe() in __wake_up_common() Use list_for_each_entry_safe() instead of list_for_each_safe() in __wake_up_common() Signed-off-by: Matthias Kaehlcke <matthias.kaehlcke@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Mike Galbraith <efault@gmx.de> Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-15 15:00:02 +00:00
list_for_each_entry_safe(curr, next, &q->task_list, task_list) {
[PATCH] sched: clean up fallout of recent changes Clean up some of the impact of recent (and not so recent) scheduler changes: - turning macros into nice inline functions - sanitizing and unifying variable definitions - whitespace, style consistency, 80-lines, comment correctness, spelling and curly braces police Due to the macro hell and variable placement simplifications there's even 26 bytes of .text saved: text data bss dec hex filename 25510 4153 192 29855 749f sched.o.before 25484 4153 192 29829 7485 sched.o.after [akpm@osdl.org: build fix] Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-03 07:25:40 +00:00
unsigned flags = curr->flags;
sched: Fix sync wakeups again The sync argument rename to introduce WF_* broke stuff by missing a local alias for an argument in __wake_up_common, fix it by using the more descriptive wake_flags name. This restores WF_SYNC propagation, which fixes wake_affine() behaviour, which fixes pipe-test. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-09-15 17:14:42 +00:00
if (curr->func(curr, mode, wake_flags, key) &&
[PATCH] sched: clean up fallout of recent changes Clean up some of the impact of recent (and not so recent) scheduler changes: - turning macros into nice inline functions - sanitizing and unifying variable definitions - whitespace, style consistency, 80-lines, comment correctness, spelling and curly braces police Due to the macro hell and variable placement simplifications there's even 26 bytes of .text saved: text data bss dec hex filename 25510 4153 192 29855 749f sched.o.before 25484 4153 192 29829 7485 sched.o.after [akpm@osdl.org: build fix] Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-03 07:25:40 +00:00
(flags & WQ_FLAG_EXCLUSIVE) && !--nr_exclusive)
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
break;
}
}
/**
* __wake_up - wake up threads blocked on a waitqueue.
* @q: the waitqueue
* @mode: which threads
* @nr_exclusive: how many wake-one or wake-many threads to wake up
[PATCH] DocBook: fix some descriptions Some KernelDoc descriptions are updated to match the current code. No code changes. Signed-off-by: Martin Waitz <tali@admingilde.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-05-01 15:59:26 +00:00
* @key: is directly passed to the wakeup function
sched: Document memory barriers implied by sleep/wake-up primitives Add a section to the memory barriers document to note the implied memory barriers of sleep primitives (set_current_state() and wrappers) and wake-up primitives (wake_up() and co.). Also extend the in-code comments on the wake_up() functions to note these implied barriers. [ Impact: add documentation ] Signed-off-by: David Howells <dhowells@redhat.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> LKML-Reference: <20090428140138.1192.94723.stgit@warthog.procyon.org.uk> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-28 14:01:38 +00:00
*
* It may be assumed that this function implies a write memory barrier before
* changing the task state if and only if any tasks are woken up.
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
*/
kernel: remove fastcall in kernel/* [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-08 12:19:53 +00:00
void __wake_up(wait_queue_head_t *q, unsigned int mode,
[PATCH] sched cleanups whitespace cleanups. Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-10 07:26:11 +00:00
int nr_exclusive, void *key)
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
{
unsigned long flags;
spin_lock_irqsave(&q->lock, flags);
__wake_up_common(q, mode, nr_exclusive, 0, key);
spin_unlock_irqrestore(&q->lock, flags);
}
EXPORT_SYMBOL(__wake_up);
/*
* Same as __wake_up but called with the spinlock in wait_queue_head_t held.
*/
kernel: remove fastcall in kernel/* [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-08 12:19:53 +00:00
void __wake_up_locked(wait_queue_head_t *q, unsigned int mode)
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
{
__wake_up_common(q, mode, 1, 0, NULL);
}
wait_event_interruptible_locked() interface New wait_event_interruptible{,_exclusive}_locked{,_irq} macros added. They work just like versions without _locked* suffix but require the wait queue's lock to be held. Also __wake_up_locked() is now exported as to pair it with the above macros. The use case of this new facility is when one uses wait queue's lock to protect a data structure. This may be advantageous if the structure needs to be protected by a spinlock anyway. In particular, with additional spinlock the following code has to be used to wait for a condition: spin_lock(&data.lock); ... for (ret = 0; !ret && !(condition); ) { spin_unlock(&data.lock); ret = wait_event_interruptible(data.wqh, (condition)); spin_lock(&data.lock); } ... spin_unlock(&data.lock); This looks bizarre plus wait_event_interruptible() locks the wait queue's lock anyway so there is a unlock+lock sequence where it could be avoided. To avoid those problems and benefit from wait queue's lock, a code similar to the following should be used: /* Waiting */ spin_lock(&data.wqh.lock); ... ret = wait_event_interruptible_locked(data.wqh, (condition)); ... spin_unlock(&data.wqh.lock); /* Waiting exclusively */ spin_lock(&data.whq.lock); ... ret = wait_event_interruptible_exclusive_locked(data.whq, (condition)); ... spin_unlock(&data.whq.lock); /* Waking up */ spin_lock(&data.wqh.lock); ... wake_up_locked(&data.wqh); ... spin_unlock(&data.wqh.lock); When spin_lock_irq() is used matching versions of macros need to be used (*_locked_irq()). Signed-off-by: Michal Nazarewicz <m.nazarewicz@samsung.com> Cc: Kyungmin Park <kyungmin.park@samsung.com> Cc: Marek Szyprowski <m.szyprowski@samsung.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Takashi Iwai <tiwai@suse.de> Cc: David Howells <dhowells@redhat.com> Cc: Andreas Herrmann <andreas.herrmann3@amd.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Mike Galbraith <efault@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-05-05 10:53:11 +00:00
EXPORT_SYMBOL_GPL(__wake_up_locked);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
epoll keyed wakeups: add __wake_up_locked_key() and __wake_up_sync_key() This patchset introduces wakeup hints for some of the most popular (from epoll POV) devices, so that epoll code can avoid spurious wakeups on its waiters. The problem with epoll is that the callback-based wakeups do not, ATM, carry any information about the events the wakeup is related to. So the only choice epoll has (not being able to call f_op->poll() from inside the callback), is to add the file* to a ready-list and resolve the real events later on, at epoll_wait() (or its own f_op->poll()) time. This can cause spurious wakeups, since the wake_up() itself might be for an event the caller is not interested into. The rate of these spurious wakeup can be pretty high in case of many network sockets being monitored. By allowing devices to report the events the wakeups refer to (at least the two major classes - POLLIN/POLLOUT), we are able to spare useless wakeups by proper handling inside the epoll's poll callback. Epoll will have in any case to call f_op->poll() on the file* later on, since the change to be done in order to have the full event set sent via wakeup, is too invasive for the way our f_op->poll() system works (the full event set is calculated inside the poll function - there are too many of them to even start thinking the change - also poll/select would need change too). Epoll is changed in a way that both devices which send event hints, and the ones that don't, are correctly handled. The former will gain some efficiency though. As a general rule for devices, would be to add an event mask by using key-aware wakeup macros, when making up poll wait queues. I tested it (together with the epoll's poll fix patch Andrew has in -mm) and wakeups for the supported devices are correctly filtered. Test program available here: http://www.xmailserver.org/epoll_test.c This patch: Nothing revolutionary here. Just using the available "key" that our wakeup core already support. The __wake_up_locked_key() was no brainer, since both __wake_up_locked() and __wake_up_locked_key() are thin wrappers around __wake_up_common(). The __wake_up_sync() function had a body, so the choice was between borrowing the body for __wake_up_sync_key() and calling it from __wake_up_sync(), or make an inline and calling it from both. I chose the former since in most archs it all resolves to "mov $0, REG; jmp ADDR". Signed-off-by: Davide Libenzi <davidel@xmailserver.org> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: Ingo Molnar <mingo@elte.hu> Cc: David Miller <davem@davemloft.net> Cc: William Lee Irwin III <wli@movementarian.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-03-31 22:24:20 +00:00
void __wake_up_locked_key(wait_queue_head_t *q, unsigned int mode, void *key)
{
__wake_up_common(q, mode, 1, 0, key);
}
SUNRPC: Close a race in __rpc_wait_for_completion_task() Although they run as rpciod background tasks, under normal operation (i.e. no SIGKILL), functions like nfs_sillyrename(), nfs4_proc_unlck() and nfs4_do_close() want to be fully synchronous. This means that when we exit, we want all references to the rpc_task to be gone, and we want any dentry references etc. held by that task to be released. For this reason these functions call __rpc_wait_for_completion_task(), followed by rpc_put_task() in the expectation that the latter will be releasing the last reference to the rpc_task, and thus ensuring that the callback_ops->rpc_release() has been called synchronously. This patch fixes a race which exists due to the fact that rpciod calls rpc_complete_task() (in order to wake up the callers of __rpc_wait_for_completion_task()) and then subsequently calls rpc_put_task() without ensuring that these two steps are done atomically. In order to avoid adding new spin locks, the patch uses the existing waitqueue spin lock to order the rpc_task reference count releases between the waiting process and rpciod. The common case where nobody is waiting for completion is optimised for by checking if the RPC_TASK_ASYNC flag is cleared and/or if the rpc_task reference count is 1: in those cases we drop trying to grab the spin lock, and immediately free up the rpc_task. Those few processes that need to put the rpc_task from inside an asynchronous context and that do not care about ordering are given a new helper: rpc_put_task_async(). Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-02-21 19:05:41 +00:00
EXPORT_SYMBOL_GPL(__wake_up_locked_key);
epoll keyed wakeups: add __wake_up_locked_key() and __wake_up_sync_key() This patchset introduces wakeup hints for some of the most popular (from epoll POV) devices, so that epoll code can avoid spurious wakeups on its waiters. The problem with epoll is that the callback-based wakeups do not, ATM, carry any information about the events the wakeup is related to. So the only choice epoll has (not being able to call f_op->poll() from inside the callback), is to add the file* to a ready-list and resolve the real events later on, at epoll_wait() (or its own f_op->poll()) time. This can cause spurious wakeups, since the wake_up() itself might be for an event the caller is not interested into. The rate of these spurious wakeup can be pretty high in case of many network sockets being monitored. By allowing devices to report the events the wakeups refer to (at least the two major classes - POLLIN/POLLOUT), we are able to spare useless wakeups by proper handling inside the epoll's poll callback. Epoll will have in any case to call f_op->poll() on the file* later on, since the change to be done in order to have the full event set sent via wakeup, is too invasive for the way our f_op->poll() system works (the full event set is calculated inside the poll function - there are too many of them to even start thinking the change - also poll/select would need change too). Epoll is changed in a way that both devices which send event hints, and the ones that don't, are correctly handled. The former will gain some efficiency though. As a general rule for devices, would be to add an event mask by using key-aware wakeup macros, when making up poll wait queues. I tested it (together with the epoll's poll fix patch Andrew has in -mm) and wakeups for the supported devices are correctly filtered. Test program available here: http://www.xmailserver.org/epoll_test.c This patch: Nothing revolutionary here. Just using the available "key" that our wakeup core already support. The __wake_up_locked_key() was no brainer, since both __wake_up_locked() and __wake_up_locked_key() are thin wrappers around __wake_up_common(). The __wake_up_sync() function had a body, so the choice was between borrowing the body for __wake_up_sync_key() and calling it from __wake_up_sync(), or make an inline and calling it from both. I chose the former since in most archs it all resolves to "mov $0, REG; jmp ADDR". Signed-off-by: Davide Libenzi <davidel@xmailserver.org> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: Ingo Molnar <mingo@elte.hu> Cc: David Miller <davem@davemloft.net> Cc: William Lee Irwin III <wli@movementarian.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-03-31 22:24:20 +00:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
/**
epoll keyed wakeups: add __wake_up_locked_key() and __wake_up_sync_key() This patchset introduces wakeup hints for some of the most popular (from epoll POV) devices, so that epoll code can avoid spurious wakeups on its waiters. The problem with epoll is that the callback-based wakeups do not, ATM, carry any information about the events the wakeup is related to. So the only choice epoll has (not being able to call f_op->poll() from inside the callback), is to add the file* to a ready-list and resolve the real events later on, at epoll_wait() (or its own f_op->poll()) time. This can cause spurious wakeups, since the wake_up() itself might be for an event the caller is not interested into. The rate of these spurious wakeup can be pretty high in case of many network sockets being monitored. By allowing devices to report the events the wakeups refer to (at least the two major classes - POLLIN/POLLOUT), we are able to spare useless wakeups by proper handling inside the epoll's poll callback. Epoll will have in any case to call f_op->poll() on the file* later on, since the change to be done in order to have the full event set sent via wakeup, is too invasive for the way our f_op->poll() system works (the full event set is calculated inside the poll function - there are too many of them to even start thinking the change - also poll/select would need change too). Epoll is changed in a way that both devices which send event hints, and the ones that don't, are correctly handled. The former will gain some efficiency though. As a general rule for devices, would be to add an event mask by using key-aware wakeup macros, when making up poll wait queues. I tested it (together with the epoll's poll fix patch Andrew has in -mm) and wakeups for the supported devices are correctly filtered. Test program available here: http://www.xmailserver.org/epoll_test.c This patch: Nothing revolutionary here. Just using the available "key" that our wakeup core already support. The __wake_up_locked_key() was no brainer, since both __wake_up_locked() and __wake_up_locked_key() are thin wrappers around __wake_up_common(). The __wake_up_sync() function had a body, so the choice was between borrowing the body for __wake_up_sync_key() and calling it from __wake_up_sync(), or make an inline and calling it from both. I chose the former since in most archs it all resolves to "mov $0, REG; jmp ADDR". Signed-off-by: Davide Libenzi <davidel@xmailserver.org> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: Ingo Molnar <mingo@elte.hu> Cc: David Miller <davem@davemloft.net> Cc: William Lee Irwin III <wli@movementarian.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-03-31 22:24:20 +00:00
* __wake_up_sync_key - wake up threads blocked on a waitqueue.
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
* @q: the waitqueue
* @mode: which threads
* @nr_exclusive: how many wake-one or wake-many threads to wake up
epoll keyed wakeups: add __wake_up_locked_key() and __wake_up_sync_key() This patchset introduces wakeup hints for some of the most popular (from epoll POV) devices, so that epoll code can avoid spurious wakeups on its waiters. The problem with epoll is that the callback-based wakeups do not, ATM, carry any information about the events the wakeup is related to. So the only choice epoll has (not being able to call f_op->poll() from inside the callback), is to add the file* to a ready-list and resolve the real events later on, at epoll_wait() (or its own f_op->poll()) time. This can cause spurious wakeups, since the wake_up() itself might be for an event the caller is not interested into. The rate of these spurious wakeup can be pretty high in case of many network sockets being monitored. By allowing devices to report the events the wakeups refer to (at least the two major classes - POLLIN/POLLOUT), we are able to spare useless wakeups by proper handling inside the epoll's poll callback. Epoll will have in any case to call f_op->poll() on the file* later on, since the change to be done in order to have the full event set sent via wakeup, is too invasive for the way our f_op->poll() system works (the full event set is calculated inside the poll function - there are too many of them to even start thinking the change - also poll/select would need change too). Epoll is changed in a way that both devices which send event hints, and the ones that don't, are correctly handled. The former will gain some efficiency though. As a general rule for devices, would be to add an event mask by using key-aware wakeup macros, when making up poll wait queues. I tested it (together with the epoll's poll fix patch Andrew has in -mm) and wakeups for the supported devices are correctly filtered. Test program available here: http://www.xmailserver.org/epoll_test.c This patch: Nothing revolutionary here. Just using the available "key" that our wakeup core already support. The __wake_up_locked_key() was no brainer, since both __wake_up_locked() and __wake_up_locked_key() are thin wrappers around __wake_up_common(). The __wake_up_sync() function had a body, so the choice was between borrowing the body for __wake_up_sync_key() and calling it from __wake_up_sync(), or make an inline and calling it from both. I chose the former since in most archs it all resolves to "mov $0, REG; jmp ADDR". Signed-off-by: Davide Libenzi <davidel@xmailserver.org> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: Ingo Molnar <mingo@elte.hu> Cc: David Miller <davem@davemloft.net> Cc: William Lee Irwin III <wli@movementarian.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-03-31 22:24:20 +00:00
* @key: opaque value to be passed to wakeup targets
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
*
* The sync wakeup differs that the waker knows that it will schedule
* away soon, so while the target thread will be woken up, it will not
* be migrated to another CPU - ie. the two threads are 'synchronized'
* with each other. This can prevent needless bouncing between CPUs.
*
* On UP it can prevent extra preemption.
sched: Document memory barriers implied by sleep/wake-up primitives Add a section to the memory barriers document to note the implied memory barriers of sleep primitives (set_current_state() and wrappers) and wake-up primitives (wake_up() and co.). Also extend the in-code comments on the wake_up() functions to note these implied barriers. [ Impact: add documentation ] Signed-off-by: David Howells <dhowells@redhat.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> LKML-Reference: <20090428140138.1192.94723.stgit@warthog.procyon.org.uk> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-28 14:01:38 +00:00
*
* It may be assumed that this function implies a write memory barrier before
* changing the task state if and only if any tasks are woken up.
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
*/
epoll keyed wakeups: add __wake_up_locked_key() and __wake_up_sync_key() This patchset introduces wakeup hints for some of the most popular (from epoll POV) devices, so that epoll code can avoid spurious wakeups on its waiters. The problem with epoll is that the callback-based wakeups do not, ATM, carry any information about the events the wakeup is related to. So the only choice epoll has (not being able to call f_op->poll() from inside the callback), is to add the file* to a ready-list and resolve the real events later on, at epoll_wait() (or its own f_op->poll()) time. This can cause spurious wakeups, since the wake_up() itself might be for an event the caller is not interested into. The rate of these spurious wakeup can be pretty high in case of many network sockets being monitored. By allowing devices to report the events the wakeups refer to (at least the two major classes - POLLIN/POLLOUT), we are able to spare useless wakeups by proper handling inside the epoll's poll callback. Epoll will have in any case to call f_op->poll() on the file* later on, since the change to be done in order to have the full event set sent via wakeup, is too invasive for the way our f_op->poll() system works (the full event set is calculated inside the poll function - there are too many of them to even start thinking the change - also poll/select would need change too). Epoll is changed in a way that both devices which send event hints, and the ones that don't, are correctly handled. The former will gain some efficiency though. As a general rule for devices, would be to add an event mask by using key-aware wakeup macros, when making up poll wait queues. I tested it (together with the epoll's poll fix patch Andrew has in -mm) and wakeups for the supported devices are correctly filtered. Test program available here: http://www.xmailserver.org/epoll_test.c This patch: Nothing revolutionary here. Just using the available "key" that our wakeup core already support. The __wake_up_locked_key() was no brainer, since both __wake_up_locked() and __wake_up_locked_key() are thin wrappers around __wake_up_common(). The __wake_up_sync() function had a body, so the choice was between borrowing the body for __wake_up_sync_key() and calling it from __wake_up_sync(), or make an inline and calling it from both. I chose the former since in most archs it all resolves to "mov $0, REG; jmp ADDR". Signed-off-by: Davide Libenzi <davidel@xmailserver.org> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: Ingo Molnar <mingo@elte.hu> Cc: David Miller <davem@davemloft.net> Cc: William Lee Irwin III <wli@movementarian.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-03-31 22:24:20 +00:00
void __wake_up_sync_key(wait_queue_head_t *q, unsigned int mode,
int nr_exclusive, void *key)
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
{
unsigned long flags;
sched: Rename sync arguments In order to extend the functions to have more than 1 flag (sync), rename the argument to flags, and explicitly define a WF_ space for individual flags. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-09-14 17:55:44 +00:00
int wake_flags = WF_SYNC;
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
if (unlikely(!q))
return;
if (unlikely(!nr_exclusive))
sched: Rename sync arguments In order to extend the functions to have more than 1 flag (sync), rename the argument to flags, and explicitly define a WF_ space for individual flags. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-09-14 17:55:44 +00:00
wake_flags = 0;
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
spin_lock_irqsave(&q->lock, flags);
sched: Rename sync arguments In order to extend the functions to have more than 1 flag (sync), rename the argument to flags, and explicitly define a WF_ space for individual flags. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-09-14 17:55:44 +00:00
__wake_up_common(q, mode, nr_exclusive, wake_flags, key);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
spin_unlock_irqrestore(&q->lock, flags);
}
epoll keyed wakeups: add __wake_up_locked_key() and __wake_up_sync_key() This patchset introduces wakeup hints for some of the most popular (from epoll POV) devices, so that epoll code can avoid spurious wakeups on its waiters. The problem with epoll is that the callback-based wakeups do not, ATM, carry any information about the events the wakeup is related to. So the only choice epoll has (not being able to call f_op->poll() from inside the callback), is to add the file* to a ready-list and resolve the real events later on, at epoll_wait() (or its own f_op->poll()) time. This can cause spurious wakeups, since the wake_up() itself might be for an event the caller is not interested into. The rate of these spurious wakeup can be pretty high in case of many network sockets being monitored. By allowing devices to report the events the wakeups refer to (at least the two major classes - POLLIN/POLLOUT), we are able to spare useless wakeups by proper handling inside the epoll's poll callback. Epoll will have in any case to call f_op->poll() on the file* later on, since the change to be done in order to have the full event set sent via wakeup, is too invasive for the way our f_op->poll() system works (the full event set is calculated inside the poll function - there are too many of them to even start thinking the change - also poll/select would need change too). Epoll is changed in a way that both devices which send event hints, and the ones that don't, are correctly handled. The former will gain some efficiency though. As a general rule for devices, would be to add an event mask by using key-aware wakeup macros, when making up poll wait queues. I tested it (together with the epoll's poll fix patch Andrew has in -mm) and wakeups for the supported devices are correctly filtered. Test program available here: http://www.xmailserver.org/epoll_test.c This patch: Nothing revolutionary here. Just using the available "key" that our wakeup core already support. The __wake_up_locked_key() was no brainer, since both __wake_up_locked() and __wake_up_locked_key() are thin wrappers around __wake_up_common(). The __wake_up_sync() function had a body, so the choice was between borrowing the body for __wake_up_sync_key() and calling it from __wake_up_sync(), or make an inline and calling it from both. I chose the former since in most archs it all resolves to "mov $0, REG; jmp ADDR". Signed-off-by: Davide Libenzi <davidel@xmailserver.org> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: Ingo Molnar <mingo@elte.hu> Cc: David Miller <davem@davemloft.net> Cc: William Lee Irwin III <wli@movementarian.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-03-31 22:24:20 +00:00
EXPORT_SYMBOL_GPL(__wake_up_sync_key);
/*
* __wake_up_sync - see __wake_up_sync_key()
*/
void __wake_up_sync(wait_queue_head_t *q, unsigned int mode, int nr_exclusive)
{
__wake_up_sync_key(q, mode, nr_exclusive, NULL);
}
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
EXPORT_SYMBOL_GPL(__wake_up_sync); /* For internal use only */
sched: add kernel doc for the completion, fix kernel-doc-nano-HOWTO.txt This patch adds kernel doc for the completion feature. An error in the split-man.pl PERL snippet in kernel-doc-nano-HOWTO.txt is also fixed. Signed-off-by: Kevin Diggs <kevdig@hypersurf.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-26 08:26:54 +00:00
/**
* complete: - signals a single thread waiting on this completion
* @x: holds the state of this particular completion
*
* This will wake up a single thread waiting on this completion. Threads will be
* awakened in the same order in which they were queued.
*
* See also complete_all(), wait_for_completion() and related routines.
sched: Document memory barriers implied by sleep/wake-up primitives Add a section to the memory barriers document to note the implied memory barriers of sleep primitives (set_current_state() and wrappers) and wake-up primitives (wake_up() and co.). Also extend the in-code comments on the wake_up() functions to note these implied barriers. [ Impact: add documentation ] Signed-off-by: David Howells <dhowells@redhat.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> LKML-Reference: <20090428140138.1192.94723.stgit@warthog.procyon.org.uk> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-28 14:01:38 +00:00
*
* It may be assumed that this function implies a write memory barrier before
* changing the task state if and only if any tasks are woken up.
sched: add kernel doc for the completion, fix kernel-doc-nano-HOWTO.txt This patch adds kernel doc for the completion feature. An error in the split-man.pl PERL snippet in kernel-doc-nano-HOWTO.txt is also fixed. Signed-off-by: Kevin Diggs <kevdig@hypersurf.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-26 08:26:54 +00:00
*/
sched: fix fastcall mismatch in completion APIs Jeff Dike noticed that wait_for_completion_interruptible()'s prototype had a mismatched fastcall. Fix this by removing the fastcall attributes from all the completion APIs. Found-by: Jeff Dike <jdike@linux.intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-24 16:23:48 +00:00
void complete(struct completion *x)
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
{
unsigned long flags;
spin_lock_irqsave(&x->wait.lock, flags);
x->done++;
sched: Use task_contributes_to_load, TASK_ALL and TASK_NORMAL Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
2007-12-06 16:07:07 +00:00
__wake_up_common(&x->wait, TASK_NORMAL, 1, 0, NULL);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
spin_unlock_irqrestore(&x->wait.lock, flags);
}
EXPORT_SYMBOL(complete);
sched: add kernel doc for the completion, fix kernel-doc-nano-HOWTO.txt This patch adds kernel doc for the completion feature. An error in the split-man.pl PERL snippet in kernel-doc-nano-HOWTO.txt is also fixed. Signed-off-by: Kevin Diggs <kevdig@hypersurf.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-26 08:26:54 +00:00
/**
* complete_all: - signals all threads waiting on this completion
* @x: holds the state of this particular completion
*
* This will wake up all threads waiting on this particular completion event.
sched: Document memory barriers implied by sleep/wake-up primitives Add a section to the memory barriers document to note the implied memory barriers of sleep primitives (set_current_state() and wrappers) and wake-up primitives (wake_up() and co.). Also extend the in-code comments on the wake_up() functions to note these implied barriers. [ Impact: add documentation ] Signed-off-by: David Howells <dhowells@redhat.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> LKML-Reference: <20090428140138.1192.94723.stgit@warthog.procyon.org.uk> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-28 14:01:38 +00:00
*
* It may be assumed that this function implies a write memory barrier before
* changing the task state if and only if any tasks are woken up.
sched: add kernel doc for the completion, fix kernel-doc-nano-HOWTO.txt This patch adds kernel doc for the completion feature. An error in the split-man.pl PERL snippet in kernel-doc-nano-HOWTO.txt is also fixed. Signed-off-by: Kevin Diggs <kevdig@hypersurf.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-26 08:26:54 +00:00
*/
sched: fix fastcall mismatch in completion APIs Jeff Dike noticed that wait_for_completion_interruptible()'s prototype had a mismatched fastcall. Fix this by removing the fastcall attributes from all the completion APIs. Found-by: Jeff Dike <jdike@linux.intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-24 16:23:48 +00:00
void complete_all(struct completion *x)
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
{
unsigned long flags;
spin_lock_irqsave(&x->wait.lock, flags);
x->done += UINT_MAX/2;
sched: Use task_contributes_to_load, TASK_ALL and TASK_NORMAL Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
2007-12-06 16:07:07 +00:00
__wake_up_common(&x->wait, TASK_NORMAL, 0, 0, NULL);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
spin_unlock_irqrestore(&x->wait.lock, flags);
}
EXPORT_SYMBOL(complete_all);
sched: cleanup: refactor common code of sleep_on / wait_for_completion Refactor common code of sleep_on / wait_for_completion These functions were largely cut'n'pasted. This moves the common code into single helpers instead. Advantage is about 1k less code on x86-64 and 91 lines of code removed. It adds one function call to the non timeout version of the functions; i don't expect this to be measurable. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 15:00:14 +00:00
static inline long __sched
do_wait_for_common(struct completion *x, long timeout, int state)
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
{
if (!x->done) {
DECLARE_WAITQUEUE(wait, current);
sched, wait: Use wrapper functions epoll should not touch flags in wait_queue_t. This patch introduces a new function __add_wait_queue_exclusive(), for the users, who use wait queue as a LIFO queue. __add_wait_queue_tail_exclusive() is introduced too instead of add_wait_queue_exclusive_locked(). remove_wait_queue_locked() is removed, as it is a duplicate of __remove_wait_queue(), disliked by users, and with less users. Signed-off-by: Changli Gao <xiaosuo@gmail.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Paul Menage <menage@google.com> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Davide Libenzi <davidel@xmailserver.org> Cc: <containers@lists.linux-foundation.org> LKML-Reference: <1273214006-2979-1-git-send-email-xiaosuo@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-05-07 06:33:26 +00:00
__add_wait_queue_tail_exclusive(&x->wait, &wait);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
do {
sched: do_wait_for_common: use signal_pending_state() Change do_wait_for_common() to use signal_pending_state() instead of open coding. Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-20 23:54:41 +00:00
if (signal_pending_state(state, current)) {
sched: refactor wait_for_completion_timeout() Simplify the code and fix the boundary condition of wait_for_completion_timeout(,0). We can kill the first __remove_wait_queue() as well. Signed-off-by: Ingo Molnar <mingo@elte.hu> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
2008-06-20 14:32:20 +00:00
timeout = -ERESTARTSYS;
break;
sched: cleanup: refactor common code of sleep_on / wait_for_completion Refactor common code of sleep_on / wait_for_completion These functions were largely cut'n'pasted. This moves the common code into single helpers instead. Advantage is about 1k less code on x86-64 and 91 lines of code removed. It adds one function call to the non timeout version of the functions; i don't expect this to be measurable. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 15:00:14 +00:00
}
__set_current_state(state);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
spin_unlock_irq(&x->wait.lock);
timeout = schedule_timeout(timeout);
spin_lock_irq(&x->wait.lock);
sched: refactor wait_for_completion_timeout() Simplify the code and fix the boundary condition of wait_for_completion_timeout(,0). We can kill the first __remove_wait_queue() as well. Signed-off-by: Ingo Molnar <mingo@elte.hu> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
2008-06-20 14:32:20 +00:00
} while (!x->done && timeout);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
__remove_wait_queue(&x->wait, &wait);
sched: refactor wait_for_completion_timeout() Simplify the code and fix the boundary condition of wait_for_completion_timeout(,0). We can kill the first __remove_wait_queue() as well. Signed-off-by: Ingo Molnar <mingo@elte.hu> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
2008-06-20 14:32:20 +00:00
if (!x->done)
return timeout;
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
}
x->done--;
sched: refactor wait_for_completion_timeout() Simplify the code and fix the boundary condition of wait_for_completion_timeout(,0). We can kill the first __remove_wait_queue() as well. Signed-off-by: Ingo Molnar <mingo@elte.hu> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
2008-06-20 14:32:20 +00:00
return timeout ?: 1;
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
}
sched: cleanup: refactor common code of sleep_on / wait_for_completion Refactor common code of sleep_on / wait_for_completion These functions were largely cut'n'pasted. This moves the common code into single helpers instead. Advantage is about 1k less code on x86-64 and 91 lines of code removed. It adds one function call to the non timeout version of the functions; i don't expect this to be measurable. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 15:00:14 +00:00
static long __sched
wait_for_common(struct completion *x, long timeout, int state)
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
{
might_sleep();
spin_lock_irq(&x->wait.lock);
sched: cleanup: refactor common code of sleep_on / wait_for_completion Refactor common code of sleep_on / wait_for_completion These functions were largely cut'n'pasted. This moves the common code into single helpers instead. Advantage is about 1k less code on x86-64 and 91 lines of code removed. It adds one function call to the non timeout version of the functions; i don't expect this to be measurable. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 15:00:14 +00:00
timeout = do_wait_for_common(x, timeout, state);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
spin_unlock_irq(&x->wait.lock);
sched: cleanup: refactor common code of sleep_on / wait_for_completion Refactor common code of sleep_on / wait_for_completion These functions were largely cut'n'pasted. This moves the common code into single helpers instead. Advantage is about 1k less code on x86-64 and 91 lines of code removed. It adds one function call to the non timeout version of the functions; i don't expect this to be measurable. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 15:00:14 +00:00
return timeout;
}
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
sched: add kernel doc for the completion, fix kernel-doc-nano-HOWTO.txt This patch adds kernel doc for the completion feature. An error in the split-man.pl PERL snippet in kernel-doc-nano-HOWTO.txt is also fixed. Signed-off-by: Kevin Diggs <kevdig@hypersurf.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-26 08:26:54 +00:00
/**
* wait_for_completion: - waits for completion of a task
* @x: holds the state of this particular completion
*
* This waits to be signaled for completion of a specific task. It is NOT
* interruptible and there is no timeout.
*
* See also similar routines (i.e. wait_for_completion_timeout()) with timeout
* and interrupt capability. Also see complete().
*/
sched: fix fastcall mismatch in completion APIs Jeff Dike noticed that wait_for_completion_interruptible()'s prototype had a mismatched fastcall. Fix this by removing the fastcall attributes from all the completion APIs. Found-by: Jeff Dike <jdike@linux.intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-24 16:23:48 +00:00
void __sched wait_for_completion(struct completion *x)
sched: cleanup: refactor common code of sleep_on / wait_for_completion Refactor common code of sleep_on / wait_for_completion These functions were largely cut'n'pasted. This moves the common code into single helpers instead. Advantage is about 1k less code on x86-64 and 91 lines of code removed. It adds one function call to the non timeout version of the functions; i don't expect this to be measurable. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 15:00:14 +00:00
{
wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_UNINTERRUPTIBLE);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
}
sched: cleanup: refactor common code of sleep_on / wait_for_completion Refactor common code of sleep_on / wait_for_completion These functions were largely cut'n'pasted. This moves the common code into single helpers instead. Advantage is about 1k less code on x86-64 and 91 lines of code removed. It adds one function call to the non timeout version of the functions; i don't expect this to be measurable. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 15:00:14 +00:00
EXPORT_SYMBOL(wait_for_completion);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
sched: add kernel doc for the completion, fix kernel-doc-nano-HOWTO.txt This patch adds kernel doc for the completion feature. An error in the split-man.pl PERL snippet in kernel-doc-nano-HOWTO.txt is also fixed. Signed-off-by: Kevin Diggs <kevdig@hypersurf.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-26 08:26:54 +00:00
/**
* wait_for_completion_timeout: - waits for completion of a task (w/timeout)
* @x: holds the state of this particular completion
* @timeout: timeout value in jiffies
*
* This waits for either a completion of a specific task to be signaled or for a
* specified timeout to expire. The timeout is in jiffies. It is not
* interruptible.
*/
sched: fix fastcall mismatch in completion APIs Jeff Dike noticed that wait_for_completion_interruptible()'s prototype had a mismatched fastcall. Fix this by removing the fastcall attributes from all the completion APIs. Found-by: Jeff Dike <jdike@linux.intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-24 16:23:48 +00:00
unsigned long __sched
sched: cleanup: refactor common code of sleep_on / wait_for_completion Refactor common code of sleep_on / wait_for_completion These functions were largely cut'n'pasted. This moves the common code into single helpers instead. Advantage is about 1k less code on x86-64 and 91 lines of code removed. It adds one function call to the non timeout version of the functions; i don't expect this to be measurable. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 15:00:14 +00:00
wait_for_completion_timeout(struct completion *x, unsigned long timeout)
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
{
sched: cleanup: refactor common code of sleep_on / wait_for_completion Refactor common code of sleep_on / wait_for_completion These functions were largely cut'n'pasted. This moves the common code into single helpers instead. Advantage is about 1k less code on x86-64 and 91 lines of code removed. It adds one function call to the non timeout version of the functions; i don't expect this to be measurable. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 15:00:14 +00:00
return wait_for_common(x, timeout, TASK_UNINTERRUPTIBLE);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
}
sched: cleanup: refactor common code of sleep_on / wait_for_completion Refactor common code of sleep_on / wait_for_completion These functions were largely cut'n'pasted. This moves the common code into single helpers instead. Advantage is about 1k less code on x86-64 and 91 lines of code removed. It adds one function call to the non timeout version of the functions; i don't expect this to be measurable. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 15:00:14 +00:00
EXPORT_SYMBOL(wait_for_completion_timeout);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
sched: add kernel doc for the completion, fix kernel-doc-nano-HOWTO.txt This patch adds kernel doc for the completion feature. An error in the split-man.pl PERL snippet in kernel-doc-nano-HOWTO.txt is also fixed. Signed-off-by: Kevin Diggs <kevdig@hypersurf.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-26 08:26:54 +00:00
/**
* wait_for_completion_interruptible: - waits for completion of a task (w/intr)
* @x: holds the state of this particular completion
*
* This waits for completion of a specific task to be signaled. It is
* interruptible.
*/
sched: cleanup: refactor common code of sleep_on / wait_for_completion Refactor common code of sleep_on / wait_for_completion These functions were largely cut'n'pasted. This moves the common code into single helpers instead. Advantage is about 1k less code on x86-64 and 91 lines of code removed. It adds one function call to the non timeout version of the functions; i don't expect this to be measurable. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 15:00:14 +00:00
int __sched wait_for_completion_interruptible(struct completion *x)
sched: clean up sleep_on() APIs clean up the sleep_on() APIs: - do not use fastcall - replace fragile macro magic with proper inline functions Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-09 16:52:01 +00:00
{
sched: fix return value of wait_for_completion_interruptible() The recent wait_for_completion() cleanups: commit 8cbbe86dfcfd68ad69916164bdc838d9e09adca8 Author: Andi Kleen <ak@suse.de> Date: Mon Oct 15 17:00:14 2007 +0200 sched: cleanup: refactor common code of sleep_on / wait_for_completion Refactor common code of sleep_on / wait_for_completion broke the return value of wait_for_completion_interruptible(). Previously it returned 0 on success, now -1. Fix that. Problem found by Geert Uytterhoeven. [ mingo: fixed whitespace damage ] Reported-by: Geert Uytterhoeven <Geert.Uytterhoeven@sonycom.com> Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-18 19:32:55 +00:00
long t = wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_INTERRUPTIBLE);
if (t == -ERESTARTSYS)
return t;
return 0;
sched: clean up sleep_on() APIs clean up the sleep_on() APIs: - do not use fastcall - replace fragile macro magic with proper inline functions Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-09 16:52:01 +00:00
}
sched: cleanup: refactor common code of sleep_on / wait_for_completion Refactor common code of sleep_on / wait_for_completion These functions were largely cut'n'pasted. This moves the common code into single helpers instead. Advantage is about 1k less code on x86-64 and 91 lines of code removed. It adds one function call to the non timeout version of the functions; i don't expect this to be measurable. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 15:00:14 +00:00
EXPORT_SYMBOL(wait_for_completion_interruptible);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
sched: add kernel doc for the completion, fix kernel-doc-nano-HOWTO.txt This patch adds kernel doc for the completion feature. An error in the split-man.pl PERL snippet in kernel-doc-nano-HOWTO.txt is also fixed. Signed-off-by: Kevin Diggs <kevdig@hypersurf.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-26 08:26:54 +00:00
/**
* wait_for_completion_interruptible_timeout: - waits for completion (w/(to,intr))
* @x: holds the state of this particular completion
* @timeout: timeout value in jiffies
*
* This waits for either a completion of a specific task to be signaled or for a
* specified timeout to expire. It is interruptible. The timeout is in jiffies.
*/
sched: Change wait_for_completion_*_timeout() to return a signed long wait_for_completion_*_timeout() can return: 0: if the wait timed out -ve: if the wait was interrupted +ve: if the completion was completed. As they currently return an 'unsigned long', the last two cases are not easily distinguished which can easily result in buggy code, as is the case for the recently added wait_for_completion_interruptible_timeout() call in net/sunrpc/cache.c So change them both to return 'long'. As MAX_SCHEDULE_TIMEOUT is LONG_MAX, a large +ve return value should never overflow. Signed-off-by: NeilBrown <neilb@suse.de> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: J. Bruce Fields <bfields@fieldses.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> LKML-Reference: <20110105125016.64ccab0e@notabene.brown> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-01-05 01:50:16 +00:00
long __sched
sched: cleanup: refactor common code of sleep_on / wait_for_completion Refactor common code of sleep_on / wait_for_completion These functions were largely cut'n'pasted. This moves the common code into single helpers instead. Advantage is about 1k less code on x86-64 and 91 lines of code removed. It adds one function call to the non timeout version of the functions; i don't expect this to be measurable. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 15:00:14 +00:00
wait_for_completion_interruptible_timeout(struct completion *x,
unsigned long timeout)
sched: clean up sleep_on() APIs clean up the sleep_on() APIs: - do not use fastcall - replace fragile macro magic with proper inline functions Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-09 16:52:01 +00:00
{
sched: cleanup: refactor common code of sleep_on / wait_for_completion Refactor common code of sleep_on / wait_for_completion These functions were largely cut'n'pasted. This moves the common code into single helpers instead. Advantage is about 1k less code on x86-64 and 91 lines of code removed. It adds one function call to the non timeout version of the functions; i don't expect this to be measurable. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 15:00:14 +00:00
return wait_for_common(x, timeout, TASK_INTERRUPTIBLE);
sched: clean up sleep_on() APIs clean up the sleep_on() APIs: - do not use fastcall - replace fragile macro magic with proper inline functions Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-09 16:52:01 +00:00
}
sched: cleanup: refactor common code of sleep_on / wait_for_completion Refactor common code of sleep_on / wait_for_completion These functions were largely cut'n'pasted. This moves the common code into single helpers instead. Advantage is about 1k less code on x86-64 and 91 lines of code removed. It adds one function call to the non timeout version of the functions; i don't expect this to be measurable. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 15:00:14 +00:00
EXPORT_SYMBOL(wait_for_completion_interruptible_timeout);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
sched: add kernel doc for the completion, fix kernel-doc-nano-HOWTO.txt This patch adds kernel doc for the completion feature. An error in the split-man.pl PERL snippet in kernel-doc-nano-HOWTO.txt is also fixed. Signed-off-by: Kevin Diggs <kevdig@hypersurf.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-26 08:26:54 +00:00
/**
* wait_for_completion_killable: - waits for completion of a task (killable)
* @x: holds the state of this particular completion
*
* This waits to be signaled for completion of a specific task. It can be
* interrupted by a kill signal.
*/
Add wait_for_completion_killable Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
2007-12-06 17:29:54 +00:00
int __sched wait_for_completion_killable(struct completion *x)
{
long t = wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_KILLABLE);
if (t == -ERESTARTSYS)
return t;
return 0;
}
EXPORT_SYMBOL(wait_for_completion_killable);
sched: add wait_for_completion_killable_timeout Add missing _killable_timeout variant for wait_for_completion that will return when a timeout expires or the task is killed. CC: Ingo Molnar <mingo@elte.hu> CC: Andreas Herrmann <andreas.herrmann3@amd.com> CC: Thomas Gleixner <tglx@linutronix.de> CC: Mike Galbraith <efault@gmx.de> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Sage Weil <sage@newdream.net>
2010-05-29 16:12:30 +00:00
/**
* wait_for_completion_killable_timeout: - waits for completion of a task (w/(to,killable))
* @x: holds the state of this particular completion
* @timeout: timeout value in jiffies
*
* This waits for either a completion of a specific task to be
* signaled or for a specified timeout to expire. It can be
* interrupted by a kill signal. The timeout is in jiffies.
*/
sched: Change wait_for_completion_*_timeout() to return a signed long wait_for_completion_*_timeout() can return: 0: if the wait timed out -ve: if the wait was interrupted +ve: if the completion was completed. As they currently return an 'unsigned long', the last two cases are not easily distinguished which can easily result in buggy code, as is the case for the recently added wait_for_completion_interruptible_timeout() call in net/sunrpc/cache.c So change them both to return 'long'. As MAX_SCHEDULE_TIMEOUT is LONG_MAX, a large +ve return value should never overflow. Signed-off-by: NeilBrown <neilb@suse.de> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: J. Bruce Fields <bfields@fieldses.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> LKML-Reference: <20110105125016.64ccab0e@notabene.brown> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-01-05 01:50:16 +00:00
long __sched
sched: add wait_for_completion_killable_timeout Add missing _killable_timeout variant for wait_for_completion that will return when a timeout expires or the task is killed. CC: Ingo Molnar <mingo@elte.hu> CC: Andreas Herrmann <andreas.herrmann3@amd.com> CC: Thomas Gleixner <tglx@linutronix.de> CC: Mike Galbraith <efault@gmx.de> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Sage Weil <sage@newdream.net>
2010-05-29 16:12:30 +00:00
wait_for_completion_killable_timeout(struct completion *x,
unsigned long timeout)
{
return wait_for_common(x, timeout, TASK_KILLABLE);
}
EXPORT_SYMBOL(wait_for_completion_killable_timeout);
completions: uninline try_wait_for_completion and completion_done m68k fails to build with these functions inlined in completion.h. Move them out of line into sched.c and export them to avoid this problem. Signed-off-by: Dave Chinner <david@fromorbit.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-08-15 07:40:44 +00:00
/**
* try_wait_for_completion - try to decrement a completion without blocking
* @x: completion structure
*
* Returns: 0 if a decrement cannot be done without blocking
* 1 if a decrement succeeded.
*
* If a completion is being used as a counting completion,
* attempt to decrement the counter without blocking. This
* enables us to avoid waiting if the resource the completion
* is protecting is not available.
*/
bool try_wait_for_completion(struct completion *x)
{
sched: Make wakeup side and atomic variants of completion API irq safe Alan Stern noticed that all the wakeup side (and atomic) variants of the completion APIs should be irq safe, but the newly introduced completion_done() and try_wait_for_completion() aren't. The use of the irq unsafe variants in IRQ contexts can cause crashes/hangs. Fix the problem by making them use spin_lock_irqsave() and spin_lock_irqrestore(). Reported-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Zhang Rui <rui.zhang@intel.com> Cc: pm list <linux-pm@lists.linux-foundation.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: David Chinner <david@fromorbit.com> Cc: Lachlan McIlroy <lachlan@sgi.com> LKML-Reference: <200912130007.30541.rjw@sisk.pl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-12 23:07:30 +00:00
unsigned long flags;
completions: uninline try_wait_for_completion and completion_done m68k fails to build with these functions inlined in completion.h. Move them out of line into sched.c and export them to avoid this problem. Signed-off-by: Dave Chinner <david@fromorbit.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-08-15 07:40:44 +00:00
int ret = 1;
sched: Make wakeup side and atomic variants of completion API irq safe Alan Stern noticed that all the wakeup side (and atomic) variants of the completion APIs should be irq safe, but the newly introduced completion_done() and try_wait_for_completion() aren't. The use of the irq unsafe variants in IRQ contexts can cause crashes/hangs. Fix the problem by making them use spin_lock_irqsave() and spin_lock_irqrestore(). Reported-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Zhang Rui <rui.zhang@intel.com> Cc: pm list <linux-pm@lists.linux-foundation.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: David Chinner <david@fromorbit.com> Cc: Lachlan McIlroy <lachlan@sgi.com> LKML-Reference: <200912130007.30541.rjw@sisk.pl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-12 23:07:30 +00:00
spin_lock_irqsave(&x->wait.lock, flags);
completions: uninline try_wait_for_completion and completion_done m68k fails to build with these functions inlined in completion.h. Move them out of line into sched.c and export them to avoid this problem. Signed-off-by: Dave Chinner <david@fromorbit.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-08-15 07:40:44 +00:00
if (!x->done)
ret = 0;
else
x->done--;
sched: Make wakeup side and atomic variants of completion API irq safe Alan Stern noticed that all the wakeup side (and atomic) variants of the completion APIs should be irq safe, but the newly introduced completion_done() and try_wait_for_completion() aren't. The use of the irq unsafe variants in IRQ contexts can cause crashes/hangs. Fix the problem by making them use spin_lock_irqsave() and spin_lock_irqrestore(). Reported-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Zhang Rui <rui.zhang@intel.com> Cc: pm list <linux-pm@lists.linux-foundation.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: David Chinner <david@fromorbit.com> Cc: Lachlan McIlroy <lachlan@sgi.com> LKML-Reference: <200912130007.30541.rjw@sisk.pl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-12 23:07:30 +00:00
spin_unlock_irqrestore(&x->wait.lock, flags);
completions: uninline try_wait_for_completion and completion_done m68k fails to build with these functions inlined in completion.h. Move them out of line into sched.c and export them to avoid this problem. Signed-off-by: Dave Chinner <david@fromorbit.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-08-15 07:40:44 +00:00
return ret;
}
EXPORT_SYMBOL(try_wait_for_completion);
/**
* completion_done - Test to see if a completion has any waiters
* @x: completion structure
*
* Returns: 0 if there are waiters (wait_for_completion() in progress)
* 1 if there are no waiters.
*
*/
bool completion_done(struct completion *x)
{
sched: Make wakeup side and atomic variants of completion API irq safe Alan Stern noticed that all the wakeup side (and atomic) variants of the completion APIs should be irq safe, but the newly introduced completion_done() and try_wait_for_completion() aren't. The use of the irq unsafe variants in IRQ contexts can cause crashes/hangs. Fix the problem by making them use spin_lock_irqsave() and spin_lock_irqrestore(). Reported-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Zhang Rui <rui.zhang@intel.com> Cc: pm list <linux-pm@lists.linux-foundation.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: David Chinner <david@fromorbit.com> Cc: Lachlan McIlroy <lachlan@sgi.com> LKML-Reference: <200912130007.30541.rjw@sisk.pl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-12 23:07:30 +00:00
unsigned long flags;
completions: uninline try_wait_for_completion and completion_done m68k fails to build with these functions inlined in completion.h. Move them out of line into sched.c and export them to avoid this problem. Signed-off-by: Dave Chinner <david@fromorbit.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-08-15 07:40:44 +00:00
int ret = 1;
sched: Make wakeup side and atomic variants of completion API irq safe Alan Stern noticed that all the wakeup side (and atomic) variants of the completion APIs should be irq safe, but the newly introduced completion_done() and try_wait_for_completion() aren't. The use of the irq unsafe variants in IRQ contexts can cause crashes/hangs. Fix the problem by making them use spin_lock_irqsave() and spin_lock_irqrestore(). Reported-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Zhang Rui <rui.zhang@intel.com> Cc: pm list <linux-pm@lists.linux-foundation.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: David Chinner <david@fromorbit.com> Cc: Lachlan McIlroy <lachlan@sgi.com> LKML-Reference: <200912130007.30541.rjw@sisk.pl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-12 23:07:30 +00:00
spin_lock_irqsave(&x->wait.lock, flags);
completions: uninline try_wait_for_completion and completion_done m68k fails to build with these functions inlined in completion.h. Move them out of line into sched.c and export them to avoid this problem. Signed-off-by: Dave Chinner <david@fromorbit.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-08-15 07:40:44 +00:00
if (!x->done)
ret = 0;
sched: Make wakeup side and atomic variants of completion API irq safe Alan Stern noticed that all the wakeup side (and atomic) variants of the completion APIs should be irq safe, but the newly introduced completion_done() and try_wait_for_completion() aren't. The use of the irq unsafe variants in IRQ contexts can cause crashes/hangs. Fix the problem by making them use spin_lock_irqsave() and spin_lock_irqrestore(). Reported-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Zhang Rui <rui.zhang@intel.com> Cc: pm list <linux-pm@lists.linux-foundation.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: David Chinner <david@fromorbit.com> Cc: Lachlan McIlroy <lachlan@sgi.com> LKML-Reference: <200912130007.30541.rjw@sisk.pl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-12 23:07:30 +00:00
spin_unlock_irqrestore(&x->wait.lock, flags);
completions: uninline try_wait_for_completion and completion_done m68k fails to build with these functions inlined in completion.h. Move them out of line into sched.c and export them to avoid this problem. Signed-off-by: Dave Chinner <david@fromorbit.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-08-15 07:40:44 +00:00
return ret;
}
EXPORT_SYMBOL(completion_done);
sched: cleanup: refactor common code of sleep_on / wait_for_completion Refactor common code of sleep_on / wait_for_completion These functions were largely cut'n'pasted. This moves the common code into single helpers instead. Advantage is about 1k less code on x86-64 and 91 lines of code removed. It adds one function call to the non timeout version of the functions; i don't expect this to be measurable. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 15:00:14 +00:00
static long __sched
sleep_on_common(wait_queue_head_t *q, int state, long timeout)
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
{
sched: clean up sleep_on() APIs clean up the sleep_on() APIs: - do not use fastcall - replace fragile macro magic with proper inline functions Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-09 16:52:01 +00:00
unsigned long flags;
wait_queue_t wait;
init_waitqueue_entry(&wait, current);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
sched: cleanup: refactor common code of sleep_on / wait_for_completion Refactor common code of sleep_on / wait_for_completion These functions were largely cut'n'pasted. This moves the common code into single helpers instead. Advantage is about 1k less code on x86-64 and 91 lines of code removed. It adds one function call to the non timeout version of the functions; i don't expect this to be measurable. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 15:00:14 +00:00
__set_current_state(state);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
sched: cleanup: refactor common code of sleep_on / wait_for_completion Refactor common code of sleep_on / wait_for_completion These functions were largely cut'n'pasted. This moves the common code into single helpers instead. Advantage is about 1k less code on x86-64 and 91 lines of code removed. It adds one function call to the non timeout version of the functions; i don't expect this to be measurable. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 15:00:14 +00:00
spin_lock_irqsave(&q->lock, flags);
__add_wait_queue(q, &wait);
spin_unlock(&q->lock);
timeout = schedule_timeout(timeout);
spin_lock_irq(&q->lock);
__remove_wait_queue(q, &wait);
spin_unlock_irqrestore(&q->lock, flags);
return timeout;
}
void __sched interruptible_sleep_on(wait_queue_head_t *q)
{
sleep_on_common(q, TASK_INTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
}
EXPORT_SYMBOL(interruptible_sleep_on);
sched: clean up sleep_on() APIs clean up the sleep_on() APIs: - do not use fastcall - replace fragile macro magic with proper inline functions Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-09 16:52:01 +00:00
long __sched
[PATCH] sched cleanups whitespace cleanups. Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-10 07:26:11 +00:00
interruptible_sleep_on_timeout(wait_queue_head_t *q, long timeout)
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
{
sched: cleanup: refactor common code of sleep_on / wait_for_completion Refactor common code of sleep_on / wait_for_completion These functions were largely cut'n'pasted. This moves the common code into single helpers instead. Advantage is about 1k less code on x86-64 and 91 lines of code removed. It adds one function call to the non timeout version of the functions; i don't expect this to be measurable. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 15:00:14 +00:00
return sleep_on_common(q, TASK_INTERRUPTIBLE, timeout);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
}
EXPORT_SYMBOL(interruptible_sleep_on_timeout);
sched: clean up sleep_on() APIs clean up the sleep_on() APIs: - do not use fastcall - replace fragile macro magic with proper inline functions Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-09 16:52:01 +00:00
void __sched sleep_on(wait_queue_head_t *q)
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
{
sched: cleanup: refactor common code of sleep_on / wait_for_completion Refactor common code of sleep_on / wait_for_completion These functions were largely cut'n'pasted. This moves the common code into single helpers instead. Advantage is about 1k less code on x86-64 and 91 lines of code removed. It adds one function call to the non timeout version of the functions; i don't expect this to be measurable. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 15:00:14 +00:00
sleep_on_common(q, TASK_UNINTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
}
EXPORT_SYMBOL(sleep_on);
sched: clean up sleep_on() APIs clean up the sleep_on() APIs: - do not use fastcall - replace fragile macro magic with proper inline functions Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-09 16:52:01 +00:00
long __sched sleep_on_timeout(wait_queue_head_t *q, long timeout)
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
{
sched: cleanup: refactor common code of sleep_on / wait_for_completion Refactor common code of sleep_on / wait_for_completion These functions were largely cut'n'pasted. This moves the common code into single helpers instead. Advantage is about 1k less code on x86-64 and 91 lines of code removed. It adds one function call to the non timeout version of the functions; i don't expect this to be measurable. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 15:00:14 +00:00
return sleep_on_common(q, TASK_UNINTERRUPTIBLE, timeout);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
}
EXPORT_SYMBOL(sleep_on_timeout);
[PATCH] pi-futex: scheduler support for pi Add framework to boost/unboost the priority of RT tasks. This consists of: - caching the 'normal' priority in ->normal_prio - providing a functions to set/get the priority of the task - make sched_setscheduler() aware of boosting The effective_prio() cleanups also fix a priority-calculation bug pointed out by Andrey Gelman, in set_user_nice(). has_rt_policy() fix: Peter Williams <pwil3058@bigpond.net.au> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Cc: Andrey Gelman <agelman@012.net.il> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 09:54:51 +00:00
#ifdef CONFIG_RT_MUTEXES
/*
* rt_mutex_setprio - set the current priority of a task
* @p: task
* @prio: prio value (kernel-internal form)
*
* This function changes the 'effective' priority of a task. It does
* not touch ->normal_prio like __setscheduler().
*
* Used by the rt_mutex code to implement priority inheritance logic.
*/
[PATCH] sched: cleanup, remove task_t, convert to struct task_struct cleanup: remove task_t and convert all the uses to struct task_struct. I introduced it for the scheduler anno and it was a mistake. Conversion was mostly scripted, the result was reviewed and all secondary whitespace and style impact (if any) was fixed up by hand. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-03 07:25:41 +00:00
void rt_mutex_setprio(struct task_struct *p, int prio)
[PATCH] pi-futex: scheduler support for pi Add framework to boost/unboost the priority of RT tasks. This consists of: - caching the 'normal' priority in ->normal_prio - providing a functions to set/get the priority of the task - make sched_setscheduler() aware of boosting The effective_prio() cleanups also fix a priority-calculation bug pointed out by Andrey Gelman, in set_user_nice(). has_rt_policy() fix: Peter Williams <pwil3058@bigpond.net.au> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Cc: Andrey Gelman <agelman@012.net.il> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 09:54:51 +00:00
{
sched: revert recent removal of set_curr_task() Revert removal of set_curr_task. Use put_prev_task/set_curr_task when changing groups/policies Signed-off-by: Srivatsa Vaddagiri < vatsa@linux.vnet.ibm.com> Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
2007-10-15 15:00:08 +00:00
int oldprio, on_rq, running;
[PATCH] sched: cleanup, convert sched.c-internal typedefs to struct convert: - runqueue_t to 'struct rq' - prio_array_t to 'struct prio_array' - migration_req_t to 'struct migration_req' I was the one who added these but they are both against the kernel coding style and also were used inconsistently at places. So just get rid of them at once, now that we are flushing the scheduler patch-queue anyway. Conversion was mostly scripted, the result was reviewed and all secondary whitespace and style impact (if any) was fixed up by hand. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-03 07:25:42 +00:00
struct rq *rq;
sched: Don't use possibly stale sched_class setscheduler() saves task->sched_class outside of the rq->lock held region for a check after the setscheduler changes have become effective. That might result in checking a stale value. rtmutex_setprio() has the same problem, though it is protected by p->pi_lock against setscheduler(), but for correctness sake (and to avoid bad examples) it needs to be fixed as well. Retrieve task->sched_class inside of the rq->lock held region. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: stable@kernel.org
2010-02-17 08:05:48 +00:00
const struct sched_class *prev_class;
[PATCH] pi-futex: scheduler support for pi Add framework to boost/unboost the priority of RT tasks. This consists of: - caching the 'normal' priority in ->normal_prio - providing a functions to set/get the priority of the task - make sched_setscheduler() aware of boosting The effective_prio() cleanups also fix a priority-calculation bug pointed out by Andrey Gelman, in set_user_nice(). has_rt_policy() fix: Peter Williams <pwil3058@bigpond.net.au> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Cc: Andrey Gelman <agelman@012.net.il> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 09:54:51 +00:00
BUG_ON(prio < 0 || prio > MAX_PRIO);
sched: Add p->pi_lock to task_rq_lock() In order to be able to call set_task_cpu() while either holding p->pi_lock or task_rq(p)->lock we need to hold both locks in order to stabilize task_rq(). This makes task_rq_lock() acquire both locks, and have __task_rq_lock() validate that p->pi_lock is held. This increases the locking overhead for most scheduler syscalls but allows reduction of rq->lock contention for some scheduler hot paths (ttwu). Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110405152729.232781355@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-05 15:23:51 +00:00
rq = __task_rq_lock(p);
[PATCH] pi-futex: scheduler support for pi Add framework to boost/unboost the priority of RT tasks. This consists of: - caching the 'normal' priority in ->normal_prio - providing a functions to set/get the priority of the task - make sched_setscheduler() aware of boosting The effective_prio() cleanups also fix a priority-calculation bug pointed out by Andrey Gelman, in set_user_nice(). has_rt_policy() fix: Peter Williams <pwil3058@bigpond.net.au> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Cc: Andrey Gelman <agelman@012.net.il> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 09:54:51 +00:00
tracing/sched: Add sched_pi_setprio tracepoint Add a tracepoint that shows the priority of a task being boosted via priority inheritance. Cc: Gregory Haskins <ghaskins@novell.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-09-20 19:13:34 +00:00
trace_sched_pi_setprio(p, prio);
revert 'sched: redundant reschedule when set_user_nice() boosts a prio of a task from the "expired" array' Revert commit bd53f96ca54a21c07e7a0ae1886fa623d370b85f. Con says: This is no good, sorry. The one I saw originally was with the staircase deadline cpu scheduler in situ and was different. #define TASK_PREEMPTS_CURR(p, rq) \ ((p)->prio < (rq)->curr->prio) (((p)->prio < (rq)->curr->prio) && ((p)->array == (rq)->active)) This will fail to wake up a runqueue for a task that has been migrated to the expired array of a runqueue which is otherwise idle which can happen with smp balancing, Cc: Dmitry Adamushko <dmitry.adamushko@gmail.com> Cc: Con Kolivas <kernel@kolivas.org> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-09 03:27:06 +00:00
oldprio = p->prio;
sched: Don't use possibly stale sched_class setscheduler() saves task->sched_class outside of the rq->lock held region for a check after the setscheduler changes have become effective. That might result in checking a stale value. rtmutex_setprio() has the same problem, though it is protected by p->pi_lock against setscheduler(), but for correctness sake (and to avoid bad examples) it needs to be fixed as well. Retrieve task->sched_class inside of the rq->lock held region. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: stable@kernel.org
2010-02-17 08:05:48 +00:00
prev_class = p->sched_class;
sched: Provide p->on_rq Provide a generic p->on_rq because the p->se.on_rq semantics are unfavourable for lockless wakeups but needed for sched_fair. In particular, p->on_rq is only cleared when we actually dequeue the task in schedule() and not on any random dequeue as done by things like __migrate_task() and __sched_setscheduler(). This also allows us to remove p->se usage from !sched_fair code. Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110405152728.949545047@chello.nl
2011-04-05 15:23:44 +00:00
on_rq = p->on_rq;
sched: fix crash on ia64, introduce task_current() Some services (e.g. sched_setscheduler(), rt_mutex_setprio() and sched_move_task()) must handle a given task differently in case it's the 'rq->curr' task on its run-queue. The task_running() interface is not suitable for determining such tasks for platforms with one of the following options: #define __ARCH_WANT_UNLOCKED_CTXSW #define __ARCH_WANT_INTERRUPTS_ON_CTXSW Due to the fact that it makes use of 'p->oncpu == 1' as a criterion but such a task is not necessarily 'rq->curr'. The detailed explanation is available here: https://lists.linux-foundation.org/pipermail/containers/2007-December/009262.html Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Tested-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Tested-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
2007-12-18 14:21:13 +00:00
running = task_current(rq, p);
sched: fix race in schedule() Fix a hard to trigger crash seen in the -rt kernel that also affects the vanilla scheduler. There is a race condition between schedule() and some dequeue/enqueue functions; rt_mutex_setprio(), __setscheduler() and sched_move_task(). When scheduling to idle, idle_balance() is called to pull tasks from other busy processor. It might drop the rq lock. It means that those 3 functions encounter on_rq=0 and running=1. The current task should be put when running. Here is a possible scenario: CPU0 CPU1 | schedule() | ->deactivate_task() | ->idle_balance() | -->load_balance_newidle() rt_mutex_setprio() | | --->double_lock_balance() *get lock *rel lock * on_rq=0, ruuning=1 | * sched_class is changed | *rel lock *get lock : | : ->put_prev_task_rt() ->pick_next_task_fair() => panic The current process of CPU1(P1) is scheduling. Deactivated P1, and the scheduler looks for another process on other CPU's runqueue because CPU1 will be idle. idle_balance(), load_balance_newidle() and double_lock_balance() are called and double_lock_balance() could drop the rq lock. On the other hand, CPU0 is trying to boost the priority of P1. The result of boosting only P1's prio and sched_class are changed to RT. The sched entities of P1 and P1's group are never put. It makes cfs_rq invalid, because the cfs_rq has curr and no leaf, but pick_next_task_fair() is called, then the kernel panics. Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-03-10 18:01:20 +00:00
if (on_rq)
sched: remove the 'u64 now' parameter from dequeue_task() remove the 'u64 now' parameter from dequeue_task(). ( identity transformation that causes no change in functionality. ) Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-08-09 09:16:49 +00:00
dequeue_task(rq, p, 0);
sched: fix race in schedule() Fix a hard to trigger crash seen in the -rt kernel that also affects the vanilla scheduler. There is a race condition between schedule() and some dequeue/enqueue functions; rt_mutex_setprio(), __setscheduler() and sched_move_task(). When scheduling to idle, idle_balance() is called to pull tasks from other busy processor. It might drop the rq lock. It means that those 3 functions encounter on_rq=0 and running=1. The current task should be put when running. Here is a possible scenario: CPU0 CPU1 | schedule() | ->deactivate_task() | ->idle_balance() | -->load_balance_newidle() rt_mutex_setprio() | | --->double_lock_balance() *get lock *rel lock * on_rq=0, ruuning=1 | * sched_class is changed | *rel lock *get lock : | : ->put_prev_task_rt() ->pick_next_task_fair() => panic The current process of CPU1(P1) is scheduling. Deactivated P1, and the scheduler looks for another process on other CPU's runqueue because CPU1 will be idle. idle_balance(), load_balance_newidle() and double_lock_balance() are called and double_lock_balance() could drop the rq lock. On the other hand, CPU0 is trying to boost the priority of P1. The result of boosting only P1's prio and sched_class are changed to RT. The sched entities of P1 and P1's group are never put. It makes cfs_rq invalid, because the cfs_rq has curr and no leaf, but pick_next_task_fair() is called, then the kernel panics. Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-03-10 18:01:20 +00:00
if (running)
p->sched_class->put_prev_task(rq, p);
sched: cfs core code apply the CFS core code. this change switches over the scheduler core to CFS's modular design and makes use of kernel/sched_fair/rt/idletask.c to implement Linux's scheduling policies. thanks to Andrew Morton and Thomas Gleixner for lots of detailed review feedback and for fixlets. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
2007-07-09 16:51:59 +00:00
if (rt_prio(prio))
p->sched_class = &rt_sched_class;
else
p->sched_class = &fair_sched_class;
[PATCH] pi-futex: scheduler support for pi Add framework to boost/unboost the priority of RT tasks. This consists of: - caching the 'normal' priority in ->normal_prio - providing a functions to set/get the priority of the task - make sched_setscheduler() aware of boosting The effective_prio() cleanups also fix a priority-calculation bug pointed out by Andrey Gelman, in set_user_nice(). has_rt_policy() fix: Peter Williams <pwil3058@bigpond.net.au> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Cc: Andrey Gelman <agelman@012.net.il> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 09:54:51 +00:00
p->prio = prio;
sched: fix race in schedule() Fix a hard to trigger crash seen in the -rt kernel that also affects the vanilla scheduler. There is a race condition between schedule() and some dequeue/enqueue functions; rt_mutex_setprio(), __setscheduler() and sched_move_task(). When scheduling to idle, idle_balance() is called to pull tasks from other busy processor. It might drop the rq lock. It means that those 3 functions encounter on_rq=0 and running=1. The current task should be put when running. Here is a possible scenario: CPU0 CPU1 | schedule() | ->deactivate_task() | ->idle_balance() | -->load_balance_newidle() rt_mutex_setprio() | | --->double_lock_balance() *get lock *rel lock * on_rq=0, ruuning=1 | * sched_class is changed | *rel lock *get lock : | : ->put_prev_task_rt() ->pick_next_task_fair() => panic The current process of CPU1(P1) is scheduling. Deactivated P1, and the scheduler looks for another process on other CPU's runqueue because CPU1 will be idle. idle_balance(), load_balance_newidle() and double_lock_balance() are called and double_lock_balance() could drop the rq lock. On the other hand, CPU0 is trying to boost the priority of P1. The result of boosting only P1's prio and sched_class are changed to RT. The sched entities of P1 and P1's group are never put. It makes cfs_rq invalid, because the cfs_rq has curr and no leaf, but pick_next_task_fair() is called, then the kernel panics. Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-03-10 18:01:20 +00:00
if (running)
p->sched_class->set_curr_task(rq);
sched: Fix switch_from_fair() When a task is taken out of the fair class we must ensure the vruntime is properly normalized because when we put it back in it will assume to be normalized. The case that goes wrong is when changing away from the fair class while sleeping. Sleeping tasks have non-normalized vruntime in order to make sleeper-fairness work. So treat the switch away from fair as a wakeup and preserve the relative vruntime. Also update sysrq-n to call the ->switch_{to,from} methods. Reported-by: Onkalo Samu <samu.p.onkalo@nokia.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-01-17 16:03:27 +00:00
if (on_rq)
sched: Add enqueue/dequeue flags In order to reduce the dependency on TASK_WAKING rework the enqueue interface to support a proper flags field. Replace the int wakeup, bool head arguments with an int flags argument and create the following flags: ENQUEUE_WAKEUP - the enqueue is a wakeup of a sleeping task, ENQUEUE_WAKING - the enqueue has relative vruntime due to having sched_class::task_waking() called, ENQUEUE_HEAD - the waking task should be places on the head of the priority queue (where appropriate). For symmetry also convert sched_class::dequeue() to a flags scheme. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-03-24 15:38:48 +00:00
enqueue_task(rq, p, oldprio < prio ? ENQUEUE_HEAD : 0);
sched: RT-balance, add new methods to sched_class Dmitry Adamushko found that the current implementation of the RT balancing code left out changes to the sched_setscheduler and rt_mutex_setprio. This patch addresses this issue by adding methods to the schedule classes to handle being switched out of (switched_from) and being switched into (switched_to) a sched_class. Also a method for changing of priorities is also added (prio_changed). This patch also removes some duplicate logic between rt_mutex_setprio and sched_setscheduler. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:22 +00:00
sched: Fix switch_from_fair() When a task is taken out of the fair class we must ensure the vruntime is properly normalized because when we put it back in it will assume to be normalized. The case that goes wrong is when changing away from the fair class while sleeping. Sleeping tasks have non-normalized vruntime in order to make sleeper-fairness work. So treat the switch away from fair as a wakeup and preserve the relative vruntime. Also update sysrq-n to call the ->switch_{to,from} methods. Reported-by: Onkalo Samu <samu.p.onkalo@nokia.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-01-17 16:03:27 +00:00
check_class_changed(rq, p, prev_class, oldprio);
sched: Add p->pi_lock to task_rq_lock() In order to be able to call set_task_cpu() while either holding p->pi_lock or task_rq(p)->lock we need to hold both locks in order to stabilize task_rq(). This makes task_rq_lock() acquire both locks, and have __task_rq_lock() validate that p->pi_lock is held. This increases the locking overhead for most scheduler syscalls but allows reduction of rq->lock contention for some scheduler hot paths (ttwu). Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110405152729.232781355@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-05 15:23:51 +00:00
__task_rq_unlock(rq);
[PATCH] pi-futex: scheduler support for pi Add framework to boost/unboost the priority of RT tasks. This consists of: - caching the 'normal' priority in ->normal_prio - providing a functions to set/get the priority of the task - make sched_setscheduler() aware of boosting The effective_prio() cleanups also fix a priority-calculation bug pointed out by Andrey Gelman, in set_user_nice(). has_rt_policy() fix: Peter Williams <pwil3058@bigpond.net.au> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Cc: Andrey Gelman <agelman@012.net.il> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 09:54:51 +00:00
}
#endif
[PATCH] sched: cleanup, remove task_t, convert to struct task_struct cleanup: remove task_t and convert all the uses to struct task_struct. I introduced it for the scheduler anno and it was a mistake. Conversion was mostly scripted, the result was reviewed and all secondary whitespace and style impact (if any) was fixed up by hand. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-03 07:25:41 +00:00
void set_user_nice(struct task_struct *p, long nice)
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
{
sched: cfs core code apply the CFS core code. this change switches over the scheduler core to CFS's modular design and makes use of kernel/sched_fair/rt/idletask.c to implement Linux's scheduling policies. thanks to Andrew Morton and Thomas Gleixner for lots of detailed review feedback and for fixlets. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
2007-07-09 16:51:59 +00:00
int old_prio, delta, on_rq;
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
unsigned long flags;
[PATCH] sched: cleanup, convert sched.c-internal typedefs to struct convert: - runqueue_t to 'struct rq' - prio_array_t to 'struct prio_array' - migration_req_t to 'struct migration_req' I was the one who added these but they are both against the kernel coding style and also were used inconsistently at places. So just get rid of them at once, now that we are flushing the scheduler patch-queue anyway. Conversion was mostly scripted, the result was reviewed and all secondary whitespace and style impact (if any) was fixed up by hand. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-03 07:25:42 +00:00
struct rq *rq;
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
if (TASK_NICE(p) == nice || nice < -20 || nice > 19)
return;
/*
* We have to be careful, if called from sys_setpriority(),
* the task might be in the middle of scheduling on another CPU.
*/
rq = task_rq_lock(p, &flags);
/*
* The RT priorities are set via sched_setscheduler(), but we still
* allow the 'normal' nice value to be set - but as expected
* it wont have any effect on scheduling until the task is
sched: cfs core code apply the CFS core code. this change switches over the scheduler core to CFS's modular design and makes use of kernel/sched_fair/rt/idletask.c to implement Linux's scheduling policies. thanks to Andrew Morton and Thomas Gleixner for lots of detailed review feedback and for fixlets. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
2007-07-09 16:51:59 +00:00
* SCHED_FIFO/SCHED_RR:
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
*/
sched: clean up the rt priority macros clean up the rt priority macros, pointed out by Andrew Morton. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-09 16:51:59 +00:00
if (task_has_rt_policy(p)) {
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
p->static_prio = NICE_TO_PRIO(nice);
goto out_unlock;
}
sched: Provide p->on_rq Provide a generic p->on_rq because the p->se.on_rq semantics are unfavourable for lockless wakeups but needed for sched_fair. In particular, p->on_rq is only cleared when we actually dequeue the task in schedule() and not on any random dequeue as done by things like __migrate_task() and __sched_setscheduler(). This also allows us to remove p->se usage from !sched_fair code. Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110405152728.949545047@chello.nl
2011-04-05 15:23:44 +00:00
on_rq = p->on_rq;
sched: revert revert of: fair-group: SMP-nice for group scheduling Try again.. Initial commit: 18d95a2832c1392a2d63227a7a6d433cb9f2037e Revert: 6363ca57c76b7b83639ca8c83fc285fa26a7880e Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Cc: Mike Galbraith <efault@gmx.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-27 11:41:14 +00:00
if (on_rq)
sched: remove the 'u64 now' parameter from dequeue_task() remove the 'u64 now' parameter from dequeue_task(). ( identity transformation that causes no change in functionality. ) Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-08-09 09:16:49 +00:00
dequeue_task(rq, p, 0);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
p->static_prio = NICE_TO_PRIO(nice);
[PATCH] sched: implement smpnice Problem: The introduction of separate run queues per CPU has brought with it "nice" enforcement problems that are best described by a simple example. For the sake of argument suppose that on a single CPU machine with a nice==19 hard spinner and a nice==0 hard spinner running that the nice==0 task gets 95% of the CPU and the nice==19 task gets 5% of the CPU. Now suppose that there is a system with 2 CPUs and 2 nice==19 hard spinners and 2 nice==0 hard spinners running. The user of this system would be entitled to expect that the nice==0 tasks each get 95% of a CPU and the nice==19 tasks only get 5% each. However, whether this expectation is met is pretty much down to luck as there are four equally likely distributions of the tasks to the CPUs that the load balancing code will consider to be balanced with loads of 2.0 for each CPU. Two of these distributions involve one nice==0 and one nice==19 task per CPU and in these circumstances the users expectations will be met. The other two distributions both involve both nice==0 tasks being on one CPU and both nice==19 being on the other CPU and each task will get 50% of a CPU and the user's expectations will not be met. Solution: The solution to this problem that is implemented in the attached patch is to use weighted loads when determining if the system is balanced and, when an imbalance is detected, to move an amount of weighted load between run queues (as opposed to a number of tasks) to restore the balance. Once again, the easiest way to explain why both of these measures are necessary is to use a simple example. Suppose that (in a slight variation of the above example) that we have a two CPU system with 4 nice==0 and 4 nice=19 hard spinning tasks running and that the 4 nice==0 tasks are on one CPU and the 4 nice==19 tasks are on the other CPU. The weighted loads for the two CPUs would be 4.0 and 0.2 respectively and the load balancing code would move 2 tasks resulting in one CPU with a load of 2.0 and the other with load of 2.2. If this was considered to be a big enough imbalance to justify moving a task and that task was moved using the current move_tasks() then it would move the highest priority task that it found and this would result in one CPU with a load of 3.0 and the other with a load of 1.2 which would result in the movement of a task in the opposite direction and so on -- infinite loop. If, on the other hand, an amount of load to be moved is calculated from the imbalance (in this case 0.1) and move_tasks() skips tasks until it find ones whose contributions to the weighted load are less than this amount it would move two of the nice==19 tasks resulting in a system with 2 nice==0 and 2 nice=19 on each CPU with loads of 2.1 for each CPU. One of the advantages of this mechanism is that on a system where all tasks have nice==0 the load balancing calculations would be mathematically identical to the current load balancing code. Notes: struct task_struct: has a new field load_weight which (in a trade off of space for speed) stores the contribution that this task makes to a CPU's weighted load when it is runnable. struct runqueue: has a new field raw_weighted_load which is the sum of the load_weight values for the currently runnable tasks on this run queue. This field always needs to be updated when nr_running is updated so two new inline functions inc_nr_running() and dec_nr_running() have been created to make sure that this happens. This also offers a convenient way to optimize away this part of the smpnice mechanism when CONFIG_SMP is not defined. int try_to_wake_up(): in this function the value SCHED_LOAD_BALANCE is used to represent the load contribution of a single task in various calculations in the code that decides which CPU to put the waking task on. While this would be a valid on a system where the nice values for the runnable tasks were distributed evenly around zero it will lead to anomalous load balancing if the distribution is skewed in either direction. To overcome this problem SCHED_LOAD_SCALE has been replaced by the load_weight for the relevant task or by the average load_weight per task for the queue in question (as appropriate). int move_tasks(): The modifications to this function were complicated by the fact that active_load_balance() uses it to move exactly one task without checking whether an imbalance actually exists. This precluded the simple overloading of max_nr_move with max_load_move and necessitated the addition of the latter as an extra argument to the function. The internal implementation is then modified to move up to max_nr_move tasks and max_load_move of weighted load. This slightly complicates the code where move_tasks() is called and if ever active_load_balance() is changed to not use move_tasks() the implementation of move_tasks() should be simplified accordingly. struct sched_group *find_busiest_group(): Similar to try_to_wake_up(), there are places in this function where SCHED_LOAD_SCALE is used to represent the load contribution of a single task and the same issues are created. A similar solution is adopted except that it is now the average per task contribution to a group's load (as opposed to a run queue) that is required. As this value is not directly available from the group it is calculated on the fly as the queues in the groups are visited when determining the busiest group. A key change to this function is that it is no longer to scale down *imbalance on exit as move_tasks() uses the load in its scaled form. void set_user_nice(): has been modified to update the task's load_weight field when it's nice value and also to ensure that its run queue's raw_weighted_load field is updated if it was runnable. From: "Siddha, Suresh B" <suresh.b.siddha@intel.com> With smpnice, sched groups with highest priority tasks can mask the imbalance between the other sched groups with in the same domain. This patch fixes some of the listed down scenarios by not considering the sched groups which are lightly loaded. a) on a simple 4-way MP system, if we have one high priority and 4 normal priority tasks, with smpnice we would like to see the high priority task scheduled on one cpu, two other cpus getting one normal task each and the fourth cpu getting the remaining two normal tasks. but with current smpnice extra normal priority task keeps jumping from one cpu to another cpu having the normal priority task. This is because of the busiest_has_loaded_cpus, nr_loaded_cpus logic.. We are not including the cpu with high priority task in max_load calculations but including that in total and avg_load calcuations.. leading to max_load < avg_load and load balance between cpus running normal priority tasks(2 Vs 1) will always show imbalanace as one normal priority and the extra normal priority task will keep moving from one cpu to another cpu having normal priority task.. b) 4-way system with HT (8 logical processors). Package-P0 T0 has a highest priority task, T1 is idle. Package-P1 Both T0 and T1 have 1 normal priority task each.. P2 and P3 are idle. With this patch, one of the normal priority tasks on P1 will be moved to P2 or P3.. c) With the current weighted smp nice calculations, it doesn't always make sense to look at the highest weighted runqueue in the busy group.. Consider a load balance scenario on a DP with HT system, with Package-0 containing one high priority and one low priority, Package-1 containing one low priority(with other thread being idle).. Package-1 thinks that it need to take the low priority thread from Package-0. And find_busiest_queue() returns the cpu thread with highest priority task.. And ultimately(with help of active load balance) we move high priority task to Package-1. And same continues with Package-0 now, moving high priority task from package-1 to package-0.. Even without the presence of active load balance, load balance will fail to balance the above scenario.. Fix find_busiest_queue to use "imbalance" when it is lightly loaded. [kernel@kolivas.org: sched: store weighted load on up] [kernel@kolivas.org: sched: add discrete weighted cpu load function] [suresh.b.siddha@intel.com: sched: remove dead code] Signed-off-by: Peter Williams <pwil3058@bigpond.com.au> Cc: "Siddha, Suresh B" <suresh.b.siddha@intel.com> Cc: "Chen, Kenneth W" <kenneth.w.chen@intel.com> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Con Kolivas <kernel@kolivas.org> Cc: John Hawkes <hawkes@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 09:54:34 +00:00
set_load_weight(p);
[PATCH] pi-futex: scheduler support for pi Add framework to boost/unboost the priority of RT tasks. This consists of: - caching the 'normal' priority in ->normal_prio - providing a functions to set/get the priority of the task - make sched_setscheduler() aware of boosting The effective_prio() cleanups also fix a priority-calculation bug pointed out by Andrey Gelman, in set_user_nice(). has_rt_policy() fix: Peter Williams <pwil3058@bigpond.net.au> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Cc: Andrey Gelman <agelman@012.net.il> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 09:54:51 +00:00
old_prio = p->prio;
p->prio = effective_prio(p);
delta = p->prio - old_prio;
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
sched: cfs core code apply the CFS core code. this change switches over the scheduler core to CFS's modular design and makes use of kernel/sched_fair/rt/idletask.c to implement Linux's scheduling policies. thanks to Andrew Morton and Thomas Gleixner for lots of detailed review feedback and for fixlets. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
2007-07-09 16:51:59 +00:00
if (on_rq) {
sched: Add enqueue/dequeue flags In order to reduce the dependency on TASK_WAKING rework the enqueue interface to support a proper flags field. Replace the int wakeup, bool head arguments with an int flags argument and create the following flags: ENQUEUE_WAKEUP - the enqueue is a wakeup of a sleeping task, ENQUEUE_WAKING - the enqueue has relative vruntime due to having sched_class::task_waking() called, ENQUEUE_HEAD - the waking task should be places on the head of the priority queue (where appropriate). For symmetry also convert sched_class::dequeue() to a flags scheme. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-03-24 15:38:48 +00:00
enqueue_task(rq, p, 0);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
/*
revert 'sched: redundant reschedule when set_user_nice() boosts a prio of a task from the "expired" array' Revert commit bd53f96ca54a21c07e7a0ae1886fa623d370b85f. Con says: This is no good, sorry. The one I saw originally was with the staircase deadline cpu scheduler in situ and was different. #define TASK_PREEMPTS_CURR(p, rq) \ ((p)->prio < (rq)->curr->prio) (((p)->prio < (rq)->curr->prio) && ((p)->array == (rq)->active)) This will fail to wake up a runqueue for a task that has been migrated to the expired array of a runqueue which is otherwise idle which can happen with smp balancing, Cc: Dmitry Adamushko <dmitry.adamushko@gmail.com> Cc: Con Kolivas <kernel@kolivas.org> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-09 03:27:06 +00:00
* If the task increased its priority or is running and
* lowered its priority, then reschedule its CPU:
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
*/
revert 'sched: redundant reschedule when set_user_nice() boosts a prio of a task from the "expired" array' Revert commit bd53f96ca54a21c07e7a0ae1886fa623d370b85f. Con says: This is no good, sorry. The one I saw originally was with the staircase deadline cpu scheduler in situ and was different. #define TASK_PREEMPTS_CURR(p, rq) \ ((p)->prio < (rq)->curr->prio) (((p)->prio < (rq)->curr->prio) && ((p)->array == (rq)->active)) This will fail to wake up a runqueue for a task that has been migrated to the expired array of a runqueue which is otherwise idle which can happen with smp balancing, Cc: Dmitry Adamushko <dmitry.adamushko@gmail.com> Cc: Con Kolivas <kernel@kolivas.org> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-09 03:27:06 +00:00
if (delta < 0 || (delta > 0 && task_running(rq, p)))
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
resched_task(rq->curr);
}
out_unlock:
sched: Add p->pi_lock to task_rq_lock() In order to be able to call set_task_cpu() while either holding p->pi_lock or task_rq(p)->lock we need to hold both locks in order to stabilize task_rq(). This makes task_rq_lock() acquire both locks, and have __task_rq_lock() validate that p->pi_lock is held. This increases the locking overhead for most scheduler syscalls but allows reduction of rq->lock contention for some scheduler hot paths (ttwu). Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110405152729.232781355@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-05 15:23:51 +00:00
task_rq_unlock(rq, p, &flags);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
}
EXPORT_SYMBOL(set_user_nice);
[PATCH] nice and rt-prio rlimits Add a pair of rlimits for allowing non-root tasks to raise nice and rt priorities. Defaults to traditional behavior. Originally written by Chris Wright. The patch implements a simple rlimit ceiling for the RT (and nice) priorities a task can set. The rlimit defaults to 0, meaning no change in behavior by default. A value of 50 means RT priority levels 1-50 are allowed. A value of 100 means all 99 privilege levels from 1 to 99 are allowed. CAP_SYS_NICE is blanket permission. (akpm: see http://www.uwsg.iu.edu/hypermail/linux/kernel/0503.1/1921.html for tips on integrating this with PAM). Signed-off-by: Matt Mackall <mpm@selenic.com> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-05-01 15:59:00 +00:00
/*
* can_nice - check if a task can reduce its nice value
* @p: task
* @nice: nice value
*/
[PATCH] sched: cleanup, remove task_t, convert to struct task_struct cleanup: remove task_t and convert all the uses to struct task_struct. I introduced it for the scheduler anno and it was a mistake. Conversion was mostly scripted, the result was reviewed and all secondary whitespace and style impact (if any) was fixed up by hand. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-03 07:25:41 +00:00
int can_nice(const struct task_struct *p, const int nice)
[PATCH] nice and rt-prio rlimits Add a pair of rlimits for allowing non-root tasks to raise nice and rt priorities. Defaults to traditional behavior. Originally written by Chris Wright. The patch implements a simple rlimit ceiling for the RT (and nice) priorities a task can set. The rlimit defaults to 0, meaning no change in behavior by default. A value of 50 means RT priority levels 1-50 are allowed. A value of 100 means all 99 privilege levels from 1 to 99 are allowed. CAP_SYS_NICE is blanket permission. (akpm: see http://www.uwsg.iu.edu/hypermail/linux/kernel/0503.1/1921.html for tips on integrating this with PAM). Signed-off-by: Matt Mackall <mpm@selenic.com> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-05-01 15:59:00 +00:00
{
[PATCH] Make RLIMIT_NICE ranges consistent with getpriority(2) As suggested by Michael Kerrisk <mtk-manpages@gmx.net>, make RLIMIT_NICE consistent with getpriority before it becomes available in released glibc. Signed-off-by: Matt Mackall <mpm@selenic.com> Acked-by: Ingo Molnar <mingo@elte.hu> Acked-by: Chris Wright <chrisw@osdl.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-08-18 18:24:19 +00:00
/* convert nice value [19,-20] to rlimit style value [1,40] */
int nice_rlim = 20 - nice;
[PATCH] sched: clean up fallout of recent changes Clean up some of the impact of recent (and not so recent) scheduler changes: - turning macros into nice inline functions - sanitizing and unifying variable definitions - whitespace, style consistency, 80-lines, comment correctness, spelling and curly braces police Due to the macro hell and variable placement simplifications there's even 26 bytes of .text saved: text data bss dec hex filename 25510 4153 192 29855 749f sched.o.before 25484 4153 192 29829 7485 sched.o.after [akpm@osdl.org: build fix] Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-03 07:25:40 +00:00
kernel core: use helpers for rlimits Make sure compiler won't do weird things with limits. E.g. fetching them twice may return 2 different values after writable limits are implemented. I.e. either use rlimit helpers added in commit 3e10e716abf3 ("resource: add helpers for fetching rlimits") or ACCESS_ONCE if not applicable. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Cc: Ingo Molnar <mingo@elte.hu> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: john stultz <johnstul@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-03-05 21:42:54 +00:00
return (nice_rlim <= task_rlimit(p, RLIMIT_NICE) ||
[PATCH] nice and rt-prio rlimits Add a pair of rlimits for allowing non-root tasks to raise nice and rt priorities. Defaults to traditional behavior. Originally written by Chris Wright. The patch implements a simple rlimit ceiling for the RT (and nice) priorities a task can set. The rlimit defaults to 0, meaning no change in behavior by default. A value of 50 means RT priority levels 1-50 are allowed. A value of 100 means all 99 privilege levels from 1 to 99 are allowed. CAP_SYS_NICE is blanket permission. (akpm: see http://www.uwsg.iu.edu/hypermail/linux/kernel/0503.1/1921.html for tips on integrating this with PAM). Signed-off-by: Matt Mackall <mpm@selenic.com> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-05-01 15:59:00 +00:00
capable(CAP_SYS_NICE));
}
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
#ifdef __ARCH_WANT_SYS_NICE
/*
* sys_nice - change the priority of the current process.
* @increment: priority increment
*
* sys_setpriority is a more generic, but much slower function that
* does similar things.
*/
[CVE-2009-0029] System call wrappers part 06 Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2009-01-14 13:14:08 +00:00
SYSCALL_DEFINE1(nice, int, increment)
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
{
[PATCH] sched: clean up fallout of recent changes Clean up some of the impact of recent (and not so recent) scheduler changes: - turning macros into nice inline functions - sanitizing and unifying variable definitions - whitespace, style consistency, 80-lines, comment correctness, spelling and curly braces police Due to the macro hell and variable placement simplifications there's even 26 bytes of .text saved: text data bss dec hex filename 25510 4153 192 29855 749f sched.o.before 25484 4153 192 29829 7485 sched.o.after [akpm@osdl.org: build fix] Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-03 07:25:40 +00:00
long nice, retval;
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
/*
* Setpriority might change our priority at the same moment.
* We don't have to worry. Conceptually one call occurs first
* and we have a single winner.
*/
[PATCH] nice and rt-prio rlimits Add a pair of rlimits for allowing non-root tasks to raise nice and rt priorities. Defaults to traditional behavior. Originally written by Chris Wright. The patch implements a simple rlimit ceiling for the RT (and nice) priorities a task can set. The rlimit defaults to 0, meaning no change in behavior by default. A value of 50 means RT priority levels 1-50 are allowed. A value of 100 means all 99 privilege levels from 1 to 99 are allowed. CAP_SYS_NICE is blanket permission. (akpm: see http://www.uwsg.iu.edu/hypermail/linux/kernel/0503.1/1921.html for tips on integrating this with PAM). Signed-off-by: Matt Mackall <mpm@selenic.com> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-05-01 15:59:00 +00:00
if (increment < -40)
increment = -40;
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
if (increment > 40)
increment = 40;
sched: use TASK_NICE for task_struct #define TASK_NICE(p) PRIO_TO_NICE((p)->static_prio) So it's better to use TASK_NICE here. Signed-off-by: WANG Cong <wangcong@zeuux.org> Acked-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-16 10:54:21 +00:00
nice = TASK_NICE(current) + increment;
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
if (nice < -20)
nice = -20;
if (nice > 19)
nice = 19;
[PATCH] nice and rt-prio rlimits Add a pair of rlimits for allowing non-root tasks to raise nice and rt priorities. Defaults to traditional behavior. Originally written by Chris Wright. The patch implements a simple rlimit ceiling for the RT (and nice) priorities a task can set. The rlimit defaults to 0, meaning no change in behavior by default. A value of 50 means RT priority levels 1-50 are allowed. A value of 100 means all 99 privilege levels from 1 to 99 are allowed. CAP_SYS_NICE is blanket permission. (akpm: see http://www.uwsg.iu.edu/hypermail/linux/kernel/0503.1/1921.html for tips on integrating this with PAM). Signed-off-by: Matt Mackall <mpm@selenic.com> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-05-01 15:59:00 +00:00
if (increment < 0 && !can_nice(current, nice))
return -EPERM;
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
retval = security_task_setnice(current, nice);
if (retval)
return retval;
set_user_nice(current, nice);
return 0;
}
#endif
/**
* task_prio - return the priority value of a given task.
* @p: the task in question.
*
* This is the priority value as seen by users in /proc.
* RT tasks are offset by -200. Normal tasks are centered
* around 0, value goes from -16 to +15.
*/
[PATCH] sched: cleanup, remove task_t, convert to struct task_struct cleanup: remove task_t and convert all the uses to struct task_struct. I introduced it for the scheduler anno and it was a mistake. Conversion was mostly scripted, the result was reviewed and all secondary whitespace and style impact (if any) was fixed up by hand. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-03 07:25:41 +00:00
int task_prio(const struct task_struct *p)
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
{
return p->prio - MAX_RT_PRIO;
}
/**
* task_nice - return the nice value of a given task.
* @p: the task in question.
*/
[PATCH] sched: cleanup, remove task_t, convert to struct task_struct cleanup: remove task_t and convert all the uses to struct task_struct. I introduced it for the scheduler anno and it was a mistake. Conversion was mostly scripted, the result was reviewed and all secondary whitespace and style impact (if any) was fixed up by hand. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-03 07:25:41 +00:00
int task_nice(const struct task_struct *p)
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
{
return TASK_NICE(p);
}
sched: export task_nice The API is trivial, and so is the implementation. Signed-off-by: Pavel Roskin <proski@gnu.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-03-05 21:56:37 +00:00
EXPORT_SYMBOL(task_nice);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
/**
* idle_cpu - is a given cpu idle currently?
* @cpu: the processor in question.
*/
int idle_cpu(int cpu)
{
return cpu_curr(cpu) == cpu_rq(cpu)->idle;
}
/**
* idle_task - return the idle task for a given cpu.
* @cpu: the processor in question.
*/
[PATCH] sched: cleanup, remove task_t, convert to struct task_struct cleanup: remove task_t and convert all the uses to struct task_struct. I introduced it for the scheduler anno and it was a mistake. Conversion was mostly scripted, the result was reviewed and all secondary whitespace and style impact (if any) was fixed up by hand. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-03 07:25:41 +00:00
struct task_struct *idle_task(int cpu)
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
{
return cpu_rq(cpu)->idle;
}
/**
* find_process_by_pid - find a process with a matching PID value.
* @pid: the pid in question.
*/
sched: uninline scheduler * save ~300 bytes * activate_idle_task() was moved to avoid a warning bloat-o-meter output: add/remove: 6/0 grow/shrink: 0/16 up/down: 438/-733 (-295) <=== function old new delta __enqueue_entity - 165 +165 finish_task_switch - 110 +110 update_curr_rt - 79 +79 __load_balance_iterator - 32 +32 __task_rq_unlock - 28 +28 find_process_by_pid - 24 +24 do_sched_setscheduler 133 123 -10 sys_sched_rr_get_interval 176 165 -11 sys_sched_getparam 156 145 -11 normalize_rt_tasks 482 470 -12 sched_getaffinity 112 99 -13 sys_sched_getscheduler 86 72 -14 sched_setaffinity 226 212 -14 sched_setscheduler 666 642 -24 load_balance_start_fair 33 9 -24 load_balance_next_fair 33 9 -24 dequeue_task_rt 133 67 -66 put_prev_task_rt 97 28 -69 schedule_tail 133 50 -83 schedule 682 594 -88 enqueue_entity 499 366 -133 task_new_fair 317 180 -137 Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 15:00:13 +00:00
static struct task_struct *find_process_by_pid(pid_t pid)
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
{
Uninline find_task_by_xxx set of functions The find_task_by_something is a set of macros are used to find task by pid depending on what kind of pid is proposed - global or virtual one. All of them are wrappers above the most generic one - find_task_by_pid_type_ns() - and just substitute some args for it. It turned out, that dereferencing the current->nsproxy->pid_ns construction and pushing one more argument on the stack inline cause kernel text size to grow. This patch moves all this stuff out-of-line into kernel/pid.c. Together with the next patch it saves a bit less than 400 bytes from the .text section. Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Cc: Sukadev Bhattiprolu <sukadev@us.ibm.com> Cc: Oleg Nesterov <oleg@tv-sign.ru> Cc: Paul Menage <menage@google.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-19 06:40:16 +00:00
return pid ? find_task_by_vpid(pid) : current;
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
}
/* Actually do priority change: must hold rq lock. */
sched: cfs core code apply the CFS core code. this change switches over the scheduler core to CFS's modular design and makes use of kernel/sched_fair/rt/idletask.c to implement Linux's scheduling policies. thanks to Andrew Morton and Thomas Gleixner for lots of detailed review feedback and for fixlets. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
2007-07-09 16:51:59 +00:00
static void
__setscheduler(struct rq *rq, struct task_struct *p, int policy, int prio)
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
{
p->policy = policy;
p->rt_priority = prio;
[PATCH] pi-futex: scheduler support for pi Add framework to boost/unboost the priority of RT tasks. This consists of: - caching the 'normal' priority in ->normal_prio - providing a functions to set/get the priority of the task - make sched_setscheduler() aware of boosting The effective_prio() cleanups also fix a priority-calculation bug pointed out by Andrey Gelman, in set_user_nice(). has_rt_policy() fix: Peter Williams <pwil3058@bigpond.net.au> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Cc: Andrey Gelman <agelman@012.net.il> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 09:54:51 +00:00
p->normal_prio = normal_prio(p);
/* we are holding p->pi_lock already */
p->prio = rt_mutex_getprio(p);
sched: Make sure task has correct sched_class after policy change From the code in rt_mutex_setprio(), it is evident that the intention is that task's with a RT 'prio' value as a consequence of receiving a PI boost also have their 'sched_class' field set to '&rt_sched_class'. However, Peter noticed that the code in __setscheduler() could result in this intention being frustrated. Fix it. Reported-by: Peter Williams <pwil3058@bigpond.net.au> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> LKML-Reference: <1257880321.4108.457.camel@laptop> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-11-10 19:12:01 +00:00
if (rt_prio(p->prio))
p->sched_class = &rt_sched_class;
else
p->sched_class = &fair_sched_class;
[PATCH] sched: implement smpnice Problem: The introduction of separate run queues per CPU has brought with it "nice" enforcement problems that are best described by a simple example. For the sake of argument suppose that on a single CPU machine with a nice==19 hard spinner and a nice==0 hard spinner running that the nice==0 task gets 95% of the CPU and the nice==19 task gets 5% of the CPU. Now suppose that there is a system with 2 CPUs and 2 nice==19 hard spinners and 2 nice==0 hard spinners running. The user of this system would be entitled to expect that the nice==0 tasks each get 95% of a CPU and the nice==19 tasks only get 5% each. However, whether this expectation is met is pretty much down to luck as there are four equally likely distributions of the tasks to the CPUs that the load balancing code will consider to be balanced with loads of 2.0 for each CPU. Two of these distributions involve one nice==0 and one nice==19 task per CPU and in these circumstances the users expectations will be met. The other two distributions both involve both nice==0 tasks being on one CPU and both nice==19 being on the other CPU and each task will get 50% of a CPU and the user's expectations will not be met. Solution: The solution to this problem that is implemented in the attached patch is to use weighted loads when determining if the system is balanced and, when an imbalance is detected, to move an amount of weighted load between run queues (as opposed to a number of tasks) to restore the balance. Once again, the easiest way to explain why both of these measures are necessary is to use a simple example. Suppose that (in a slight variation of the above example) that we have a two CPU system with 4 nice==0 and 4 nice=19 hard spinning tasks running and that the 4 nice==0 tasks are on one CPU and the 4 nice==19 tasks are on the other CPU. The weighted loads for the two CPUs would be 4.0 and 0.2 respectively and the load balancing code would move 2 tasks resulting in one CPU with a load of 2.0 and the other with load of 2.2. If this was considered to be a big enough imbalance to justify moving a task and that task was moved using the current move_tasks() then it would move the highest priority task that it found and this would result in one CPU with a load of 3.0 and the other with a load of 1.2 which would result in the movement of a task in the opposite direction and so on -- infinite loop. If, on the other hand, an amount of load to be moved is calculated from the imbalance (in this case 0.1) and move_tasks() skips tasks until it find ones whose contributions to the weighted load are less than this amount it would move two of the nice==19 tasks resulting in a system with 2 nice==0 and 2 nice=19 on each CPU with loads of 2.1 for each CPU. One of the advantages of this mechanism is that on a system where all tasks have nice==0 the load balancing calculations would be mathematically identical to the current load balancing code. Notes: struct task_struct: has a new field load_weight which (in a trade off of space for speed) stores the contribution that this task makes to a CPU's weighted load when it is runnable. struct runqueue: has a new field raw_weighted_load which is the sum of the load_weight values for the currently runnable tasks on this run queue. This field always needs to be updated when nr_running is updated so two new inline functions inc_nr_running() and dec_nr_running() have been created to make sure that this happens. This also offers a convenient way to optimize away this part of the smpnice mechanism when CONFIG_SMP is not defined. int try_to_wake_up(): in this function the value SCHED_LOAD_BALANCE is used to represent the load contribution of a single task in various calculations in the code that decides which CPU to put the waking task on. While this would be a valid on a system where the nice values for the runnable tasks were distributed evenly around zero it will lead to anomalous load balancing if the distribution is skewed in either direction. To overcome this problem SCHED_LOAD_SCALE has been replaced by the load_weight for the relevant task or by the average load_weight per task for the queue in question (as appropriate). int move_tasks(): The modifications to this function were complicated by the fact that active_load_balance() uses it to move exactly one task without checking whether an imbalance actually exists. This precluded the simple overloading of max_nr_move with max_load_move and necessitated the addition of the latter as an extra argument to the function. The internal implementation is then modified to move up to max_nr_move tasks and max_load_move of weighted load. This slightly complicates the code where move_tasks() is called and if ever active_load_balance() is changed to not use move_tasks() the implementation of move_tasks() should be simplified accordingly. struct sched_group *find_busiest_group(): Similar to try_to_wake_up(), there are places in this function where SCHED_LOAD_SCALE is used to represent the load contribution of a single task and the same issues are created. A similar solution is adopted except that it is now the average per task contribution to a group's load (as opposed to a run queue) that is required. As this value is not directly available from the group it is calculated on the fly as the queues in the groups are visited when determining the busiest group. A key change to this function is that it is no longer to scale down *imbalance on exit as move_tasks() uses the load in its scaled form. void set_user_nice(): has been modified to update the task's load_weight field when it's nice value and also to ensure that its run queue's raw_weighted_load field is updated if it was runnable. From: "Siddha, Suresh B" <suresh.b.siddha@intel.com> With smpnice, sched groups with highest priority tasks can mask the imbalance between the other sched groups with in the same domain. This patch fixes some of the listed down scenarios by not considering the sched groups which are lightly loaded. a) on a simple 4-way MP system, if we have one high priority and 4 normal priority tasks, with smpnice we would like to see the high priority task scheduled on one cpu, two other cpus getting one normal task each and the fourth cpu getting the remaining two normal tasks. but with current smpnice extra normal priority task keeps jumping from one cpu to another cpu having the normal priority task. This is because of the busiest_has_loaded_cpus, nr_loaded_cpus logic.. We are not including the cpu with high priority task in max_load calculations but including that in total and avg_load calcuations.. leading to max_load < avg_load and load balance between cpus running normal priority tasks(2 Vs 1) will always show imbalanace as one normal priority and the extra normal priority task will keep moving from one cpu to another cpu having normal priority task.. b) 4-way system with HT (8 logical processors). Package-P0 T0 has a highest priority task, T1 is idle. Package-P1 Both T0 and T1 have 1 normal priority task each.. P2 and P3 are idle. With this patch, one of the normal priority tasks on P1 will be moved to P2 or P3.. c) With the current weighted smp nice calculations, it doesn't always make sense to look at the highest weighted runqueue in the busy group.. Consider a load balance scenario on a DP with HT system, with Package-0 containing one high priority and one low priority, Package-1 containing one low priority(with other thread being idle).. Package-1 thinks that it need to take the low priority thread from Package-0. And find_busiest_queue() returns the cpu thread with highest priority task.. And ultimately(with help of active load balance) we move high priority task to Package-1. And same continues with Package-0 now, moving high priority task from package-1 to package-0.. Even without the presence of active load balance, load balance will fail to balance the above scenario.. Fix find_busiest_queue to use "imbalance" when it is lightly loaded. [kernel@kolivas.org: sched: store weighted load on up] [kernel@kolivas.org: sched: add discrete weighted cpu load function] [suresh.b.siddha@intel.com: sched: remove dead code] Signed-off-by: Peter Williams <pwil3058@bigpond.com.au> Cc: "Siddha, Suresh B" <suresh.b.siddha@intel.com> Cc: "Chen, Kenneth W" <kenneth.w.chen@intel.com> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Con Kolivas <kernel@kolivas.org> Cc: John Hawkes <hawkes@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 09:54:34 +00:00
set_load_weight(p);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
}
CRED: Use RCU to access another task's creds and to release a task's own creds Use RCU to access another task's creds and to release a task's own creds. This means that it will be possible for the credentials of a task to be replaced without another task (a) requiring a full lock to read them, and (b) seeing deallocated memory. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: James Morris <jmorris@namei.org> Acked-by: Serge Hallyn <serue@us.ibm.com> Signed-off-by: James Morris <jmorris@namei.org>
2008-11-13 23:39:19 +00:00
/*
* check the target process has a UID that matches the current process's
*/
static bool check_same_owner(struct task_struct *p)
{
const struct cred *cred = current_cred(), *pcred;
bool match;
rcu_read_lock();
pcred = __task_cred(p);
userns: user namespaces: convert several capable() calls CAP_IPC_OWNER and CAP_IPC_LOCK can be checked against current_user_ns(), because the resource comes from current's own ipc namespace. setuid/setgid are to uids in own namespace, so again checks can be against current_user_ns(). Changelog: Jan 11: Use task_ns_capable() in place of sched_capable(). Jan 11: Use nsown_capable() as suggested by Bastian Blank. Jan 11: Clarify (hopefully) some logic in futex and sched.c Feb 15: use ns_capable for ipc, not nsown_capable Feb 23: let copy_ipcs handle setting ipc_ns->user_ns Feb 23: pass ns down rather than taking it from current [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Serge E. Hallyn <serge.hallyn@canonical.com> Acked-by: "Eric W. Biederman" <ebiederm@xmission.com> Acked-by: Daniel Lezcano <daniel.lezcano@free.fr> Acked-by: David Howells <dhowells@redhat.com> Cc: James Morris <jmorris@namei.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-23 23:43:24 +00:00
if (cred->user->user_ns == pcred->user->user_ns)
match = (cred->euid == pcred->euid ||
cred->euid == pcred->uid);
else
match = false;
CRED: Use RCU to access another task's creds and to release a task's own creds Use RCU to access another task's creds and to release a task's own creds. This means that it will be possible for the credentials of a task to be replaced without another task (a) requiring a full lock to read them, and (b) seeing deallocated memory. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: James Morris <jmorris@namei.org> Acked-by: Serge Hallyn <serue@us.ibm.com> Signed-off-by: James Morris <jmorris@namei.org>
2008-11-13 23:39:19 +00:00
rcu_read_unlock();
return match;
}
sched: add new API sched_setscheduler_nocheck: add a flag to control access checks Hidehiro Kawai noticed that sched_setscheduler() can fail in stop_machine: it calls sched_setscheduler() from insmod, which can have CAP_SYS_MODULE without CAP_SYS_NICE. Two cases could have failed, so are changed to sched_setscheduler_nocheck: kernel/softirq.c:cpu_callback() - CPU hotplug callback kernel/stop_machine.c:__stop_machine_run() - Called from various places, including modprobe() Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Jeremy Fitzhardinge <jeremy@goop.org> Cc: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: linux-mm@kvack.org Cc: sugita <yumiko.sugita.yf@hitachi.com> Cc: Satoshi OSHIMA <satoshi.oshima.fk@hitachi.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-23 03:55:38 +00:00
static int __sched_setscheduler(struct task_struct *p, int policy,
sched: Make sched_param argument static in sched_setscheduler() callers Andrew Morton pointed out almost all sched_setscheduler() callers are using fixed parameters and can be converted to static. It reduces runtime memory use a little. Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Reported-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: James Morris <jmorris@namei.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-20 23:01:12 +00:00
const struct sched_param *param, bool user)
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
{
sched: revert recent removal of set_curr_task() Revert removal of set_curr_task. Use put_prev_task/set_curr_task when changing groups/policies Signed-off-by: Srivatsa Vaddagiri < vatsa@linux.vnet.ibm.com> Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
2007-10-15 15:00:08 +00:00
int retval, oldprio, oldpolicy = -1, on_rq, running;
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
unsigned long flags;
sched: Don't use possibly stale sched_class setscheduler() saves task->sched_class outside of the rq->lock held region for a check after the setscheduler changes have become effective. That might result in checking a stale value. rtmutex_setprio() has the same problem, though it is protected by p->pi_lock against setscheduler(), but for correctness sake (and to avoid bad examples) it needs to be fixed as well. Retrieve task->sched_class inside of the rq->lock held region. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: stable@kernel.org
2010-02-17 08:05:48 +00:00
const struct sched_class *prev_class;
[PATCH] sched: cleanup, convert sched.c-internal typedefs to struct convert: - runqueue_t to 'struct rq' - prio_array_t to 'struct prio_array' - migration_req_t to 'struct migration_req' I was the one who added these but they are both against the kernel coding style and also were used inconsistently at places. So just get rid of them at once, now that we are flushing the scheduler patch-queue anyway. Conversion was mostly scripted, the result was reviewed and all secondary whitespace and style impact (if any) was fixed up by hand. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-03 07:25:42 +00:00
struct rq *rq;
sched: Introduce SCHED_RESET_ON_FORK scheduling policy flag This patch introduces a new flag SCHED_RESET_ON_FORK which can be passed to the kernel via sched_setscheduler(), ORed in the policy parameter. If set this will make sure that when the process forks a) the scheduling priority is reset to DEFAULT_PRIO if it was higher and b) the scheduling policy is reset to SCHED_NORMAL if it was either SCHED_FIFO or SCHED_RR. Why have this? Currently, if a process is real-time scheduled this will 'leak' to all its child processes. For security reasons it is often (always?) a good idea to make sure that if a process acquires RT scheduling this is confined to this process and only this process. More specifically this makes the per-process resource limit RLIMIT_RTTIME useful for security purposes, because it makes it impossible to use a fork bomb to circumvent the per-process RLIMIT_RTTIME accounting. This feature is also useful for tools like 'renice' which can then change the nice level of a process without having this spill to all its child processes. Why expose this via sched_setscheduler() and not other syscalls such as prctl() or sched_setparam()? prctl() does not take a pid parameter. Due to that it would be impossible to modify this flag for other processes than the current one. The struct passed to sched_setparam() can unfortunately not be extended without breaking compatibility, since sched_setparam() lacks a size parameter. How to use this from userspace? In your RT program simply replace this: sched_setscheduler(pid, SCHED_FIFO, &param); by this: sched_setscheduler(pid, SCHED_FIFO|SCHED_RESET_ON_FORK, &param); Signed-off-by: Lennart Poettering <lennart@poettering.net> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20090615152714.GA29092@tango.0pointer.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-06-15 15:17:47 +00:00
int reset_on_fork;
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
[PATCH] BUG() if setscheduler is called from interrupt context Thomas Gleixner is adding the call to a rtmutex function in setscheduler. This call grabs a spin_lock that is not always protected by interrupts disabled. So this means that setscheduler cant be called from interrupt context. To prevent this from happening in the future, this patch adds a BUG_ON(in_interrupt()) in that function. (Thanks to akpm <aka. Andrew Morton> for this suggestion). Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 09:54:44 +00:00
/* may grab non-irq protected spin_locks */
BUG_ON(in_interrupt());
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
recheck:
/* double check policy once rq lock held */
sched: Introduce SCHED_RESET_ON_FORK scheduling policy flag This patch introduces a new flag SCHED_RESET_ON_FORK which can be passed to the kernel via sched_setscheduler(), ORed in the policy parameter. If set this will make sure that when the process forks a) the scheduling priority is reset to DEFAULT_PRIO if it was higher and b) the scheduling policy is reset to SCHED_NORMAL if it was either SCHED_FIFO or SCHED_RR. Why have this? Currently, if a process is real-time scheduled this will 'leak' to all its child processes. For security reasons it is often (always?) a good idea to make sure that if a process acquires RT scheduling this is confined to this process and only this process. More specifically this makes the per-process resource limit RLIMIT_RTTIME useful for security purposes, because it makes it impossible to use a fork bomb to circumvent the per-process RLIMIT_RTTIME accounting. This feature is also useful for tools like 'renice' which can then change the nice level of a process without having this spill to all its child processes. Why expose this via sched_setscheduler() and not other syscalls such as prctl() or sched_setparam()? prctl() does not take a pid parameter. Due to that it would be impossible to modify this flag for other processes than the current one. The struct passed to sched_setparam() can unfortunately not be extended without breaking compatibility, since sched_setparam() lacks a size parameter. How to use this from userspace? In your RT program simply replace this: sched_setscheduler(pid, SCHED_FIFO, &param); by this: sched_setscheduler(pid, SCHED_FIFO|SCHED_RESET_ON_FORK, &param); Signed-off-by: Lennart Poettering <lennart@poettering.net> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20090615152714.GA29092@tango.0pointer.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-06-15 15:17:47 +00:00
if (policy < 0) {
reset_on_fork = p->sched_reset_on_fork;
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
policy = oldpolicy = p->policy;
sched: Introduce SCHED_RESET_ON_FORK scheduling policy flag This patch introduces a new flag SCHED_RESET_ON_FORK which can be passed to the kernel via sched_setscheduler(), ORed in the policy parameter. If set this will make sure that when the process forks a) the scheduling priority is reset to DEFAULT_PRIO if it was higher and b) the scheduling policy is reset to SCHED_NORMAL if it was either SCHED_FIFO or SCHED_RR. Why have this? Currently, if a process is real-time scheduled this will 'leak' to all its child processes. For security reasons it is often (always?) a good idea to make sure that if a process acquires RT scheduling this is confined to this process and only this process. More specifically this makes the per-process resource limit RLIMIT_RTTIME useful for security purposes, because it makes it impossible to use a fork bomb to circumvent the per-process RLIMIT_RTTIME accounting. This feature is also useful for tools like 'renice' which can then change the nice level of a process without having this spill to all its child processes. Why expose this via sched_setscheduler() and not other syscalls such as prctl() or sched_setparam()? prctl() does not take a pid parameter. Due to that it would be impossible to modify this flag for other processes than the current one. The struct passed to sched_setparam() can unfortunately not be extended without breaking compatibility, since sched_setparam() lacks a size parameter. How to use this from userspace? In your RT program simply replace this: sched_setscheduler(pid, SCHED_FIFO, &param); by this: sched_setscheduler(pid, SCHED_FIFO|SCHED_RESET_ON_FORK, &param); Signed-off-by: Lennart Poettering <lennart@poettering.net> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20090615152714.GA29092@tango.0pointer.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-06-15 15:17:47 +00:00
} else {
reset_on_fork = !!(policy & SCHED_RESET_ON_FORK);
policy &= ~SCHED_RESET_ON_FORK;
if (policy != SCHED_FIFO && policy != SCHED_RR &&
policy != SCHED_NORMAL && policy != SCHED_BATCH &&
policy != SCHED_IDLE)
return -EINVAL;
}
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
/*
* Valid priorities for SCHED_FIFO and SCHED_RR are
sched: cfs core code apply the CFS core code. this change switches over the scheduler core to CFS's modular design and makes use of kernel/sched_fair/rt/idletask.c to implement Linux's scheduling policies. thanks to Andrew Morton and Thomas Gleixner for lots of detailed review feedback and for fixlets. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
2007-07-09 16:51:59 +00:00
* 1..MAX_USER_RT_PRIO-1, valid priority for SCHED_NORMAL,
* SCHED_BATCH and SCHED_IDLE is 0.
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
*/
if (param->sched_priority < 0 ||
[PATCH] sched cleanups whitespace cleanups. Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-10 07:26:11 +00:00
(p->mm && param->sched_priority > MAX_USER_RT_PRIO-1) ||
[PATCH] fix MAX_USER_RT_PRIO and MAX_RT_PRIO Here's the patch again to fix the code to handle if the values between MAX_USER_RT_PRIO and MAX_RT_PRIO are different. Without this patch, an SMP system will crash if the values are different. Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Dean Nelson <dcn@sgi.com> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-07-25 20:28:39 +00:00
(!p->mm && param->sched_priority > MAX_RT_PRIO-1))
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
return -EINVAL;
sched: clean up the rt priority macros clean up the rt priority macros, pointed out by Andrew Morton. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-09 16:51:59 +00:00
if (rt_policy(policy) != (param->sched_priority != 0))
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
return -EINVAL;
[PATCH] Changing RT priority without CAP_SYS_NICE Presently, a process without the capability CAP_SYS_NICE can not change its own policy, which is OK. But it can also not decrease its RT priority (if scheduled with policy SCHED_RR or SCHED_FIFO), which is what this patch changes. The rationale is the same as for the nice value: a process should be able to require less priority for itself. Increasing the priority is still not allowed. This is for example useful if you give a multithreaded user process a RT priority, and the process would like to organize its internal threads using priorities also. Then you can give the process the highest priority needed N, and the process starts its threads with lower priorities: N-1, N-2... The POSIX norm says that the permissions are implementation specific, so I think we can do that. In a sense, it makes the permissions consistent whatever the policy is: with this patch, process scheduled by SCHED_FIFO, SCHED_RR and SCHED_OTHER can all decrease their priority. From: Ingo Molnar <mingo@elte.hu> cleaned up and merged to -mm. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-25 21:57:32 +00:00
/*
* Allow unprivileged RT tasks to decrease priority:
*/
sched: add new API sched_setscheduler_nocheck: add a flag to control access checks Hidehiro Kawai noticed that sched_setscheduler() can fail in stop_machine: it calls sched_setscheduler() from insmod, which can have CAP_SYS_MODULE without CAP_SYS_NICE. Two cases could have failed, so are changed to sched_setscheduler_nocheck: kernel/softirq.c:cpu_callback() - CPU hotplug callback kernel/stop_machine.c:__stop_machine_run() - Called from various places, including modprobe() Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Jeremy Fitzhardinge <jeremy@goop.org> Cc: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: linux-mm@kvack.org Cc: sugita <yumiko.sugita.yf@hitachi.com> Cc: Satoshi OSHIMA <satoshi.oshima.fk@hitachi.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-23 03:55:38 +00:00
if (user && !capable(CAP_SYS_NICE)) {
sched: clean up the rt priority macros clean up the rt priority macros, pointed out by Andrew Morton. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-09 16:51:59 +00:00
if (rt_policy(policy)) {
sched: __sched_setscheduler: Read the RLIMIT_RTPRIO value lockless __sched_setscheduler() takes lock_task_sighand() to access task->signal. This is not needed since ea6d290c, ->signal can't go away. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20100610230944.GA25903@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-06-10 23:09:44 +00:00
unsigned long rlim_rtprio =
task_rlimit(p, RLIMIT_RTPRIO);
[PATCH] sched_setscheduler: fix? policy checks I am not sure this patch is correct: I can't understand what the current code does, and I don't know what it was supposed to do. The comment says: * can't change policy, except between SCHED_NORMAL * and SCHED_BATCH: The code: if (((policy != SCHED_NORMAL && p->policy != SCHED_BATCH) && (policy != SCHED_BATCH && p->policy != SCHED_NORMAL)) && But this is equivalent to: if ( (is_rt_policy(policy) && has_rt_policy(p)) && which means something different. We can't _decrease_ the current ->rt_priority with such a check (if rlim[RLIMIT_RTPRIO] == 0). Probably, it was supposed to be: if ( !(policy == SCHED_NORMAL && p->policy == SCHED_BATCH) && !(policy == SCHED_BATCH && p->policy == SCHED_NORMAL) this matches the comment, but strange: it doesn't allow to _drop_ the realtime priority when rlim[RLIMIT_RTPRIO] == 0. I think the right check would be: /* can't set/change rt policy */ if (is_rt_policy(policy) && policy != p->policy && !rlim_rtprio) return -EPERM; Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@elte.hu> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-29 09:00:50 +00:00
/* can't set/change the rt policy */
if (policy != p->policy && !rlim_rtprio)
return -EPERM;
/* can't increase priority */
if (param->sched_priority > p->rt_priority &&
param->sched_priority > rlim_rtprio)
return -EPERM;
}
sched: Allow users with sufficient RLIMIT_NICE to change from SCHED_IDLE policy The current scheduler implementation returns -EPERM when trying to change from SCHED_IDLE to SCHED_OTHER or SCHED_BATCH. Since SCHED_IDLE is considered to be a nice 20 on steroids, changing to another policy should be allowed provided the RLIMIT_NICE is accounted for. This patch allows the following test-case to pass with RLIMIT_NICE=40, but still fail with RLIMIT_NICE=10 when the calling process is run from a typical shell (nice 0, or 20 in rlimit terms). int main() { int ret; struct sched_param sp; sp.sched_priority = 0; /* switch to SCHED_IDLE */ ret = sched_setscheduler(0, SCHED_IDLE, &sp); printf("setscheduler IDLE: %d\n", ret); if (ret) return ret; /* switch back to SCHED_OTHER */ ret = sched_setscheduler(0, SCHED_OTHER, &sp); printf("setscheduler OTHER: %d\n", ret); return ret; } $ ulimit -e 40 $ ./test setscheduler IDLE: 0 setscheduler OTHER: 0 $ ulimit -e 10 $ ulimit -e 10 $ ./test setscheduler IDLE: 0 setscheduler OTHER: -1 Signed-off-by: Darren Hart <dvhart@linux.intel.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Richard Purdie <richard.purdie@linuxfoundation.org> LKML-Reference: <4D657BEE.4040608@linux.intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-02-17 23:37:07 +00:00
sched: cfs core code apply the CFS core code. this change switches over the scheduler core to CFS's modular design and makes use of kernel/sched_fair/rt/idletask.c to implement Linux's scheduling policies. thanks to Andrew Morton and Thomas Gleixner for lots of detailed review feedback and for fixlets. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
2007-07-09 16:51:59 +00:00
/*
sched: Allow users with sufficient RLIMIT_NICE to change from SCHED_IDLE policy The current scheduler implementation returns -EPERM when trying to change from SCHED_IDLE to SCHED_OTHER or SCHED_BATCH. Since SCHED_IDLE is considered to be a nice 20 on steroids, changing to another policy should be allowed provided the RLIMIT_NICE is accounted for. This patch allows the following test-case to pass with RLIMIT_NICE=40, but still fail with RLIMIT_NICE=10 when the calling process is run from a typical shell (nice 0, or 20 in rlimit terms). int main() { int ret; struct sched_param sp; sp.sched_priority = 0; /* switch to SCHED_IDLE */ ret = sched_setscheduler(0, SCHED_IDLE, &sp); printf("setscheduler IDLE: %d\n", ret); if (ret) return ret; /* switch back to SCHED_OTHER */ ret = sched_setscheduler(0, SCHED_OTHER, &sp); printf("setscheduler OTHER: %d\n", ret); return ret; } $ ulimit -e 40 $ ./test setscheduler IDLE: 0 setscheduler OTHER: 0 $ ulimit -e 10 $ ulimit -e 10 $ ./test setscheduler IDLE: 0 setscheduler OTHER: -1 Signed-off-by: Darren Hart <dvhart@linux.intel.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Richard Purdie <richard.purdie@linuxfoundation.org> LKML-Reference: <4D657BEE.4040608@linux.intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-02-17 23:37:07 +00:00
* Treat SCHED_IDLE as nice 20. Only allow a switch to
* SCHED_NORMAL if the RLIMIT_NICE would normally permit it.
sched: cfs core code apply the CFS core code. this change switches over the scheduler core to CFS's modular design and makes use of kernel/sched_fair/rt/idletask.c to implement Linux's scheduling policies. thanks to Andrew Morton and Thomas Gleixner for lots of detailed review feedback and for fixlets. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
2007-07-09 16:51:59 +00:00
*/
sched: Allow users with sufficient RLIMIT_NICE to change from SCHED_IDLE policy The current scheduler implementation returns -EPERM when trying to change from SCHED_IDLE to SCHED_OTHER or SCHED_BATCH. Since SCHED_IDLE is considered to be a nice 20 on steroids, changing to another policy should be allowed provided the RLIMIT_NICE is accounted for. This patch allows the following test-case to pass with RLIMIT_NICE=40, but still fail with RLIMIT_NICE=10 when the calling process is run from a typical shell (nice 0, or 20 in rlimit terms). int main() { int ret; struct sched_param sp; sp.sched_priority = 0; /* switch to SCHED_IDLE */ ret = sched_setscheduler(0, SCHED_IDLE, &sp); printf("setscheduler IDLE: %d\n", ret); if (ret) return ret; /* switch back to SCHED_OTHER */ ret = sched_setscheduler(0, SCHED_OTHER, &sp); printf("setscheduler OTHER: %d\n", ret); return ret; } $ ulimit -e 40 $ ./test setscheduler IDLE: 0 setscheduler OTHER: 0 $ ulimit -e 10 $ ulimit -e 10 $ ./test setscheduler IDLE: 0 setscheduler OTHER: -1 Signed-off-by: Darren Hart <dvhart@linux.intel.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Richard Purdie <richard.purdie@linuxfoundation.org> LKML-Reference: <4D657BEE.4040608@linux.intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-02-17 23:37:07 +00:00
if (p->policy == SCHED_IDLE && policy != SCHED_IDLE) {
if (!can_nice(p, TASK_NICE(p)))
return -EPERM;
}
[PATCH] do_sched_setscheduler(): don't take tasklist_lock Use rcu locks instead. sched_setscheduler() now takes ->siglock before reading ->signal->rlim[]. Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@elte.hu> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-29 09:00:48 +00:00
[PATCH] Changing RT priority without CAP_SYS_NICE Presently, a process without the capability CAP_SYS_NICE can not change its own policy, which is OK. But it can also not decrease its RT priority (if scheduled with policy SCHED_RR or SCHED_FIFO), which is what this patch changes. The rationale is the same as for the nice value: a process should be able to require less priority for itself. Increasing the priority is still not allowed. This is for example useful if you give a multithreaded user process a RT priority, and the process would like to organize its internal threads using priorities also. Then you can give the process the highest priority needed N, and the process starts its threads with lower priorities: N-1, N-2... The POSIX norm says that the permissions are implementation specific, so I think we can do that. In a sense, it makes the permissions consistent whatever the policy is: with this patch, process scheduled by SCHED_FIFO, SCHED_RR and SCHED_OTHER can all decrease their priority. From: Ingo Molnar <mingo@elte.hu> cleaned up and merged to -mm. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-25 21:57:32 +00:00
/* can't change other user's priorities */
CRED: Use RCU to access another task's creds and to release a task's own creds Use RCU to access another task's creds and to release a task's own creds. This means that it will be possible for the credentials of a task to be replaced without another task (a) requiring a full lock to read them, and (b) seeing deallocated memory. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: James Morris <jmorris@namei.org> Acked-by: Serge Hallyn <serue@us.ibm.com> Signed-off-by: James Morris <jmorris@namei.org>
2008-11-13 23:39:19 +00:00
if (!check_same_owner(p))
[PATCH] Changing RT priority without CAP_SYS_NICE Presently, a process without the capability CAP_SYS_NICE can not change its own policy, which is OK. But it can also not decrease its RT priority (if scheduled with policy SCHED_RR or SCHED_FIFO), which is what this patch changes. The rationale is the same as for the nice value: a process should be able to require less priority for itself. Increasing the priority is still not allowed. This is for example useful if you give a multithreaded user process a RT priority, and the process would like to organize its internal threads using priorities also. Then you can give the process the highest priority needed N, and the process starts its threads with lower priorities: N-1, N-2... The POSIX norm says that the permissions are implementation specific, so I think we can do that. In a sense, it makes the permissions consistent whatever the policy is: with this patch, process scheduled by SCHED_FIFO, SCHED_RR and SCHED_OTHER can all decrease their priority. From: Ingo Molnar <mingo@elte.hu> cleaned up and merged to -mm. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-25 21:57:32 +00:00
return -EPERM;
sched: Introduce SCHED_RESET_ON_FORK scheduling policy flag This patch introduces a new flag SCHED_RESET_ON_FORK which can be passed to the kernel via sched_setscheduler(), ORed in the policy parameter. If set this will make sure that when the process forks a) the scheduling priority is reset to DEFAULT_PRIO if it was higher and b) the scheduling policy is reset to SCHED_NORMAL if it was either SCHED_FIFO or SCHED_RR. Why have this? Currently, if a process is real-time scheduled this will 'leak' to all its child processes. For security reasons it is often (always?) a good idea to make sure that if a process acquires RT scheduling this is confined to this process and only this process. More specifically this makes the per-process resource limit RLIMIT_RTTIME useful for security purposes, because it makes it impossible to use a fork bomb to circumvent the per-process RLIMIT_RTTIME accounting. This feature is also useful for tools like 'renice' which can then change the nice level of a process without having this spill to all its child processes. Why expose this via sched_setscheduler() and not other syscalls such as prctl() or sched_setparam()? prctl() does not take a pid parameter. Due to that it would be impossible to modify this flag for other processes than the current one. The struct passed to sched_setparam() can unfortunately not be extended without breaking compatibility, since sched_setparam() lacks a size parameter. How to use this from userspace? In your RT program simply replace this: sched_setscheduler(pid, SCHED_FIFO, &param); by this: sched_setscheduler(pid, SCHED_FIFO|SCHED_RESET_ON_FORK, &param); Signed-off-by: Lennart Poettering <lennart@poettering.net> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20090615152714.GA29092@tango.0pointer.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-06-15 15:17:47 +00:00
/* Normal users shall not reset the sched_reset_on_fork flag */
if (p->sched_reset_on_fork && !reset_on_fork)
return -EPERM;
[PATCH] Changing RT priority without CAP_SYS_NICE Presently, a process without the capability CAP_SYS_NICE can not change its own policy, which is OK. But it can also not decrease its RT priority (if scheduled with policy SCHED_RR or SCHED_FIFO), which is what this patch changes. The rationale is the same as for the nice value: a process should be able to require less priority for itself. Increasing the priority is still not allowed. This is for example useful if you give a multithreaded user process a RT priority, and the process would like to organize its internal threads using priorities also. Then you can give the process the highest priority needed N, and the process starts its threads with lower priorities: N-1, N-2... The POSIX norm says that the permissions are implementation specific, so I think we can do that. In a sense, it makes the permissions consistent whatever the policy is: with this patch, process scheduled by SCHED_FIFO, SCHED_RR and SCHED_OTHER can all decrease their priority. From: Ingo Molnar <mingo@elte.hu> cleaned up and merged to -mm. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-25 21:57:32 +00:00
}
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
__sched_setscheduler: don't do any policy checks when not "user" The "user" parameter to __sched_setscheduler indicates whether the change is being done on behalf of a user process or not. If not, we shouldn't apply any permissions checks, so don't call security_task_setscheduler(). Signed-off-by: Jeremy Fitzhardinge <jeremy@goop.org> Tested-by: Steve Wise <swise@opengridcomputing.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-08-03 16:33:03 +00:00
if (user) {
security: remove unused parameter from security_task_setscheduler() All security modules shouldn't change sched_param parameter of security_task_setscheduler(). This is not only meaningless, but also make a harmful result if caller pass a static variable. This patch remove policy and sched_param parameter from security_task_setscheduler() becuase none of security module is using it. Cc: James Morris <jmorris@namei.org> Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: James Morris <jmorris@namei.org>
2010-10-14 19:21:18 +00:00
retval = security_task_setscheduler(p);
__sched_setscheduler: don't do any policy checks when not "user" The "user" parameter to __sched_setscheduler indicates whether the change is being done on behalf of a user process or not. If not, we shouldn't apply any permissions checks, so don't call security_task_setscheduler(). Signed-off-by: Jeremy Fitzhardinge <jeremy@goop.org> Tested-by: Steve Wise <swise@opengridcomputing.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-08-03 16:33:03 +00:00
if (retval)
return retval;
}
[PATCH] pi-futex: scheduler support for pi Add framework to boost/unboost the priority of RT tasks. This consists of: - caching the 'normal' priority in ->normal_prio - providing a functions to set/get the priority of the task - make sched_setscheduler() aware of boosting The effective_prio() cleanups also fix a priority-calculation bug pointed out by Andrey Gelman, in set_user_nice(). has_rt_policy() fix: Peter Williams <pwil3058@bigpond.net.au> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Cc: Andrey Gelman <agelman@012.net.il> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 09:54:51 +00:00
/*
* make sure no PI-waiters arrive (or leave) while we are
* changing the priority of the task:
sched: Add p->pi_lock to task_rq_lock() In order to be able to call set_task_cpu() while either holding p->pi_lock or task_rq(p)->lock we need to hold both locks in order to stabilize task_rq(). This makes task_rq_lock() acquire both locks, and have __task_rq_lock() validate that p->pi_lock is held. This increases the locking overhead for most scheduler syscalls but allows reduction of rq->lock contention for some scheduler hot paths (ttwu). Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110405152729.232781355@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-05 15:23:51 +00:00
*
Fix common misspellings Fixes generated by 'codespell' and manually reviewed. Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
2011-03-31 01:57:33 +00:00
* To be able to change p->policy safely, the appropriate
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
* runqueue lock must be held.
*/
sched: Add p->pi_lock to task_rq_lock() In order to be able to call set_task_cpu() while either holding p->pi_lock or task_rq(p)->lock we need to hold both locks in order to stabilize task_rq(). This makes task_rq_lock() acquire both locks, and have __task_rq_lock() validate that p->pi_lock is held. This increases the locking overhead for most scheduler syscalls but allows reduction of rq->lock contention for some scheduler hot paths (ttwu). Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110405152729.232781355@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-05 15:23:51 +00:00
rq = task_rq_lock(p, &flags);
sched: Fix PROVE_RCU vs cpu_cgroup PROVE_RCU has a few issues with the cpu_cgroup because the scheduler typically holds rq->lock around the css rcu derefs but the generic cgroup code doesn't (and can't) know about that lock. Provide means to add extra checks to the css dereference and use that in the scheduler to annotate its users. The addition of rq->lock to these checks is correct because the cgroup_subsys::attach() method takes the rq->lock for each task it moves, therefore by holding that lock, we ensure the task is pinned to the current cgroup and the RCU derefence is valid. That leaves one genuine race in __sched_setscheduler() where we used task_group() without holding any of the required locks and thus raced with the cgroup code. Solve this by moving the check under the appropriate lock. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-06-08 09:40:42 +00:00
sched: Create special class for stop/migrate work In order to separate the stop/migrate work thread from the SCHED_FIFO implementation, create a special class for it that is of higher priority than SCHED_FIFO itself. This currently solves a problem where cpu-hotplug consumes so much cpu-time that the SCHED_FIFO class gets throttled, but has the bandwidth replenishment timer pending on the now dead cpu. It is also required for when we add the planned deadline scheduling class above SCHED_FIFO, as the stop/migrate thread still needs to transcent those tasks. Tested-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1285165776.2275.1022.camel@laptop> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-09-22 11:53:15 +00:00
/*
* Changing the policy of the stop threads its a very bad idea
*/
if (p == rq->stop) {
sched: Add p->pi_lock to task_rq_lock() In order to be able to call set_task_cpu() while either holding p->pi_lock or task_rq(p)->lock we need to hold both locks in order to stabilize task_rq(). This makes task_rq_lock() acquire both locks, and have __task_rq_lock() validate that p->pi_lock is held. This increases the locking overhead for most scheduler syscalls but allows reduction of rq->lock contention for some scheduler hot paths (ttwu). Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110405152729.232781355@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-05 15:23:51 +00:00
task_rq_unlock(rq, p, &flags);
sched: Create special class for stop/migrate work In order to separate the stop/migrate work thread from the SCHED_FIFO implementation, create a special class for it that is of higher priority than SCHED_FIFO itself. This currently solves a problem where cpu-hotplug consumes so much cpu-time that the SCHED_FIFO class gets throttled, but has the bandwidth replenishment timer pending on the now dead cpu. It is also required for when we add the planned deadline scheduling class above SCHED_FIFO, as the stop/migrate thread still needs to transcent those tasks. Tested-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1285165776.2275.1022.camel@laptop> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-09-22 11:53:15 +00:00
return -EINVAL;
}
sched: Leave sched_setscheduler() earlier if possible, do not disturb SCHED_FIFO tasks sched_setscheduler() (in sched.c) is called in order of changing the scheduling policy and/or the real-time priority of a task. Thus, if we find out that neither of those are actually being modified, it is possible to return earlier and save the overhead of a full deactivate+activate cycle of the task in question. Beside that, if we have more than one SCHED_FIFO task with the same priority on the same rq (which means they share the same priority queue) having one of them changing its position in the priority queue because of a sched_setscheduler (as it happens by means of the deactivate+activate) that does not actually change the priority violates POSIX which states, for SCHED_FIFO: "If a thread whose policy or priority has been modified by pthread_setschedprio() is a running thread or is runnable, the effect on its position in the thread list depends on the direction of the modification, as follows: a. <...> b. If the priority is unchanged, the thread does not change position in the thread list. c. <...>" http://pubs.opengroup.org/onlinepubs/009695399/functions/xsh_chap02_08.html (ed: And the POSIX specification here does, briefly and somewhat unexpectedly, match what common sense tells us as well. ) Signed-off-by: Dario Faggioli <raistlin@linux.it> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1300971618.3960.82.camel@Palantir> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-03-24 13:00:18 +00:00
/*
* If not changing anything there's no need to proceed further:
*/
if (unlikely(policy == p->policy && (!rt_policy(policy) ||
param->sched_priority == p->rt_priority))) {
__task_rq_unlock(rq);
raw_spin_unlock_irqrestore(&p->pi_lock, flags);
return 0;
}
sched: Fix PROVE_RCU vs cpu_cgroup PROVE_RCU has a few issues with the cpu_cgroup because the scheduler typically holds rq->lock around the css rcu derefs but the generic cgroup code doesn't (and can't) know about that lock. Provide means to add extra checks to the css dereference and use that in the scheduler to annotate its users. The addition of rq->lock to these checks is correct because the cgroup_subsys::attach() method takes the rq->lock for each task it moves, therefore by holding that lock, we ensure the task is pinned to the current cgroup and the RCU derefence is valid. That leaves one genuine race in __sched_setscheduler() where we used task_group() without holding any of the required locks and thus raced with the cgroup code. Solve this by moving the check under the appropriate lock. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-06-08 09:40:42 +00:00
#ifdef CONFIG_RT_GROUP_SCHED
if (user) {
/*
* Do not allow realtime tasks into groups that have no runtime
* assigned.
*/
if (rt_bandwidth_enabled() && rt_policy(policy) &&
sched, autogroup: Fix CONFIG_RT_GROUP_SCHED sched_setscheduler() failure If CONFIG_RT_GROUP_SCHED is set, __sched_setscheduler() fails due to autogroup not allocating rt_runtime. Free unused/unusable rt_se and rt_rq, redirect RT tasks to the root task group, and tell __sched_setscheduler() that it's ok. Reported-and-tested-by: Bharata B Rao <bharata@linux.vnet.ibm.com> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1294890890.8089.39.camel@marge.simson.net> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-01-13 03:54:50 +00:00
task_group(p)->rt_bandwidth.rt_runtime == 0 &&
!task_group_is_autogroup(task_group(p))) {
sched: Add p->pi_lock to task_rq_lock() In order to be able to call set_task_cpu() while either holding p->pi_lock or task_rq(p)->lock we need to hold both locks in order to stabilize task_rq(). This makes task_rq_lock() acquire both locks, and have __task_rq_lock() validate that p->pi_lock is held. This increases the locking overhead for most scheduler syscalls but allows reduction of rq->lock contention for some scheduler hot paths (ttwu). Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110405152729.232781355@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-05 15:23:51 +00:00
task_rq_unlock(rq, p, &flags);
sched: Fix PROVE_RCU vs cpu_cgroup PROVE_RCU has a few issues with the cpu_cgroup because the scheduler typically holds rq->lock around the css rcu derefs but the generic cgroup code doesn't (and can't) know about that lock. Provide means to add extra checks to the css dereference and use that in the scheduler to annotate its users. The addition of rq->lock to these checks is correct because the cgroup_subsys::attach() method takes the rq->lock for each task it moves, therefore by holding that lock, we ensure the task is pinned to the current cgroup and the RCU derefence is valid. That leaves one genuine race in __sched_setscheduler() where we used task_group() without holding any of the required locks and thus raced with the cgroup code. Solve this by moving the check under the appropriate lock. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-06-08 09:40:42 +00:00
return -EPERM;
}
}
#endif
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
/* recheck policy now with rq lock held */
if (unlikely(oldpolicy != -1 && oldpolicy != p->policy)) {
policy = oldpolicy = -1;
sched: Add p->pi_lock to task_rq_lock() In order to be able to call set_task_cpu() while either holding p->pi_lock or task_rq(p)->lock we need to hold both locks in order to stabilize task_rq(). This makes task_rq_lock() acquire both locks, and have __task_rq_lock() validate that p->pi_lock is held. This increases the locking overhead for most scheduler syscalls but allows reduction of rq->lock contention for some scheduler hot paths (ttwu). Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110405152729.232781355@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-05 15:23:51 +00:00
task_rq_unlock(rq, p, &flags);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
goto recheck;
}
sched: Provide p->on_rq Provide a generic p->on_rq because the p->se.on_rq semantics are unfavourable for lockless wakeups but needed for sched_fair. In particular, p->on_rq is only cleared when we actually dequeue the task in schedule() and not on any random dequeue as done by things like __migrate_task() and __sched_setscheduler(). This also allows us to remove p->se usage from !sched_fair code. Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110405152728.949545047@chello.nl
2011-04-05 15:23:44 +00:00
on_rq = p->on_rq;
sched: fix crash on ia64, introduce task_current() Some services (e.g. sched_setscheduler(), rt_mutex_setprio() and sched_move_task()) must handle a given task differently in case it's the 'rq->curr' task on its run-queue. The task_running() interface is not suitable for determining such tasks for platforms with one of the following options: #define __ARCH_WANT_UNLOCKED_CTXSW #define __ARCH_WANT_INTERRUPTS_ON_CTXSW Due to the fact that it makes use of 'p->oncpu == 1' as a criterion but such a task is not necessarily 'rq->curr'. The detailed explanation is available here: https://lists.linux-foundation.org/pipermail/containers/2007-December/009262.html Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Tested-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Tested-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
2007-12-18 14:21:13 +00:00
running = task_current(rq, p);
sched: fix race in schedule() Fix a hard to trigger crash seen in the -rt kernel that also affects the vanilla scheduler. There is a race condition between schedule() and some dequeue/enqueue functions; rt_mutex_setprio(), __setscheduler() and sched_move_task(). When scheduling to idle, idle_balance() is called to pull tasks from other busy processor. It might drop the rq lock. It means that those 3 functions encounter on_rq=0 and running=1. The current task should be put when running. Here is a possible scenario: CPU0 CPU1 | schedule() | ->deactivate_task() | ->idle_balance() | -->load_balance_newidle() rt_mutex_setprio() | | --->double_lock_balance() *get lock *rel lock * on_rq=0, ruuning=1 | * sched_class is changed | *rel lock *get lock : | : ->put_prev_task_rt() ->pick_next_task_fair() => panic The current process of CPU1(P1) is scheduling. Deactivated P1, and the scheduler looks for another process on other CPU's runqueue because CPU1 will be idle. idle_balance(), load_balance_newidle() and double_lock_balance() are called and double_lock_balance() could drop the rq lock. On the other hand, CPU0 is trying to boost the priority of P1. The result of boosting only P1's prio and sched_class are changed to RT. The sched entities of P1 and P1's group are never put. It makes cfs_rq invalid, because the cfs_rq has curr and no leaf, but pick_next_task_fair() is called, then the kernel panics. Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-03-10 18:01:20 +00:00
if (on_rq)
sched: remove the 'u64 now' parameter from deactivate_task() remove the 'u64 now' parameter from deactivate_task(). ( identity transformation that causes no change in functionality. ) Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-08-09 09:16:49 +00:00
deactivate_task(rq, p, 0);
sched: fix race in schedule() Fix a hard to trigger crash seen in the -rt kernel that also affects the vanilla scheduler. There is a race condition between schedule() and some dequeue/enqueue functions; rt_mutex_setprio(), __setscheduler() and sched_move_task(). When scheduling to idle, idle_balance() is called to pull tasks from other busy processor. It might drop the rq lock. It means that those 3 functions encounter on_rq=0 and running=1. The current task should be put when running. Here is a possible scenario: CPU0 CPU1 | schedule() | ->deactivate_task() | ->idle_balance() | -->load_balance_newidle() rt_mutex_setprio() | | --->double_lock_balance() *get lock *rel lock * on_rq=0, ruuning=1 | * sched_class is changed | *rel lock *get lock : | : ->put_prev_task_rt() ->pick_next_task_fair() => panic The current process of CPU1(P1) is scheduling. Deactivated P1, and the scheduler looks for another process on other CPU's runqueue because CPU1 will be idle. idle_balance(), load_balance_newidle() and double_lock_balance() are called and double_lock_balance() could drop the rq lock. On the other hand, CPU0 is trying to boost the priority of P1. The result of boosting only P1's prio and sched_class are changed to RT. The sched entities of P1 and P1's group are never put. It makes cfs_rq invalid, because the cfs_rq has curr and no leaf, but pick_next_task_fair() is called, then the kernel panics. Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-03-10 18:01:20 +00:00
if (running)
p->sched_class->put_prev_task(rq, p);
sched: rework enqueue/dequeue_entity() to get rid of set_curr_task() rework enqueue/dequeue_entity() to get rid of sched_class::set_curr_task(). This simplifies sched_setscheduler(), rt_mutex_setprio() and sched_move_tasks(). text data bss dec hex filename 24330 2734 20 27084 69cc sched.o.before 24233 2730 20 26983 6967 sched.o.after Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-15 15:00:08 +00:00
sched: Introduce SCHED_RESET_ON_FORK scheduling policy flag This patch introduces a new flag SCHED_RESET_ON_FORK which can be passed to the kernel via sched_setscheduler(), ORed in the policy parameter. If set this will make sure that when the process forks a) the scheduling priority is reset to DEFAULT_PRIO if it was higher and b) the scheduling policy is reset to SCHED_NORMAL if it was either SCHED_FIFO or SCHED_RR. Why have this? Currently, if a process is real-time scheduled this will 'leak' to all its child processes. For security reasons it is often (always?) a good idea to make sure that if a process acquires RT scheduling this is confined to this process and only this process. More specifically this makes the per-process resource limit RLIMIT_RTTIME useful for security purposes, because it makes it impossible to use a fork bomb to circumvent the per-process RLIMIT_RTTIME accounting. This feature is also useful for tools like 'renice' which can then change the nice level of a process without having this spill to all its child processes. Why expose this via sched_setscheduler() and not other syscalls such as prctl() or sched_setparam()? prctl() does not take a pid parameter. Due to that it would be impossible to modify this flag for other processes than the current one. The struct passed to sched_setparam() can unfortunately not be extended without breaking compatibility, since sched_setparam() lacks a size parameter. How to use this from userspace? In your RT program simply replace this: sched_setscheduler(pid, SCHED_FIFO, &param); by this: sched_setscheduler(pid, SCHED_FIFO|SCHED_RESET_ON_FORK, &param); Signed-off-by: Lennart Poettering <lennart@poettering.net> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20090615152714.GA29092@tango.0pointer.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-06-15 15:17:47 +00:00
p->sched_reset_on_fork = reset_on_fork;
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
oldprio = p->prio;
sched: Don't use possibly stale sched_class setscheduler() saves task->sched_class outside of the rq->lock held region for a check after the setscheduler changes have become effective. That might result in checking a stale value. rtmutex_setprio() has the same problem, though it is protected by p->pi_lock against setscheduler(), but for correctness sake (and to avoid bad examples) it needs to be fixed as well. Retrieve task->sched_class inside of the rq->lock held region. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: stable@kernel.org
2010-02-17 08:05:48 +00:00
prev_class = p->sched_class;
sched: cfs core code apply the CFS core code. this change switches over the scheduler core to CFS's modular design and makes use of kernel/sched_fair/rt/idletask.c to implement Linux's scheduling policies. thanks to Andrew Morton and Thomas Gleixner for lots of detailed review feedback and for fixlets. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
2007-07-09 16:51:59 +00:00
__setscheduler(rq, p, policy, param->sched_priority);
sched: rework enqueue/dequeue_entity() to get rid of set_curr_task() rework enqueue/dequeue_entity() to get rid of sched_class::set_curr_task(). This simplifies sched_setscheduler(), rt_mutex_setprio() and sched_move_tasks(). text data bss dec hex filename 24330 2734 20 27084 69cc sched.o.before 24233 2730 20 26983 6967 sched.o.after Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-15 15:00:08 +00:00
sched: fix race in schedule() Fix a hard to trigger crash seen in the -rt kernel that also affects the vanilla scheduler. There is a race condition between schedule() and some dequeue/enqueue functions; rt_mutex_setprio(), __setscheduler() and sched_move_task(). When scheduling to idle, idle_balance() is called to pull tasks from other busy processor. It might drop the rq lock. It means that those 3 functions encounter on_rq=0 and running=1. The current task should be put when running. Here is a possible scenario: CPU0 CPU1 | schedule() | ->deactivate_task() | ->idle_balance() | -->load_balance_newidle() rt_mutex_setprio() | | --->double_lock_balance() *get lock *rel lock * on_rq=0, ruuning=1 | * sched_class is changed | *rel lock *get lock : | : ->put_prev_task_rt() ->pick_next_task_fair() => panic The current process of CPU1(P1) is scheduling. Deactivated P1, and the scheduler looks for another process on other CPU's runqueue because CPU1 will be idle. idle_balance(), load_balance_newidle() and double_lock_balance() are called and double_lock_balance() could drop the rq lock. On the other hand, CPU0 is trying to boost the priority of P1. The result of boosting only P1's prio and sched_class are changed to RT. The sched entities of P1 and P1's group are never put. It makes cfs_rq invalid, because the cfs_rq has curr and no leaf, but pick_next_task_fair() is called, then the kernel panics. Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-03-10 18:01:20 +00:00
if (running)
p->sched_class->set_curr_task(rq);
sched: Fix switch_from_fair() When a task is taken out of the fair class we must ensure the vruntime is properly normalized because when we put it back in it will assume to be normalized. The case that goes wrong is when changing away from the fair class while sleeping. Sleeping tasks have non-normalized vruntime in order to make sleeper-fairness work. So treat the switch away from fair as a wakeup and preserve the relative vruntime. Also update sysrq-n to call the ->switch_{to,from} methods. Reported-by: Onkalo Samu <samu.p.onkalo@nokia.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-01-17 16:03:27 +00:00
if (on_rq)
sched: cfs core code apply the CFS core code. this change switches over the scheduler core to CFS's modular design and makes use of kernel/sched_fair/rt/idletask.c to implement Linux's scheduling policies. thanks to Andrew Morton and Thomas Gleixner for lots of detailed review feedback and for fixlets. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
2007-07-09 16:51:59 +00:00
activate_task(rq, p, 0);
sched: RT-balance, add new methods to sched_class Dmitry Adamushko found that the current implementation of the RT balancing code left out changes to the sched_setscheduler and rt_mutex_setprio. This patch addresses this issue by adding methods to the schedule classes to handle being switched out of (switched_from) and being switched into (switched_to) a sched_class. Also a method for changing of priorities is also added (prio_changed). This patch also removes some duplicate logic between rt_mutex_setprio and sched_setscheduler. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:22 +00:00
sched: Fix switch_from_fair() When a task is taken out of the fair class we must ensure the vruntime is properly normalized because when we put it back in it will assume to be normalized. The case that goes wrong is when changing away from the fair class while sleeping. Sleeping tasks have non-normalized vruntime in order to make sleeper-fairness work. So treat the switch away from fair as a wakeup and preserve the relative vruntime. Also update sysrq-n to call the ->switch_{to,from} methods. Reported-by: Onkalo Samu <samu.p.onkalo@nokia.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-01-17 16:03:27 +00:00
check_class_changed(rq, p, prev_class, oldprio);
sched: Add p->pi_lock to task_rq_lock() In order to be able to call set_task_cpu() while either holding p->pi_lock or task_rq(p)->lock we need to hold both locks in order to stabilize task_rq(). This makes task_rq_lock() acquire both locks, and have __task_rq_lock() validate that p->pi_lock is held. This increases the locking overhead for most scheduler syscalls but allows reduction of rq->lock contention for some scheduler hot paths (ttwu). Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110405152729.232781355@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-05 15:23:51 +00:00
task_rq_unlock(rq, p, &flags);
[PATCH] pi-futex: scheduler support for pi Add framework to boost/unboost the priority of RT tasks. This consists of: - caching the 'normal' priority in ->normal_prio - providing a functions to set/get the priority of the task - make sched_setscheduler() aware of boosting The effective_prio() cleanups also fix a priority-calculation bug pointed out by Andrey Gelman, in set_user_nice(). has_rt_policy() fix: Peter Williams <pwil3058@bigpond.net.au> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Cc: Andrey Gelman <agelman@012.net.il> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 09:54:51 +00:00
[PATCH] rtmutex: Propagate priority settings into PI lock chains When the priority of a task, which is blocked on a lock, changes we must propagate this change into the PI lock chain. Therefor the chain walk code is changed to get rid of the references to current to avoid false positives in the deadlock detector, as setscheduler might be called by a task which holds the lock on which the task whose priority is changed is blocked. Also add some comments about the get/put_task_struct usage to avoid confusion. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 09:55:02 +00:00
rt_mutex_adjust_pi(p);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
return 0;
}
sched: add new API sched_setscheduler_nocheck: add a flag to control access checks Hidehiro Kawai noticed that sched_setscheduler() can fail in stop_machine: it calls sched_setscheduler() from insmod, which can have CAP_SYS_MODULE without CAP_SYS_NICE. Two cases could have failed, so are changed to sched_setscheduler_nocheck: kernel/softirq.c:cpu_callback() - CPU hotplug callback kernel/stop_machine.c:__stop_machine_run() - Called from various places, including modprobe() Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Jeremy Fitzhardinge <jeremy@goop.org> Cc: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: linux-mm@kvack.org Cc: sugita <yumiko.sugita.yf@hitachi.com> Cc: Satoshi OSHIMA <satoshi.oshima.fk@hitachi.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-23 03:55:38 +00:00
/**
* sched_setscheduler - change the scheduling policy and/or RT priority of a thread.
* @p: the task in question.
* @policy: new policy.
* @param: structure containing the new RT priority.
*
* NOTE that the task may be already dead.
*/
int sched_setscheduler(struct task_struct *p, int policy,
sched: Make sched_param argument static in sched_setscheduler() callers Andrew Morton pointed out almost all sched_setscheduler() callers are using fixed parameters and can be converted to static. It reduces runtime memory use a little. Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Reported-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: James Morris <jmorris@namei.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-20 23:01:12 +00:00
const struct sched_param *param)
sched: add new API sched_setscheduler_nocheck: add a flag to control access checks Hidehiro Kawai noticed that sched_setscheduler() can fail in stop_machine: it calls sched_setscheduler() from insmod, which can have CAP_SYS_MODULE without CAP_SYS_NICE. Two cases could have failed, so are changed to sched_setscheduler_nocheck: kernel/softirq.c:cpu_callback() - CPU hotplug callback kernel/stop_machine.c:__stop_machine_run() - Called from various places, including modprobe() Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Jeremy Fitzhardinge <jeremy@goop.org> Cc: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: linux-mm@kvack.org Cc: sugita <yumiko.sugita.yf@hitachi.com> Cc: Satoshi OSHIMA <satoshi.oshima.fk@hitachi.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-23 03:55:38 +00:00
{
return __sched_setscheduler(p, policy, param, true);
}
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
EXPORT_SYMBOL_GPL(sched_setscheduler);
sched: add new API sched_setscheduler_nocheck: add a flag to control access checks Hidehiro Kawai noticed that sched_setscheduler() can fail in stop_machine: it calls sched_setscheduler() from insmod, which can have CAP_SYS_MODULE without CAP_SYS_NICE. Two cases could have failed, so are changed to sched_setscheduler_nocheck: kernel/softirq.c:cpu_callback() - CPU hotplug callback kernel/stop_machine.c:__stop_machine_run() - Called from various places, including modprobe() Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Jeremy Fitzhardinge <jeremy@goop.org> Cc: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: linux-mm@kvack.org Cc: sugita <yumiko.sugita.yf@hitachi.com> Cc: Satoshi OSHIMA <satoshi.oshima.fk@hitachi.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-23 03:55:38 +00:00
/**
* sched_setscheduler_nocheck - change the scheduling policy and/or RT priority of a thread from kernelspace.
* @p: the task in question.
* @policy: new policy.
* @param: structure containing the new RT priority.
*
* Just like sched_setscheduler, only don't bother checking if the
* current context has permission. For example, this is needed in
* stop_machine(): we create temporary high priority worker threads,
* but our caller might not have that capability.
*/
int sched_setscheduler_nocheck(struct task_struct *p, int policy,
sched: Make sched_param argument static in sched_setscheduler() callers Andrew Morton pointed out almost all sched_setscheduler() callers are using fixed parameters and can be converted to static. It reduces runtime memory use a little. Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Reported-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: James Morris <jmorris@namei.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-20 23:01:12 +00:00
const struct sched_param *param)
sched: add new API sched_setscheduler_nocheck: add a flag to control access checks Hidehiro Kawai noticed that sched_setscheduler() can fail in stop_machine: it calls sched_setscheduler() from insmod, which can have CAP_SYS_MODULE without CAP_SYS_NICE. Two cases could have failed, so are changed to sched_setscheduler_nocheck: kernel/softirq.c:cpu_callback() - CPU hotplug callback kernel/stop_machine.c:__stop_machine_run() - Called from various places, including modprobe() Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Jeremy Fitzhardinge <jeremy@goop.org> Cc: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: linux-mm@kvack.org Cc: sugita <yumiko.sugita.yf@hitachi.com> Cc: Satoshi OSHIMA <satoshi.oshima.fk@hitachi.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-23 03:55:38 +00:00
{
return __sched_setscheduler(p, policy, param, false);
}
[PATCH] sched cleanups whitespace cleanups. Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-10 07:26:11 +00:00
static int
do_sched_setscheduler(pid_t pid, int policy, struct sched_param __user *param)
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
{
struct sched_param lparam;
struct task_struct *p;
[PATCH] sched: cleanup, remove task_t, convert to struct task_struct cleanup: remove task_t and convert all the uses to struct task_struct. I introduced it for the scheduler anno and it was a mistake. Conversion was mostly scripted, the result was reviewed and all secondary whitespace and style impact (if any) was fixed up by hand. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-03 07:25:41 +00:00
int retval;
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
if (!param || pid < 0)
return -EINVAL;
if (copy_from_user(&lparam, param, sizeof(struct sched_param)))
return -EFAULT;
[PATCH] do_sched_setscheduler(): don't take tasklist_lock Use rcu locks instead. sched_setscheduler() now takes ->siglock before reading ->signal->rlim[]. Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@elte.hu> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-29 09:00:48 +00:00
rcu_read_lock();
retval = -ESRCH;
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
p = find_process_by_pid(pid);
[PATCH] do_sched_setscheduler(): don't take tasklist_lock Use rcu locks instead. sched_setscheduler() now takes ->siglock before reading ->signal->rlim[]. Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@elte.hu> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-29 09:00:48 +00:00
if (p != NULL)
retval = sched_setscheduler(p, policy, &lparam);
rcu_read_unlock();
[PATCH] sched: cleanup, remove task_t, convert to struct task_struct cleanup: remove task_t and convert all the uses to struct task_struct. I introduced it for the scheduler anno and it was a mistake. Conversion was mostly scripted, the result was reviewed and all secondary whitespace and style impact (if any) was fixed up by hand. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-03 07:25:41 +00:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
return retval;
}
/**
* sys_sched_setscheduler - set/change the scheduler policy and RT priority
* @pid: the pid in question.
* @policy: new policy.
* @param: structure containing the new RT priority.
*/
[CVE-2009-0029] System call wrappers part 06 Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2009-01-14 13:14:08 +00:00
SYSCALL_DEFINE3(sched_setscheduler, pid_t, pid, int, policy,
struct sched_param __user *, param)
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
{
[PATCH] fix sched_setscheduler semantics Currently, a negative policy argument passed into the 'sys_sched_setscheduler()' system call, will return with success. However, the manpage for 'sys_sched_setscheduler' says: EINVAL The scheduling policy is not one of the recognized policies, or the parameter p does not make sense for the policy. Signed-off-by: Jason Baron <jbaron@redhat.com> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-19 01:43:03 +00:00
/* negative values for policy are not valid */
if (policy < 0)
return -EINVAL;
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
return do_sched_setscheduler(pid, policy, param);
}
/**
* sys_sched_setparam - set/change the RT priority of a thread
* @pid: the pid in question.
* @param: structure containing the new RT priority.
*/
[CVE-2009-0029] System call wrappers part 06 Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2009-01-14 13:14:08 +00:00
SYSCALL_DEFINE2(sched_setparam, pid_t, pid, struct sched_param __user *, param)
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
{
return do_sched_setscheduler(pid, -1, param);
}
/**
* sys_sched_getscheduler - get the policy (scheduling class) of a thread
* @pid: the pid in question.
*/
[CVE-2009-0029] System call wrappers part 06 Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2009-01-14 13:14:08 +00:00
SYSCALL_DEFINE1(sched_getscheduler, pid_t, pid)
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
{
[PATCH] sched: cleanup, remove task_t, convert to struct task_struct cleanup: remove task_t and convert all the uses to struct task_struct. I introduced it for the scheduler anno and it was a mistake. Conversion was mostly scripted, the result was reviewed and all secondary whitespace and style impact (if any) was fixed up by hand. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-03 07:25:41 +00:00
struct task_struct *p;
sched: cleanup: remove unnecessary gotos Replace loops implemented with gotos with real loops. Replace err = ...; goto x; x: return err; with return ...; No functional changes. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 15:00:14 +00:00
int retval;
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
if (pid < 0)
sched: cleanup: remove unnecessary gotos Replace loops implemented with gotos with real loops. Replace err = ...; goto x; x: return err; with return ...; No functional changes. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 15:00:14 +00:00
return -EINVAL;
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
retval = -ESRCH;
sched: Use rcu in sys_sched_getscheduler/sys_sched_getparam() read_lock(&tasklist_lock) does not protect sys_sched_getscheduler and sys_sched_getparam() against a concurrent update of the policy or scheduler parameters as do_sched_setscheduler() does not take the tasklist_lock. The accessed integers can be retrieved w/o locking and are snapshots anyway. Using rcu_read_lock() to protect find_task_by_vpid() and prevent the task struct from going away is not changing the above situation. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <20091209100706.753790977@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-09 10:14:58 +00:00
rcu_read_lock();
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
p = find_process_by_pid(pid);
if (p) {
retval = security_task_getscheduler(p);
if (!retval)
sched: Introduce SCHED_RESET_ON_FORK scheduling policy flag This patch introduces a new flag SCHED_RESET_ON_FORK which can be passed to the kernel via sched_setscheduler(), ORed in the policy parameter. If set this will make sure that when the process forks a) the scheduling priority is reset to DEFAULT_PRIO if it was higher and b) the scheduling policy is reset to SCHED_NORMAL if it was either SCHED_FIFO or SCHED_RR. Why have this? Currently, if a process is real-time scheduled this will 'leak' to all its child processes. For security reasons it is often (always?) a good idea to make sure that if a process acquires RT scheduling this is confined to this process and only this process. More specifically this makes the per-process resource limit RLIMIT_RTTIME useful for security purposes, because it makes it impossible to use a fork bomb to circumvent the per-process RLIMIT_RTTIME accounting. This feature is also useful for tools like 'renice' which can then change the nice level of a process without having this spill to all its child processes. Why expose this via sched_setscheduler() and not other syscalls such as prctl() or sched_setparam()? prctl() does not take a pid parameter. Due to that it would be impossible to modify this flag for other processes than the current one. The struct passed to sched_setparam() can unfortunately not be extended without breaking compatibility, since sched_setparam() lacks a size parameter. How to use this from userspace? In your RT program simply replace this: sched_setscheduler(pid, SCHED_FIFO, &param); by this: sched_setscheduler(pid, SCHED_FIFO|SCHED_RESET_ON_FORK, &param); Signed-off-by: Lennart Poettering <lennart@poettering.net> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20090615152714.GA29092@tango.0pointer.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-06-15 15:17:47 +00:00
retval = p->policy
| (p->sched_reset_on_fork ? SCHED_RESET_ON_FORK : 0);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
}
sched: Use rcu in sys_sched_getscheduler/sys_sched_getparam() read_lock(&tasklist_lock) does not protect sys_sched_getscheduler and sys_sched_getparam() against a concurrent update of the policy or scheduler parameters as do_sched_setscheduler() does not take the tasklist_lock. The accessed integers can be retrieved w/o locking and are snapshots anyway. Using rcu_read_lock() to protect find_task_by_vpid() and prevent the task struct from going away is not changing the above situation. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <20091209100706.753790977@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-09 10:14:58 +00:00
rcu_read_unlock();
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
return retval;
}
/**
sched: Introduce SCHED_RESET_ON_FORK scheduling policy flag This patch introduces a new flag SCHED_RESET_ON_FORK which can be passed to the kernel via sched_setscheduler(), ORed in the policy parameter. If set this will make sure that when the process forks a) the scheduling priority is reset to DEFAULT_PRIO if it was higher and b) the scheduling policy is reset to SCHED_NORMAL if it was either SCHED_FIFO or SCHED_RR. Why have this? Currently, if a process is real-time scheduled this will 'leak' to all its child processes. For security reasons it is often (always?) a good idea to make sure that if a process acquires RT scheduling this is confined to this process and only this process. More specifically this makes the per-process resource limit RLIMIT_RTTIME useful for security purposes, because it makes it impossible to use a fork bomb to circumvent the per-process RLIMIT_RTTIME accounting. This feature is also useful for tools like 'renice' which can then change the nice level of a process without having this spill to all its child processes. Why expose this via sched_setscheduler() and not other syscalls such as prctl() or sched_setparam()? prctl() does not take a pid parameter. Due to that it would be impossible to modify this flag for other processes than the current one. The struct passed to sched_setparam() can unfortunately not be extended without breaking compatibility, since sched_setparam() lacks a size parameter. How to use this from userspace? In your RT program simply replace this: sched_setscheduler(pid, SCHED_FIFO, &param); by this: sched_setscheduler(pid, SCHED_FIFO|SCHED_RESET_ON_FORK, &param); Signed-off-by: Lennart Poettering <lennart@poettering.net> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20090615152714.GA29092@tango.0pointer.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-06-15 15:17:47 +00:00
* sys_sched_getparam - get the RT priority of a thread
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
* @pid: the pid in question.
* @param: structure containing the RT priority.
*/
[CVE-2009-0029] System call wrappers part 06 Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2009-01-14 13:14:08 +00:00
SYSCALL_DEFINE2(sched_getparam, pid_t, pid, struct sched_param __user *, param)
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
{
struct sched_param lp;
[PATCH] sched: cleanup, remove task_t, convert to struct task_struct cleanup: remove task_t and convert all the uses to struct task_struct. I introduced it for the scheduler anno and it was a mistake. Conversion was mostly scripted, the result was reviewed and all secondary whitespace and style impact (if any) was fixed up by hand. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-03 07:25:41 +00:00
struct task_struct *p;
sched: cleanup: remove unnecessary gotos Replace loops implemented with gotos with real loops. Replace err = ...; goto x; x: return err; with return ...; No functional changes. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 15:00:14 +00:00
int retval;
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
if (!param || pid < 0)
sched: cleanup: remove unnecessary gotos Replace loops implemented with gotos with real loops. Replace err = ...; goto x; x: return err; with return ...; No functional changes. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 15:00:14 +00:00
return -EINVAL;
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
sched: Use rcu in sys_sched_getscheduler/sys_sched_getparam() read_lock(&tasklist_lock) does not protect sys_sched_getscheduler and sys_sched_getparam() against a concurrent update of the policy or scheduler parameters as do_sched_setscheduler() does not take the tasklist_lock. The accessed integers can be retrieved w/o locking and are snapshots anyway. Using rcu_read_lock() to protect find_task_by_vpid() and prevent the task struct from going away is not changing the above situation. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <20091209100706.753790977@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-09 10:14:58 +00:00
rcu_read_lock();
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
p = find_process_by_pid(pid);
retval = -ESRCH;
if (!p)
goto out_unlock;
retval = security_task_getscheduler(p);
if (retval)
goto out_unlock;
lp.sched_priority = p->rt_priority;
sched: Use rcu in sys_sched_getscheduler/sys_sched_getparam() read_lock(&tasklist_lock) does not protect sys_sched_getscheduler and sys_sched_getparam() against a concurrent update of the policy or scheduler parameters as do_sched_setscheduler() does not take the tasklist_lock. The accessed integers can be retrieved w/o locking and are snapshots anyway. Using rcu_read_lock() to protect find_task_by_vpid() and prevent the task struct from going away is not changing the above situation. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <20091209100706.753790977@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-09 10:14:58 +00:00
rcu_read_unlock();
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
/*
* This one might sleep, we cannot do it with a spinlock held ...
*/
retval = copy_to_user(param, &lp, sizeof(*param)) ? -EFAULT : 0;
return retval;
out_unlock:
sched: Use rcu in sys_sched_getscheduler/sys_sched_getparam() read_lock(&tasklist_lock) does not protect sys_sched_getscheduler and sys_sched_getparam() against a concurrent update of the policy or scheduler parameters as do_sched_setscheduler() does not take the tasklist_lock. The accessed integers can be retrieved w/o locking and are snapshots anyway. Using rcu_read_lock() to protect find_task_by_vpid() and prevent the task struct from going away is not changing the above situation. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <20091209100706.753790977@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-09 10:14:58 +00:00
rcu_read_unlock();
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
return retval;
}
sched: convert remaining old-style cpumask operators Impact: Trivial API conversion NR_CPUS -> nr_cpu_ids cpumask_t -> struct cpumask sizeof(cpumask_t) -> cpumask_size() cpumask_a = cpumask_b -> cpumask_copy(&cpumask_a, &cpumask_b) cpu_set() -> cpumask_set_cpu() first_cpu() -> cpumask_first() cpumask_of_cpu() -> cpumask_of() cpus_* -> cpumask_* There are some FIXMEs where we all archs to complete infrastructure (patches have been sent): cpu_coregroup_map -> cpu_coregroup_mask node_to_cpumask* -> cpumask_of_node There is also one FIXME where we pass an array of cpumasks to partition_sched_domains(): this implies knowing the definition of 'struct cpumask' and the size of a cpumask. This will be fixed in a future patch. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-24 16:05:14 +00:00
long sched_setaffinity(pid_t pid, const struct cpumask *in_mask)
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
{
sched: convert struct (sys_)sched_setaffinity() to cpumask_var_t. Impact: stack usage reduction Dynamically allocating cpumasks (when CONFIG_CPUMASK_OFFSTACK) saves space on the stack. cpumask_var_t is just a struct cpumask for !CONFIG_CPUMASK_OFFSTACK. Note the removal of the initializer of new_mask: since the first thing we did was "cpus_and(new_mask, new_mask, cpus_allowed)" I just changed that to "cpumask_and(new_mask, in_mask, cpus_allowed);". Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-24 16:05:11 +00:00
cpumask_var_t cpus_allowed, new_mask;
[PATCH] sched: cleanup, remove task_t, convert to struct task_struct cleanup: remove task_t and convert all the uses to struct task_struct. I introduced it for the scheduler anno and it was a mistake. Conversion was mostly scripted, the result was reviewed and all secondary whitespace and style impact (if any) was fixed up by hand. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-03 07:25:41 +00:00
struct task_struct *p;
int retval;
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
cpu-hotplug: replace per-subsystem mutexes with get_online_cpus() This patch converts the known per-subsystem mutexes to get_online_cpus put_online_cpus. It also eliminates the CPU_LOCK_ACQUIRE and CPU_LOCK_RELEASE hotplug notification events. Signed-off-by: Gautham R Shenoy <ego@in.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:02 +00:00
get_online_cpus();
sched: Use rcu in sched_get/set_affinity() tasklist_lock is held read locked to protect the find_task_by_vpid() call and to prevent the task going away. sched_setaffinity acquires a task struct ref and drops tasklist lock right away. The access to the cpus_allowed mask is protected by rq->lock. rcu_read_lock() provides the same protection here. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <20091209100706.789059966@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-09 10:15:01 +00:00
rcu_read_lock();
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
p = find_process_by_pid(pid);
if (!p) {
sched: Use rcu in sched_get/set_affinity() tasklist_lock is held read locked to protect the find_task_by_vpid() call and to prevent the task going away. sched_setaffinity acquires a task struct ref and drops tasklist lock right away. The access to the cpus_allowed mask is protected by rq->lock. rcu_read_lock() provides the same protection here. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <20091209100706.789059966@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-09 10:15:01 +00:00
rcu_read_unlock();
cpu-hotplug: replace per-subsystem mutexes with get_online_cpus() This patch converts the known per-subsystem mutexes to get_online_cpus put_online_cpus. It also eliminates the CPU_LOCK_ACQUIRE and CPU_LOCK_RELEASE hotplug notification events. Signed-off-by: Gautham R Shenoy <ego@in.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:02 +00:00
put_online_cpus();
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
return -ESRCH;
}
sched: Use rcu in sched_get/set_affinity() tasklist_lock is held read locked to protect the find_task_by_vpid() call and to prevent the task going away. sched_setaffinity acquires a task struct ref and drops tasklist lock right away. The access to the cpus_allowed mask is protected by rq->lock. rcu_read_lock() provides the same protection here. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <20091209100706.789059966@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-09 10:15:01 +00:00
/* Prevent p going away */
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
get_task_struct(p);
sched: Use rcu in sched_get/set_affinity() tasklist_lock is held read locked to protect the find_task_by_vpid() call and to prevent the task going away. sched_setaffinity acquires a task struct ref and drops tasklist lock right away. The access to the cpus_allowed mask is protected by rq->lock. rcu_read_lock() provides the same protection here. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <20091209100706.789059966@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-09 10:15:01 +00:00
rcu_read_unlock();
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
sched: convert struct (sys_)sched_setaffinity() to cpumask_var_t. Impact: stack usage reduction Dynamically allocating cpumasks (when CONFIG_CPUMASK_OFFSTACK) saves space on the stack. cpumask_var_t is just a struct cpumask for !CONFIG_CPUMASK_OFFSTACK. Note the removal of the initializer of new_mask: since the first thing we did was "cpus_and(new_mask, new_mask, cpus_allowed)" I just changed that to "cpumask_and(new_mask, in_mask, cpus_allowed);". Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-24 16:05:11 +00:00
if (!alloc_cpumask_var(&cpus_allowed, GFP_KERNEL)) {
retval = -ENOMEM;
goto out_put_task;
}
if (!alloc_cpumask_var(&new_mask, GFP_KERNEL)) {
retval = -ENOMEM;
goto out_free_cpus_allowed;
}
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
retval = -EPERM;
userns: user namespaces: convert several capable() calls CAP_IPC_OWNER and CAP_IPC_LOCK can be checked against current_user_ns(), because the resource comes from current's own ipc namespace. setuid/setgid are to uids in own namespace, so again checks can be against current_user_ns(). Changelog: Jan 11: Use task_ns_capable() in place of sched_capable(). Jan 11: Use nsown_capable() as suggested by Bastian Blank. Jan 11: Clarify (hopefully) some logic in futex and sched.c Feb 15: use ns_capable for ipc, not nsown_capable Feb 23: let copy_ipcs handle setting ipc_ns->user_ns Feb 23: pass ns down rather than taking it from current [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Serge E. Hallyn <serge.hallyn@canonical.com> Acked-by: "Eric W. Biederman" <ebiederm@xmission.com> Acked-by: Daniel Lezcano <daniel.lezcano@free.fr> Acked-by: David Howells <dhowells@redhat.com> Cc: James Morris <jmorris@namei.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-23 23:43:24 +00:00
if (!check_same_owner(p) && !task_ns_capable(p, CAP_SYS_NICE))
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
goto out_unlock;
security: remove unused parameter from security_task_setscheduler() All security modules shouldn't change sched_param parameter of security_task_setscheduler(). This is not only meaningless, but also make a harmful result if caller pass a static variable. This patch remove policy and sched_param parameter from security_task_setscheduler() becuase none of security module is using it. Cc: James Morris <jmorris@namei.org> Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: James Morris <jmorris@namei.org>
2010-10-14 19:21:18 +00:00
retval = security_task_setscheduler(p);
[PATCH] SELinux: add security hooks to {get,set}affinity This patch adds LSM hooks into the setaffinity and getaffinity functions to enable security modules to control these operations between tasks with task_setscheduler and task_getscheduler LSM hooks. Signed-off-by: David Quigley <dpquigl@tycho.nsa.gov> Acked-by: Stephen Smalley <sds@tycho.nsa.gov> Signed-off-by: James Morris <jmorris@namei.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-23 09:03:59 +00:00
if (retval)
goto out_unlock;
sched: convert struct (sys_)sched_setaffinity() to cpumask_var_t. Impact: stack usage reduction Dynamically allocating cpumasks (when CONFIG_CPUMASK_OFFSTACK) saves space on the stack. cpumask_var_t is just a struct cpumask for !CONFIG_CPUMASK_OFFSTACK. Note the removal of the initializer of new_mask: since the first thing we did was "cpus_and(new_mask, new_mask, cpus_allowed)" I just changed that to "cpumask_and(new_mask, in_mask, cpus_allowed);". Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-24 16:05:11 +00:00
cpuset_cpus_allowed(p, cpus_allowed);
cpumask_and(new_mask, in_mask, cpus_allowed);
sched: Unindent labels Labels should be on column 0. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-17 19:46:10 +00:00
again:
sched: convert struct (sys_)sched_setaffinity() to cpumask_var_t. Impact: stack usage reduction Dynamically allocating cpumasks (when CONFIG_CPUMASK_OFFSTACK) saves space on the stack. cpumask_var_t is just a struct cpumask for !CONFIG_CPUMASK_OFFSTACK. Note the removal of the initializer of new_mask: since the first thing we did was "cpus_and(new_mask, new_mask, cpus_allowed)" I just changed that to "cpumask_and(new_mask, in_mask, cpus_allowed);". Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-24 16:05:11 +00:00
retval = set_cpus_allowed_ptr(p, new_mask);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
Fix cpusets update_cpumask Cause writes to cpuset "cpus" file to update cpus_allowed for member tasks: - collect batches of tasks under tasklist_lock and then call set_cpus_allowed() on them outside the lock (since this can sleep). - add a simple generic priority heap type to allow efficient collection of batches of tasks to be processed without duplicating or missing any tasks in subsequent batches. - make "cpus" file update a no-op if the mask hasn't changed - fix race between update_cpumask() and sched_setaffinity() by making sched_setaffinity() post-check that it's not running on any cpus outside cpuset_cpus_allowed(). [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Paul Menage <menage@google.com> Cc: Paul Jackson <pj@sgi.com> Cc: David Rientjes <rientjes@google.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Cedric Le Goater <clg@fr.ibm.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Serge Hallyn <serue@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-19 06:40:22 +00:00
if (!retval) {
sched: convert struct (sys_)sched_setaffinity() to cpumask_var_t. Impact: stack usage reduction Dynamically allocating cpumasks (when CONFIG_CPUMASK_OFFSTACK) saves space on the stack. cpumask_var_t is just a struct cpumask for !CONFIG_CPUMASK_OFFSTACK. Note the removal of the initializer of new_mask: since the first thing we did was "cpus_and(new_mask, new_mask, cpus_allowed)" I just changed that to "cpumask_and(new_mask, in_mask, cpus_allowed);". Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-24 16:05:11 +00:00
cpuset_cpus_allowed(p, cpus_allowed);
if (!cpumask_subset(new_mask, cpus_allowed)) {
Fix cpusets update_cpumask Cause writes to cpuset "cpus" file to update cpus_allowed for member tasks: - collect batches of tasks under tasklist_lock and then call set_cpus_allowed() on them outside the lock (since this can sleep). - add a simple generic priority heap type to allow efficient collection of batches of tasks to be processed without duplicating or missing any tasks in subsequent batches. - make "cpus" file update a no-op if the mask hasn't changed - fix race between update_cpumask() and sched_setaffinity() by making sched_setaffinity() post-check that it's not running on any cpus outside cpuset_cpus_allowed(). [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Paul Menage <menage@google.com> Cc: Paul Jackson <pj@sgi.com> Cc: David Rientjes <rientjes@google.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Cedric Le Goater <clg@fr.ibm.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Serge Hallyn <serue@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-19 06:40:22 +00:00
/*
* We must have raced with a concurrent cpuset
* update. Just reset the cpus_allowed to the
* cpuset's cpus_allowed
*/
sched: convert struct (sys_)sched_setaffinity() to cpumask_var_t. Impact: stack usage reduction Dynamically allocating cpumasks (when CONFIG_CPUMASK_OFFSTACK) saves space on the stack. cpumask_var_t is just a struct cpumask for !CONFIG_CPUMASK_OFFSTACK. Note the removal of the initializer of new_mask: since the first thing we did was "cpus_and(new_mask, new_mask, cpus_allowed)" I just changed that to "cpumask_and(new_mask, in_mask, cpus_allowed);". Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-24 16:05:11 +00:00
cpumask_copy(new_mask, cpus_allowed);
Fix cpusets update_cpumask Cause writes to cpuset "cpus" file to update cpus_allowed for member tasks: - collect batches of tasks under tasklist_lock and then call set_cpus_allowed() on them outside the lock (since this can sleep). - add a simple generic priority heap type to allow efficient collection of batches of tasks to be processed without duplicating or missing any tasks in subsequent batches. - make "cpus" file update a no-op if the mask hasn't changed - fix race between update_cpumask() and sched_setaffinity() by making sched_setaffinity() post-check that it's not running on any cpus outside cpuset_cpus_allowed(). [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Paul Menage <menage@google.com> Cc: Paul Jackson <pj@sgi.com> Cc: David Rientjes <rientjes@google.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Cedric Le Goater <clg@fr.ibm.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Serge Hallyn <serue@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-19 06:40:22 +00:00
goto again;
}
}
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
out_unlock:
sched: convert struct (sys_)sched_setaffinity() to cpumask_var_t. Impact: stack usage reduction Dynamically allocating cpumasks (when CONFIG_CPUMASK_OFFSTACK) saves space on the stack. cpumask_var_t is just a struct cpumask for !CONFIG_CPUMASK_OFFSTACK. Note the removal of the initializer of new_mask: since the first thing we did was "cpus_and(new_mask, new_mask, cpus_allowed)" I just changed that to "cpumask_and(new_mask, in_mask, cpus_allowed);". Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-24 16:05:11 +00:00
free_cpumask_var(new_mask);
out_free_cpus_allowed:
free_cpumask_var(cpus_allowed);
out_put_task:
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
put_task_struct(p);
cpu-hotplug: replace per-subsystem mutexes with get_online_cpus() This patch converts the known per-subsystem mutexes to get_online_cpus put_online_cpus. It also eliminates the CPU_LOCK_ACQUIRE and CPU_LOCK_RELEASE hotplug notification events. Signed-off-by: Gautham R Shenoy <ego@in.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:02 +00:00
put_online_cpus();
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
return retval;
}
static int get_user_cpu_mask(unsigned long __user *user_mask_ptr, unsigned len,
sched: convert remaining old-style cpumask operators Impact: Trivial API conversion NR_CPUS -> nr_cpu_ids cpumask_t -> struct cpumask sizeof(cpumask_t) -> cpumask_size() cpumask_a = cpumask_b -> cpumask_copy(&cpumask_a, &cpumask_b) cpu_set() -> cpumask_set_cpu() first_cpu() -> cpumask_first() cpumask_of_cpu() -> cpumask_of() cpus_* -> cpumask_* There are some FIXMEs where we all archs to complete infrastructure (patches have been sent): cpu_coregroup_map -> cpu_coregroup_mask node_to_cpumask* -> cpumask_of_node There is also one FIXME where we pass an array of cpumasks to partition_sched_domains(): this implies knowing the definition of 'struct cpumask' and the size of a cpumask. This will be fixed in a future patch. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-24 16:05:14 +00:00
struct cpumask *new_mask)
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
{
sched: convert remaining old-style cpumask operators Impact: Trivial API conversion NR_CPUS -> nr_cpu_ids cpumask_t -> struct cpumask sizeof(cpumask_t) -> cpumask_size() cpumask_a = cpumask_b -> cpumask_copy(&cpumask_a, &cpumask_b) cpu_set() -> cpumask_set_cpu() first_cpu() -> cpumask_first() cpumask_of_cpu() -> cpumask_of() cpus_* -> cpumask_* There are some FIXMEs where we all archs to complete infrastructure (patches have been sent): cpu_coregroup_map -> cpu_coregroup_mask node_to_cpumask* -> cpumask_of_node There is also one FIXME where we pass an array of cpumasks to partition_sched_domains(): this implies knowing the definition of 'struct cpumask' and the size of a cpumask. This will be fixed in a future patch. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-24 16:05:14 +00:00
if (len < cpumask_size())
cpumask_clear(new_mask);
else if (len > cpumask_size())
len = cpumask_size();
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
return copy_from_user(new_mask, user_mask_ptr, len) ? -EFAULT : 0;
}
/**
* sys_sched_setaffinity - set the cpu affinity of a process
* @pid: pid of the process
* @len: length in bytes of the bitmask pointed to by user_mask_ptr
* @user_mask_ptr: user-space pointer to the new cpu mask
*/
[CVE-2009-0029] System call wrappers part 06 Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2009-01-14 13:14:08 +00:00
SYSCALL_DEFINE3(sched_setaffinity, pid_t, pid, unsigned int, len,
unsigned long __user *, user_mask_ptr)
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
{
sched: convert struct (sys_)sched_setaffinity() to cpumask_var_t. Impact: stack usage reduction Dynamically allocating cpumasks (when CONFIG_CPUMASK_OFFSTACK) saves space on the stack. cpumask_var_t is just a struct cpumask for !CONFIG_CPUMASK_OFFSTACK. Note the removal of the initializer of new_mask: since the first thing we did was "cpus_and(new_mask, new_mask, cpus_allowed)" I just changed that to "cpumask_and(new_mask, in_mask, cpus_allowed);". Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-24 16:05:11 +00:00
cpumask_var_t new_mask;
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
int retval;
sched: convert struct (sys_)sched_setaffinity() to cpumask_var_t. Impact: stack usage reduction Dynamically allocating cpumasks (when CONFIG_CPUMASK_OFFSTACK) saves space on the stack. cpumask_var_t is just a struct cpumask for !CONFIG_CPUMASK_OFFSTACK. Note the removal of the initializer of new_mask: since the first thing we did was "cpus_and(new_mask, new_mask, cpus_allowed)" I just changed that to "cpumask_and(new_mask, in_mask, cpus_allowed);". Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-24 16:05:11 +00:00
if (!alloc_cpumask_var(&new_mask, GFP_KERNEL))
return -ENOMEM;
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
sched: convert struct (sys_)sched_setaffinity() to cpumask_var_t. Impact: stack usage reduction Dynamically allocating cpumasks (when CONFIG_CPUMASK_OFFSTACK) saves space on the stack. cpumask_var_t is just a struct cpumask for !CONFIG_CPUMASK_OFFSTACK. Note the removal of the initializer of new_mask: since the first thing we did was "cpus_and(new_mask, new_mask, cpus_allowed)" I just changed that to "cpumask_and(new_mask, in_mask, cpus_allowed);". Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-24 16:05:11 +00:00
retval = get_user_cpu_mask(user_mask_ptr, len, new_mask);
if (retval == 0)
retval = sched_setaffinity(pid, new_mask);
free_cpumask_var(new_mask);
return retval;
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
}
sched: convert remaining old-style cpumask operators Impact: Trivial API conversion NR_CPUS -> nr_cpu_ids cpumask_t -> struct cpumask sizeof(cpumask_t) -> cpumask_size() cpumask_a = cpumask_b -> cpumask_copy(&cpumask_a, &cpumask_b) cpu_set() -> cpumask_set_cpu() first_cpu() -> cpumask_first() cpumask_of_cpu() -> cpumask_of() cpus_* -> cpumask_* There are some FIXMEs where we all archs to complete infrastructure (patches have been sent): cpu_coregroup_map -> cpu_coregroup_mask node_to_cpumask* -> cpumask_of_node There is also one FIXME where we pass an array of cpumasks to partition_sched_domains(): this implies knowing the definition of 'struct cpumask' and the size of a cpumask. This will be fixed in a future patch. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-24 16:05:14 +00:00
long sched_getaffinity(pid_t pid, struct cpumask *mask)
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
{
[PATCH] sched: cleanup, remove task_t, convert to struct task_struct cleanup: remove task_t and convert all the uses to struct task_struct. I introduced it for the scheduler anno and it was a mistake. Conversion was mostly scripted, the result was reviewed and all secondary whitespace and style impact (if any) was fixed up by hand. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-03 07:25:41 +00:00
struct task_struct *p;
sched: Protect task->cpus_allowed access in sched_getaffinity() sched_getaffinity() is not protected against a concurrent modification of the tasks affinity. Serialize the access with task_rq_lock(task). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <20091208202026.769251187@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-08 20:24:16 +00:00
unsigned long flags;
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
int retval;
cpu-hotplug: replace per-subsystem mutexes with get_online_cpus() This patch converts the known per-subsystem mutexes to get_online_cpus put_online_cpus. It also eliminates the CPU_LOCK_ACQUIRE and CPU_LOCK_RELEASE hotplug notification events. Signed-off-by: Gautham R Shenoy <ego@in.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:02 +00:00
get_online_cpus();
sched: Use rcu in sched_get/set_affinity() tasklist_lock is held read locked to protect the find_task_by_vpid() call and to prevent the task going away. sched_setaffinity acquires a task struct ref and drops tasklist lock right away. The access to the cpus_allowed mask is protected by rq->lock. rcu_read_lock() provides the same protection here. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <20091209100706.789059966@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-09 10:15:01 +00:00
rcu_read_lock();
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
retval = -ESRCH;
p = find_process_by_pid(pid);
if (!p)
goto out_unlock;
[PATCH] SELinux: add security hooks to {get,set}affinity This patch adds LSM hooks into the setaffinity and getaffinity functions to enable security modules to control these operations between tasks with task_setscheduler and task_getscheduler LSM hooks. Signed-off-by: David Quigley <dpquigl@tycho.nsa.gov> Acked-by: Stephen Smalley <sds@tycho.nsa.gov> Signed-off-by: James Morris <jmorris@namei.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-23 09:03:59 +00:00
retval = security_task_getscheduler(p);
if (retval)
goto out_unlock;
sched: Serialize p->cpus_allowed and ttwu() using p->pi_lock Currently p->pi_lock already serializes p->sched_class, also put p->cpus_allowed and try_to_wake_up() under it, this prepares the way to do the first part of ttwu() without holding rq->lock. By having p->sched_class and p->cpus_allowed serialized by p->pi_lock, we prepare the way to call select_task_rq() without holding rq->lock. Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110405152728.990364093@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-05 15:23:45 +00:00
raw_spin_lock_irqsave(&p->pi_lock, flags);
sched: convert remaining old-style cpumask operators Impact: Trivial API conversion NR_CPUS -> nr_cpu_ids cpumask_t -> struct cpumask sizeof(cpumask_t) -> cpumask_size() cpumask_a = cpumask_b -> cpumask_copy(&cpumask_a, &cpumask_b) cpu_set() -> cpumask_set_cpu() first_cpu() -> cpumask_first() cpumask_of_cpu() -> cpumask_of() cpus_* -> cpumask_* There are some FIXMEs where we all archs to complete infrastructure (patches have been sent): cpu_coregroup_map -> cpu_coregroup_mask node_to_cpumask* -> cpumask_of_node There is also one FIXME where we pass an array of cpumasks to partition_sched_domains(): this implies knowing the definition of 'struct cpumask' and the size of a cpumask. This will be fixed in a future patch. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-24 16:05:14 +00:00
cpumask_and(mask, &p->cpus_allowed, cpu_online_mask);
sched: Serialize p->cpus_allowed and ttwu() using p->pi_lock Currently p->pi_lock already serializes p->sched_class, also put p->cpus_allowed and try_to_wake_up() under it, this prepares the way to do the first part of ttwu() without holding rq->lock. By having p->sched_class and p->cpus_allowed serialized by p->pi_lock, we prepare the way to call select_task_rq() without holding rq->lock. Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110405152728.990364093@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-05 15:23:45 +00:00
raw_spin_unlock_irqrestore(&p->pi_lock, flags);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
out_unlock:
sched: Use rcu in sched_get/set_affinity() tasklist_lock is held read locked to protect the find_task_by_vpid() call and to prevent the task going away. sched_setaffinity acquires a task struct ref and drops tasklist lock right away. The access to the cpus_allowed mask is protected by rq->lock. rcu_read_lock() provides the same protection here. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <20091209100706.789059966@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-09 10:15:01 +00:00
rcu_read_unlock();
cpu-hotplug: replace per-subsystem mutexes with get_online_cpus() This patch converts the known per-subsystem mutexes to get_online_cpus put_online_cpus. It also eliminates the CPU_LOCK_ACQUIRE and CPU_LOCK_RELEASE hotplug notification events. Signed-off-by: Gautham R Shenoy <ego@in.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:02 +00:00
put_online_cpus();
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
sched: clean up sched_getaffinity() here's another tiny cleanup. The generated code is not affected (gcc is smart enough) but for people looking over the code it is just irritating to have the extra conditional. Signed-off-by: Ulrich Drepper <drepper@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-08-09 09:16:46 +00:00
return retval;
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
}
/**
* sys_sched_getaffinity - get the cpu affinity of a process
* @pid: pid of the process
* @len: length in bytes of the bitmask pointed to by user_mask_ptr
* @user_mask_ptr: user-space pointer to hold the current cpu mask
*/
[CVE-2009-0029] System call wrappers part 06 Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2009-01-14 13:14:08 +00:00
SYSCALL_DEFINE3(sched_getaffinity, pid_t, pid, unsigned int, len,
unsigned long __user *, user_mask_ptr)
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
{
int ret;
sched: convert sys_sched_getaffinity() to cpumask_var_t. Impact: stack usage reduction Dynamically allocating cpumasks (when CONFIG_CPUMASK_OFFSTACK) saves space in the stack. cpumask_var_t is just a struct cpumask for !CONFIG_CPUMASK_OFFSTACK. Some jiggling here to make sure we always exit at the bottom (so we hit the free_cpumask_var there). Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-24 16:05:11 +00:00
cpumask_var_t mask;
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
sched: Fix sched_getaffinity() taskset on 2.6.34-rc3 fails on one of my ppc64 test boxes with the following error: sched_getaffinity(0, 16, 0x10029650030) = -1 EINVAL (Invalid argument) This box has 128 threads and 16 bytes is enough to cover it. Commit cd3d8031eb4311e516329aee03c79a08333141f1 (sched: sched_getaffinity(): Allow less than NR_CPUS length) is comparing this 16 bytes agains nr_cpu_ids. Fix it by comparing nr_cpu_ids to the number of bits in the cpumask we pass in. Signed-off-by: Anton Blanchard <anton@samba.org> Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Sharyathi Nagesh <sharyath@in.ibm.com> Cc: Ulrich Drepper <drepper@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Jack Steiner <steiner@sgi.com> Cc: Russ Anderson <rja@sgi.com> Cc: Mike Travis <travis@sgi.com> LKML-Reference: <20100406070218.GM5594@kryten> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-04-06 07:02:19 +00:00
if ((len * BITS_PER_BYTE) < nr_cpu_ids)
sched: sched_getaffinity(): Allow less than NR_CPUS length [ Note, this commit changes the syscall ABI for > 1024 CPUs systems. ] Recently, some distro decided to use NR_CPUS=4096 for mysterious reasons. Unfortunately, glibc sched interface has the following definition: # define __CPU_SETSIZE 1024 # define __NCPUBITS (8 * sizeof (__cpu_mask)) typedef unsigned long int __cpu_mask; typedef struct { __cpu_mask __bits[__CPU_SETSIZE / __NCPUBITS]; } cpu_set_t; It mean, if NR_CPUS is bigger than 1024, cpu_set_t makes an ABI issue ... More recently, Sharyathi Nagesh reported following test program makes misterious syscall failure: ----------------------------------------------------------------------- #define _GNU_SOURCE #include<stdio.h> #include<errno.h> #include<sched.h> int main() { cpu_set_t set; if (sched_getaffinity(0, sizeof(cpu_set_t), &set) < 0) printf("\n Call is failing with:%d", errno); } ----------------------------------------------------------------------- Because the kernel assumes len argument of sched_getaffinity() is bigger than NR_CPUS. But now it is not correct. Now we are faced with the following annoying dilemma, due to the limitations of the glibc interface built in years ago: (1) if we change glibc's __CPU_SETSIZE definition, we lost binary compatibility of _all_ application. (2) if we don't change it, we also lost binary compatibility of Sharyathi's use case. Then, I would propse to change the rule of the len argument of sched_getaffinity(). Old: len should be bigger than NR_CPUS New: len should be bigger than maximum possible cpu id This creates the following behavior: (A) In the real 4096 cpus machine, the above test program still return -EINVAL. (B) NR_CPUS=4096 but the machine have less than 1024 cpus (almost all machines in the world), the above can run successfully. Fortunatelly, BIG SGI machine is mainly used for HPC use case. It means they can rebuild their programs. IOW we hope they are not annoyed by this issue ... Reported-by: Sharyathi Nagesh <sharyath@in.ibm.com> Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Acked-by: Ulrich Drepper <drepper@redhat.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Jack Steiner <steiner@sgi.com> Cc: Russ Anderson <rja@sgi.com> Cc: Mike Travis <travis@sgi.com> LKML-Reference: <20100312161316.9520.A69D9226@jp.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-03-12 07:15:36 +00:00
return -EINVAL;
if (len & (sizeof(unsigned long)-1))
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
return -EINVAL;
sched: convert sys_sched_getaffinity() to cpumask_var_t. Impact: stack usage reduction Dynamically allocating cpumasks (when CONFIG_CPUMASK_OFFSTACK) saves space in the stack. cpumask_var_t is just a struct cpumask for !CONFIG_CPUMASK_OFFSTACK. Some jiggling here to make sure we always exit at the bottom (so we hit the free_cpumask_var there). Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-24 16:05:11 +00:00
if (!alloc_cpumask_var(&mask, GFP_KERNEL))
return -ENOMEM;
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
sched: convert sys_sched_getaffinity() to cpumask_var_t. Impact: stack usage reduction Dynamically allocating cpumasks (when CONFIG_CPUMASK_OFFSTACK) saves space in the stack. cpumask_var_t is just a struct cpumask for !CONFIG_CPUMASK_OFFSTACK. Some jiggling here to make sure we always exit at the bottom (so we hit the free_cpumask_var there). Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-24 16:05:11 +00:00
ret = sched_getaffinity(pid, mask);
if (ret == 0) {
sched: Use proper type in sched_getaffinity() Using the proper type fixes the following compiler warning: kernel/sched.c:4850: warning: comparison of distinct pointer types lacks a cast Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: torvalds@linux-foundation.org Cc: travis@sgi.com Cc: peterz@infradead.org Cc: drepper@redhat.com Cc: rja@sgi.com Cc: sharyath@in.ibm.com Cc: steiner@sgi.com LKML-Reference: <20100317090046.4C79.A69D9226@jp.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-03-17 00:36:58 +00:00
size_t retlen = min_t(size_t, len, cpumask_size());
sched: sched_getaffinity(): Allow less than NR_CPUS length [ Note, this commit changes the syscall ABI for > 1024 CPUs systems. ] Recently, some distro decided to use NR_CPUS=4096 for mysterious reasons. Unfortunately, glibc sched interface has the following definition: # define __CPU_SETSIZE 1024 # define __NCPUBITS (8 * sizeof (__cpu_mask)) typedef unsigned long int __cpu_mask; typedef struct { __cpu_mask __bits[__CPU_SETSIZE / __NCPUBITS]; } cpu_set_t; It mean, if NR_CPUS is bigger than 1024, cpu_set_t makes an ABI issue ... More recently, Sharyathi Nagesh reported following test program makes misterious syscall failure: ----------------------------------------------------------------------- #define _GNU_SOURCE #include<stdio.h> #include<errno.h> #include<sched.h> int main() { cpu_set_t set; if (sched_getaffinity(0, sizeof(cpu_set_t), &set) < 0) printf("\n Call is failing with:%d", errno); } ----------------------------------------------------------------------- Because the kernel assumes len argument of sched_getaffinity() is bigger than NR_CPUS. But now it is not correct. Now we are faced with the following annoying dilemma, due to the limitations of the glibc interface built in years ago: (1) if we change glibc's __CPU_SETSIZE definition, we lost binary compatibility of _all_ application. (2) if we don't change it, we also lost binary compatibility of Sharyathi's use case. Then, I would propse to change the rule of the len argument of sched_getaffinity(). Old: len should be bigger than NR_CPUS New: len should be bigger than maximum possible cpu id This creates the following behavior: (A) In the real 4096 cpus machine, the above test program still return -EINVAL. (B) NR_CPUS=4096 but the machine have less than 1024 cpus (almost all machines in the world), the above can run successfully. Fortunatelly, BIG SGI machine is mainly used for HPC use case. It means they can rebuild their programs. IOW we hope they are not annoyed by this issue ... Reported-by: Sharyathi Nagesh <sharyath@in.ibm.com> Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Acked-by: Ulrich Drepper <drepper@redhat.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Jack Steiner <steiner@sgi.com> Cc: Russ Anderson <rja@sgi.com> Cc: Mike Travis <travis@sgi.com> LKML-Reference: <20100312161316.9520.A69D9226@jp.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-03-12 07:15:36 +00:00
if (copy_to_user(user_mask_ptr, mask, retlen))
sched: convert sys_sched_getaffinity() to cpumask_var_t. Impact: stack usage reduction Dynamically allocating cpumasks (when CONFIG_CPUMASK_OFFSTACK) saves space in the stack. cpumask_var_t is just a struct cpumask for !CONFIG_CPUMASK_OFFSTACK. Some jiggling here to make sure we always exit at the bottom (so we hit the free_cpumask_var there). Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-24 16:05:11 +00:00
ret = -EFAULT;
else
sched: sched_getaffinity(): Allow less than NR_CPUS length [ Note, this commit changes the syscall ABI for > 1024 CPUs systems. ] Recently, some distro decided to use NR_CPUS=4096 for mysterious reasons. Unfortunately, glibc sched interface has the following definition: # define __CPU_SETSIZE 1024 # define __NCPUBITS (8 * sizeof (__cpu_mask)) typedef unsigned long int __cpu_mask; typedef struct { __cpu_mask __bits[__CPU_SETSIZE / __NCPUBITS]; } cpu_set_t; It mean, if NR_CPUS is bigger than 1024, cpu_set_t makes an ABI issue ... More recently, Sharyathi Nagesh reported following test program makes misterious syscall failure: ----------------------------------------------------------------------- #define _GNU_SOURCE #include<stdio.h> #include<errno.h> #include<sched.h> int main() { cpu_set_t set; if (sched_getaffinity(0, sizeof(cpu_set_t), &set) < 0) printf("\n Call is failing with:%d", errno); } ----------------------------------------------------------------------- Because the kernel assumes len argument of sched_getaffinity() is bigger than NR_CPUS. But now it is not correct. Now we are faced with the following annoying dilemma, due to the limitations of the glibc interface built in years ago: (1) if we change glibc's __CPU_SETSIZE definition, we lost binary compatibility of _all_ application. (2) if we don't change it, we also lost binary compatibility of Sharyathi's use case. Then, I would propse to change the rule of the len argument of sched_getaffinity(). Old: len should be bigger than NR_CPUS New: len should be bigger than maximum possible cpu id This creates the following behavior: (A) In the real 4096 cpus machine, the above test program still return -EINVAL. (B) NR_CPUS=4096 but the machine have less than 1024 cpus (almost all machines in the world), the above can run successfully. Fortunatelly, BIG SGI machine is mainly used for HPC use case. It means they can rebuild their programs. IOW we hope they are not annoyed by this issue ... Reported-by: Sharyathi Nagesh <sharyath@in.ibm.com> Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Acked-by: Ulrich Drepper <drepper@redhat.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Jack Steiner <steiner@sgi.com> Cc: Russ Anderson <rja@sgi.com> Cc: Mike Travis <travis@sgi.com> LKML-Reference: <20100312161316.9520.A69D9226@jp.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-03-12 07:15:36 +00:00
ret = retlen;
sched: convert sys_sched_getaffinity() to cpumask_var_t. Impact: stack usage reduction Dynamically allocating cpumasks (when CONFIG_CPUMASK_OFFSTACK) saves space in the stack. cpumask_var_t is just a struct cpumask for !CONFIG_CPUMASK_OFFSTACK. Some jiggling here to make sure we always exit at the bottom (so we hit the free_cpumask_var there). Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-24 16:05:11 +00:00
}
free_cpumask_var(mask);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
sched: convert sys_sched_getaffinity() to cpumask_var_t. Impact: stack usage reduction Dynamically allocating cpumasks (when CONFIG_CPUMASK_OFFSTACK) saves space in the stack. cpumask_var_t is just a struct cpumask for !CONFIG_CPUMASK_OFFSTACK. Some jiggling here to make sure we always exit at the bottom (so we hit the free_cpumask_var there). Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-24 16:05:11 +00:00
return ret;
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
}
/**
* sys_sched_yield - yield the current processor to other threads.
*
sched: cfs core code apply the CFS core code. this change switches over the scheduler core to CFS's modular design and makes use of kernel/sched_fair/rt/idletask.c to implement Linux's scheduling policies. thanks to Andrew Morton and Thomas Gleixner for lots of detailed review feedback and for fixlets. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
2007-07-09 16:51:59 +00:00
* This function yields the current CPU to other tasks. If there are no
* other threads running on this CPU then this function will return.
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
*/
[CVE-2009-0029] System call wrappers part 06 Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2009-01-14 13:14:08 +00:00
SYSCALL_DEFINE0(sched_yield)
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
{
[PATCH] sched: cleanup, convert sched.c-internal typedefs to struct convert: - runqueue_t to 'struct rq' - prio_array_t to 'struct prio_array' - migration_req_t to 'struct migration_req' I was the one who added these but they are both against the kernel coding style and also were used inconsistently at places. So just get rid of them at once, now that we are flushing the scheduler patch-queue anyway. Conversion was mostly scripted, the result was reviewed and all secondary whitespace and style impact (if any) was fixed up by hand. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-03 07:25:42 +00:00
struct rq *rq = this_rq_lock();
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
sched: clean up schedstats, cnt -> count rename all 'cnt' fields and variables to the less yucky 'count' name. yuckage noticed by Andrew Morton. no change in code, other than the /proc/sched_debug bkl_count string got a bit larger: text data bss dec hex filename 38236 3506 24 41766 a326 sched.o.before 38240 3506 24 41770 a32a sched.o.after Signed-off-by: Ingo Molnar <mingo@elte.hu> Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-15 15:00:12 +00:00
schedstat_inc(rq, yld_count);
sched: simplify sched_class::yield_task() the 'p' (task_struct) parameter in the sched_class :: yield_task() is redundant as the caller is always the 'current'. Get rid of it. text data bss dec hex filename 24341 2734 20 27095 69d7 sched.o.before 24330 2734 20 27084 69cc sched.o.after Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-15 15:00:08 +00:00
current->sched_class->yield_task(rq);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
/*
* Since we are going to call schedule() anyway, there's
* no need to preempt or enable interrupts:
*/
__release(rq->lock);
[PATCH] lockdep: prove spinlock rwlock locking correctness Use the lock validator framework to prove spinlock and rwlock locking correctness. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-03 07:24:54 +00:00
spin_release(&rq->lock.dep_map, 1, _THIS_IP_);
locking: Further name space cleanups The name space hierarchy for the internal lock functions is now a bit backwards. raw_spin* functions map to _spin* which use __spin*, while we would like to have _raw_spin* and __raw_spin*. _raw_spin* is already used by lock debugging, so rename those funtions to do_raw_spin* to free up the _raw_spin* name space. No functional change. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Ingo Molnar <mingo@elte.hu>
2009-12-03 19:55:53 +00:00
do_raw_spin_unlock(&rq->lock);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
preempt_enable_no_resched();
schedule();
return 0;
}
sched: optimize cond_resched() Optimize cond_resched() by removing one conditional. Currently cond_resched() checks system_state == SYSTEM_RUNNING in order to avoid scheduling before the scheduler is running. We can however, as per suggestion of Matt, use PREEMPT_ACTIVE to accomplish that very same. Suggested-by: Matt Mackall <mpm@selenic.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Matt Mackall <mpm@selenic.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-07-10 12:57:57 +00:00
static inline int should_resched(void)
{
return need_resched() && !(preempt_count() & PREEMPT_ACTIVE);
}
[PATCH] cond_resched() fix Fix a bug identified by Zou Nan hai <nanhai.zou@intel.com>: If the system is in state SYSTEM_BOOTING, and need_resched() is true, cond_resched() returns true even though it didn't reschedule. Consequently need_resched() remains true and JBD locks up. Fix that by teaching cond_resched() to only return true if it really did call schedule(). cond_resched_lock() and cond_resched_softirq() have a problem too. If we're in SYSTEM_BOOTING state and need_resched() is true, these functions will drop the lock and will then try to call schedule(), but the SYSTEM_BOOTING state will prevent schedule() from being called. So on return, need_resched() will still be true, but cond_resched_lock() has to return 1 to tell the caller that the lock was dropped. The caller will probably lock up. Bottom line: if these functions dropped the lock, they _must_ call schedule() to clear need_resched(). Make it so. Also, uninline __cond_resched(). It's largeish, and slowpath. Acked-by: Ingo Molnar <mingo@elte.hu> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-30 08:56:00 +00:00
static void __cond_resched(void)
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
{
sched: Drop the need_resched() loop from cond_resched() The schedule() function is a loop that reschedules the current task while the TIF_NEED_RESCHED flag is set: void schedule(void) { need_resched: /* schedule code */ if (need_resched()) goto need_resched; } And cond_resched() repeat this loop: do { add_preempt_count(PREEMPT_ACTIVE); schedule(); sub_preempt_count(PREEMPT_ACTIVE); } while(need_resched()); This loop is needless because schedule() already did the check and nothing can set TIF_NEED_RESCHED between schedule() exit and the loop check in need_resched(). Then remove this needless loop. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1247725694-6082-1-git-send-email-fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-07-16 13:44:29 +00:00
add_preempt_count(PREEMPT_ACTIVE);
schedule();
sub_preempt_count(PREEMPT_ACTIVE);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
}
sched: do not do cond_resched() when CONFIG_PREEMPT Why do we even have cond_resched when real preemption is on? It seems to be a waste of space and time. remove cond_resched with CONFIG_PREEMPT on. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:28 +00:00
int __sched _cond_resched(void)
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
{
sched: optimize cond_resched() Optimize cond_resched() by removing one conditional. Currently cond_resched() checks system_state == SYSTEM_RUNNING in order to avoid scheduling before the scheduler is running. We can however, as per suggestion of Matt, use PREEMPT_ACTIVE to accomplish that very same. Suggested-by: Matt Mackall <mpm@selenic.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Matt Mackall <mpm@selenic.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-07-10 12:57:57 +00:00
if (should_resched()) {
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
__cond_resched();
return 1;
}
return 0;
}
sched: do not do cond_resched() when CONFIG_PREEMPT Why do we even have cond_resched when real preemption is on? It seems to be a waste of space and time. remove cond_resched with CONFIG_PREEMPT on. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:28 +00:00
EXPORT_SYMBOL(_cond_resched);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
/*
sched: Pull up the might_sleep() check into cond_resched() might_sleep() is called late-ish in cond_resched(), after the need_resched()/preempt enabled/system running tests are checked. It's better to check the sleeps while atomic earlier and not depend on some environment datas that reduce the chances to detect a problem. Also define cond_resched_*() helpers as macros, so that the FILE/LINE reported in the sleeping while atomic warning displays the real origin and not sched.h Changes in v2: - Call __might_sleep() directly instead of might_sleep() which may call cond_resched() - Turn cond_resched() into a macro so that the file:line couple reported refers to the caller of cond_resched() and not __cond_resched() itself. Changes in v3: - Also propagate this __might_sleep() pull up to cond_resched_lock() and cond_resched_softirq() Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1247725694-6082-6-git-send-email-fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-07-16 13:44:29 +00:00
* __cond_resched_lock() - if a reschedule is pending, drop the given lock,
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
* call schedule, and on return reacquire the lock.
*
sched: style cleanups style cleanup of various changes that were done recently. no code changed: text data bss dec hex filename 23680 2542 28 26250 668a sched.o.before 23680 2542 28 26250 668a sched.o.after Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-12-05 14:46:09 +00:00
* This works OK both with and without CONFIG_PREEMPT. We do strange low-level
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
* operations here to prevent schedule() from being called twice (once via
* spin_unlock(), once by hand).
*/
sched: Pull up the might_sleep() check into cond_resched() might_sleep() is called late-ish in cond_resched(), after the need_resched()/preempt enabled/system running tests are checked. It's better to check the sleeps while atomic earlier and not depend on some environment datas that reduce the chances to detect a problem. Also define cond_resched_*() helpers as macros, so that the FILE/LINE reported in the sleeping while atomic warning displays the real origin and not sched.h Changes in v2: - Call __might_sleep() directly instead of might_sleep() which may call cond_resched() - Turn cond_resched() into a macro so that the file:line couple reported refers to the caller of cond_resched() and not __cond_resched() itself. Changes in v3: - Also propagate this __might_sleep() pull up to cond_resched_lock() and cond_resched_softirq() Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1247725694-6082-6-git-send-email-fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-07-16 13:44:29 +00:00
int __cond_resched_lock(spinlock_t *lock)
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
{
sched: optimize cond_resched() Optimize cond_resched() by removing one conditional. Currently cond_resched() checks system_state == SYSTEM_RUNNING in order to avoid scheduling before the scheduler is running. We can however, as per suggestion of Matt, use PREEMPT_ACTIVE to accomplish that very same. Suggested-by: Matt Mackall <mpm@selenic.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Matt Mackall <mpm@selenic.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-07-10 12:57:57 +00:00
int resched = should_resched();
[PATCH] cond_resched_lock() fix On one path, cond_resched_lock() fails to return true if it dropped the lock. We think this might be causing the crashes in JBD's log_do_checkpoint(). Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-13 22:52:32 +00:00
int ret = 0;
lockdep: Introduce lockdep_assert_held() Add a lockdep helper to validate that we indeed are the owner of a lock. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-07-20 17:16:29 +00:00
lockdep_assert_held(lock);
spinlock: lockbreak cleanup The break_lock data structure and code for spinlocks is quite nasty. Not only does it double the size of a spinlock but it changes locking to a potentially less optimal trylock. Put all of that under CONFIG_GENERIC_LOCKBREAK, and introduce a __raw_spin_is_contended that uses the lock data itself to determine whether there are waiters on the lock, to be used if CONFIG_GENERIC_LOCKBREAK is not set. Rename need_lockbreak to spin_needbreak, make it use spin_is_contended to decouple it from the spinlock implementation, and make it typesafe (rwlocks do not have any need_lockbreak sites -- why do they even get bloated up with that break_lock then?). Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 12:31:20 +00:00
if (spin_needbreak(lock) || resched) {
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
spin_unlock(lock);
sched: optimize cond_resched() Optimize cond_resched() by removing one conditional. Currently cond_resched() checks system_state == SYSTEM_RUNNING in order to avoid scheduling before the scheduler is running. We can however, as per suggestion of Matt, use PREEMPT_ACTIVE to accomplish that very same. Suggested-by: Matt Mackall <mpm@selenic.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Matt Mackall <mpm@selenic.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-07-10 12:57:57 +00:00
if (resched)
spinlock: lockbreak cleanup The break_lock data structure and code for spinlocks is quite nasty. Not only does it double the size of a spinlock but it changes locking to a potentially less optimal trylock. Put all of that under CONFIG_GENERIC_LOCKBREAK, and introduce a __raw_spin_is_contended that uses the lock data itself to determine whether there are waiters on the lock, to be used if CONFIG_GENERIC_LOCKBREAK is not set. Rename need_lockbreak to spin_needbreak, make it use spin_is_contended to decouple it from the spinlock implementation, and make it typesafe (rwlocks do not have any need_lockbreak sites -- why do they even get bloated up with that break_lock then?). Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 12:31:20 +00:00
__cond_resched();
else
cpu_relax();
[PATCH] cond_resched_lock() fix On one path, cond_resched_lock() fails to return true if it dropped the lock. We think this might be causing the crashes in JBD's log_do_checkpoint(). Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-13 22:52:32 +00:00
ret = 1;
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
spin_lock(lock);
}
[PATCH] cond_resched_lock() fix On one path, cond_resched_lock() fails to return true if it dropped the lock. We think this might be causing the crashes in JBD's log_do_checkpoint(). Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-13 22:52:32 +00:00
return ret;
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
}
sched: Pull up the might_sleep() check into cond_resched() might_sleep() is called late-ish in cond_resched(), after the need_resched()/preempt enabled/system running tests are checked. It's better to check the sleeps while atomic earlier and not depend on some environment datas that reduce the chances to detect a problem. Also define cond_resched_*() helpers as macros, so that the FILE/LINE reported in the sleeping while atomic warning displays the real origin and not sched.h Changes in v2: - Call __might_sleep() directly instead of might_sleep() which may call cond_resched() - Turn cond_resched() into a macro so that the file:line couple reported refers to the caller of cond_resched() and not __cond_resched() itself. Changes in v3: - Also propagate this __might_sleep() pull up to cond_resched_lock() and cond_resched_softirq() Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1247725694-6082-6-git-send-email-fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-07-16 13:44:29 +00:00
EXPORT_SYMBOL(__cond_resched_lock);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
sched: Pull up the might_sleep() check into cond_resched() might_sleep() is called late-ish in cond_resched(), after the need_resched()/preempt enabled/system running tests are checked. It's better to check the sleeps while atomic earlier and not depend on some environment datas that reduce the chances to detect a problem. Also define cond_resched_*() helpers as macros, so that the FILE/LINE reported in the sleeping while atomic warning displays the real origin and not sched.h Changes in v2: - Call __might_sleep() directly instead of might_sleep() which may call cond_resched() - Turn cond_resched() into a macro so that the file:line couple reported refers to the caller of cond_resched() and not __cond_resched() itself. Changes in v3: - Also propagate this __might_sleep() pull up to cond_resched_lock() and cond_resched_softirq() Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1247725694-6082-6-git-send-email-fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-07-16 13:44:29 +00:00
int __sched __cond_resched_softirq(void)
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
{
BUG_ON(!in_softirq());
sched: optimize cond_resched() Optimize cond_resched() by removing one conditional. Currently cond_resched() checks system_state == SYSTEM_RUNNING in order to avoid scheduling before the scheduler is running. We can however, as per suggestion of Matt, use PREEMPT_ACTIVE to accomplish that very same. Suggested-by: Matt Mackall <mpm@selenic.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Matt Mackall <mpm@selenic.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-07-10 12:57:57 +00:00
if (should_resched()) {
Prevent going idle with softirq pending The NOHZ patch contains a check for softirqs pending when a CPU goes idle. The BUG is unrelated to NOHZ, it just was made visible by the NOHZ patch. The BUG showed up mainly on P4 / hyperthreading enabled machines which lead the investigations into the wrong direction in the first place. The real cause is in cond_resched_softirq(): cond_resched_softirq() is enabling softirqs without invoking the softirq daemon when softirqs are pending. This leads to the warning message in the NOHZ idle code: t1 runs softirq disabled code on CPU#0 interrupt happens, softirq is raised, but deferred (softirqs disabled) t1 calls cond_resched_softirq() enables softirqs via _local_bh_enable() calls schedule() t2 runs t1 is migrated to CPU#1 t2 is done and invokes idle() NOHZ detects the pending softirq Fix: change _local_bh_enable() to local_bh_enable() so the softirq daemon is invoked. Thanks to Anant Nitya for debugging this with great patience ! Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-23 20:58:18 +00:00
local_bh_enable();
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
__cond_resched();
local_bh_disable();
return 1;
}
return 0;
}
sched: Pull up the might_sleep() check into cond_resched() might_sleep() is called late-ish in cond_resched(), after the need_resched()/preempt enabled/system running tests are checked. It's better to check the sleeps while atomic earlier and not depend on some environment datas that reduce the chances to detect a problem. Also define cond_resched_*() helpers as macros, so that the FILE/LINE reported in the sleeping while atomic warning displays the real origin and not sched.h Changes in v2: - Call __might_sleep() directly instead of might_sleep() which may call cond_resched() - Turn cond_resched() into a macro so that the file:line couple reported refers to the caller of cond_resched() and not __cond_resched() itself. Changes in v3: - Also propagate this __might_sleep() pull up to cond_resched_lock() and cond_resched_softirq() Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1247725694-6082-6-git-send-email-fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-07-16 13:44:29 +00:00
EXPORT_SYMBOL(__cond_resched_softirq);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
/**
* yield - yield the current processor to other threads.
*
[PATCH] Numerous fixes to kernel-doc info in source files. A variety of (mostly) innocuous fixes to the embedded kernel-doc content in source files, including: * make multi-line initial descriptions single line * denote some function names, constants and structs as such * change erroneous opening '/*' to '/**' in a few places * reword some text for clarity Signed-off-by: Robert P. J. Day <rpjday@mindspring.com> Cc: "Randy.Dunlap" <rdunlap@xenotime.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-10 09:45:59 +00:00
* This is a shortcut for kernel-space yielding - it marks the
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
* thread runnable and calls sys_sched_yield().
*/
void __sched yield(void)
{
set_current_state(TASK_RUNNING);
sys_sched_yield();
}
EXPORT_SYMBOL(yield);
sched: Add yield_to(task, preempt) functionality Currently only implemented for fair class tasks. Add a yield_to_task method() to the fair scheduling class. allowing the caller of yield_to() to accelerate another thread in it's thread group, task group. Implemented via a scheduler hint, using cfs_rq->next to encourage the target being selected. We can rely on pick_next_entity to keep things fair, so noone can accelerate a thread that has already used its fair share of CPU time. This also means callers should only call yield_to when they really mean it. Calling it too often can result in the scheduler just ignoring the hint. Signed-off-by: Rik van Riel <riel@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20110201095051.4ddb7738@annuminas.surriel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-02-01 14:50:51 +00:00
/**
* yield_to - yield the current processor to another thread in
* your thread group, or accelerate that thread toward the
* processor it's on.
sched: Fix yield_to kernel-doc Add missing function parameters for yield_to(): Warning(kernel/sched.c:5470): No description found for parameter 'p' Warning(kernel/sched.c:5470): No description found for parameter 'preempt' Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Cc: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <20110318093453.8f7489a4.randy.dunlap@oracle.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-03-18 16:34:53 +00:00
* @p: target task
* @preempt: whether task preemption is allowed or not
sched: Add yield_to(task, preempt) functionality Currently only implemented for fair class tasks. Add a yield_to_task method() to the fair scheduling class. allowing the caller of yield_to() to accelerate another thread in it's thread group, task group. Implemented via a scheduler hint, using cfs_rq->next to encourage the target being selected. We can rely on pick_next_entity to keep things fair, so noone can accelerate a thread that has already used its fair share of CPU time. This also means callers should only call yield_to when they really mean it. Calling it too often can result in the scheduler just ignoring the hint. Signed-off-by: Rik van Riel <riel@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20110201095051.4ddb7738@annuminas.surriel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-02-01 14:50:51 +00:00
*
* It's the caller's job to ensure that the target task struct
* can't go away on us before we can do any checks.
*
* Returns true if we indeed boosted the target task.
*/
bool __sched yield_to(struct task_struct *p, bool preempt)
{
struct task_struct *curr = current;
struct rq *rq, *p_rq;
unsigned long flags;
bool yielded = 0;
local_irq_save(flags);
rq = this_rq();
again:
p_rq = task_rq(p);
double_rq_lock(rq, p_rq);
while (task_rq(p) != p_rq) {
double_rq_unlock(rq, p_rq);
goto again;
}
if (!curr->sched_class->yield_to_task)
goto out;
if (curr->sched_class != p->sched_class)
goto out;
if (task_running(p_rq, p) || p->state)
goto out;
yielded = curr->sched_class->yield_to_task(rq, p, preempt);
sched: Resched proper CPU on yield_to() yield_to_task_fair() has code to resched the CPU of yielding task when the intention is to resched the CPU of the task that is being yielded to. Change here fixes the problem and also makes the resched conditional on rq != p_rq. Signed-off-by: Venkatesh Pallipadi <venki@google.com> Reviewed-by: Rik van Riel <riel@redhat.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1299025701-22168-1-git-send-email-venki@google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-03-02 00:28:21 +00:00
if (yielded) {
sched: Add yield_to(task, preempt) functionality Currently only implemented for fair class tasks. Add a yield_to_task method() to the fair scheduling class. allowing the caller of yield_to() to accelerate another thread in it's thread group, task group. Implemented via a scheduler hint, using cfs_rq->next to encourage the target being selected. We can rely on pick_next_entity to keep things fair, so noone can accelerate a thread that has already used its fair share of CPU time. This also means callers should only call yield_to when they really mean it. Calling it too often can result in the scheduler just ignoring the hint. Signed-off-by: Rik van Riel <riel@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20110201095051.4ddb7738@annuminas.surriel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-02-01 14:50:51 +00:00
schedstat_inc(rq, yld_count);
sched: Resched proper CPU on yield_to() yield_to_task_fair() has code to resched the CPU of yielding task when the intention is to resched the CPU of the task that is being yielded to. Change here fixes the problem and also makes the resched conditional on rq != p_rq. Signed-off-by: Venkatesh Pallipadi <venki@google.com> Reviewed-by: Rik van Riel <riel@redhat.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1299025701-22168-1-git-send-email-venki@google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-03-02 00:28:21 +00:00
/*
* Make p's CPU reschedule; pick_next_entity takes care of
* fairness.
*/
if (preempt && rq != p_rq)
resched_task(p_rq->curr);
}
sched: Add yield_to(task, preempt) functionality Currently only implemented for fair class tasks. Add a yield_to_task method() to the fair scheduling class. allowing the caller of yield_to() to accelerate another thread in it's thread group, task group. Implemented via a scheduler hint, using cfs_rq->next to encourage the target being selected. We can rely on pick_next_entity to keep things fair, so noone can accelerate a thread that has already used its fair share of CPU time. This also means callers should only call yield_to when they really mean it. Calling it too often can result in the scheduler just ignoring the hint. Signed-off-by: Rik van Riel <riel@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20110201095051.4ddb7738@annuminas.surriel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-02-01 14:50:51 +00:00
out:
double_rq_unlock(rq, p_rq);
local_irq_restore(flags);
if (yielded)
schedule();
return yielded;
}
EXPORT_SYMBOL_GPL(yield_to);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
/*
sched: style cleanups style cleanup of various changes that were done recently. no code changed: text data bss dec hex filename 23680 2542 28 26250 668a sched.o.before 23680 2542 28 26250 668a sched.o.after Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-12-05 14:46:09 +00:00
* This task is about to go to sleep on IO. Increment rq->nr_iowait so
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
* that process accounting knows that this is a task in IO wait state.
*/
void __sched io_schedule(void)
{
sched: Hide runqueues from direct reference at source code level for __raw_get_cpu_var() Hide __raw_get_cpu_var() as well - thus all the direct references to runqueues will abstracted out. Signed-off-by: Hitoshi Mitake <mitake@dcl.info.waseda.ac.jp> LKML-Reference: <20090629.144457.886429910353660979.mitake@dcl.info.waseda.ac.jp> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-06-29 05:44:57 +00:00
struct rq *rq = raw_rq();
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
[PATCH] per-task-delay-accounting: sync block I/O and swapin delay collection Unlike earlier iterations of the delay accounting patches, now delays are only collected for the actual I/O waits rather than try and cover the delays seen in I/O submission paths. Account separately for block I/O delays incurred as a result of swapin page faults whose frequency can be affected by the task/process' rss limit. Hence swapin delays can act as feedback for rss limit changes independent of I/O priority changes. Signed-off-by: Shailabh Nagar <nagar@watson.ibm.com> Signed-off-by: Balbir Singh <balbir@in.ibm.com> Cc: Jes Sorensen <jes@sgi.com> Cc: Peter Chubb <peterc@gelato.unsw.edu.au> Cc: Erich Focht <efocht@ess.nec.de> Cc: Levent Serinol <lserinol@gmail.com> Cc: Jay Lan <jlan@engr.sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-14 07:24:37 +00:00
delayacct_blkio_start();
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
atomic_inc(&rq->nr_iowait);
block: initial patch for on-stack per-task plugging This patch adds support for creating a queuing context outside of the queue itself. This enables us to batch up pieces of IO before grabbing the block device queue lock and submitting them to the IO scheduler. The context is created on the stack of the process and assigned in the task structure, so that we can auto-unplug it if we hit a schedule event. The current queue plugging happens implicitly if IO is submitted to an empty device, yet callers have to remember to unplug that IO when they are going to wait for it. This is an ugly API and has caused bugs in the past. Additionally, it requires hacks in the vm (->sync_page() callback) to handle that logic. By switching to an explicit plugging scheme we make the API a lot nicer and can get rid of the ->sync_page() hack in the vm. Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2011-03-08 12:19:51 +00:00
blk_flush_plug(current);
sched: Provide iowait counters For counting how long an application has been waiting for (disk) IO, there currently is only the HZ sample driven information available, while for all other counters in this class, a high resolution version is available via CONFIG_SCHEDSTATS. In order to make an improved bootchart tool possible, we also need a higher resolution version of the iowait time. This patch below adds this scheduler statistic to the kernel. Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <4A64B813.1080506@linux.intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-07-20 18:26:58 +00:00
current->in_iowait = 1;
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
schedule();
sched: Provide iowait counters For counting how long an application has been waiting for (disk) IO, there currently is only the HZ sample driven information available, while for all other counters in this class, a high resolution version is available via CONFIG_SCHEDSTATS. In order to make an improved bootchart tool possible, we also need a higher resolution version of the iowait time. This patch below adds this scheduler statistic to the kernel. Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <4A64B813.1080506@linux.intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-07-20 18:26:58 +00:00
current->in_iowait = 0;
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
atomic_dec(&rq->nr_iowait);
[PATCH] per-task-delay-accounting: sync block I/O and swapin delay collection Unlike earlier iterations of the delay accounting patches, now delays are only collected for the actual I/O waits rather than try and cover the delays seen in I/O submission paths. Account separately for block I/O delays incurred as a result of swapin page faults whose frequency can be affected by the task/process' rss limit. Hence swapin delays can act as feedback for rss limit changes independent of I/O priority changes. Signed-off-by: Shailabh Nagar <nagar@watson.ibm.com> Signed-off-by: Balbir Singh <balbir@in.ibm.com> Cc: Jes Sorensen <jes@sgi.com> Cc: Peter Chubb <peterc@gelato.unsw.edu.au> Cc: Erich Focht <efocht@ess.nec.de> Cc: Levent Serinol <lserinol@gmail.com> Cc: Jay Lan <jlan@engr.sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-14 07:24:37 +00:00
delayacct_blkio_end();
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
}
EXPORT_SYMBOL(io_schedule);
long __sched io_schedule_timeout(long timeout)
{
sched: Hide runqueues from direct reference at source code level for __raw_get_cpu_var() Hide __raw_get_cpu_var() as well - thus all the direct references to runqueues will abstracted out. Signed-off-by: Hitoshi Mitake <mitake@dcl.info.waseda.ac.jp> LKML-Reference: <20090629.144457.886429910353660979.mitake@dcl.info.waseda.ac.jp> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-06-29 05:44:57 +00:00
struct rq *rq = raw_rq();
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
long ret;
[PATCH] per-task-delay-accounting: sync block I/O and swapin delay collection Unlike earlier iterations of the delay accounting patches, now delays are only collected for the actual I/O waits rather than try and cover the delays seen in I/O submission paths. Account separately for block I/O delays incurred as a result of swapin page faults whose frequency can be affected by the task/process' rss limit. Hence swapin delays can act as feedback for rss limit changes independent of I/O priority changes. Signed-off-by: Shailabh Nagar <nagar@watson.ibm.com> Signed-off-by: Balbir Singh <balbir@in.ibm.com> Cc: Jes Sorensen <jes@sgi.com> Cc: Peter Chubb <peterc@gelato.unsw.edu.au> Cc: Erich Focht <efocht@ess.nec.de> Cc: Levent Serinol <lserinol@gmail.com> Cc: Jay Lan <jlan@engr.sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-14 07:24:37 +00:00
delayacct_blkio_start();
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
atomic_inc(&rq->nr_iowait);
block: initial patch for on-stack per-task plugging This patch adds support for creating a queuing context outside of the queue itself. This enables us to batch up pieces of IO before grabbing the block device queue lock and submitting them to the IO scheduler. The context is created on the stack of the process and assigned in the task structure, so that we can auto-unplug it if we hit a schedule event. The current queue plugging happens implicitly if IO is submitted to an empty device, yet callers have to remember to unplug that IO when they are going to wait for it. This is an ugly API and has caused bugs in the past. Additionally, it requires hacks in the vm (->sync_page() callback) to handle that logic. By switching to an explicit plugging scheme we make the API a lot nicer and can get rid of the ->sync_page() hack in the vm. Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2011-03-08 12:19:51 +00:00
blk_flush_plug(current);
sched: Provide iowait counters For counting how long an application has been waiting for (disk) IO, there currently is only the HZ sample driven information available, while for all other counters in this class, a high resolution version is available via CONFIG_SCHEDSTATS. In order to make an improved bootchart tool possible, we also need a higher resolution version of the iowait time. This patch below adds this scheduler statistic to the kernel. Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <4A64B813.1080506@linux.intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-07-20 18:26:58 +00:00
current->in_iowait = 1;
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
ret = schedule_timeout(timeout);
sched: Provide iowait counters For counting how long an application has been waiting for (disk) IO, there currently is only the HZ sample driven information available, while for all other counters in this class, a high resolution version is available via CONFIG_SCHEDSTATS. In order to make an improved bootchart tool possible, we also need a higher resolution version of the iowait time. This patch below adds this scheduler statistic to the kernel. Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <4A64B813.1080506@linux.intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-07-20 18:26:58 +00:00
current->in_iowait = 0;
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
atomic_dec(&rq->nr_iowait);
[PATCH] per-task-delay-accounting: sync block I/O and swapin delay collection Unlike earlier iterations of the delay accounting patches, now delays are only collected for the actual I/O waits rather than try and cover the delays seen in I/O submission paths. Account separately for block I/O delays incurred as a result of swapin page faults whose frequency can be affected by the task/process' rss limit. Hence swapin delays can act as feedback for rss limit changes independent of I/O priority changes. Signed-off-by: Shailabh Nagar <nagar@watson.ibm.com> Signed-off-by: Balbir Singh <balbir@in.ibm.com> Cc: Jes Sorensen <jes@sgi.com> Cc: Peter Chubb <peterc@gelato.unsw.edu.au> Cc: Erich Focht <efocht@ess.nec.de> Cc: Levent Serinol <lserinol@gmail.com> Cc: Jay Lan <jlan@engr.sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-14 07:24:37 +00:00
delayacct_blkio_end();
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
return ret;
}
/**
* sys_sched_get_priority_max - return maximum RT priority.
* @policy: scheduling class.
*
* this syscall returns the maximum rt_priority that can be used
* by a given scheduling class.
*/
[CVE-2009-0029] System call wrappers part 06 Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2009-01-14 13:14:08 +00:00
SYSCALL_DEFINE1(sched_get_priority_max, int, policy)
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
{
int ret = -EINVAL;
switch (policy) {
case SCHED_FIFO:
case SCHED_RR:
ret = MAX_USER_RT_PRIO-1;
break;
case SCHED_NORMAL:
[PATCH] sched: add new SCHED_BATCH policy Add a new SCHED_BATCH (3) scheduling policy: such tasks are presumed CPU-intensive, and will acquire a constant +5 priority level penalty. Such policy is nice for workloads that are non-interactive, but which do not want to give up their nice levels. The policy is also useful for workloads that want a deterministic scheduling policy without interactivity causing extra preemptions (between that workload's tasks). Signed-off-by: Ingo Molnar <mingo@elte.hu> Cc: Michael Kerrisk <mtk-manpages@gmx.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-14 21:20:41 +00:00
case SCHED_BATCH:
sched: cfs core code apply the CFS core code. this change switches over the scheduler core to CFS's modular design and makes use of kernel/sched_fair/rt/idletask.c to implement Linux's scheduling policies. thanks to Andrew Morton and Thomas Gleixner for lots of detailed review feedback and for fixlets. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
2007-07-09 16:51:59 +00:00
case SCHED_IDLE:
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
ret = 0;
break;
}
return ret;
}
/**
* sys_sched_get_priority_min - return minimum RT priority.
* @policy: scheduling class.
*
* this syscall returns the minimum rt_priority that can be used
* by a given scheduling class.
*/
[CVE-2009-0029] System call wrappers part 06 Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2009-01-14 13:14:08 +00:00
SYSCALL_DEFINE1(sched_get_priority_min, int, policy)
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
{
int ret = -EINVAL;
switch (policy) {
case SCHED_FIFO:
case SCHED_RR:
ret = 1;
break;
case SCHED_NORMAL:
[PATCH] sched: add new SCHED_BATCH policy Add a new SCHED_BATCH (3) scheduling policy: such tasks are presumed CPU-intensive, and will acquire a constant +5 priority level penalty. Such policy is nice for workloads that are non-interactive, but which do not want to give up their nice levels. The policy is also useful for workloads that want a deterministic scheduling policy without interactivity causing extra preemptions (between that workload's tasks). Signed-off-by: Ingo Molnar <mingo@elte.hu> Cc: Michael Kerrisk <mtk-manpages@gmx.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-14 21:20:41 +00:00
case SCHED_BATCH:
sched: cfs core code apply the CFS core code. this change switches over the scheduler core to CFS's modular design and makes use of kernel/sched_fair/rt/idletask.c to implement Linux's scheduling policies. thanks to Andrew Morton and Thomas Gleixner for lots of detailed review feedback and for fixlets. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
2007-07-09 16:51:59 +00:00
case SCHED_IDLE:
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
ret = 0;
}
return ret;
}
/**
* sys_sched_rr_get_interval - return the default timeslice of a process.
* @pid: pid of the process.
* @interval: userspace pointer to the timeslice value.
*
* this syscall writes the default timeslice value of a given process
* into the user-space timespec buffer. A value of '0' means infinity.
*/
[CVE-2009-0029] System call wrappers part 08 Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2009-01-14 13:14:10 +00:00
SYSCALL_DEFINE2(sched_rr_get_interval, pid_t, pid,
[CVE-2009-0029] System call wrappers part 07 Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2009-01-14 13:14:09 +00:00
struct timespec __user *, interval)
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
{
[PATCH] sched: cleanup, remove task_t, convert to struct task_struct cleanup: remove task_t and convert all the uses to struct task_struct. I introduced it for the scheduler anno and it was a mistake. Conversion was mostly scripted, the result was reviewed and all secondary whitespace and style impact (if any) was fixed up by hand. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-03 07:25:41 +00:00
struct task_struct *p;
sched: tidy up SCHED_RR - make timeslices of SCHED_RR tasks constant and not dependent on task's static_prio [1] ; - remove obsolete code (timeslice related bits); - make sched_rr_get_interval() return something more meaningful [2] for SCHED_OTHER tasks. [1] according to the following link, it's not compliant with SUSv3 (not sure though, what is the reference for us :-) http://lkml.org/lkml/2007/3/7/656 [2] the interval is dynamic and can be depicted as follows "should a task be one of the runnable tasks at this particular moment, it would expect to run for this interval of time before being re-scheduled by the scheduler tick". (i.e. it's more precise if a task is runnable at the moment) yeah, this seems to require task_rq_lock/unlock() but this is not a hot path. results: (SCHED_FIFO) dimm@earth:~/storage/prog$ sudo chrt -f 10 ./rr_interval time_slice: 0 : 0 (SCHED_RR) dimm@earth:~/storage/prog$ sudo chrt 10 ./rr_interval time_slice: 0 : 99984800 (SCHED_NORMAL) dimm@earth:~/storage/prog$ ./rr_interval time_slice: 0 : 19996960 (SCHED_NORMAL + a cpu_hog of similar 'weight' on the same CPU --- so should be a half of the previous result) dimm@earth:~/storage/prog$ taskset 1 ./rr_interval time_slice: 0 : 9998480 Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 15:00:13 +00:00
unsigned int time_slice;
sched: Protect sched_rr_get_param() access to task->sched_class sched_rr_get_param calls task->sched_class->get_rr_interval(task) without protection against a concurrent sched_setscheduler() call which modifies task->sched_class. Serialize the access with task_rq_lock(task) and hand the rq pointer into get_rr_interval() as it's needed at least in the sched_fair implementation. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <alpine.LFD.2.00.0912090930120.3089@localhost.localdomain> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-09 08:32:03 +00:00
unsigned long flags;
struct rq *rq;
sched: cleanup: remove unnecessary gotos Replace loops implemented with gotos with real loops. Replace err = ...; goto x; x: return err; with return ...; No functional changes. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 15:00:14 +00:00
int retval;
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
struct timespec t;
if (pid < 0)
sched: cleanup: remove unnecessary gotos Replace loops implemented with gotos with real loops. Replace err = ...; goto x; x: return err; with return ...; No functional changes. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 15:00:14 +00:00
return -EINVAL;
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
retval = -ESRCH;
sched: Use rcu in sched_get_rr_param() read_lock(&tasklist_lock) does not protect sys_sched_get_rr_param() against a concurrent update of the policy or scheduler parameters as do_sched_scheduler() does not take the tasklist_lock. The access to task->sched_class->get_rr_interval is protected by task_rq_lock(task). Use rcu_read_lock() to protect find_task_by_vpid() and prevent the task struct from going away. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <20091209100706.862897167@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-09 10:15:11 +00:00
rcu_read_lock();
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
p = find_process_by_pid(pid);
if (!p)
goto out_unlock;
retval = security_task_getscheduler(p);
if (retval)
goto out_unlock;
sched: Protect sched_rr_get_param() access to task->sched_class sched_rr_get_param calls task->sched_class->get_rr_interval(task) without protection against a concurrent sched_setscheduler() call which modifies task->sched_class. Serialize the access with task_rq_lock(task) and hand the rq pointer into get_rr_interval() as it's needed at least in the sched_fair implementation. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <alpine.LFD.2.00.0912090930120.3089@localhost.localdomain> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-09 08:32:03 +00:00
rq = task_rq_lock(p, &flags);
time_slice = p->sched_class->get_rr_interval(rq, p);
sched: Add p->pi_lock to task_rq_lock() In order to be able to call set_task_cpu() while either holding p->pi_lock or task_rq(p)->lock we need to hold both locks in order to stabilize task_rq(). This makes task_rq_lock() acquire both locks, and have __task_rq_lock() validate that p->pi_lock is held. This increases the locking overhead for most scheduler syscalls but allows reduction of rq->lock contention for some scheduler hot paths (ttwu). Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110405152729.232781355@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-05 15:23:51 +00:00
task_rq_unlock(rq, p, &flags);
sched: tidy up SCHED_RR - make timeslices of SCHED_RR tasks constant and not dependent on task's static_prio [1] ; - remove obsolete code (timeslice related bits); - make sched_rr_get_interval() return something more meaningful [2] for SCHED_OTHER tasks. [1] according to the following link, it's not compliant with SUSv3 (not sure though, what is the reference for us :-) http://lkml.org/lkml/2007/3/7/656 [2] the interval is dynamic and can be depicted as follows "should a task be one of the runnable tasks at this particular moment, it would expect to run for this interval of time before being re-scheduled by the scheduler tick". (i.e. it's more precise if a task is runnable at the moment) yeah, this seems to require task_rq_lock/unlock() but this is not a hot path. results: (SCHED_FIFO) dimm@earth:~/storage/prog$ sudo chrt -f 10 ./rr_interval time_slice: 0 : 0 (SCHED_RR) dimm@earth:~/storage/prog$ sudo chrt 10 ./rr_interval time_slice: 0 : 99984800 (SCHED_NORMAL) dimm@earth:~/storage/prog$ ./rr_interval time_slice: 0 : 19996960 (SCHED_NORMAL + a cpu_hog of similar 'weight' on the same CPU --- so should be a half of the previous result) dimm@earth:~/storage/prog$ taskset 1 ./rr_interval time_slice: 0 : 9998480 Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 15:00:13 +00:00
sched: Use rcu in sched_get_rr_param() read_lock(&tasklist_lock) does not protect sys_sched_get_rr_param() against a concurrent update of the policy or scheduler parameters as do_sched_scheduler() does not take the tasklist_lock. The access to task->sched_class->get_rr_interval is protected by task_rq_lock(task). Use rcu_read_lock() to protect find_task_by_vpid() and prevent the task struct from going away. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <20091209100706.862897167@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-09 10:15:11 +00:00
rcu_read_unlock();
sched: tidy up SCHED_RR - make timeslices of SCHED_RR tasks constant and not dependent on task's static_prio [1] ; - remove obsolete code (timeslice related bits); - make sched_rr_get_interval() return something more meaningful [2] for SCHED_OTHER tasks. [1] according to the following link, it's not compliant with SUSv3 (not sure though, what is the reference for us :-) http://lkml.org/lkml/2007/3/7/656 [2] the interval is dynamic and can be depicted as follows "should a task be one of the runnable tasks at this particular moment, it would expect to run for this interval of time before being re-scheduled by the scheduler tick". (i.e. it's more precise if a task is runnable at the moment) yeah, this seems to require task_rq_lock/unlock() but this is not a hot path. results: (SCHED_FIFO) dimm@earth:~/storage/prog$ sudo chrt -f 10 ./rr_interval time_slice: 0 : 0 (SCHED_RR) dimm@earth:~/storage/prog$ sudo chrt 10 ./rr_interval time_slice: 0 : 99984800 (SCHED_NORMAL) dimm@earth:~/storage/prog$ ./rr_interval time_slice: 0 : 19996960 (SCHED_NORMAL + a cpu_hog of similar 'weight' on the same CPU --- so should be a half of the previous result) dimm@earth:~/storage/prog$ taskset 1 ./rr_interval time_slice: 0 : 9998480 Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 15:00:13 +00:00
jiffies_to_timespec(time_slice, &t);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
retval = copy_to_user(interval, &t, sizeof(t)) ? -EFAULT : 0;
return retval;
sched: cleanup: remove unnecessary gotos Replace loops implemented with gotos with real loops. Replace err = ...; goto x; x: return err; with return ...; No functional changes. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 15:00:14 +00:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
out_unlock:
sched: Use rcu in sched_get_rr_param() read_lock(&tasklist_lock) does not protect sys_sched_get_rr_param() against a concurrent update of the policy or scheduler parameters as do_sched_scheduler() does not take the tasklist_lock. The access to task->sched_class->get_rr_interval is protected by task_rq_lock(task). Use rcu_read_lock() to protect find_task_by_vpid() and prevent the task struct from going away. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <20091209100706.862897167@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-09 10:15:11 +00:00
rcu_read_unlock();
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
return retval;
}
ftrace: make the task state char-string visible to all The tracer wants to be able to convert the state number into a user visible character. This patch pulls that conversion string out the scheduler into the header. This way if it were to ever change, other parts of the kernel will know. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-12 19:20:41 +00:00
static const char stat_nam[] = TASK_STATE_TO_CHAR_STR;
[PATCH] sched: cleanup, remove task_t, convert to struct task_struct cleanup: remove task_t and convert all the uses to struct task_struct. I introduced it for the scheduler anno and it was a mistake. Conversion was mostly scripted, the result was reviewed and all secondary whitespace and style impact (if any) was fixed up by hand. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-03 07:25:41 +00:00
softlockup: automatically detect hung TASK_UNINTERRUPTIBLE tasks this patch extends the soft-lockup detector to automatically detect hung TASK_UNINTERRUPTIBLE tasks. Such hung tasks are printed the following way: ------------------> INFO: task prctl:3042 blocked for more than 120 seconds. "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message prctl D fd5e3793 0 3042 2997 f6050f38 00000046 00000001 fd5e3793 00000009 c06d8264 c06dae80 00000286 f6050f40 f6050f00 f7d34d90 f7d34fc8 c1e1be80 00000001 f6050000 00000000 f7e92d00 00000286 f6050f18 c0489d1a f6050f40 00006605 00000000 c0133a5b Call Trace: [<c04883a5>] schedule_timeout+0x6d/0x8b [<c04883d8>] schedule_timeout_uninterruptible+0x15/0x17 [<c0133a76>] msleep+0x10/0x16 [<c0138974>] sys_prctl+0x30/0x1e2 [<c0104c52>] sysenter_past_esp+0x5f/0xa5 ======================= 2 locks held by prctl/3042: #0: (&sb->s_type->i_mutex_key#5){--..}, at: [<c0197d11>] do_fsync+0x38/0x7a #1: (jbd_handle){--..}, at: [<c01ca3d2>] journal_start+0xc7/0xe9 <------------------ the current default timeout is 120 seconds. Such messages are printed up to 10 times per bootup. If the system has crashed already then the messages are not printed. if lockdep is enabled then all held locks are printed as well. this feature is a natural extension to the softlockup-detector (kernel locked up without scheduling) and to the NMI watchdog (kernel locked up with IRQs disabled). [ Gautham R Shenoy <ego@in.ibm.com>: CPU hotplug fixes. ] [ Andrew Morton <akpm@linux-foundation.org>: build warning fix. ] Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
2008-01-25 20:08:02 +00:00
void sched_show_task(struct task_struct *p)
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
{
unsigned long free = 0;
[PATCH] sched: cleanup, remove task_t, convert to struct task_struct cleanup: remove task_t and convert all the uses to struct task_struct. I introduced it for the scheduler anno and it was a mistake. Conversion was mostly scripted, the result was reviewed and all secondary whitespace and style impact (if any) was fixed up by hand. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-03 07:25:41 +00:00
unsigned state;
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
state = p->state ? __ffs(p->state) + 1 : 0;
sched: Make task dump print all 15 chars of proc comm Signed-off-by: Erik Gilling <konkers@android.com> Signed-off-by: John Stultz <john.stultz@linaro.org> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1290218934-8544-3-git-send-email-john.stultz@linaro.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-20 02:08:51 +00:00
printk(KERN_INFO "%-15.15s %c", p->comm,
[PATCH] small kernel/sched.c cleanup - constify and optimize stat_nam (thanks to Michael Tokarev!) - spelling and comment fixes Signed-off-by: Andreas Mohr <andi@lisas.de> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-10 11:43:52 +00:00
state < sizeof(stat_nam) - 1 ? stat_nam[state] : '?');
[PATCH] sched: fix show_task()/show_tasks() output fix show_task()/show_tasks() output: - there's no sibling info anymore - the fields were not aligned properly with the description - get rid of the lazy-TLB output: it's been quite some time since we last had a bug there, and when we had a bug it wasnt helped a bit by this debug output. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-11 19:21:47 +00:00
#if BITS_PER_LONG == 32
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
if (state == TASK_RUNNING)
sched: Restore printk sanity Revert the braindead pr_* crap. (Commit 663997d "sched: Use pr_fmt() and pr_<level>()") It's dumb and causes stupid "sched: " strings all over the place. Signed-off-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Mike Galbraith <efault@gmx.de> Cc: Joe Perches <joe@perches.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> LKML-Reference: <1261315437.4314.6.camel@laptop> [ i dont mind the pr_*() patterns that much - but Peter dislikes them with a vengence. ] [ - v2: remove spurious diffstat from changelog :-/ ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-20 13:23:57 +00:00
printk(KERN_CONT " running ");
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
else
sched: Restore printk sanity Revert the braindead pr_* crap. (Commit 663997d "sched: Use pr_fmt() and pr_<level>()") It's dumb and causes stupid "sched: " strings all over the place. Signed-off-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Mike Galbraith <efault@gmx.de> Cc: Joe Perches <joe@perches.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> LKML-Reference: <1261315437.4314.6.camel@laptop> [ i dont mind the pr_*() patterns that much - but Peter dislikes them with a vengence. ] [ - v2: remove spurious diffstat from changelog :-/ ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-20 13:23:57 +00:00
printk(KERN_CONT " %08lx ", thread_saved_pc(p));
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
#else
if (state == TASK_RUNNING)
sched: Restore printk sanity Revert the braindead pr_* crap. (Commit 663997d "sched: Use pr_fmt() and pr_<level>()") It's dumb and causes stupid "sched: " strings all over the place. Signed-off-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Mike Galbraith <efault@gmx.de> Cc: Joe Perches <joe@perches.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> LKML-Reference: <1261315437.4314.6.camel@laptop> [ i dont mind the pr_*() patterns that much - but Peter dislikes them with a vengence. ] [ - v2: remove spurious diffstat from changelog :-/ ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-20 13:23:57 +00:00
printk(KERN_CONT " running task ");
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
else
sched: Restore printk sanity Revert the braindead pr_* crap. (Commit 663997d "sched: Use pr_fmt() and pr_<level>()") It's dumb and causes stupid "sched: " strings all over the place. Signed-off-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Mike Galbraith <efault@gmx.de> Cc: Joe Perches <joe@perches.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> LKML-Reference: <1261315437.4314.6.camel@laptop> [ i dont mind the pr_*() patterns that much - but Peter dislikes them with a vengence. ] [ - v2: remove spurious diffstat from changelog :-/ ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-20 13:23:57 +00:00
printk(KERN_CONT " %016lx ", thread_saved_pc(p));
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
#endif
#ifdef CONFIG_DEBUG_STACK_USAGE
stackprotector: use canary at end of stack to indicate overruns at oops time (Updated with a common max-stack-used checker that knows about the canary, as suggested by Joe Perches) Use a canary at the end of the stack to clearly indicate at oops time whether the stack has ever overflowed. This is a very simple implementation with a couple of drawbacks: 1) a thread may legitimately use exactly up to the last word on the stack -- but the chances of doing this and then oopsing later seem slim 2) it's possible that the stack usage isn't dense enough that the canary location could get skipped over -- but the worst that happens is that we don't flag the overrun -- though this happens fairly often in my testing :( With the code in place, an intentionally-bloated stack oops might do: BUG: unable to handle kernel paging request at ffff8103f84cc680 IP: [<ffffffff810253df>] update_curr+0x9a/0xa8 PGD 8063 PUD 0 Thread overran stack or stack corrupted Oops: 0000 [1] SMP CPU 0 ... ... unless the stack overrun is so bad that it corrupts some other thread. Signed-off-by: Eric Sandeen <sandeen@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-04-22 21:38:23 +00:00
free = stack_not_used(p);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
#endif
sched: Restore printk sanity Revert the braindead pr_* crap. (Commit 663997d "sched: Use pr_fmt() and pr_<level>()") It's dumb and causes stupid "sched: " strings all over the place. Signed-off-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Mike Galbraith <efault@gmx.de> Cc: Joe Perches <joe@perches.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> LKML-Reference: <1261315437.4314.6.camel@laptop> [ i dont mind the pr_*() patterns that much - but Peter dislikes them with a vengence. ] [ - v2: remove spurious diffstat from changelog :-/ ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-20 13:23:57 +00:00
printk(KERN_CONT "%5lu %5d %6d 0x%08lx\n", free,
sched: emit thread info flags with stack trace When a thread is oom killed and fails to exit, it's helpful to know which threads have access to memory reserves if the machine livelocks. This is done by testing for the TIF_MEMDIE thread info flag and should be displayed alongside stack traces to identify tasks that have access to such reserves but are still stuck allocating pages, for instance. It would probably be helpful in other cases as well, so all thread info flags are emitted when showing a task. ( v2: fix warning reported by Stephen Rothwell ) [ Impact: extend debug printout info ] Signed-off-by: David Rientjes <rientjes@google.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Stephen Rothwell <sfr@canb.auug.org.au> LKML-Reference: <alpine.DEB.2.00.0905040136390.15831@chino.kir.corp.google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-05-04 08:38:05 +00:00
task_pid_nr(p), task_pid_nr(p->real_parent),
(unsigned long)task_thread_info(p)->flags);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
sched: print backtrace of running tasks too The attached patch is something really simple that can sometimes help in getting more info out of a hung system. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:34 +00:00
show_stack(p, NULL);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
}
[PATCH] SysRq-X: show blocked tasks Add SysRq-X support: show blocked (TASK_UNINTERRUPTIBLE) tasks only. Useful for debugging IO stalls. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-07 04:35:59 +00:00
void show_state_filter(unsigned long state_filter)
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
{
[PATCH] sched: cleanup, remove task_t, convert to struct task_struct cleanup: remove task_t and convert all the uses to struct task_struct. I introduced it for the scheduler anno and it was a mistake. Conversion was mostly scripted, the result was reviewed and all secondary whitespace and style impact (if any) was fixed up by hand. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-03 07:25:41 +00:00
struct task_struct *g, *p;
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
[PATCH] sched: fix show_task()/show_tasks() output fix show_task()/show_tasks() output: - there's no sibling info anymore - the fields were not aligned properly with the description - get rid of the lazy-TLB output: it's been quite some time since we last had a bug there, and when we had a bug it wasnt helped a bit by this debug output. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-11 19:21:47 +00:00
#if BITS_PER_LONG == 32
sched: Restore printk sanity Revert the braindead pr_* crap. (Commit 663997d "sched: Use pr_fmt() and pr_<level>()") It's dumb and causes stupid "sched: " strings all over the place. Signed-off-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Mike Galbraith <efault@gmx.de> Cc: Joe Perches <joe@perches.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> LKML-Reference: <1261315437.4314.6.camel@laptop> [ i dont mind the pr_*() patterns that much - but Peter dislikes them with a vengence. ] [ - v2: remove spurious diffstat from changelog :-/ ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-20 13:23:57 +00:00
printk(KERN_INFO
" task PC stack pid father\n");
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
#else
sched: Restore printk sanity Revert the braindead pr_* crap. (Commit 663997d "sched: Use pr_fmt() and pr_<level>()") It's dumb and causes stupid "sched: " strings all over the place. Signed-off-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Mike Galbraith <efault@gmx.de> Cc: Joe Perches <joe@perches.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> LKML-Reference: <1261315437.4314.6.camel@laptop> [ i dont mind the pr_*() patterns that much - but Peter dislikes them with a vengence. ] [ - v2: remove spurious diffstat from changelog :-/ ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-20 13:23:57 +00:00
printk(KERN_INFO
" task PC stack pid father\n");
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
#endif
read_lock(&tasklist_lock);
do_each_thread(g, p) {
/*
* reset the NMI-timeout, listing all files on a slow
Fix common misspellings Fixes generated by 'codespell' and manually reviewed. Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
2011-03-31 01:57:33 +00:00
* console might take a lot of time:
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
*/
touch_nmi_watchdog();
make SysRq-T show all tasks again show_state() (SysRq-T) developed the buggy habbit of not showing TASK_RUNNING tasks. This was due to the mistaken belief that state_filter == -1 would be a pass-through filter - while in reality it did not let TASK_RUNNING == 0 p->state values through. Fix this by restoring the original '!state_filter means all tasks' special-case i had in the original version. Test-built and test-booted on i686, SysRq-T now works as intended. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-04-26 03:50:03 +00:00
if (!state_filter || (p->state & state_filter))
softlockup: automatically detect hung TASK_UNINTERRUPTIBLE tasks this patch extends the soft-lockup detector to automatically detect hung TASK_UNINTERRUPTIBLE tasks. Such hung tasks are printed the following way: ------------------> INFO: task prctl:3042 blocked for more than 120 seconds. "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message prctl D fd5e3793 0 3042 2997 f6050f38 00000046 00000001 fd5e3793 00000009 c06d8264 c06dae80 00000286 f6050f40 f6050f00 f7d34d90 f7d34fc8 c1e1be80 00000001 f6050000 00000000 f7e92d00 00000286 f6050f18 c0489d1a f6050f40 00006605 00000000 c0133a5b Call Trace: [<c04883a5>] schedule_timeout+0x6d/0x8b [<c04883d8>] schedule_timeout_uninterruptible+0x15/0x17 [<c0133a76>] msleep+0x10/0x16 [<c0138974>] sys_prctl+0x30/0x1e2 [<c0104c52>] sysenter_past_esp+0x5f/0xa5 ======================= 2 locks held by prctl/3042: #0: (&sb->s_type->i_mutex_key#5){--..}, at: [<c0197d11>] do_fsync+0x38/0x7a #1: (jbd_handle){--..}, at: [<c01ca3d2>] journal_start+0xc7/0xe9 <------------------ the current default timeout is 120 seconds. Such messages are printed up to 10 times per bootup. If the system has crashed already then the messages are not printed. if lockdep is enabled then all held locks are printed as well. this feature is a natural extension to the softlockup-detector (kernel locked up without scheduling) and to the NMI watchdog (kernel locked up with IRQs disabled). [ Gautham R Shenoy <ego@in.ibm.com>: CPU hotplug fixes. ] [ Andrew Morton <akpm@linux-foundation.org>: build warning fix. ] Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
2008-01-25 20:08:02 +00:00
sched_show_task(p);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
} while_each_thread(g, p);
add touch_all_softlockup_watchdogs() Add touch_all_softlockup_watchdogs() to allow the softlockup watchdog timers on all cpus to be updated. This is used to prevent sysrq-t from generating a spurious watchdog message when generating lots of output. Softlockup watchdogs use sched_clock() as its timebase, which is inherently per-cpu (at least, when it is measuring unstolen time). Because of this, it isn't possible for one CPU to directly update the other CPU's timers, but it is possible to tell the other CPUs to do update themselves appropriately. Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com> Acked-by: Chris Lalancette <clalance@redhat.com> Signed-off-by: Prarit Bhargava <prarit@redhat.com> Cc: Rick Lindsley <ricklind@us.ibm.com> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-08 07:28:05 +00:00
touch_all_softlockup_watchdogs();
sched: cfs core code apply the CFS core code. this change switches over the scheduler core to CFS's modular design and makes use of kernel/sched_fair/rt/idletask.c to implement Linux's scheduling policies. thanks to Andrew Morton and Thomas Gleixner for lots of detailed review feedback and for fixlets. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
2007-07-09 16:51:59 +00:00
#ifdef CONFIG_SCHED_DEBUG
sysrq_sched_debug_show();
#endif
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
read_unlock(&tasklist_lock);
[PATCH] SysRq-X: show blocked tasks Add SysRq-X support: show blocked (TASK_UNINTERRUPTIBLE) tasks only. Useful for debugging IO stalls. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-07 04:35:59 +00:00
/*
* Only show locks if all tasks are dumped:
*/
sched.c: Call debug_show_all_locks() when dumping all tasks In commit v2.6.21-691-g39bc89f ("make SysRq-T show all tasks again") the interface of show_state_filter() was changed: zero valued 'state_filter' specifies "dump all tasks" (instead of -1). However, the condition for calling debug_show_all_locks() ("show locks if all tasks are dumped") was not updated accordingly. Signed-off-by: Shmulik Ladkani <shmulik.ladkani@gmail.com> Cc: peterz@infradead.org LKML-Reference: <4b0d2fe4.0ab6660a.6437.3cfc@mx.google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-11-25 13:23:41 +00:00
if (!state_filter)
[PATCH] SysRq-X: show blocked tasks Add SysRq-X support: show blocked (TASK_UNINTERRUPTIBLE) tasks only. Useful for debugging IO stalls. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-07 04:35:59 +00:00
debug_show_all_locks();
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
}
sched: add init_idle_bootup_task() add the init_idle_bootup_task() callback to the bootup thread, unused at the moment. (CFS will use it to switch the scheduling class of the boot thread to the idle class) Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-09 16:51:58 +00:00
void __cpuinit init_idle_bootup_task(struct task_struct *idle)
{
sched: cfs core code apply the CFS core code. this change switches over the scheduler core to CFS's modular design and makes use of kernel/sched_fair/rt/idletask.c to implement Linux's scheduling policies. thanks to Andrew Morton and Thomas Gleixner for lots of detailed review feedback and for fixlets. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
2007-07-09 16:51:59 +00:00
idle->sched_class = &idle_sched_class;
sched: add init_idle_bootup_task() add the init_idle_bootup_task() callback to the bootup thread, unused at the moment. (CFS will use it to switch the scheduling class of the boot thread to the idle class) Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-09 16:51:58 +00:00
}
[PATCH] Tweak idle thread setup semantics This patch tweaks idle thread setup semantics a bit: instead of setting NEED_RESCHED in init_idle(), we do an explicit schedule() before calling into cpu_idle(). This patch, while having no negative side-effects, enables wider use of cond_resched()s. (which might happen in the stock kernel too, but it's particulary important for voluntary-preempt) Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-28 14:40:42 +00:00
/**
* init_idle - set up an idle thread for a given CPU
* @idle: task in question
* @cpu: cpu the idle task belongs to
*
* NOTE: this function does not set the idle thread's NEED_RESCHED
* flag, to make booting more robust.
*/
[PATCH] sched: force /sbin/init off isolated cpus Force /sbin/init off isolated cpus (unless every CPU is specified as an isolcpu). Users seem to think that the isolated CPUs shouldn't have much running on them to begin with. That's fair enough: intuitive, I guess. It also means that the cpu affinity masks of tasks will not include isolcpus by default, which is also more intuitive, perhaps. /sbin/init is spawned from the boot CPU's idle thread, and /sbin/init starts the rest of userspace. So if the boot CPU is specified to be an isolcpu, then prior to this patch, all of userspace will be run there. (throw in a couple of plausible devinit -> cpuinit conversions I spotted while we're here). Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: Dimitri Sivanich <sivanich@sgi.com> Acked-by: Paul Jackson <pj@sgi.com> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-03 08:14:04 +00:00
void __cpuinit init_idle(struct task_struct *idle, int cpu)
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
{
[PATCH] sched: cleanup, convert sched.c-internal typedefs to struct convert: - runqueue_t to 'struct rq' - prio_array_t to 'struct prio_array' - migration_req_t to 'struct migration_req' I was the one who added these but they are both against the kernel coding style and also were used inconsistently at places. So just get rid of them at once, now that we are flushing the scheduler patch-queue anyway. Conversion was mostly scripted, the result was reviewed and all secondary whitespace and style impact (if any) was fixed up by hand. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-03 07:25:42 +00:00
struct rq *rq = cpu_rq(cpu);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
unsigned long flags;
sched: Convert rq->lock to raw_spinlock Convert locks which cannot be sleeping locks in preempt-rt to raw_spinlocks. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Ingo Molnar <mingo@elte.hu>
2009-11-17 13:28:38 +00:00
raw_spin_lock_irqsave(&rq->lock, flags);
sched: fix init_idle()'s use of sched_clock() Maciej Rutecki reported: > I have this bug during suspend to disk: > > [ 188.592151] Enabling non-boot CPUs ... > [ 188.592151] SMP alternatives: switching to SMP code > [ 188.666058] BUG: using smp_processor_id() in preemptible > [00000000] > code: suspend_to_disk/2934 > [ 188.666064] caller is native_sched_clock+0x2b/0x80 Which, as noted by Linus, was caused by me, via: 7cbaef9c "sched: optimize sched_clock() a bit" Move the rq locking a bit earlier in the initialization sequence, that will make the sched_clock() call in init_idle() non-preemptible. Reported-by: Maciej Rutecki <maciej.rutecki@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-12 19:05:50 +00:00
sched: cfs core code apply the CFS core code. this change switches over the scheduler core to CFS's modular design and makes use of kernel/sched_fair/rt/idletask.c to implement Linux's scheduling policies. thanks to Andrew Morton and Thomas Gleixner for lots of detailed review feedback and for fixlets. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
2007-07-09 16:51:59 +00:00
__sched_fork(idle);
sched: Use TASK_WAKING for fork wakups For later convenience use TASK_WAKING for fresh tasks. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> LKML-Reference: <20091216170517.732561278@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-16 17:04:35 +00:00
idle->state = TASK_RUNNING;
sched: cfs core code apply the CFS core code. this change switches over the scheduler core to CFS's modular design and makes use of kernel/sched_fair/rt/idletask.c to implement Linux's scheduling policies. thanks to Andrew Morton and Thomas Gleixner for lots of detailed review feedback and for fixlets. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
2007-07-09 16:51:59 +00:00
idle->se.exec_start = sched_clock();
cpuset: Fix cpuset_cpus_allowed_fallback(), don't update tsk->rt.nr_cpus_allowed The rule is, we have to update tsk->rt.nr_cpus_allowed if we change tsk->cpus_allowed. Otherwise RT scheduler may confuse. Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/4DD4B3FA.5060901@jp.fujitsu.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-05-19 06:08:58 +00:00
do_set_cpus_allowed(idle, cpumask_of(cpu));
sched: fix RCU lockdep splat from task_group() This addresses the following RCU lockdep splat: [0.051203] CPU0: AMD QEMU Virtual CPU version 0.12.4 stepping 03 [0.052999] lockdep: fixing up alternatives. [0.054105] [0.054106] =================================================== [0.054999] [ INFO: suspicious rcu_dereference_check() usage. ] [0.054999] --------------------------------------------------- [0.054999] kernel/sched.c:616 invoked rcu_dereference_check() without protection! [0.054999] [0.054999] other info that might help us debug this: [0.054999] [0.054999] [0.054999] rcu_scheduler_active = 1, debug_locks = 1 [0.054999] 3 locks held by swapper/1: [0.054999] #0: (cpu_add_remove_lock){+.+.+.}, at: [<ffffffff814be933>] cpu_up+0x42/0x6a [0.054999] #1: (cpu_hotplug.lock){+.+.+.}, at: [<ffffffff810400d8>] cpu_hotplug_begin+0x2a/0x51 [0.054999] #2: (&rq->lock){-.-...}, at: [<ffffffff814be2f7>] init_idle+0x2f/0x113 [0.054999] [0.054999] stack backtrace: [0.054999] Pid: 1, comm: swapper Not tainted 2.6.35 #1 [0.054999] Call Trace: [0.054999] [<ffffffff81068054>] lockdep_rcu_dereference+0x9b/0xa3 [0.054999] [<ffffffff810325c3>] task_group+0x7b/0x8a [0.054999] [<ffffffff810325e5>] set_task_rq+0x13/0x40 [0.054999] [<ffffffff814be39a>] init_idle+0xd2/0x113 [0.054999] [<ffffffff814be78a>] fork_idle+0xb8/0xc7 [0.054999] [<ffffffff81068717>] ? mark_held_locks+0x4d/0x6b [0.054999] [<ffffffff814bcebd>] do_fork_idle+0x17/0x2b [0.054999] [<ffffffff814bc89b>] native_cpu_up+0x1c1/0x724 [0.054999] [<ffffffff814bcea6>] ? do_fork_idle+0x0/0x2b [0.054999] [<ffffffff814be876>] _cpu_up+0xac/0x127 [0.054999] [<ffffffff814be946>] cpu_up+0x55/0x6a [0.054999] [<ffffffff81ab562a>] kernel_init+0xe1/0x1ff [0.054999] [<ffffffff81003854>] kernel_thread_helper+0x4/0x10 [0.054999] [<ffffffff814c353c>] ? restore_args+0x0/0x30 [0.054999] [<ffffffff81ab5549>] ? kernel_init+0x0/0x1ff [0.054999] [<ffffffff81003850>] ? kernel_thread_helper+0x0/0x10 [0.056074] Booting Node 0, Processors #1lockdep: fixing up alternatives. [0.130045] #2lockdep: fixing up alternatives. [0.203089] #3 Ok. [0.275286] Brought up 4 CPUs [0.276005] Total of 4 processors activated (16017.17 BogoMIPS). The cgroup_subsys_state structures referenced by idle tasks are never freed, because the idle tasks should be part of the root cgroup, which is not removable. The problem is that while we do in-fact hold rq->lock, the newly spawned idle thread's cpu is not yet set to the correct cpu so the lockdep check in task_group(): lockdep_is_held(&task_rq(p)->lock) will fail. But this is a chicken and egg problem. Setting the CPU's runqueue requires that the CPU's runqueue already be set. ;-) So insert an RCU read-side critical section to avoid the complaint. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2010-09-16 15:50:31 +00:00
/*
* We're having a chicken and egg problem, even though we are
* holding rq->lock, the cpu isn't yet set to this cpu so the
* lockdep check in task_group() will fail.
*
* Similar case to sched_fork(). / Alternatively we could
* use task_rq_lock() here and obtain the other rq->lock.
*
* Silence PROVE_RCU
*/
rcu_read_lock();
sched: cfs core code apply the CFS core code. this change switches over the scheduler core to CFS's modular design and makes use of kernel/sched_fair/rt/idletask.c to implement Linux's scheduling policies. thanks to Andrew Morton and Thomas Gleixner for lots of detailed review feedback and for fixlets. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
2007-07-09 16:51:59 +00:00
__set_task_cpu(idle, cpu);
sched: fix RCU lockdep splat from task_group() This addresses the following RCU lockdep splat: [0.051203] CPU0: AMD QEMU Virtual CPU version 0.12.4 stepping 03 [0.052999] lockdep: fixing up alternatives. [0.054105] [0.054106] =================================================== [0.054999] [ INFO: suspicious rcu_dereference_check() usage. ] [0.054999] --------------------------------------------------- [0.054999] kernel/sched.c:616 invoked rcu_dereference_check() without protection! [0.054999] [0.054999] other info that might help us debug this: [0.054999] [0.054999] [0.054999] rcu_scheduler_active = 1, debug_locks = 1 [0.054999] 3 locks held by swapper/1: [0.054999] #0: (cpu_add_remove_lock){+.+.+.}, at: [<ffffffff814be933>] cpu_up+0x42/0x6a [0.054999] #1: (cpu_hotplug.lock){+.+.+.}, at: [<ffffffff810400d8>] cpu_hotplug_begin+0x2a/0x51 [0.054999] #2: (&rq->lock){-.-...}, at: [<ffffffff814be2f7>] init_idle+0x2f/0x113 [0.054999] [0.054999] stack backtrace: [0.054999] Pid: 1, comm: swapper Not tainted 2.6.35 #1 [0.054999] Call Trace: [0.054999] [<ffffffff81068054>] lockdep_rcu_dereference+0x9b/0xa3 [0.054999] [<ffffffff810325c3>] task_group+0x7b/0x8a [0.054999] [<ffffffff810325e5>] set_task_rq+0x13/0x40 [0.054999] [<ffffffff814be39a>] init_idle+0xd2/0x113 [0.054999] [<ffffffff814be78a>] fork_idle+0xb8/0xc7 [0.054999] [<ffffffff81068717>] ? mark_held_locks+0x4d/0x6b [0.054999] [<ffffffff814bcebd>] do_fork_idle+0x17/0x2b [0.054999] [<ffffffff814bc89b>] native_cpu_up+0x1c1/0x724 [0.054999] [<ffffffff814bcea6>] ? do_fork_idle+0x0/0x2b [0.054999] [<ffffffff814be876>] _cpu_up+0xac/0x127 [0.054999] [<ffffffff814be946>] cpu_up+0x55/0x6a [0.054999] [<ffffffff81ab562a>] kernel_init+0xe1/0x1ff [0.054999] [<ffffffff81003854>] kernel_thread_helper+0x4/0x10 [0.054999] [<ffffffff814c353c>] ? restore_args+0x0/0x30 [0.054999] [<ffffffff81ab5549>] ? kernel_init+0x0/0x1ff [0.054999] [<ffffffff81003850>] ? kernel_thread_helper+0x0/0x10 [0.056074] Booting Node 0, Processors #1lockdep: fixing up alternatives. [0.130045] #2lockdep: fixing up alternatives. [0.203089] #3 Ok. [0.275286] Brought up 4 CPUs [0.276005] Total of 4 processors activated (16017.17 BogoMIPS). The cgroup_subsys_state structures referenced by idle tasks are never freed, because the idle tasks should be part of the root cgroup, which is not removable. The problem is that while we do in-fact hold rq->lock, the newly spawned idle thread's cpu is not yet set to the correct cpu so the lockdep check in task_group(): lockdep_is_held(&task_rq(p)->lock) will fail. But this is a chicken and egg problem. Setting the CPU's runqueue requires that the CPU's runqueue already be set. ;-) So insert an RCU read-side critical section to avoid the complaint. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2010-09-16 15:50:31 +00:00
rcu_read_unlock();
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
rq->curr = rq->idle = idle;
sched: Always provide p->on_cpu Always provide p->on_cpu so that we can determine if its on a cpu without having to lock the rq. Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110405152728.785452014@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-05 15:23:40 +00:00
#if defined(CONFIG_SMP)
idle->on_cpu = 1;
[PATCH] sched: cleanup context switch locking Instead of requiring architecture code to interact with the scheduler's locking implementation, provide a couple of defines that can be used by the architecture to request runqueue unlocked context switches, and ask for interrupts to be enabled over the context switch. Also replaces the "switch_lock" used by these architectures with an oncpu flag (note, not a potentially slow bitflag). This eliminates one bus locked memory operation when context switching, and simplifies the task_running function. Signed-off-by: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-25 21:57:23 +00:00
#endif
sched: Convert rq->lock to raw_spinlock Convert locks which cannot be sleeping locks in preempt-rt to raw_spinlocks. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Ingo Molnar <mingo@elte.hu>
2009-11-17 13:28:38 +00:00
raw_spin_unlock_irqrestore(&rq->lock, flags);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
/* Set the preempt count _outside_ the spinlocks! */
[PATCH] m68k: introduce task_thread_info new helper - task_thread_info(task). On platforms that have thread_info allocated separately (i.e. in default case) it simply returns task->thread_info. m68k wants (and for good reasons) to embed its thread_info into task_struct. So it will (in later patch) have task_thread_info() of its own. For now we just add a macro for generic case and convert existing instances of its body in core kernel to uses of new macro. Obviously safe - all normal architectures get the same preprocessor output they used to get. Signed-off-by: Al Viro <viro@parcelfarce.linux.theplanet.co.uk> Signed-off-by: Roman Zippel <zippel@linux-m68k.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-14 00:06:55 +00:00
task_thread_info(idle)->preempt_count = 0;
sched: Get rid of lock_depth Neil Brown pointed out that lock_depth somehow escaped the BKL removal work. Let's get rid of it now. Note that the perf scripting utilities still have a bunch of code for dealing with common_lock_depth in tracepoints; I have left that in place in case anybody wants to use that code with older kernels. Suggested-by: Neil Brown <neilb@suse.de> Signed-off-by: Jonathan Corbet <corbet@lwn.net> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110422111910.456c0e84@bike.lwn.net Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-22 17:19:10 +00:00
sched: cfs core code apply the CFS core code. this change switches over the scheduler core to CFS's modular design and makes use of kernel/sched_fair/rt/idletask.c to implement Linux's scheduling policies. thanks to Andrew Morton and Thomas Gleixner for lots of detailed review feedback and for fixlets. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
2007-07-09 16:51:59 +00:00
/*
* The idle tasks have their own, simple scheduling class:
*/
idle->sched_class = &idle_sched_class;
ftrace: Fix memory leak with function graph and cpu hotplug When the fuction graph tracer starts, it needs to make a special stack for each task to save the real return values of the tasks. All running tasks have this stack created, as well as any new tasks. On CPU hot plug, the new idle task will allocate a stack as well when init_idle() is called. The problem is that cpu hotplug does not create a new idle_task. Instead it uses the idle task that existed when the cpu went down. ftrace_graph_init_task() will add a new ret_stack to the task that is given to it. Because a clone will make the task have a stack of its parent it does not check if the task's ret_stack is already NULL or not. When the CPU hotplug code starts a CPU up again, it will allocate a new stack even though one already existed for it. The solution is to treat the idle_task specially. In fact, the function_graph code already does, just not at init_idle(). Instead of using the ftrace_graph_init_task() for the idle task, which that function expects the task to be a clone, have a separate ftrace_graph_init_idle_task(). Also, we will create a per_cpu ret_stack that is used by the idle task. When we call ftrace_graph_init_idle_task() it will check if the idle task's ret_stack is NULL, if it is, then it will assign it the per_cpu ret_stack. Reported-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Suggested-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Stable Tree <stable@kernel.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-02-11 02:26:13 +00:00
ftrace_graph_init_idle_task(idle, cpu);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
}
/*
* In a system that switches off the HZ timer nohz_cpu_mask
* indicates which cpus entered this state. This is used
* in the rcu update to wait only for active cpus. For system
* which do not switch off the HZ timer nohz_cpu_mask should
sched: convert nohz_cpu_mask to cpumask_var_t. Impact: (future) size reduction for large NR_CPUS. Dynamically allocating cpumasks (when CONFIG_CPUMASK_OFFSTACK) saves space for small nr_cpu_ids but big CONFIG_NR_CPUS. cpumask_var_t is just a struct cpumask for !CONFIG_CPUMASK_OFFSTACK. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-24 16:05:04 +00:00
* always be CPU_BITS_NONE.
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
*/
sched: convert nohz_cpu_mask to cpumask_var_t. Impact: (future) size reduction for large NR_CPUS. Dynamically allocating cpumasks (when CONFIG_CPUMASK_OFFSTACK) saves space for small nr_cpu_ids but big CONFIG_NR_CPUS. cpumask_var_t is just a struct cpumask for !CONFIG_CPUMASK_OFFSTACK. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-24 16:05:04 +00:00
cpumask_var_t nohz_cpu_mask;
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
sched: reintroduce SMP tunings again Yanmin Zhang reported an aim7 regression and bisected it down to: | commit 38ad464d410dadceda1563f36bdb0be7fe4c8938 | Author: Ingo Molnar <mingo@elte.hu> | Date: Mon Oct 15 17:00:02 2007 +0200 | | sched: uniform tunings | | use the same defaults on both UP and SMP. fix this by reintroducing similar SMP tunings again. This resolves the regression. (also update the comments to match the ilog2(nr_cpus) tuning effect) Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-11-09 21:39:38 +00:00
/*
* Increase the granularity value when there are more CPUs,
* because with more CPUs the 'effective latency' as visible
* to users decreases. But the relationship is not linear,
* so pick a second-best guess by going with the log2 of the
* number of CPUs.
*
* This idea comes from the SD scheduler of Con Kolivas:
*/
sched: Update normalized values on user updates via proc The normalized values are also recalculated in case the scaling factor changes. This patch updates the internally used scheduler tuning values that are normalized to one cpu in case a user sets new values via sysfs. Together with patch 2 of this series this allows to let user configured values scale (or not) to cpu add/remove events taking place later. Signed-off-by: Christian Ehrhardt <ehrhardt@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1259579808-11357-4-git-send-email-ehrhardt@linux.vnet.ibm.com> [ v2: fix warning ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-11-30 11:16:48 +00:00
static int get_update_sysctl_factor(void)
sched: reintroduce SMP tunings again Yanmin Zhang reported an aim7 regression and bisected it down to: | commit 38ad464d410dadceda1563f36bdb0be7fe4c8938 | Author: Ingo Molnar <mingo@elte.hu> | Date: Mon Oct 15 17:00:02 2007 +0200 | | sched: uniform tunings | | use the same defaults on both UP and SMP. fix this by reintroducing similar SMP tunings again. This resolves the regression. (also update the comments to match the ilog2(nr_cpus) tuning effect) Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-11-09 21:39:38 +00:00
{
sched: Fix build warning in get_update_sysctl_factor() Signed-off-by: Mike Galbraith <efault@gmx.de> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu> LKML-Reference: <new-submission>
2009-12-10 08:25:53 +00:00
unsigned int cpus = min_t(int, num_online_cpus(), 8);
sched: Make tunable scaling style configurable As scaling now takes place on all kind of cpu add/remove events a user that configures values via proc should be able to configure if his set values are still rescaled or kept whatever happens. As the comments state that log2 was just a second guess that worked the interface is not just designed for on/off, but to choose a scaling type. Currently this allows none, log and linear, but more important it allwos us to keep the interface even if someone has an even better idea how to scale the values. Signed-off-by: Christian Ehrhardt <ehrhardt@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1259579808-11357-3-git-send-email-ehrhardt@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-11-30 11:16:47 +00:00
unsigned int factor;
switch (sysctl_sched_tunable_scaling) {
case SCHED_TUNABLESCALING_NONE:
factor = 1;
break;
case SCHED_TUNABLESCALING_LINEAR:
factor = cpus;
break;
case SCHED_TUNABLESCALING_LOG:
default:
factor = 1 + ilog2(cpus);
break;
}
sched: reintroduce SMP tunings again Yanmin Zhang reported an aim7 regression and bisected it down to: | commit 38ad464d410dadceda1563f36bdb0be7fe4c8938 | Author: Ingo Molnar <mingo@elte.hu> | Date: Mon Oct 15 17:00:02 2007 +0200 | | sched: uniform tunings | | use the same defaults on both UP and SMP. fix this by reintroducing similar SMP tunings again. This resolves the regression. (also update the comments to match the ilog2(nr_cpus) tuning effect) Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-11-09 21:39:38 +00:00
sched: Update normalized values on user updates via proc The normalized values are also recalculated in case the scaling factor changes. This patch updates the internally used scheduler tuning values that are normalized to one cpu in case a user sets new values via sysfs. Together with patch 2 of this series this allows to let user configured values scale (or not) to cpu add/remove events taking place later. Signed-off-by: Christian Ehrhardt <ehrhardt@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1259579808-11357-4-git-send-email-ehrhardt@linux.vnet.ibm.com> [ v2: fix warning ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-11-30 11:16:48 +00:00
return factor;
}
sched: reintroduce SMP tunings again Yanmin Zhang reported an aim7 regression and bisected it down to: | commit 38ad464d410dadceda1563f36bdb0be7fe4c8938 | Author: Ingo Molnar <mingo@elte.hu> | Date: Mon Oct 15 17:00:02 2007 +0200 | | sched: uniform tunings | | use the same defaults on both UP and SMP. fix this by reintroducing similar SMP tunings again. This resolves the regression. (also update the comments to match the ilog2(nr_cpus) tuning effect) Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-11-09 21:39:38 +00:00
sched: Update normalized values on user updates via proc The normalized values are also recalculated in case the scaling factor changes. This patch updates the internally used scheduler tuning values that are normalized to one cpu in case a user sets new values via sysfs. Together with patch 2 of this series this allows to let user configured values scale (or not) to cpu add/remove events taking place later. Signed-off-by: Christian Ehrhardt <ehrhardt@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1259579808-11357-4-git-send-email-ehrhardt@linux.vnet.ibm.com> [ v2: fix warning ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-11-30 11:16:48 +00:00
static void update_sysctl(void)
{
unsigned int factor = get_update_sysctl_factor();
sched: reintroduce SMP tunings again Yanmin Zhang reported an aim7 regression and bisected it down to: | commit 38ad464d410dadceda1563f36bdb0be7fe4c8938 | Author: Ingo Molnar <mingo@elte.hu> | Date: Mon Oct 15 17:00:02 2007 +0200 | | sched: uniform tunings | | use the same defaults on both UP and SMP. fix this by reintroducing similar SMP tunings again. This resolves the regression. (also update the comments to match the ilog2(nr_cpus) tuning effect) Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-11-09 21:39:38 +00:00
sched: Fix missing sched tunable recalculation on cpu add/remove Based on Peter Zijlstras patch suggestion this enables recalculation of the scheduler tunables in response of a change in the number of cpus. It also adds a max of eight cpus that are considered in that scaling. Signed-off-by: Christian Ehrhardt <ehrhardt@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1259579808-11357-2-git-send-email-ehrhardt@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-11-30 11:16:46 +00:00
#define SET_SYSCTL(name) \
(sysctl_##name = (factor) * normalized_sysctl_##name)
SET_SYSCTL(sched_min_granularity);
SET_SYSCTL(sched_latency);
SET_SYSCTL(sched_wakeup_granularity);
#undef SET_SYSCTL
}
sched: scale sysctl_sched_shares_ratelimit with nr_cpus David reported that his Niagra spend a little too much time in tg_shares_up(), which considering he has a large cpu count makes sense. So scale the ratelimit value with the number of cpus like we do for other controls as well. Reported-by: David Miller <davem@davemloft.net> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-04 06:54:26 +00:00
sched: Fix missing sched tunable recalculation on cpu add/remove Based on Peter Zijlstras patch suggestion this enables recalculation of the scheduler tunables in response of a change in the number of cpus. It also adds a max of eight cpus that are considered in that scaling. Signed-off-by: Christian Ehrhardt <ehrhardt@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1259579808-11357-2-git-send-email-ehrhardt@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-11-30 11:16:46 +00:00
static inline void sched_init_granularity(void)
{
update_sysctl();
sched: reintroduce SMP tunings again Yanmin Zhang reported an aim7 regression and bisected it down to: | commit 38ad464d410dadceda1563f36bdb0be7fe4c8938 | Author: Ingo Molnar <mingo@elte.hu> | Date: Mon Oct 15 17:00:02 2007 +0200 | | sched: uniform tunings | | use the same defaults on both UP and SMP. fix this by reintroducing similar SMP tunings again. This resolves the regression. (also update the comments to match the ilog2(nr_cpus) tuning effect) Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-11-09 21:39:38 +00:00
}
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
#ifdef CONFIG_SMP
cpuset: Fix cpuset_cpus_allowed_fallback(), don't update tsk->rt.nr_cpus_allowed The rule is, we have to update tsk->rt.nr_cpus_allowed if we change tsk->cpus_allowed. Otherwise RT scheduler may confuse. Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/4DD4B3FA.5060901@jp.fujitsu.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-05-19 06:08:58 +00:00
void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask)
{
if (p->sched_class && p->sched_class->set_cpus_allowed)
p->sched_class->set_cpus_allowed(p, new_mask);
else {
cpumask_copy(&p->cpus_allowed, new_mask);
p->rt.nr_cpus_allowed = cpumask_weight(new_mask);
}
}
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
/*
* This is how migration works:
*
sched: replace migration_thread with cpu_stop Currently migration_thread is serving three purposes - migration pusher, context to execute active_load_balance() and forced context switcher for expedited RCU synchronize_sched. All three roles are hardcoded into migration_thread() and determining which job is scheduled is slightly messy. This patch kills migration_thread and replaces all three uses with cpu_stop. The three different roles of migration_thread() are splitted into three separate cpu_stop callbacks - migration_cpu_stop(), active_load_balance_cpu_stop() and synchronize_sched_expedited_cpu_stop() - and each use case now simply asks cpu_stop to execute the callback as necessary. synchronize_sched_expedited() was implemented with private preallocated resources and custom multi-cpu queueing and waiting logic, both of which are provided by cpu_stop. synchronize_sched_expedited_count is made atomic and all other shared resources along with the mutex are dropped. synchronize_sched_expedited() also implemented a check to detect cases where not all the callback got executed on their assigned cpus and fall back to synchronize_sched(). If called with cpu hotplug blocked, cpu_stop already guarantees that and the condition cannot happen; otherwise, stop_machine() would break. However, this patch preserves the paranoid check using a cpumask to record on which cpus the stopper ran so that it can serve as a bisection point if something actually goes wrong theree. Because the internal execution state is no longer visible, rcu_expedited_torture_stats() is removed. This patch also renames cpu_stop threads to from "stopper/%d" to "migration/%d". The names of these threads ultimately don't matter and there's no reason to make unnecessary userland visible changes. With this patch applied, stop_machine() and sched now share the same resources. stop_machine() is faster without wasting any resources and sched migration users are much cleaner. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Dipankar Sarma <dipankar@in.ibm.com> Cc: Josh Triplett <josh@freedesktop.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Dimitri Sivanich <sivanich@sgi.com>
2010-05-06 16:49:21 +00:00
* 1) we invoke migration_cpu_stop() on the target CPU using
* stop_one_cpu().
* 2) stopper starts to run (implicitly forcing the migrated thread
* off the CPU)
* 3) it checks whether the migrated task is still in the wrong runqueue.
* 4) if it's in the wrong runqueue then the migration thread removes
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
* it and puts it into the right queue.
sched: replace migration_thread with cpu_stop Currently migration_thread is serving three purposes - migration pusher, context to execute active_load_balance() and forced context switcher for expedited RCU synchronize_sched. All three roles are hardcoded into migration_thread() and determining which job is scheduled is slightly messy. This patch kills migration_thread and replaces all three uses with cpu_stop. The three different roles of migration_thread() are splitted into three separate cpu_stop callbacks - migration_cpu_stop(), active_load_balance_cpu_stop() and synchronize_sched_expedited_cpu_stop() - and each use case now simply asks cpu_stop to execute the callback as necessary. synchronize_sched_expedited() was implemented with private preallocated resources and custom multi-cpu queueing and waiting logic, both of which are provided by cpu_stop. synchronize_sched_expedited_count is made atomic and all other shared resources along with the mutex are dropped. synchronize_sched_expedited() also implemented a check to detect cases where not all the callback got executed on their assigned cpus and fall back to synchronize_sched(). If called with cpu hotplug blocked, cpu_stop already guarantees that and the condition cannot happen; otherwise, stop_machine() would break. However, this patch preserves the paranoid check using a cpumask to record on which cpus the stopper ran so that it can serve as a bisection point if something actually goes wrong theree. Because the internal execution state is no longer visible, rcu_expedited_torture_stats() is removed. This patch also renames cpu_stop threads to from "stopper/%d" to "migration/%d". The names of these threads ultimately don't matter and there's no reason to make unnecessary userland visible changes. With this patch applied, stop_machine() and sched now share the same resources. stop_machine() is faster without wasting any resources and sched migration users are much cleaner. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Dipankar Sarma <dipankar@in.ibm.com> Cc: Josh Triplett <josh@freedesktop.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Dimitri Sivanich <sivanich@sgi.com>
2010-05-06 16:49:21 +00:00
* 5) stopper completes and stop_one_cpu() returns and the migration
* is done.
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
*/
/*
* Change a given task's CPU affinity. Migrate the thread to a
* proper CPU and schedule it away if the CPU it's executing on
* is removed from the allowed bitmask.
*
* NOTE: the caller must have a valid reference to the task, the
sched: style cleanups style cleanup of various changes that were done recently. no code changed: text data bss dec hex filename 23680 2542 28 26250 668a sched.o.before 23680 2542 28 26250 668a sched.o.after Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-12-05 14:46:09 +00:00
* task must not exit() & deallocate itself prematurely. The
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
* call is not atomic; no spinlocks may be held.
*/
sched: convert remaining old-style cpumask operators Impact: Trivial API conversion NR_CPUS -> nr_cpu_ids cpumask_t -> struct cpumask sizeof(cpumask_t) -> cpumask_size() cpumask_a = cpumask_b -> cpumask_copy(&cpumask_a, &cpumask_b) cpu_set() -> cpumask_set_cpu() first_cpu() -> cpumask_first() cpumask_of_cpu() -> cpumask_of() cpus_* -> cpumask_* There are some FIXMEs where we all archs to complete infrastructure (patches have been sent): cpu_coregroup_map -> cpu_coregroup_mask node_to_cpumask* -> cpumask_of_node There is also one FIXME where we pass an array of cpumasks to partition_sched_domains(): this implies knowing the definition of 'struct cpumask' and the size of a cpumask. This will be fixed in a future patch. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-24 16:05:14 +00:00
int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask)
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
{
unsigned long flags;
[PATCH] sched: cleanup, convert sched.c-internal typedefs to struct convert: - runqueue_t to 'struct rq' - prio_array_t to 'struct prio_array' - migration_req_t to 'struct migration_req' I was the one who added these but they are both against the kernel coding style and also were used inconsistently at places. So just get rid of them at once, now that we are flushing the scheduler patch-queue anyway. Conversion was mostly scripted, the result was reviewed and all secondary whitespace and style impact (if any) was fixed up by hand. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-03 07:25:42 +00:00
struct rq *rq;
sched: replace migration_thread with cpu_stop Currently migration_thread is serving three purposes - migration pusher, context to execute active_load_balance() and forced context switcher for expedited RCU synchronize_sched. All three roles are hardcoded into migration_thread() and determining which job is scheduled is slightly messy. This patch kills migration_thread and replaces all three uses with cpu_stop. The three different roles of migration_thread() are splitted into three separate cpu_stop callbacks - migration_cpu_stop(), active_load_balance_cpu_stop() and synchronize_sched_expedited_cpu_stop() - and each use case now simply asks cpu_stop to execute the callback as necessary. synchronize_sched_expedited() was implemented with private preallocated resources and custom multi-cpu queueing and waiting logic, both of which are provided by cpu_stop. synchronize_sched_expedited_count is made atomic and all other shared resources along with the mutex are dropped. synchronize_sched_expedited() also implemented a check to detect cases where not all the callback got executed on their assigned cpus and fall back to synchronize_sched(). If called with cpu hotplug blocked, cpu_stop already guarantees that and the condition cannot happen; otherwise, stop_machine() would break. However, this patch preserves the paranoid check using a cpumask to record on which cpus the stopper ran so that it can serve as a bisection point if something actually goes wrong theree. Because the internal execution state is no longer visible, rcu_expedited_torture_stats() is removed. This patch also renames cpu_stop threads to from "stopper/%d" to "migration/%d". The names of these threads ultimately don't matter and there's no reason to make unnecessary userland visible changes. With this patch applied, stop_machine() and sched now share the same resources. stop_machine() is faster without wasting any resources and sched migration users are much cleaner. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Dipankar Sarma <dipankar@in.ibm.com> Cc: Josh Triplett <josh@freedesktop.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Dimitri Sivanich <sivanich@sgi.com>
2010-05-06 16:49:21 +00:00
unsigned int dest_cpu;
[PATCH] sched: clean up fallout of recent changes Clean up some of the impact of recent (and not so recent) scheduler changes: - turning macros into nice inline functions - sanitizing and unifying variable definitions - whitespace, style consistency, 80-lines, comment correctness, spelling and curly braces police Due to the macro hell and variable placement simplifications there's even 26 bytes of .text saved: text data bss dec hex filename 25510 4153 192 29855 749f sched.o.before 25484 4153 192 29829 7485 sched.o.after [akpm@osdl.org: build fix] Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-03 07:25:40 +00:00
int ret = 0;
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
rq = task_rq_lock(p, &flags);
sched: Ensure set_task_cpu() is never called on blocked tasks In order to clean up the set_task_cpu() rq dependencies we need to ensure it is never called on blocked tasks because such usage does not pair with consistent rq->lock usage. This puts the migration burden on ttwu(). Furthermore we need to close a race against changing ->cpus_allowed, since select_task_rq() runs with only preemption disabled. For sched_fork() this is safe because the child isn't in the tasklist yet, for wakeup we fix this by synchronizing set_cpus_allowed_ptr() against TASK_WAKING, which leaves sched_exec to be a problem This also closes a hole in (6ad4c1888 sched: Fix balance vs hotplug race) where ->select_task_rq() doesn't validate the result against the sched_domain/root_domain. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> LKML-Reference: <20091216170517.807938893@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-16 17:04:36 +00:00
sched: Avoid going ahead if ->cpus_allowed is not changed If cpumask_equal(&p->cpus_allowed, new_mask) is true, seems there is no reason to prevent set_cpus_allowed_ptr() return directly. Signed-off-by: Yong Zhang <yong.zhang0@gmail.com> Acked-by: Hillf Danton <dhillf@gmail.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110509140705.GA2219@zhy Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-05-09 14:07:05 +00:00
if (cpumask_equal(&p->cpus_allowed, new_mask))
goto out;
sched: Fix balance vs hotplug race Since (e761b77: cpu hotplug, sched: Introduce cpu_active_map and redo sched domain managment) we have cpu_active_mask which is suppose to rule scheduler migration and load-balancing, except it never (fully) did. The particular problem being solved here is a crash in try_to_wake_up() where select_task_rq() ends up selecting an offline cpu because select_task_rq_fair() trusts the sched_domain tree to reflect the current state of affairs, similarly select_task_rq_rt() trusts the root_domain. However, the sched_domains are updated from CPU_DEAD, which is after the cpu is taken offline and after stop_machine is done. Therefore it can race perfectly well with code assuming the domains are right. Cure this by building the domains from cpu_active_mask on CPU_DOWN_PREPARE. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-11-25 12:31:39 +00:00
if (!cpumask_intersects(new_mask, cpu_active_mask)) {
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
ret = -EINVAL;
goto out;
}
sched: Avoid going ahead if ->cpus_allowed is not changed If cpumask_equal(&p->cpus_allowed, new_mask) is true, seems there is no reason to prevent set_cpus_allowed_ptr() return directly. Signed-off-by: Yong Zhang <yong.zhang0@gmail.com> Acked-by: Hillf Danton <dhillf@gmail.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110509140705.GA2219@zhy Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-05-09 14:07:05 +00:00
if (unlikely((p->flags & PF_THREAD_BOUND) && p != current)) {
sched: prevent bound kthreads from changing cpus_allowed Kthreads that have called kthread_bind() are bound to specific cpus, so other tasks should not be able to change their cpus_allowed from under them. Otherwise, it is possible to move kthreads, such as the migration or software watchdog threads, so they are not allowed access to the cpu they work on. Cc: Peter Zijlstra <peterz@infradead.org> Cc: Paul Menage <menage@google.com> Cc: Paul Jackson <pj@sgi.com> Signed-off-by: David Rientjes <rientjes@google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-05 19:57:11 +00:00
ret = -EINVAL;
goto out;
}
cpuset: Fix cpuset_cpus_allowed_fallback(), don't update tsk->rt.nr_cpus_allowed The rule is, we have to update tsk->rt.nr_cpus_allowed if we change tsk->cpus_allowed. Otherwise RT scheduler may confuse. Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/4DD4B3FA.5060901@jp.fujitsu.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-05-19 06:08:58 +00:00
do_set_cpus_allowed(p, new_mask);
sched: add RT-balance cpu-weight Some RT tasks (particularly kthreads) are bound to one specific CPU. It is fairly common for two or more bound tasks to get queued up at the same time. Consider, for instance, softirq_timer and softirq_sched. A timer goes off in an ISR which schedules softirq_thread to run at RT50. Then the timer handler determines that it's time to smp-rebalance the system so it schedules softirq_sched to run. So we are in a situation where we have two RT50 tasks queued, and the system will go into rt-overload condition to request other CPUs for help. This causes two problems in the current code: 1) If a high-priority bound task and a low-priority unbounded task queue up behind the running task, we will fail to ever relocate the unbounded task because we terminate the search on the first unmovable task. 2) We spend precious futile cycles in the fast-path trying to pull overloaded tasks over. It is therefore optimial to strive to avoid the overhead all together if we can cheaply detect the condition before overload even occurs. This patch tries to achieve this optimization by utilizing the hamming weight of the task->cpus_allowed mask. A weight of 1 indicates that the task cannot be migrated. We will then utilize this information to skip non-migratable tasks and to eliminate uncessary rebalance attempts. We introduce a per-rq variable to count the number of migratable tasks that are currently running. We only go into overload if we have more than one rt task, AND at least one of them is migratable. In addition, we introduce a per-task variable to cache the cpus_allowed weight, since the hamming calculation is probably relatively expensive. We only update the cached value when the mask is updated which should be relatively infrequent, especially compared to scheduling frequency in the fast path. Signed-off-by: Gregory Haskins <ghaskins@novell.com> Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:07 +00:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
/* Can the task run on the task's current CPU? If so, we're done */
sched: convert remaining old-style cpumask operators Impact: Trivial API conversion NR_CPUS -> nr_cpu_ids cpumask_t -> struct cpumask sizeof(cpumask_t) -> cpumask_size() cpumask_a = cpumask_b -> cpumask_copy(&cpumask_a, &cpumask_b) cpu_set() -> cpumask_set_cpu() first_cpu() -> cpumask_first() cpumask_of_cpu() -> cpumask_of() cpus_* -> cpumask_* There are some FIXMEs where we all archs to complete infrastructure (patches have been sent): cpu_coregroup_map -> cpu_coregroup_mask node_to_cpumask* -> cpumask_of_node There is also one FIXME where we pass an array of cpumasks to partition_sched_domains(): this implies knowing the definition of 'struct cpumask' and the size of a cpumask. This will be fixed in a future patch. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-24 16:05:14 +00:00
if (cpumask_test_cpu(task_cpu(p), new_mask))
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
goto out;
sched: replace migration_thread with cpu_stop Currently migration_thread is serving three purposes - migration pusher, context to execute active_load_balance() and forced context switcher for expedited RCU synchronize_sched. All three roles are hardcoded into migration_thread() and determining which job is scheduled is slightly messy. This patch kills migration_thread and replaces all three uses with cpu_stop. The three different roles of migration_thread() are splitted into three separate cpu_stop callbacks - migration_cpu_stop(), active_load_balance_cpu_stop() and synchronize_sched_expedited_cpu_stop() - and each use case now simply asks cpu_stop to execute the callback as necessary. synchronize_sched_expedited() was implemented with private preallocated resources and custom multi-cpu queueing and waiting logic, both of which are provided by cpu_stop. synchronize_sched_expedited_count is made atomic and all other shared resources along with the mutex are dropped. synchronize_sched_expedited() also implemented a check to detect cases where not all the callback got executed on their assigned cpus and fall back to synchronize_sched(). If called with cpu hotplug blocked, cpu_stop already guarantees that and the condition cannot happen; otherwise, stop_machine() would break. However, this patch preserves the paranoid check using a cpumask to record on which cpus the stopper ran so that it can serve as a bisection point if something actually goes wrong theree. Because the internal execution state is no longer visible, rcu_expedited_torture_stats() is removed. This patch also renames cpu_stop threads to from "stopper/%d" to "migration/%d". The names of these threads ultimately don't matter and there's no reason to make unnecessary userland visible changes. With this patch applied, stop_machine() and sched now share the same resources. stop_machine() is faster without wasting any resources and sched migration users are much cleaner. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Dipankar Sarma <dipankar@in.ibm.com> Cc: Josh Triplett <josh@freedesktop.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Dimitri Sivanich <sivanich@sgi.com>
2010-05-06 16:49:21 +00:00
dest_cpu = cpumask_any_and(cpu_active_mask, new_mask);
sched: Remove need_migrate_task() Oleg noticed that need_migrate_task() doesn't need the ->on_cpu check now that ttwu() doesn't do remote enqueues for !->on_rq && ->on_cpu, so remove the helper and replace the single instance with a direct ->on_rq test. Suggested-by: Oleg Nesterov <oleg@redhat.com> Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110405152729.556674812@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-05 15:23:59 +00:00
if (p->on_rq) {
sched: replace migration_thread with cpu_stop Currently migration_thread is serving three purposes - migration pusher, context to execute active_load_balance() and forced context switcher for expedited RCU synchronize_sched. All three roles are hardcoded into migration_thread() and determining which job is scheduled is slightly messy. This patch kills migration_thread and replaces all three uses with cpu_stop. The three different roles of migration_thread() are splitted into three separate cpu_stop callbacks - migration_cpu_stop(), active_load_balance_cpu_stop() and synchronize_sched_expedited_cpu_stop() - and each use case now simply asks cpu_stop to execute the callback as necessary. synchronize_sched_expedited() was implemented with private preallocated resources and custom multi-cpu queueing and waiting logic, both of which are provided by cpu_stop. synchronize_sched_expedited_count is made atomic and all other shared resources along with the mutex are dropped. synchronize_sched_expedited() also implemented a check to detect cases where not all the callback got executed on their assigned cpus and fall back to synchronize_sched(). If called with cpu hotplug blocked, cpu_stop already guarantees that and the condition cannot happen; otherwise, stop_machine() would break. However, this patch preserves the paranoid check using a cpumask to record on which cpus the stopper ran so that it can serve as a bisection point if something actually goes wrong theree. Because the internal execution state is no longer visible, rcu_expedited_torture_stats() is removed. This patch also renames cpu_stop threads to from "stopper/%d" to "migration/%d". The names of these threads ultimately don't matter and there's no reason to make unnecessary userland visible changes. With this patch applied, stop_machine() and sched now share the same resources. stop_machine() is faster without wasting any resources and sched migration users are much cleaner. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Dipankar Sarma <dipankar@in.ibm.com> Cc: Josh Triplett <josh@freedesktop.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Dimitri Sivanich <sivanich@sgi.com>
2010-05-06 16:49:21 +00:00
struct migration_arg arg = { p, dest_cpu };
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
/* Need help from migration thread: drop lock and wait. */
sched: Add p->pi_lock to task_rq_lock() In order to be able to call set_task_cpu() while either holding p->pi_lock or task_rq(p)->lock we need to hold both locks in order to stabilize task_rq(). This makes task_rq_lock() acquire both locks, and have __task_rq_lock() validate that p->pi_lock is held. This increases the locking overhead for most scheduler syscalls but allows reduction of rq->lock contention for some scheduler hot paths (ttwu). Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110405152729.232781355@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-05 15:23:51 +00:00
task_rq_unlock(rq, p, &flags);
sched: replace migration_thread with cpu_stop Currently migration_thread is serving three purposes - migration pusher, context to execute active_load_balance() and forced context switcher for expedited RCU synchronize_sched. All three roles are hardcoded into migration_thread() and determining which job is scheduled is slightly messy. This patch kills migration_thread and replaces all three uses with cpu_stop. The three different roles of migration_thread() are splitted into three separate cpu_stop callbacks - migration_cpu_stop(), active_load_balance_cpu_stop() and synchronize_sched_expedited_cpu_stop() - and each use case now simply asks cpu_stop to execute the callback as necessary. synchronize_sched_expedited() was implemented with private preallocated resources and custom multi-cpu queueing and waiting logic, both of which are provided by cpu_stop. synchronize_sched_expedited_count is made atomic and all other shared resources along with the mutex are dropped. synchronize_sched_expedited() also implemented a check to detect cases where not all the callback got executed on their assigned cpus and fall back to synchronize_sched(). If called with cpu hotplug blocked, cpu_stop already guarantees that and the condition cannot happen; otherwise, stop_machine() would break. However, this patch preserves the paranoid check using a cpumask to record on which cpus the stopper ran so that it can serve as a bisection point if something actually goes wrong theree. Because the internal execution state is no longer visible, rcu_expedited_torture_stats() is removed. This patch also renames cpu_stop threads to from "stopper/%d" to "migration/%d". The names of these threads ultimately don't matter and there's no reason to make unnecessary userland visible changes. With this patch applied, stop_machine() and sched now share the same resources. stop_machine() is faster without wasting any resources and sched migration users are much cleaner. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Dipankar Sarma <dipankar@in.ibm.com> Cc: Josh Triplett <josh@freedesktop.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Dimitri Sivanich <sivanich@sgi.com>
2010-05-06 16:49:21 +00:00
stop_one_cpu(cpu_of(rq), migration_cpu_stop, &arg);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
tlb_migrate_finish(p->mm);
return 0;
}
out:
sched: Add p->pi_lock to task_rq_lock() In order to be able to call set_task_cpu() while either holding p->pi_lock or task_rq(p)->lock we need to hold both locks in order to stabilize task_rq(). This makes task_rq_lock() acquire both locks, and have __task_rq_lock() validate that p->pi_lock is held. This increases the locking overhead for most scheduler syscalls but allows reduction of rq->lock contention for some scheduler hot paths (ttwu). Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110405152729.232781355@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-05 15:23:51 +00:00
task_rq_unlock(rq, p, &flags);
[PATCH] sched: clean up fallout of recent changes Clean up some of the impact of recent (and not so recent) scheduler changes: - turning macros into nice inline functions - sanitizing and unifying variable definitions - whitespace, style consistency, 80-lines, comment correctness, spelling and curly braces police Due to the macro hell and variable placement simplifications there's even 26 bytes of .text saved: text data bss dec hex filename 25510 4153 192 29855 749f sched.o.before 25484 4153 192 29829 7485 sched.o.after [akpm@osdl.org: build fix] Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-03 07:25:40 +00:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
return ret;
}
sched: add new set_cpus_allowed_ptr function Add a new function that accepts a pointer to the "newly allowed cpus" cpumask argument. int set_cpus_allowed_ptr(struct task_struct *p, const cpumask_t *new_mask) The current set_cpus_allowed() function is modified to use the above but this does not result in an ABI change. And with some compiler optimization help, it may not introduce any additional overhead. Additionally, to enforce the read only nature of the new_mask arg, the "const" property is migrated to sub-functions called by set_cpus_allowed. This silences compiler warnings. Signed-off-by: Mike Travis <travis@sgi.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-03-26 21:23:49 +00:00
EXPORT_SYMBOL_GPL(set_cpus_allowed_ptr);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
/*
sched: style cleanups style cleanup of various changes that were done recently. no code changed: text data bss dec hex filename 23680 2542 28 26250 668a sched.o.before 23680 2542 28 26250 668a sched.o.after Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-12-05 14:46:09 +00:00
* Move (not current) task off this cpu, onto dest cpu. We're doing
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
* this because either it can't run here any more (set_cpus_allowed()
* away from this CPU, or CPU going down), or because we're
* attempting to rebalance this task on exec (sched_exec).
*
* So we race with normal scheduler movements, but that's OK, as long
* as the task is no longer on this CPU.
[PATCH] sched: CPU hotplug race vs. set_cpus_allowed() There is a race between set_cpus_allowed() and move_task_off_dead_cpu(). __migrate_task() doesn't report any err code, so task can be left on its runqueue if its cpus_allowed mask changed so that dest_cpu is not longer a possible target. Also, chaning cpus_allowed mask requires rq->lock being held. Signed-off-by: Kirill Korotaev <dev@openvz.org> Acked-By: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 09:54:32 +00:00
*
* Returns non-zero if task was successfully migrated.
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
*/
[PATCH] sched: CPU hotplug race vs. set_cpus_allowed() There is a race between set_cpus_allowed() and move_task_off_dead_cpu(). __migrate_task() doesn't report any err code, so task can be left on its runqueue if its cpus_allowed mask changed so that dest_cpu is not longer a possible target. Also, chaning cpus_allowed mask requires rq->lock being held. Signed-off-by: Kirill Korotaev <dev@openvz.org> Acked-By: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 09:54:32 +00:00
static int __migrate_task(struct task_struct *p, int src_cpu, int dest_cpu)
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
{
[PATCH] sched: cleanup, convert sched.c-internal typedefs to struct convert: - runqueue_t to 'struct rq' - prio_array_t to 'struct prio_array' - migration_req_t to 'struct migration_req' I was the one who added these but they are both against the kernel coding style and also were used inconsistently at places. So just get rid of them at once, now that we are flushing the scheduler patch-queue anyway. Conversion was mostly scripted, the result was reviewed and all secondary whitespace and style impact (if any) was fixed up by hand. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-03 07:25:42 +00:00
struct rq *rq_dest, *rq_src;
sched: Ensure set_task_cpu() is never called on blocked tasks In order to clean up the set_task_cpu() rq dependencies we need to ensure it is never called on blocked tasks because such usage does not pair with consistent rq->lock usage. This puts the migration burden on ttwu(). Furthermore we need to close a race against changing ->cpus_allowed, since select_task_rq() runs with only preemption disabled. For sched_fork() this is safe because the child isn't in the tasklist yet, for wakeup we fix this by synchronizing set_cpus_allowed_ptr() against TASK_WAKING, which leaves sched_exec to be a problem This also closes a hole in (6ad4c1888 sched: Fix balance vs hotplug race) where ->select_task_rq() doesn't validate the result against the sched_domain/root_domain. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> LKML-Reference: <20091216170517.807938893@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-16 17:04:36 +00:00
int ret = 0;
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
cpu hotplug, sched: Introduce cpu_active_map and redo sched domain managment (take 2) This is based on Linus' idea of creating cpu_active_map that prevents scheduler load balancer from migrating tasks to the cpu that is going down. It allows us to simplify domain management code and avoid unecessary domain rebuilds during cpu hotplug event handling. Please ignore the cpusets part for now. It needs some more work in order to avoid crazy lock nesting. Although I did simplfy and unify domain reinitialization logic. We now simply call partition_sched_domains() in all the cases. This means that we're using exact same code paths as in cpusets case and hence the test below cover cpusets too. Cpuset changes to make rebuild_sched_domains() callable from various contexts are in the separate patch (right next after this one). This not only boots but also easily handles while true; do make clean; make -j 8; done and while true; do on-off-cpu 1; done at the same time. (on-off-cpu 1 simple does echo 0/1 > /sys/.../cpu1/online thing). Suprisingly the box (dual-core Core2) is quite usable. In fact I'm typing this on right now in gnome-terminal and things are moving just fine. Also this is running with most of the debug features enabled (lockdep, mutex, etc) no BUG_ONs or lockdep complaints so far. I believe I addressed all of the Dmitry's comments for original Linus' version. I changed both fair and rt balancer to mask out non-active cpus. And replaced cpu_is_offline() with !cpu_active() in the main scheduler code where it made sense (to me). Signed-off-by: Max Krasnyanskiy <maxk@qualcomm.com> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Gregory Haskins <ghaskins@novell.com> Cc: dmitry.adamushko@gmail.com Cc: pj@sgi.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-15 11:43:49 +00:00
if (unlikely(!cpu_active(dest_cpu)))
[PATCH] sched: CPU hotplug race vs. set_cpus_allowed() There is a race between set_cpus_allowed() and move_task_off_dead_cpu(). __migrate_task() doesn't report any err code, so task can be left on its runqueue if its cpus_allowed mask changed so that dest_cpu is not longer a possible target. Also, chaning cpus_allowed mask requires rq->lock being held. Signed-off-by: Kirill Korotaev <dev@openvz.org> Acked-By: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 09:54:32 +00:00
return ret;
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
rq_src = cpu_rq(src_cpu);
rq_dest = cpu_rq(dest_cpu);
sched: Add p->pi_lock to task_rq_lock() In order to be able to call set_task_cpu() while either holding p->pi_lock or task_rq(p)->lock we need to hold both locks in order to stabilize task_rq(). This makes task_rq_lock() acquire both locks, and have __task_rq_lock() validate that p->pi_lock is held. This increases the locking overhead for most scheduler syscalls but allows reduction of rq->lock contention for some scheduler hot paths (ttwu). Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110405152729.232781355@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-05 15:23:51 +00:00
raw_spin_lock(&p->pi_lock);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
double_rq_lock(rq_src, rq_dest);
/* Already moved. */
if (task_cpu(p) != src_cpu)
sched: fix cpu hotplug, cleanup Clean up __migrate_task(): to just have separate "done" and "fail" cases, instead of that "out" case with random error behavior. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-10 18:25:03 +00:00
goto done;
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
/* Affinity changed (again). */
sched: convert remaining old-style cpumask operators Impact: Trivial API conversion NR_CPUS -> nr_cpu_ids cpumask_t -> struct cpumask sizeof(cpumask_t) -> cpumask_size() cpumask_a = cpumask_b -> cpumask_copy(&cpumask_a, &cpumask_b) cpu_set() -> cpumask_set_cpu() first_cpu() -> cpumask_first() cpumask_of_cpu() -> cpumask_of() cpus_* -> cpumask_* There are some FIXMEs where we all archs to complete infrastructure (patches have been sent): cpu_coregroup_map -> cpu_coregroup_mask node_to_cpumask* -> cpumask_of_node There is also one FIXME where we pass an array of cpumasks to partition_sched_domains(): this implies knowing the definition of 'struct cpumask' and the size of a cpumask. This will be fixed in a future patch. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-24 16:05:14 +00:00
if (!cpumask_test_cpu(dest_cpu, &p->cpus_allowed))
sched: fix cpu hotplug, cleanup Clean up __migrate_task(): to just have separate "done" and "fail" cases, instead of that "out" case with random error behavior. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-10 18:25:03 +00:00
goto fail;
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
sched: Ensure set_task_cpu() is never called on blocked tasks In order to clean up the set_task_cpu() rq dependencies we need to ensure it is never called on blocked tasks because such usage does not pair with consistent rq->lock usage. This puts the migration burden on ttwu(). Furthermore we need to close a race against changing ->cpus_allowed, since select_task_rq() runs with only preemption disabled. For sched_fork() this is safe because the child isn't in the tasklist yet, for wakeup we fix this by synchronizing set_cpus_allowed_ptr() against TASK_WAKING, which leaves sched_exec to be a problem This also closes a hole in (6ad4c1888 sched: Fix balance vs hotplug race) where ->select_task_rq() doesn't validate the result against the sched_domain/root_domain. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> LKML-Reference: <20091216170517.807938893@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-16 17:04:36 +00:00
/*
* If we're not on a rq, the next wake-up will ensure we're
* placed properly.
*/
sched: Provide p->on_rq Provide a generic p->on_rq because the p->se.on_rq semantics are unfavourable for lockless wakeups but needed for sched_fair. In particular, p->on_rq is only cleared when we actually dequeue the task in schedule() and not on any random dequeue as done by things like __migrate_task() and __sched_setscheduler(). This also allows us to remove p->se usage from !sched_fair code. Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110405152728.949545047@chello.nl
2011-04-05 15:23:44 +00:00
if (p->on_rq) {
sched: remove the 'u64 now' parameter from deactivate_task() remove the 'u64 now' parameter from deactivate_task(). ( identity transformation that causes no change in functionality. ) Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-08-09 09:16:49 +00:00
deactivate_task(rq_src, p, 0);
sched: Ensure set_task_cpu() is never called on blocked tasks In order to clean up the set_task_cpu() rq dependencies we need to ensure it is never called on blocked tasks because such usage does not pair with consistent rq->lock usage. This puts the migration burden on ttwu(). Furthermore we need to close a race against changing ->cpus_allowed, since select_task_rq() runs with only preemption disabled. For sched_fork() this is safe because the child isn't in the tasklist yet, for wakeup we fix this by synchronizing set_cpus_allowed_ptr() against TASK_WAKING, which leaves sched_exec to be a problem This also closes a hole in (6ad4c1888 sched: Fix balance vs hotplug race) where ->select_task_rq() doesn't validate the result against the sched_domain/root_domain. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> LKML-Reference: <20091216170517.807938893@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-16 17:04:36 +00:00
set_task_cpu(p, dest_cpu);
sched: cfs core code apply the CFS core code. this change switches over the scheduler core to CFS's modular design and makes use of kernel/sched_fair/rt/idletask.c to implement Linux's scheduling policies. thanks to Andrew Morton and Thomas Gleixner for lots of detailed review feedback and for fixlets. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
2007-07-09 16:51:59 +00:00
activate_task(rq_dest, p, 0);
sched: wakeup preempt when small overlap Lin Ming reported a 10% OLTP regression against 2.6.27-rc4. The difference seems to come from different preemption agressiveness, which affects the cache footprint of the workload and its effective cache trashing. Aggresively preempt a task if its avg overlap is very small, this should avoid the task going to sleep and find it still running when we schedule back to it - saving a wakeup. Reported-by: Lin Ming <ming.m.lin@intel.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-20 21:38:02 +00:00
check_preempt_curr(rq_dest, p, 0);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
}
sched: fix cpu hotplug, cleanup Clean up __migrate_task(): to just have separate "done" and "fail" cases, instead of that "out" case with random error behavior. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-10 18:25:03 +00:00
done:
[PATCH] sched: CPU hotplug race vs. set_cpus_allowed() There is a race between set_cpus_allowed() and move_task_off_dead_cpu(). __migrate_task() doesn't report any err code, so task can be left on its runqueue if its cpus_allowed mask changed so that dest_cpu is not longer a possible target. Also, chaning cpus_allowed mask requires rq->lock being held. Signed-off-by: Kirill Korotaev <dev@openvz.org> Acked-By: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 09:54:32 +00:00
ret = 1;
sched: fix cpu hotplug, cleanup Clean up __migrate_task(): to just have separate "done" and "fail" cases, instead of that "out" case with random error behavior. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-10 18:25:03 +00:00
fail:
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
double_rq_unlock(rq_src, rq_dest);
sched: Add p->pi_lock to task_rq_lock() In order to be able to call set_task_cpu() while either holding p->pi_lock or task_rq(p)->lock we need to hold both locks in order to stabilize task_rq(). This makes task_rq_lock() acquire both locks, and have __task_rq_lock() validate that p->pi_lock is held. This increases the locking overhead for most scheduler syscalls but allows reduction of rq->lock contention for some scheduler hot paths (ttwu). Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110405152729.232781355@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-05 15:23:51 +00:00
raw_spin_unlock(&p->pi_lock);
[PATCH] sched: CPU hotplug race vs. set_cpus_allowed() There is a race between set_cpus_allowed() and move_task_off_dead_cpu(). __migrate_task() doesn't report any err code, so task can be left on its runqueue if its cpus_allowed mask changed so that dest_cpu is not longer a possible target. Also, chaning cpus_allowed mask requires rq->lock being held. Signed-off-by: Kirill Korotaev <dev@openvz.org> Acked-By: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 09:54:32 +00:00
return ret;
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
}
/*
sched: replace migration_thread with cpu_stop Currently migration_thread is serving three purposes - migration pusher, context to execute active_load_balance() and forced context switcher for expedited RCU synchronize_sched. All three roles are hardcoded into migration_thread() and determining which job is scheduled is slightly messy. This patch kills migration_thread and replaces all three uses with cpu_stop. The three different roles of migration_thread() are splitted into three separate cpu_stop callbacks - migration_cpu_stop(), active_load_balance_cpu_stop() and synchronize_sched_expedited_cpu_stop() - and each use case now simply asks cpu_stop to execute the callback as necessary. synchronize_sched_expedited() was implemented with private preallocated resources and custom multi-cpu queueing and waiting logic, both of which are provided by cpu_stop. synchronize_sched_expedited_count is made atomic and all other shared resources along with the mutex are dropped. synchronize_sched_expedited() also implemented a check to detect cases where not all the callback got executed on their assigned cpus and fall back to synchronize_sched(). If called with cpu hotplug blocked, cpu_stop already guarantees that and the condition cannot happen; otherwise, stop_machine() would break. However, this patch preserves the paranoid check using a cpumask to record on which cpus the stopper ran so that it can serve as a bisection point if something actually goes wrong theree. Because the internal execution state is no longer visible, rcu_expedited_torture_stats() is removed. This patch also renames cpu_stop threads to from "stopper/%d" to "migration/%d". The names of these threads ultimately don't matter and there's no reason to make unnecessary userland visible changes. With this patch applied, stop_machine() and sched now share the same resources. stop_machine() is faster without wasting any resources and sched migration users are much cleaner. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Dipankar Sarma <dipankar@in.ibm.com> Cc: Josh Triplett <josh@freedesktop.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Dimitri Sivanich <sivanich@sgi.com>
2010-05-06 16:49:21 +00:00
* migration_cpu_stop - this will be executed by a highprio stopper thread
* and performs thread migration by bumping thread off CPU then
* 'pushing' onto another runqueue.
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
*/
sched: replace migration_thread with cpu_stop Currently migration_thread is serving three purposes - migration pusher, context to execute active_load_balance() and forced context switcher for expedited RCU synchronize_sched. All three roles are hardcoded into migration_thread() and determining which job is scheduled is slightly messy. This patch kills migration_thread and replaces all three uses with cpu_stop. The three different roles of migration_thread() are splitted into three separate cpu_stop callbacks - migration_cpu_stop(), active_load_balance_cpu_stop() and synchronize_sched_expedited_cpu_stop() - and each use case now simply asks cpu_stop to execute the callback as necessary. synchronize_sched_expedited() was implemented with private preallocated resources and custom multi-cpu queueing and waiting logic, both of which are provided by cpu_stop. synchronize_sched_expedited_count is made atomic and all other shared resources along with the mutex are dropped. synchronize_sched_expedited() also implemented a check to detect cases where not all the callback got executed on their assigned cpus and fall back to synchronize_sched(). If called with cpu hotplug blocked, cpu_stop already guarantees that and the condition cannot happen; otherwise, stop_machine() would break. However, this patch preserves the paranoid check using a cpumask to record on which cpus the stopper ran so that it can serve as a bisection point if something actually goes wrong theree. Because the internal execution state is no longer visible, rcu_expedited_torture_stats() is removed. This patch also renames cpu_stop threads to from "stopper/%d" to "migration/%d". The names of these threads ultimately don't matter and there's no reason to make unnecessary userland visible changes. With this patch applied, stop_machine() and sched now share the same resources. stop_machine() is faster without wasting any resources and sched migration users are much cleaner. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Dipankar Sarma <dipankar@in.ibm.com> Cc: Josh Triplett <josh@freedesktop.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Dimitri Sivanich <sivanich@sgi.com>
2010-05-06 16:49:21 +00:00
static int migration_cpu_stop(void *data)
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
{
sched: replace migration_thread with cpu_stop Currently migration_thread is serving three purposes - migration pusher, context to execute active_load_balance() and forced context switcher for expedited RCU synchronize_sched. All three roles are hardcoded into migration_thread() and determining which job is scheduled is slightly messy. This patch kills migration_thread and replaces all three uses with cpu_stop. The three different roles of migration_thread() are splitted into three separate cpu_stop callbacks - migration_cpu_stop(), active_load_balance_cpu_stop() and synchronize_sched_expedited_cpu_stop() - and each use case now simply asks cpu_stop to execute the callback as necessary. synchronize_sched_expedited() was implemented with private preallocated resources and custom multi-cpu queueing and waiting logic, both of which are provided by cpu_stop. synchronize_sched_expedited_count is made atomic and all other shared resources along with the mutex are dropped. synchronize_sched_expedited() also implemented a check to detect cases where not all the callback got executed on their assigned cpus and fall back to synchronize_sched(). If called with cpu hotplug blocked, cpu_stop already guarantees that and the condition cannot happen; otherwise, stop_machine() would break. However, this patch preserves the paranoid check using a cpumask to record on which cpus the stopper ran so that it can serve as a bisection point if something actually goes wrong theree. Because the internal execution state is no longer visible, rcu_expedited_torture_stats() is removed. This patch also renames cpu_stop threads to from "stopper/%d" to "migration/%d". The names of these threads ultimately don't matter and there's no reason to make unnecessary userland visible changes. With this patch applied, stop_machine() and sched now share the same resources. stop_machine() is faster without wasting any resources and sched migration users are much cleaner. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Dipankar Sarma <dipankar@in.ibm.com> Cc: Josh Triplett <josh@freedesktop.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Dimitri Sivanich <sivanich@sgi.com>
2010-05-06 16:49:21 +00:00
struct migration_arg *arg = data;
do CPU_DEAD migrating under read_lock(tasklist) instead of write_lock_irq(tasklist) Currently move_task_off_dead_cpu() is called under write_lock_irq(tasklist). This means it can't use task_lock() which is needed to improve migrating to take task's ->cpuset into account. Change the code to call move_task_off_dead_cpu() with irqs enabled, and change migrate_live_tasks() to use read_lock(tasklist). This all is a preparation for the futher changes proposed by Cliff Wickman, see http://marc.info/?t=117327786100003 Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Cc: Cliff Wickman <cpw@sgi.com> Cc: Gautham R Shenoy <ego@in.ibm.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Srivatsa Vaddagiri <vatsa@in.ibm.com> Cc: Akinobu Mita <akinobu.mita@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-17 06:30:56 +00:00
sched: replace migration_thread with cpu_stop Currently migration_thread is serving three purposes - migration pusher, context to execute active_load_balance() and forced context switcher for expedited RCU synchronize_sched. All three roles are hardcoded into migration_thread() and determining which job is scheduled is slightly messy. This patch kills migration_thread and replaces all three uses with cpu_stop. The three different roles of migration_thread() are splitted into three separate cpu_stop callbacks - migration_cpu_stop(), active_load_balance_cpu_stop() and synchronize_sched_expedited_cpu_stop() - and each use case now simply asks cpu_stop to execute the callback as necessary. synchronize_sched_expedited() was implemented with private preallocated resources and custom multi-cpu queueing and waiting logic, both of which are provided by cpu_stop. synchronize_sched_expedited_count is made atomic and all other shared resources along with the mutex are dropped. synchronize_sched_expedited() also implemented a check to detect cases where not all the callback got executed on their assigned cpus and fall back to synchronize_sched(). If called with cpu hotplug blocked, cpu_stop already guarantees that and the condition cannot happen; otherwise, stop_machine() would break. However, this patch preserves the paranoid check using a cpumask to record on which cpus the stopper ran so that it can serve as a bisection point if something actually goes wrong theree. Because the internal execution state is no longer visible, rcu_expedited_torture_stats() is removed. This patch also renames cpu_stop threads to from "stopper/%d" to "migration/%d". The names of these threads ultimately don't matter and there's no reason to make unnecessary userland visible changes. With this patch applied, stop_machine() and sched now share the same resources. stop_machine() is faster without wasting any resources and sched migration users are much cleaner. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Dipankar Sarma <dipankar@in.ibm.com> Cc: Josh Triplett <josh@freedesktop.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Dimitri Sivanich <sivanich@sgi.com>
2010-05-06 16:49:21 +00:00
/*
* The original target cpu might have gone down and we might
* be on another cpu but it doesn't matter.
*/
do CPU_DEAD migrating under read_lock(tasklist) instead of write_lock_irq(tasklist) Currently move_task_off_dead_cpu() is called under write_lock_irq(tasklist). This means it can't use task_lock() which is needed to improve migrating to take task's ->cpuset into account. Change the code to call move_task_off_dead_cpu() with irqs enabled, and change migrate_live_tasks() to use read_lock(tasklist). This all is a preparation for the futher changes proposed by Cliff Wickman, see http://marc.info/?t=117327786100003 Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Cc: Cliff Wickman <cpw@sgi.com> Cc: Gautham R Shenoy <ego@in.ibm.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Srivatsa Vaddagiri <vatsa@in.ibm.com> Cc: Akinobu Mita <akinobu.mita@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-17 06:30:56 +00:00
local_irq_disable();
sched: replace migration_thread with cpu_stop Currently migration_thread is serving three purposes - migration pusher, context to execute active_load_balance() and forced context switcher for expedited RCU synchronize_sched. All three roles are hardcoded into migration_thread() and determining which job is scheduled is slightly messy. This patch kills migration_thread and replaces all three uses with cpu_stop. The three different roles of migration_thread() are splitted into three separate cpu_stop callbacks - migration_cpu_stop(), active_load_balance_cpu_stop() and synchronize_sched_expedited_cpu_stop() - and each use case now simply asks cpu_stop to execute the callback as necessary. synchronize_sched_expedited() was implemented with private preallocated resources and custom multi-cpu queueing and waiting logic, both of which are provided by cpu_stop. synchronize_sched_expedited_count is made atomic and all other shared resources along with the mutex are dropped. synchronize_sched_expedited() also implemented a check to detect cases where not all the callback got executed on their assigned cpus and fall back to synchronize_sched(). If called with cpu hotplug blocked, cpu_stop already guarantees that and the condition cannot happen; otherwise, stop_machine() would break. However, this patch preserves the paranoid check using a cpumask to record on which cpus the stopper ran so that it can serve as a bisection point if something actually goes wrong theree. Because the internal execution state is no longer visible, rcu_expedited_torture_stats() is removed. This patch also renames cpu_stop threads to from "stopper/%d" to "migration/%d". The names of these threads ultimately don't matter and there's no reason to make unnecessary userland visible changes. With this patch applied, stop_machine() and sched now share the same resources. stop_machine() is faster without wasting any resources and sched migration users are much cleaner. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Dipankar Sarma <dipankar@in.ibm.com> Cc: Josh Triplett <josh@freedesktop.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Dimitri Sivanich <sivanich@sgi.com>
2010-05-06 16:49:21 +00:00
__migrate_task(arg->task, raw_smp_processor_id(), arg->dest_cpu);
do CPU_DEAD migrating under read_lock(tasklist) instead of write_lock_irq(tasklist) Currently move_task_off_dead_cpu() is called under write_lock_irq(tasklist). This means it can't use task_lock() which is needed to improve migrating to take task's ->cpuset into account. Change the code to call move_task_off_dead_cpu() with irqs enabled, and change migrate_live_tasks() to use read_lock(tasklist). This all is a preparation for the futher changes proposed by Cliff Wickman, see http://marc.info/?t=117327786100003 Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Cc: Cliff Wickman <cpw@sgi.com> Cc: Gautham R Shenoy <ego@in.ibm.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Srivatsa Vaddagiri <vatsa@in.ibm.com> Cc: Akinobu Mita <akinobu.mita@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-17 06:30:56 +00:00
local_irq_enable();
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
return 0;
do CPU_DEAD migrating under read_lock(tasklist) instead of write_lock_irq(tasklist) Currently move_task_off_dead_cpu() is called under write_lock_irq(tasklist). This means it can't use task_lock() which is needed to improve migrating to take task's ->cpuset into account. Change the code to call move_task_off_dead_cpu() with irqs enabled, and change migrate_live_tasks() to use read_lock(tasklist). This all is a preparation for the futher changes proposed by Cliff Wickman, see http://marc.info/?t=117327786100003 Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Cc: Cliff Wickman <cpw@sgi.com> Cc: Gautham R Shenoy <ego@in.ibm.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Srivatsa Vaddagiri <vatsa@in.ibm.com> Cc: Akinobu Mita <akinobu.mita@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-17 06:30:56 +00:00
}
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
#ifdef CONFIG_HOTPLUG_CPU
sched: Simplify cpu-hot-unplug task migration While discussing the need for sched_idle_next(), Oleg remarked that since try_to_wake_up() ensures sleeping tasks will end up running on a sane cpu, we can do away with migrate_live_tasks(). If we then extend the existing hack of migrating current from CPU_DYING to migrating the full rq worth of tasks from CPU_DYING, the need for the sched_idle_next() abomination disappears as well, since idle will be the only possible thread left after the migration thread stops. This greatly simplifies the hot-unplug task migration path, as can be seen from the resulting code reduction (and about half the new lines are comments). Suggested-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1289851597.2109.547.camel@laptop> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-13 18:32:29 +00:00
[PATCH] move_task_off_dead_cpu() should be called with disabled ints move_task_off_dead_cpu() requires interrupts to be disabled, while migrate_dead() calls it with enabled interrupts. Added appropriate comments to functions and added BUG_ON(!irqs_disabled()) into double_rq_lock() and double_lock_balance() which are the origin sources of such bugs. Signed-off-by: Kirill Korotaev <dev@openvz.org> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 10:20:11 +00:00
/*
sched: Simplify cpu-hot-unplug task migration While discussing the need for sched_idle_next(), Oleg remarked that since try_to_wake_up() ensures sleeping tasks will end up running on a sane cpu, we can do away with migrate_live_tasks(). If we then extend the existing hack of migrating current from CPU_DYING to migrating the full rq worth of tasks from CPU_DYING, the need for the sched_idle_next() abomination disappears as well, since idle will be the only possible thread left after the migration thread stops. This greatly simplifies the hot-unplug task migration path, as can be seen from the resulting code reduction (and about half the new lines are comments). Suggested-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1289851597.2109.547.camel@laptop> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-13 18:32:29 +00:00
* Ensures that the idle task is using init_mm right before its cpu goes
* offline.
[PATCH] move_task_off_dead_cpu() should be called with disabled ints move_task_off_dead_cpu() requires interrupts to be disabled, while migrate_dead() calls it with enabled interrupts. Added appropriate comments to functions and added BUG_ON(!irqs_disabled()) into double_rq_lock() and double_lock_balance() which are the origin sources of such bugs. Signed-off-by: Kirill Korotaev <dev@openvz.org> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 10:20:11 +00:00
*/
sched: Simplify cpu-hot-unplug task migration While discussing the need for sched_idle_next(), Oleg remarked that since try_to_wake_up() ensures sleeping tasks will end up running on a sane cpu, we can do away with migrate_live_tasks(). If we then extend the existing hack of migrating current from CPU_DYING to migrating the full rq worth of tasks from CPU_DYING, the need for the sched_idle_next() abomination disappears as well, since idle will be the only possible thread left after the migration thread stops. This greatly simplifies the hot-unplug task migration path, as can be seen from the resulting code reduction (and about half the new lines are comments). Suggested-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1289851597.2109.547.camel@laptop> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-13 18:32:29 +00:00
void idle_task_exit(void)
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
{
sched: Simplify cpu-hot-unplug task migration While discussing the need for sched_idle_next(), Oleg remarked that since try_to_wake_up() ensures sleeping tasks will end up running on a sane cpu, we can do away with migrate_live_tasks(). If we then extend the existing hack of migrating current from CPU_DYING to migrating the full rq worth of tasks from CPU_DYING, the need for the sched_idle_next() abomination disappears as well, since idle will be the only possible thread left after the migration thread stops. This greatly simplifies the hot-unplug task migration path, as can be seen from the resulting code reduction (and about half the new lines are comments). Suggested-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1289851597.2109.547.camel@laptop> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-13 18:32:29 +00:00
struct mm_struct *mm = current->active_mm;
sched: avoid stack var in move_task_off_dead_cpu Impact: stack usage reduction With some care, we can avoid needing a temporary cpumask (we can't really allocate here, since we can't fail). This version calls cpuset_cpus_allowed_locked() with the task_rq_lock held. I'm fairly sure this works, but there might be a deadlock hiding. And of course, we can't get rid of the last cpumask on stack until we can use cpumask_of_node instead of node_to_cpumask. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-24 16:05:11 +00:00
sched: Simplify cpu-hot-unplug task migration While discussing the need for sched_idle_next(), Oleg remarked that since try_to_wake_up() ensures sleeping tasks will end up running on a sane cpu, we can do away with migrate_live_tasks(). If we then extend the existing hack of migrating current from CPU_DYING to migrating the full rq worth of tasks from CPU_DYING, the need for the sched_idle_next() abomination disappears as well, since idle will be the only possible thread left after the migration thread stops. This greatly simplifies the hot-unplug task migration path, as can be seen from the resulting code reduction (and about half the new lines are comments). Suggested-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1289851597.2109.547.camel@laptop> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-13 18:32:29 +00:00
BUG_ON(cpu_online(smp_processor_id()));
sched: avoid stack var in move_task_off_dead_cpu Impact: stack usage reduction With some care, we can avoid needing a temporary cpumask (we can't really allocate here, since we can't fail). This version calls cpuset_cpus_allowed_locked() with the task_rq_lock held. I'm fairly sure this works, but there might be a deadlock hiding. And of course, we can't get rid of the last cpumask on stack until we can use cpumask_of_node instead of node_to_cpumask. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-24 16:05:11 +00:00
sched: Simplify cpu-hot-unplug task migration While discussing the need for sched_idle_next(), Oleg remarked that since try_to_wake_up() ensures sleeping tasks will end up running on a sane cpu, we can do away with migrate_live_tasks(). If we then extend the existing hack of migrating current from CPU_DYING to migrating the full rq worth of tasks from CPU_DYING, the need for the sched_idle_next() abomination disappears as well, since idle will be the only possible thread left after the migration thread stops. This greatly simplifies the hot-unplug task migration path, as can be seen from the resulting code reduction (and about half the new lines are comments). Suggested-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1289851597.2109.547.camel@laptop> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-13 18:32:29 +00:00
if (mm != &init_mm)
switch_mm(mm, &init_mm, current);
mmdrop(mm);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
}
/*
* While a dead CPU has no uninterruptible tasks queued at this point,
* it might still have a nonzero ->nr_uninterruptible counter, because
* for performance reasons the counter is not stricly tracking tasks to
* their home CPUs. So we just add the counter to another CPU's counter,
* to keep the global sum constant after CPU-down:
*/
[PATCH] sched: cleanup, convert sched.c-internal typedefs to struct convert: - runqueue_t to 'struct rq' - prio_array_t to 'struct prio_array' - migration_req_t to 'struct migration_req' I was the one who added these but they are both against the kernel coding style and also were used inconsistently at places. So just get rid of them at once, now that we are flushing the scheduler patch-queue anyway. Conversion was mostly scripted, the result was reviewed and all secondary whitespace and style impact (if any) was fixed up by hand. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-03 07:25:42 +00:00
static void migrate_nr_uninterruptible(struct rq *rq_src)
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
{
sched: Fix balance vs hotplug race Since (e761b77: cpu hotplug, sched: Introduce cpu_active_map and redo sched domain managment) we have cpu_active_mask which is suppose to rule scheduler migration and load-balancing, except it never (fully) did. The particular problem being solved here is a crash in try_to_wake_up() where select_task_rq() ends up selecting an offline cpu because select_task_rq_fair() trusts the sched_domain tree to reflect the current state of affairs, similarly select_task_rq_rt() trusts the root_domain. However, the sched_domains are updated from CPU_DEAD, which is after the cpu is taken offline and after stop_machine is done. Therefore it can race perfectly well with code assuming the domains are right. Cure this by building the domains from cpu_active_mask on CPU_DOWN_PREPARE. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-11-25 12:31:39 +00:00
struct rq *rq_dest = cpu_rq(cpumask_any(cpu_active_mask));
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
rq_dest->nr_uninterruptible += rq_src->nr_uninterruptible;
rq_src->nr_uninterruptible = 0;
}
sched: cfs core code apply the CFS core code. this change switches over the scheduler core to CFS's modular design and makes use of kernel/sched_fair/rt/idletask.c to implement Linux's scheduling policies. thanks to Andrew Morton and Thomas Gleixner for lots of detailed review feedback and for fixlets. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
2007-07-09 16:51:59 +00:00
/*
sched: Simplify cpu-hot-unplug task migration While discussing the need for sched_idle_next(), Oleg remarked that since try_to_wake_up() ensures sleeping tasks will end up running on a sane cpu, we can do away with migrate_live_tasks(). If we then extend the existing hack of migrating current from CPU_DYING to migrating the full rq worth of tasks from CPU_DYING, the need for the sched_idle_next() abomination disappears as well, since idle will be the only possible thread left after the migration thread stops. This greatly simplifies the hot-unplug task migration path, as can be seen from the resulting code reduction (and about half the new lines are comments). Suggested-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1289851597.2109.547.camel@laptop> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-13 18:32:29 +00:00
* remove the tasks which were accounted by rq from calc_load_tasks.
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
*/
sched: Simplify cpu-hot-unplug task migration While discussing the need for sched_idle_next(), Oleg remarked that since try_to_wake_up() ensures sleeping tasks will end up running on a sane cpu, we can do away with migrate_live_tasks(). If we then extend the existing hack of migrating current from CPU_DYING to migrating the full rq worth of tasks from CPU_DYING, the need for the sched_idle_next() abomination disappears as well, since idle will be the only possible thread left after the migration thread stops. This greatly simplifies the hot-unplug task migration path, as can be seen from the resulting code reduction (and about half the new lines are comments). Suggested-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1289851597.2109.547.camel@laptop> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-13 18:32:29 +00:00
static void calc_global_load_remove(struct rq *rq)
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
{
sched: Simplify cpu-hot-unplug task migration While discussing the need for sched_idle_next(), Oleg remarked that since try_to_wake_up() ensures sleeping tasks will end up running on a sane cpu, we can do away with migrate_live_tasks(). If we then extend the existing hack of migrating current from CPU_DYING to migrating the full rq worth of tasks from CPU_DYING, the need for the sched_idle_next() abomination disappears as well, since idle will be the only possible thread left after the migration thread stops. This greatly simplifies the hot-unplug task migration path, as can be seen from the resulting code reduction (and about half the new lines are comments). Suggested-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1289851597.2109.547.camel@laptop> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-13 18:32:29 +00:00
atomic_long_sub(rq->calc_load_active, &calc_load_tasks);
rq->calc_load_active = 0;
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
}
[PATCH] sched: clean up fallout of recent changes Clean up some of the impact of recent (and not so recent) scheduler changes: - turning macros into nice inline functions - sanitizing and unifying variable definitions - whitespace, style consistency, 80-lines, comment correctness, spelling and curly braces police Due to the macro hell and variable placement simplifications there's even 26 bytes of .text saved: text data bss dec hex filename 25510 4153 192 29855 749f sched.o.before 25484 4153 192 29829 7485 sched.o.after [akpm@osdl.org: build fix] Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-03 07:25:40 +00:00
/*
sched: Simplify cpu-hot-unplug task migration While discussing the need for sched_idle_next(), Oleg remarked that since try_to_wake_up() ensures sleeping tasks will end up running on a sane cpu, we can do away with migrate_live_tasks(). If we then extend the existing hack of migrating current from CPU_DYING to migrating the full rq worth of tasks from CPU_DYING, the need for the sched_idle_next() abomination disappears as well, since idle will be the only possible thread left after the migration thread stops. This greatly simplifies the hot-unplug task migration path, as can be seen from the resulting code reduction (and about half the new lines are comments). Suggested-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1289851597.2109.547.camel@laptop> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-13 18:32:29 +00:00
* Migrate all tasks from the rq, sleeping tasks will be migrated by
* try_to_wake_up()->select_task_rq().
*
* Called with rq->lock held even though we'er in stop_machine() and
* there's no concurrency possible, we hold the required locks anyway
* because of lock validation efforts.
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
*/
sched: Simplify cpu-hot-unplug task migration While discussing the need for sched_idle_next(), Oleg remarked that since try_to_wake_up() ensures sleeping tasks will end up running on a sane cpu, we can do away with migrate_live_tasks(). If we then extend the existing hack of migrating current from CPU_DYING to migrating the full rq worth of tasks from CPU_DYING, the need for the sched_idle_next() abomination disappears as well, since idle will be the only possible thread left after the migration thread stops. This greatly simplifies the hot-unplug task migration path, as can be seen from the resulting code reduction (and about half the new lines are comments). Suggested-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1289851597.2109.547.camel@laptop> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-13 18:32:29 +00:00
static void migrate_tasks(unsigned int dead_cpu)
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
{
[PATCH] sched: cleanup, convert sched.c-internal typedefs to struct convert: - runqueue_t to 'struct rq' - prio_array_t to 'struct prio_array' - migration_req_t to 'struct migration_req' I was the one who added these but they are both against the kernel coding style and also were used inconsistently at places. So just get rid of them at once, now that we are flushing the scheduler patch-queue anyway. Conversion was mostly scripted, the result was reviewed and all secondary whitespace and style impact (if any) was fixed up by hand. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-03 07:25:42 +00:00
struct rq *rq = cpu_rq(dead_cpu);
sched: Simplify cpu-hot-unplug task migration While discussing the need for sched_idle_next(), Oleg remarked that since try_to_wake_up() ensures sleeping tasks will end up running on a sane cpu, we can do away with migrate_live_tasks(). If we then extend the existing hack of migrating current from CPU_DYING to migrating the full rq worth of tasks from CPU_DYING, the need for the sched_idle_next() abomination disappears as well, since idle will be the only possible thread left after the migration thread stops. This greatly simplifies the hot-unplug task migration path, as can be seen from the resulting code reduction (and about half the new lines are comments). Suggested-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1289851597.2109.547.camel@laptop> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-13 18:32:29 +00:00
struct task_struct *next, *stop = rq->stop;
int dest_cpu;
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
/*
sched: Simplify cpu-hot-unplug task migration While discussing the need for sched_idle_next(), Oleg remarked that since try_to_wake_up() ensures sleeping tasks will end up running on a sane cpu, we can do away with migrate_live_tasks(). If we then extend the existing hack of migrating current from CPU_DYING to migrating the full rq worth of tasks from CPU_DYING, the need for the sched_idle_next() abomination disappears as well, since idle will be the only possible thread left after the migration thread stops. This greatly simplifies the hot-unplug task migration path, as can be seen from the resulting code reduction (and about half the new lines are comments). Suggested-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1289851597.2109.547.camel@laptop> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-13 18:32:29 +00:00
* Fudge the rq selection such that the below task selection loop
* doesn't get stuck on the currently eligible stop task.
*
* We're currently inside stop_machine() and the rq is either stuck
* in the stop_machine_cpu_stop() loop, or we're executing this code,
* either way we should never end up calling schedule() until we're
* done here.
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
*/
sched: Simplify cpu-hot-unplug task migration While discussing the need for sched_idle_next(), Oleg remarked that since try_to_wake_up() ensures sleeping tasks will end up running on a sane cpu, we can do away with migrate_live_tasks(). If we then extend the existing hack of migrating current from CPU_DYING to migrating the full rq worth of tasks from CPU_DYING, the need for the sched_idle_next() abomination disappears as well, since idle will be the only possible thread left after the migration thread stops. This greatly simplifies the hot-unplug task migration path, as can be seen from the resulting code reduction (and about half the new lines are comments). Suggested-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1289851597.2109.547.camel@laptop> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-13 18:32:29 +00:00
rq->stop = NULL;
[PATCH] sched: clean up fallout of recent changes Clean up some of the impact of recent (and not so recent) scheduler changes: - turning macros into nice inline functions - sanitizing and unifying variable definitions - whitespace, style consistency, 80-lines, comment correctness, spelling and curly braces police Due to the macro hell and variable placement simplifications there's even 26 bytes of .text saved: text data bss dec hex filename 25510 4153 192 29855 749f sched.o.before 25484 4153 192 29829 7485 sched.o.after [akpm@osdl.org: build fix] Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-03 07:25:40 +00:00
sched: cfs core code apply the CFS core code. this change switches over the scheduler core to CFS's modular design and makes use of kernel/sched_fair/rt/idletask.c to implement Linux's scheduling policies. thanks to Andrew Morton and Thomas Gleixner for lots of detailed review feedback and for fixlets. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
2007-07-09 16:51:59 +00:00
for ( ; ; ) {
sched: Simplify cpu-hot-unplug task migration While discussing the need for sched_idle_next(), Oleg remarked that since try_to_wake_up() ensures sleeping tasks will end up running on a sane cpu, we can do away with migrate_live_tasks(). If we then extend the existing hack of migrating current from CPU_DYING to migrating the full rq worth of tasks from CPU_DYING, the need for the sched_idle_next() abomination disappears as well, since idle will be the only possible thread left after the migration thread stops. This greatly simplifies the hot-unplug task migration path, as can be seen from the resulting code reduction (and about half the new lines are comments). Suggested-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1289851597.2109.547.camel@laptop> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-13 18:32:29 +00:00
/*
* There's this thread running, bail when that's the only
* remaining thread.
*/
if (rq->nr_running == 1)
sched: cfs core code apply the CFS core code. this change switches over the scheduler core to CFS's modular design and makes use of kernel/sched_fair/rt/idletask.c to implement Linux's scheduling policies. thanks to Andrew Morton and Thomas Gleixner for lots of detailed review feedback and for fixlets. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
2007-07-09 16:51:59 +00:00
break;
sched: Simplify cpu-hot-unplug task migration While discussing the need for sched_idle_next(), Oleg remarked that since try_to_wake_up() ensures sleeping tasks will end up running on a sane cpu, we can do away with migrate_live_tasks(). If we then extend the existing hack of migrating current from CPU_DYING to migrating the full rq worth of tasks from CPU_DYING, the need for the sched_idle_next() abomination disappears as well, since idle will be the only possible thread left after the migration thread stops. This greatly simplifies the hot-unplug task migration path, as can be seen from the resulting code reduction (and about half the new lines are comments). Suggested-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1289851597.2109.547.camel@laptop> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-13 18:32:29 +00:00
sched: kill unused parameter of pick_next_task() Impact: micro-optimization Parameter "prev" is not used really. Signed-off-by: Wang Chen <wangchen@cn.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-02 05:55:26 +00:00
next = pick_next_task(rq);
sched: Simplify cpu-hot-unplug task migration While discussing the need for sched_idle_next(), Oleg remarked that since try_to_wake_up() ensures sleeping tasks will end up running on a sane cpu, we can do away with migrate_live_tasks(). If we then extend the existing hack of migrating current from CPU_DYING to migrating the full rq worth of tasks from CPU_DYING, the need for the sched_idle_next() abomination disappears as well, since idle will be the only possible thread left after the migration thread stops. This greatly simplifies the hot-unplug task migration path, as can be seen from the resulting code reduction (and about half the new lines are comments). Suggested-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1289851597.2109.547.camel@laptop> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-13 18:32:29 +00:00
BUG_ON(!next);
sched: fix cpu hotplug the CPU hotplug problems (crashes under high-volume unplug+replug tests) seem to be related to migrate_dead_tasks(). Firstly I added traces to see all tasks being migrated with migrate_live_tasks() and migrate_dead_tasks(). On my setup the problem pops up (the one with "se == NULL" in the loop of pick_next_task_fair()) shortly after the traces indicate that some has been migrated with migrate_dead_tasks()). btw., I can reproduce it much faster now with just a plain cpu down/up loop. [disclaimer] Well, unless I'm really missing something important in this late hour [/desclaimer] pick_next_task() is not something appropriate for migrate_dead_tasks() :-) the following change seems to eliminate the problem on my setup (although, I kept it running only for a few minutes to get a few messages indicating migrate_dead_tasks() does move tasks and the system is still ok) Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-28 22:16:56 +00:00
next->sched_class->put_prev_task(rq, next);
[PATCH] sched: debug feature - make the sched-domains tree runtime-tweakable debugging feature: make the sched-domains tree runtime-tweakable. Signed-off-by: Andrew Morton <akpm@linux-foundation.org> [ mingo@elte.hu: made it depend on CONFIG_SCHED_DEBUG & small updates ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-26 11:40:43 +00:00
sched: Simplify cpu-hot-unplug task migration While discussing the need for sched_idle_next(), Oleg remarked that since try_to_wake_up() ensures sleeping tasks will end up running on a sane cpu, we can do away with migrate_live_tasks(). If we then extend the existing hack of migrating current from CPU_DYING to migrating the full rq worth of tasks from CPU_DYING, the need for the sched_idle_next() abomination disappears as well, since idle will be the only possible thread left after the migration thread stops. This greatly simplifies the hot-unplug task migration path, as can be seen from the resulting code reduction (and about half the new lines are comments). Suggested-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1289851597.2109.547.camel@laptop> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-13 18:32:29 +00:00
/* Find suitable destination for @next, with force if needed. */
dest_cpu = select_fallback_rq(dead_cpu, next);
raw_spin_unlock(&rq->lock);
__migrate_task(next, dead_cpu, dest_cpu);
raw_spin_lock(&rq->lock);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
}
sched, timers: move calc_load() to scheduler Dimitri Sivanich noticed that xtime_lock is held write locked across calc_load() which iterates over all online CPUs. That can cause long latencies for xtime_lock readers on large SMP systems. The load average calculation is an rough estimate anyway so there is no real need to protect the readers vs. the update. It's not a problem when the avenrun array is updated while a reader copies the values. Instead of iterating over all online CPUs let the scheduler_tick code update the number of active tasks shortly before the avenrun update happens. The avenrun update itself is handled by the CPU which calls do_timer(). [ Impact: reduce xtime_lock write locked section ] Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org>
2009-04-11 08:43:41 +00:00
sched: Simplify cpu-hot-unplug task migration While discussing the need for sched_idle_next(), Oleg remarked that since try_to_wake_up() ensures sleeping tasks will end up running on a sane cpu, we can do away with migrate_live_tasks(). If we then extend the existing hack of migrating current from CPU_DYING to migrating the full rq worth of tasks from CPU_DYING, the need for the sched_idle_next() abomination disappears as well, since idle will be the only possible thread left after the migration thread stops. This greatly simplifies the hot-unplug task migration path, as can be seen from the resulting code reduction (and about half the new lines are comments). Suggested-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1289851597.2109.547.camel@laptop> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-13 18:32:29 +00:00
rq->stop = stop;
sched, timers: move calc_load() to scheduler Dimitri Sivanich noticed that xtime_lock is held write locked across calc_load() which iterates over all online CPUs. That can cause long latencies for xtime_lock readers on large SMP systems. The load average calculation is an rough estimate anyway so there is no real need to protect the readers vs. the update. It's not a problem when the avenrun array is updated while a reader copies the values. Instead of iterating over all online CPUs let the scheduler_tick code update the number of active tasks shortly before the avenrun update happens. The avenrun update itself is handled by the CPU which calls do_timer(). [ Impact: reduce xtime_lock write locked section ] Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org>
2009-04-11 08:43:41 +00:00
}
sched: Simplify cpu-hot-unplug task migration While discussing the need for sched_idle_next(), Oleg remarked that since try_to_wake_up() ensures sleeping tasks will end up running on a sane cpu, we can do away with migrate_live_tasks(). If we then extend the existing hack of migrating current from CPU_DYING to migrating the full rq worth of tasks from CPU_DYING, the need for the sched_idle_next() abomination disappears as well, since idle will be the only possible thread left after the migration thread stops. This greatly simplifies the hot-unplug task migration path, as can be seen from the resulting code reduction (and about half the new lines are comments). Suggested-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1289851597.2109.547.camel@laptop> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-13 18:32:29 +00:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
#endif /* CONFIG_HOTPLUG_CPU */
[PATCH] sched: debug feature - make the sched-domains tree runtime-tweakable debugging feature: make the sched-domains tree runtime-tweakable. Signed-off-by: Andrew Morton <akpm@linux-foundation.org> [ mingo@elte.hu: made it depend on CONFIG_SCHED_DEBUG & small updates ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-26 11:40:43 +00:00
#if defined(CONFIG_SCHED_DEBUG) && defined(CONFIG_SYSCTL)
static struct ctl_table sd_ctl_dir[] = {
sched: remove binary sysctls from kernel.sched_domain kernel.sched_domain hierarchy is under CTL_UNNUMBERED and thus unreachable to sysctl(2). Generating .ctl_number's in such situation is not useful. Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-08-09 09:16:46 +00:00
{
.procname = "sched_domain",
sched: fix sysctl directory permissions There are two remaining gotchas: - The directories have impossible permissions (writeable). - The ctl_name for the kernel directory is inconsistent with everything else. It should be CTL_KERN. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-08-23 13:18:02 +00:00
.mode = 0555,
sched: remove binary sysctls from kernel.sched_domain kernel.sched_domain hierarchy is under CTL_UNNUMBERED and thus unreachable to sysctl(2). Generating .ctl_number's in such situation is not useful. Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-08-09 09:16:46 +00:00
},
sysctl kernel: Remove binary sysctl logic Now that sys_sysctl is a generic wrapper around /proc/sys .ctl_name and .strategy members of sysctl tables are dead code. Remove them. Cc: Ingo Molnar <mingo@elte.hu> Cc: Peter Zijlstra <peterz@infradead.org> Cc: David Howells <dhowells@redhat.com> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2009-11-05 23:38:40 +00:00
{}
[PATCH] sched: debug feature - make the sched-domains tree runtime-tweakable debugging feature: make the sched-domains tree runtime-tweakable. Signed-off-by: Andrew Morton <akpm@linux-foundation.org> [ mingo@elte.hu: made it depend on CONFIG_SCHED_DEBUG & small updates ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-26 11:40:43 +00:00
};
static struct ctl_table sd_ctl_root[] = {
sched: remove binary sysctls from kernel.sched_domain kernel.sched_domain hierarchy is under CTL_UNNUMBERED and thus unreachable to sysctl(2). Generating .ctl_number's in such situation is not useful. Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-08-09 09:16:46 +00:00
{
.procname = "kernel",
sched: fix sysctl directory permissions There are two remaining gotchas: - The directories have impossible permissions (writeable). - The ctl_name for the kernel directory is inconsistent with everything else. It should be CTL_KERN. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-08-23 13:18:02 +00:00
.mode = 0555,
sched: remove binary sysctls from kernel.sched_domain kernel.sched_domain hierarchy is under CTL_UNNUMBERED and thus unreachable to sysctl(2). Generating .ctl_number's in such situation is not useful. Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-08-09 09:16:46 +00:00
.child = sd_ctl_dir,
},
sysctl kernel: Remove binary sysctl logic Now that sys_sysctl is a generic wrapper around /proc/sys .ctl_name and .strategy members of sysctl tables are dead code. Remove them. Cc: Ingo Molnar <mingo@elte.hu> Cc: Peter Zijlstra <peterz@infradead.org> Cc: David Howells <dhowells@redhat.com> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2009-11-05 23:38:40 +00:00
{}
[PATCH] sched: debug feature - make the sched-domains tree runtime-tweakable debugging feature: make the sched-domains tree runtime-tweakable. Signed-off-by: Andrew Morton <akpm@linux-foundation.org> [ mingo@elte.hu: made it depend on CONFIG_SCHED_DEBUG & small updates ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-26 11:40:43 +00:00
};
static struct ctl_table *sd_alloc_ctl_entry(int n)
{
struct ctl_table *entry =
sched: domain sysctl fixes: use kcalloc() kcalloc checks for n * sizeof(element) overflows and it zeros. Signed-off-by: Milton Miller <miltonm@bga.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 15:00:19 +00:00
kcalloc(n, sizeof(struct ctl_table), GFP_KERNEL);
[PATCH] sched: debug feature - make the sched-domains tree runtime-tweakable debugging feature: make the sched-domains tree runtime-tweakable. Signed-off-by: Andrew Morton <akpm@linux-foundation.org> [ mingo@elte.hu: made it depend on CONFIG_SCHED_DEBUG & small updates ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-26 11:40:43 +00:00
return entry;
}
sched: domain sysctl fixes: unregister the sysctl table before domains Unregister and free the sysctl table before destroying domains, then rebuild and register after creating the new domains. This prevents the sysctl table from pointing to freed memory for root to write. Signed-off-by: Milton Miller <miltonm@bga.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 15:00:19 +00:00
static void sd_free_ctl_entry(struct ctl_table **tablep)
{
sched: more robust sd-sysctl entry freeing It occurred to me this morning that the procname field was dynamically allocated and needed to be freed. I started to put in break statements when allocation failed but it was approaching 50% error handling code. I came up with this alternative of looping while entry->mode is set and checking proc_handler instead of ->table. Alternatively, the string version of the domain name and cpu number could be stored the structs. I verified by compiling CONFIG_DEBUG_SLAB and checking the allocation counts after taking a cpuset exclusive and back. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-17 14:55:11 +00:00
struct ctl_table *entry;
sched: domain sysctl fixes: unregister the sysctl table before domains Unregister and free the sysctl table before destroying domains, then rebuild and register after creating the new domains. This prevents the sysctl table from pointing to freed memory for root to write. Signed-off-by: Milton Miller <miltonm@bga.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 15:00:19 +00:00
sched: more robust sd-sysctl entry freeing It occurred to me this morning that the procname field was dynamically allocated and needed to be freed. I started to put in break statements when allocation failed but it was approaching 50% error handling code. I came up with this alternative of looping while entry->mode is set and checking proc_handler instead of ->table. Alternatively, the string version of the domain name and cpu number could be stored the structs. I verified by compiling CONFIG_DEBUG_SLAB and checking the allocation counts after taking a cpuset exclusive and back. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-17 14:55:11 +00:00
/*
* In the intermediate directories, both the child directory and
* procname are dynamically allocated and could fail but the mode
sched: style cleanups style cleanup of various changes that were done recently. no code changed: text data bss dec hex filename 23680 2542 28 26250 668a sched.o.before 23680 2542 28 26250 668a sched.o.after Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-12-05 14:46:09 +00:00
* will always be set. In the lowest directory the names are
sched: more robust sd-sysctl entry freeing It occurred to me this morning that the procname field was dynamically allocated and needed to be freed. I started to put in break statements when allocation failed but it was approaching 50% error handling code. I came up with this alternative of looping while entry->mode is set and checking proc_handler instead of ->table. Alternatively, the string version of the domain name and cpu number could be stored the structs. I verified by compiling CONFIG_DEBUG_SLAB and checking the allocation counts after taking a cpuset exclusive and back. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-17 14:55:11 +00:00
* static strings and all have proc handlers.
*/
for (entry = *tablep; entry->mode; entry++) {
sched: domain sysctl fixes: unregister the sysctl table before domains Unregister and free the sysctl table before destroying domains, then rebuild and register after creating the new domains. This prevents the sysctl table from pointing to freed memory for root to write. Signed-off-by: Milton Miller <miltonm@bga.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 15:00:19 +00:00
if (entry->child)
sd_free_ctl_entry(&entry->child);
sched: more robust sd-sysctl entry freeing It occurred to me this morning that the procname field was dynamically allocated and needed to be freed. I started to put in break statements when allocation failed but it was approaching 50% error handling code. I came up with this alternative of looping while entry->mode is set and checking proc_handler instead of ->table. Alternatively, the string version of the domain name and cpu number could be stored the structs. I verified by compiling CONFIG_DEBUG_SLAB and checking the allocation counts after taking a cpuset exclusive and back. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-17 14:55:11 +00:00
if (entry->proc_handler == NULL)
kfree(entry->procname);
}
sched: domain sysctl fixes: unregister the sysctl table before domains Unregister and free the sysctl table before destroying domains, then rebuild and register after creating the new domains. This prevents the sysctl table from pointing to freed memory for root to write. Signed-off-by: Milton Miller <miltonm@bga.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 15:00:19 +00:00
kfree(*tablep);
*tablep = NULL;
}
[PATCH] sched: debug feature - make the sched-domains tree runtime-tweakable debugging feature: make the sched-domains tree runtime-tweakable. Signed-off-by: Andrew Morton <akpm@linux-foundation.org> [ mingo@elte.hu: made it depend on CONFIG_SCHED_DEBUG & small updates ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-26 11:40:43 +00:00
static void
sched: remove binary sysctls from kernel.sched_domain kernel.sched_domain hierarchy is under CTL_UNNUMBERED and thus unreachable to sysctl(2). Generating .ctl_number's in such situation is not useful. Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-08-09 09:16:46 +00:00
set_table_entry(struct ctl_table *entry,
[PATCH] sched: debug feature - make the sched-domains tree runtime-tweakable debugging feature: make the sched-domains tree runtime-tweakable. Signed-off-by: Andrew Morton <akpm@linux-foundation.org> [ mingo@elte.hu: made it depend on CONFIG_SCHED_DEBUG & small updates ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-26 11:40:43 +00:00
const char *procname, void *data, int maxlen,
mode_t mode, proc_handler *proc_handler)
{
entry->procname = procname;
entry->data = data;
entry->maxlen = maxlen;
entry->mode = mode;
entry->proc_handler = proc_handler;
}
static struct ctl_table *
sd_alloc_ctl_domain_table(struct sched_domain *sd)
{
sched debug: add name to sched_domain sysctl entries add /proc/sys/kernel/sched_domain/cpu0/domain0/name, to make it easier to see which specific scheduler domain remained at that entry. Since we process the scheduler domain tree and simplify it, it's not always immediately clear during debugging which domain came from where. depends on CONFIG_SCHED_DEBUG=y. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-09 09:35:51 +00:00
struct ctl_table *table = sd_alloc_ctl_entry(13);
[PATCH] sched: debug feature - make the sched-domains tree runtime-tweakable debugging feature: make the sched-domains tree runtime-tweakable. Signed-off-by: Andrew Morton <akpm@linux-foundation.org> [ mingo@elte.hu: made it depend on CONFIG_SCHED_DEBUG & small updates ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-26 11:40:43 +00:00
sched: domain sysctl fixes: do not crash on allocation failure Now that we are calling this at runtime, a more relaxed error path is suggested. If an allocation fails, we just register the partial table, which will show empty directories. Signed-off-by: Milton Miller <miltonm@bga.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 15:00:19 +00:00
if (table == NULL)
return NULL;
sched: remove binary sysctls from kernel.sched_domain kernel.sched_domain hierarchy is under CTL_UNNUMBERED and thus unreachable to sysctl(2). Generating .ctl_number's in such situation is not useful. Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-08-09 09:16:46 +00:00
set_table_entry(&table[0], "min_interval", &sd->min_interval,
[PATCH] sched: debug feature - make the sched-domains tree runtime-tweakable debugging feature: make the sched-domains tree runtime-tweakable. Signed-off-by: Andrew Morton <akpm@linux-foundation.org> [ mingo@elte.hu: made it depend on CONFIG_SCHED_DEBUG & small updates ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-26 11:40:43 +00:00
sizeof(long), 0644, proc_doulongvec_minmax);
sched: remove binary sysctls from kernel.sched_domain kernel.sched_domain hierarchy is under CTL_UNNUMBERED and thus unreachable to sysctl(2). Generating .ctl_number's in such situation is not useful. Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-08-09 09:16:46 +00:00
set_table_entry(&table[1], "max_interval", &sd->max_interval,
[PATCH] sched: debug feature - make the sched-domains tree runtime-tweakable debugging feature: make the sched-domains tree runtime-tweakable. Signed-off-by: Andrew Morton <akpm@linux-foundation.org> [ mingo@elte.hu: made it depend on CONFIG_SCHED_DEBUG & small updates ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-26 11:40:43 +00:00
sizeof(long), 0644, proc_doulongvec_minmax);
sched: remove binary sysctls from kernel.sched_domain kernel.sched_domain hierarchy is under CTL_UNNUMBERED and thus unreachable to sysctl(2). Generating .ctl_number's in such situation is not useful. Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-08-09 09:16:46 +00:00
set_table_entry(&table[2], "busy_idx", &sd->busy_idx,
[PATCH] sched: debug feature - make the sched-domains tree runtime-tweakable debugging feature: make the sched-domains tree runtime-tweakable. Signed-off-by: Andrew Morton <akpm@linux-foundation.org> [ mingo@elte.hu: made it depend on CONFIG_SCHED_DEBUG & small updates ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-26 11:40:43 +00:00
sizeof(int), 0644, proc_dointvec_minmax);
sched: remove binary sysctls from kernel.sched_domain kernel.sched_domain hierarchy is under CTL_UNNUMBERED and thus unreachable to sysctl(2). Generating .ctl_number's in such situation is not useful. Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-08-09 09:16:46 +00:00
set_table_entry(&table[3], "idle_idx", &sd->idle_idx,
[PATCH] sched: debug feature - make the sched-domains tree runtime-tweakable debugging feature: make the sched-domains tree runtime-tweakable. Signed-off-by: Andrew Morton <akpm@linux-foundation.org> [ mingo@elte.hu: made it depend on CONFIG_SCHED_DEBUG & small updates ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-26 11:40:43 +00:00
sizeof(int), 0644, proc_dointvec_minmax);
sched: remove binary sysctls from kernel.sched_domain kernel.sched_domain hierarchy is under CTL_UNNUMBERED and thus unreachable to sysctl(2). Generating .ctl_number's in such situation is not useful. Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-08-09 09:16:46 +00:00
set_table_entry(&table[4], "newidle_idx", &sd->newidle_idx,
[PATCH] sched: debug feature - make the sched-domains tree runtime-tweakable debugging feature: make the sched-domains tree runtime-tweakable. Signed-off-by: Andrew Morton <akpm@linux-foundation.org> [ mingo@elte.hu: made it depend on CONFIG_SCHED_DEBUG & small updates ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-26 11:40:43 +00:00
sizeof(int), 0644, proc_dointvec_minmax);
sched: remove binary sysctls from kernel.sched_domain kernel.sched_domain hierarchy is under CTL_UNNUMBERED and thus unreachable to sysctl(2). Generating .ctl_number's in such situation is not useful. Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-08-09 09:16:46 +00:00
set_table_entry(&table[5], "wake_idx", &sd->wake_idx,
[PATCH] sched: debug feature - make the sched-domains tree runtime-tweakable debugging feature: make the sched-domains tree runtime-tweakable. Signed-off-by: Andrew Morton <akpm@linux-foundation.org> [ mingo@elte.hu: made it depend on CONFIG_SCHED_DEBUG & small updates ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-26 11:40:43 +00:00
sizeof(int), 0644, proc_dointvec_minmax);
sched: remove binary sysctls from kernel.sched_domain kernel.sched_domain hierarchy is under CTL_UNNUMBERED and thus unreachable to sysctl(2). Generating .ctl_number's in such situation is not useful. Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-08-09 09:16:46 +00:00
set_table_entry(&table[6], "forkexec_idx", &sd->forkexec_idx,
[PATCH] sched: debug feature - make the sched-domains tree runtime-tweakable debugging feature: make the sched-domains tree runtime-tweakable. Signed-off-by: Andrew Morton <akpm@linux-foundation.org> [ mingo@elte.hu: made it depend on CONFIG_SCHED_DEBUG & small updates ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-26 11:40:43 +00:00
sizeof(int), 0644, proc_dointvec_minmax);
sched: remove binary sysctls from kernel.sched_domain kernel.sched_domain hierarchy is under CTL_UNNUMBERED and thus unreachable to sysctl(2). Generating .ctl_number's in such situation is not useful. Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-08-09 09:16:46 +00:00
set_table_entry(&table[7], "busy_factor", &sd->busy_factor,
[PATCH] sched: debug feature - make the sched-domains tree runtime-tweakable debugging feature: make the sched-domains tree runtime-tweakable. Signed-off-by: Andrew Morton <akpm@linux-foundation.org> [ mingo@elte.hu: made it depend on CONFIG_SCHED_DEBUG & small updates ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-26 11:40:43 +00:00
sizeof(int), 0644, proc_dointvec_minmax);
sched: remove binary sysctls from kernel.sched_domain kernel.sched_domain hierarchy is under CTL_UNNUMBERED and thus unreachable to sysctl(2). Generating .ctl_number's in such situation is not useful. Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-08-09 09:16:46 +00:00
set_table_entry(&table[8], "imbalance_pct", &sd->imbalance_pct,
[PATCH] sched: debug feature - make the sched-domains tree runtime-tweakable debugging feature: make the sched-domains tree runtime-tweakable. Signed-off-by: Andrew Morton <akpm@linux-foundation.org> [ mingo@elte.hu: made it depend on CONFIG_SCHED_DEBUG & small updates ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-26 11:40:43 +00:00
sizeof(int), 0644, proc_dointvec_minmax);
sched: some proc entries are missed in sched_domain sys_ctl debug code cache_nice_tries and flags entry do not appear in proc fs sched_domain directory, because ctl_table entry is skipped. This patch fixes the issue. Signed-off-by: Zou Nan hai <nanhai.zou@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 15:00:14 +00:00
set_table_entry(&table[9], "cache_nice_tries",
[PATCH] sched: debug feature - make the sched-domains tree runtime-tweakable debugging feature: make the sched-domains tree runtime-tweakable. Signed-off-by: Andrew Morton <akpm@linux-foundation.org> [ mingo@elte.hu: made it depend on CONFIG_SCHED_DEBUG & small updates ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-26 11:40:43 +00:00
&sd->cache_nice_tries,
sizeof(int), 0644, proc_dointvec_minmax);
sched: some proc entries are missed in sched_domain sys_ctl debug code cache_nice_tries and flags entry do not appear in proc fs sched_domain directory, because ctl_table entry is skipped. This patch fixes the issue. Signed-off-by: Zou Nan hai <nanhai.zou@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 15:00:14 +00:00
set_table_entry(&table[10], "flags", &sd->flags,
[PATCH] sched: debug feature - make the sched-domains tree runtime-tweakable debugging feature: make the sched-domains tree runtime-tweakable. Signed-off-by: Andrew Morton <akpm@linux-foundation.org> [ mingo@elte.hu: made it depend on CONFIG_SCHED_DEBUG & small updates ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-26 11:40:43 +00:00
sizeof(int), 0644, proc_dointvec_minmax);
sched debug: add name to sched_domain sysctl entries add /proc/sys/kernel/sched_domain/cpu0/domain0/name, to make it easier to see which specific scheduler domain remained at that entry. Since we process the scheduler domain tree and simplify it, it's not always immediately clear during debugging which domain came from where. depends on CONFIG_SCHED_DEBUG=y. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-09 09:35:51 +00:00
set_table_entry(&table[11], "name", sd->name,
CORENAME_MAX_SIZE, 0444, proc_dostring);
/* &table[12] is terminator */
[PATCH] sched: debug feature - make the sched-domains tree runtime-tweakable debugging feature: make the sched-domains tree runtime-tweakable. Signed-off-by: Andrew Morton <akpm@linux-foundation.org> [ mingo@elte.hu: made it depend on CONFIG_SCHED_DEBUG & small updates ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-26 11:40:43 +00:00
return table;
}
sched: clean up sd_alloc_ctl_cpu_table() definition clean up sd_alloc_ctl_cpu_table() definition. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-11-28 14:52:56 +00:00
static ctl_table *sd_alloc_ctl_cpu_table(int cpu)
[PATCH] sched: debug feature - make the sched-domains tree runtime-tweakable debugging feature: make the sched-domains tree runtime-tweakable. Signed-off-by: Andrew Morton <akpm@linux-foundation.org> [ mingo@elte.hu: made it depend on CONFIG_SCHED_DEBUG & small updates ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-26 11:40:43 +00:00
{
struct ctl_table *entry, *table;
struct sched_domain *sd;
int domain_num = 0, i;
char buf[32];
for_each_domain(cpu, sd)
domain_num++;
entry = table = sd_alloc_ctl_entry(domain_num + 1);
sched: domain sysctl fixes: do not crash on allocation failure Now that we are calling this at runtime, a more relaxed error path is suggested. If an allocation fails, we just register the partial table, which will show empty directories. Signed-off-by: Milton Miller <miltonm@bga.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 15:00:19 +00:00
if (table == NULL)
return NULL;
[PATCH] sched: debug feature - make the sched-domains tree runtime-tweakable debugging feature: make the sched-domains tree runtime-tweakable. Signed-off-by: Andrew Morton <akpm@linux-foundation.org> [ mingo@elte.hu: made it depend on CONFIG_SCHED_DEBUG & small updates ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-26 11:40:43 +00:00
i = 0;
for_each_domain(cpu, sd) {
snprintf(buf, 32, "domain%d", i);
entry->procname = kstrdup(buf, GFP_KERNEL);
sched: fix sysctl directory permissions There are two remaining gotchas: - The directories have impossible permissions (writeable). - The ctl_name for the kernel directory is inconsistent with everything else. It should be CTL_KERN. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-08-23 13:18:02 +00:00
entry->mode = 0555;
[PATCH] sched: debug feature - make the sched-domains tree runtime-tweakable debugging feature: make the sched-domains tree runtime-tweakable. Signed-off-by: Andrew Morton <akpm@linux-foundation.org> [ mingo@elte.hu: made it depend on CONFIG_SCHED_DEBUG & small updates ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-26 11:40:43 +00:00
entry->child = sd_alloc_ctl_domain_table(sd);
entry++;
i++;
}
return table;
}
static struct ctl_table_header *sd_sysctl_header;
sched: domain sysctl fixes: unregister the sysctl table before domains Unregister and free the sysctl table before destroying domains, then rebuild and register after creating the new domains. This prevents the sysctl table from pointing to freed memory for root to write. Signed-off-by: Milton Miller <miltonm@bga.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 15:00:19 +00:00
static void register_sched_domain_sysctl(void)
[PATCH] sched: debug feature - make the sched-domains tree runtime-tweakable debugging feature: make the sched-domains tree runtime-tweakable. Signed-off-by: Andrew Morton <akpm@linux-foundation.org> [ mingo@elte.hu: made it depend on CONFIG_SCHED_DEBUG & small updates ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-26 11:40:43 +00:00
{
sched: Fix balance vs hotplug race Since (e761b77: cpu hotplug, sched: Introduce cpu_active_map and redo sched domain managment) we have cpu_active_mask which is suppose to rule scheduler migration and load-balancing, except it never (fully) did. The particular problem being solved here is a crash in try_to_wake_up() where select_task_rq() ends up selecting an offline cpu because select_task_rq_fair() trusts the sched_domain tree to reflect the current state of affairs, similarly select_task_rq_rt() trusts the root_domain. However, the sched_domains are updated from CPU_DEAD, which is after the cpu is taken offline and after stop_machine is done. Therefore it can race perfectly well with code assuming the domains are right. Cure this by building the domains from cpu_active_mask on CPU_DOWN_PREPARE. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-11-25 12:31:39 +00:00
int i, cpu_num = num_possible_cpus();
[PATCH] sched: debug feature - make the sched-domains tree runtime-tweakable debugging feature: make the sched-domains tree runtime-tweakable. Signed-off-by: Andrew Morton <akpm@linux-foundation.org> [ mingo@elte.hu: made it depend on CONFIG_SCHED_DEBUG & small updates ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-26 11:40:43 +00:00
struct ctl_table *entry = sd_alloc_ctl_entry(cpu_num + 1);
char buf[32];
sched: fix sched_domain sysctl registration again commit 029190c515f15f512ac85de8fc686d4dbd0ae731 (cpuset sched_load_balance flag) was not tested SCHED_DEBUG enabled as committed as it dereferences NULL when used and it reordered the sysctl registration to cause it to never show any domains or their tunables. Fixes: 1) restore arch_init_sched_domains ordering we can't walk the domains before we build them presently we register cpus with empty directories (no domain directories or files). 2) make unregister_sched_domain_sysctl do nothing when already unregistered detach_destroy_domains is now called one set of cpus at a time unregister_syctl dereferences NULL if called with a null. While the the function would always dereference null if called twice, in the previous code it was always called once and then was followed a register. So only the hidden bug of the sysctl_root_table not being allocated followed by an attempt to free it would have shown the error. 3) always call unregister and register in partition_sched_domains The code is "smart" about unregistering only needed domains. Since we aren't guaranteed any calls to unregister, always unregister. Without calling register on the way out we will not have a table or any sysctl tree. 4) warn if register is called without unregistering The previous table memory is lost, leaving pointers to the later freed memory in sysctl and leaking the memory of the tables. Before this patch on a 2-core 4-thread box compiled for SMT and NUMA, the domains appear empty (there are actually 3 levels per cpu). And as soon as two domains a null pointer is dereferenced (unreliable in this case is stack garbage): bu19a:~# ls -R /proc/sys/kernel/sched_domain/ /proc/sys/kernel/sched_domain/: cpu0 cpu1 cpu2 cpu3 /proc/sys/kernel/sched_domain/cpu0: /proc/sys/kernel/sched_domain/cpu1: /proc/sys/kernel/sched_domain/cpu2: /proc/sys/kernel/sched_domain/cpu3: bu19a:~# mkdir /dev/cpuset bu19a:~# mount -tcpuset cpuset /dev/cpuset/ bu19a:~# cd /dev/cpuset/ bu19a:/dev/cpuset# echo 0 > sched_load_balance bu19a:/dev/cpuset# mkdir one bu19a:/dev/cpuset# echo 1 > one/cpus bu19a:/dev/cpuset# echo 0 > one/sched_load_balance Unable to handle kernel paging request for data at address 0x00000018 Faulting instruction address: 0xc00000000006b608 NIP: c00000000006b608 LR: c00000000006b604 CTR: 0000000000000000 REGS: c000000018d973f0 TRAP: 0300 Not tainted (2.6.23-bml) MSR: 9000000000009032 <EE,ME,IR,DR> CR: 28242442 XER: 00000000 DAR: 0000000000000018, DSISR: 0000000040000000 TASK = c00000001912e340[1987] 'bash' THREAD: c000000018d94000 CPU: 2 .. NIP [c00000000006b608] .unregister_sysctl_table+0x38/0x110 LR [c00000000006b604] .unregister_sysctl_table+0x34/0x110 Call Trace: [c000000018d97670] [c000000007017270] 0xc000000007017270 (unreliable) [c000000018d97720] [c000000000058710] .detach_destroy_domains+0x30/0xb0 [c000000018d977b0] [c00000000005cf1c] .partition_sched_domains+0x1bc/0x230 [c000000018d97870] [c00000000009fdc4] .rebuild_sched_domains+0xb4/0x4c0 [c000000018d97970] [c0000000000a02e8] .update_flag+0x118/0x170 [c000000018d97a80] [c0000000000a1768] .cpuset_common_file_write+0x568/0x820 [c000000018d97c00] [c00000000009d95c] .cgroup_file_write+0x7c/0x180 [c000000018d97cf0] [c0000000000e76b8] .vfs_write+0xe8/0x1b0 [c000000018d97d90] [c0000000000e810c] .sys_write+0x4c/0x90 [c000000018d97e30] [c00000000000852c] syscall_exit+0x0/0x40 Signed-off-by: Milton Miller <miltonm@bga.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-24 16:23:48 +00:00
WARN_ON(sd_ctl_dir[0].child);
sd_ctl_dir[0].child = entry;
sched: domain sysctl fixes: do not crash on allocation failure Now that we are calling this at runtime, a more relaxed error path is suggested. If an allocation fails, we just register the partial table, which will show empty directories. Signed-off-by: Milton Miller <miltonm@bga.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 15:00:19 +00:00
if (entry == NULL)
return;
sched: Fix balance vs hotplug race Since (e761b77: cpu hotplug, sched: Introduce cpu_active_map and redo sched domain managment) we have cpu_active_mask which is suppose to rule scheduler migration and load-balancing, except it never (fully) did. The particular problem being solved here is a crash in try_to_wake_up() where select_task_rq() ends up selecting an offline cpu because select_task_rq_fair() trusts the sched_domain tree to reflect the current state of affairs, similarly select_task_rq_rt() trusts the root_domain. However, the sched_domains are updated from CPU_DEAD, which is after the cpu is taken offline and after stop_machine is done. Therefore it can race perfectly well with code assuming the domains are right. Cure this by building the domains from cpu_active_mask on CPU_DOWN_PREPARE. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-11-25 12:31:39 +00:00
for_each_possible_cpu(i) {
[PATCH] sched: debug feature - make the sched-domains tree runtime-tweakable debugging feature: make the sched-domains tree runtime-tweakable. Signed-off-by: Andrew Morton <akpm@linux-foundation.org> [ mingo@elte.hu: made it depend on CONFIG_SCHED_DEBUG & small updates ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-26 11:40:43 +00:00
snprintf(buf, 32, "cpu%d", i);
entry->procname = kstrdup(buf, GFP_KERNEL);
sched: fix sysctl directory permissions There are two remaining gotchas: - The directories have impossible permissions (writeable). - The ctl_name for the kernel directory is inconsistent with everything else. It should be CTL_KERN. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-08-23 13:18:02 +00:00
entry->mode = 0555;
[PATCH] sched: debug feature - make the sched-domains tree runtime-tweakable debugging feature: make the sched-domains tree runtime-tweakable. Signed-off-by: Andrew Morton <akpm@linux-foundation.org> [ mingo@elte.hu: made it depend on CONFIG_SCHED_DEBUG & small updates ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-26 11:40:43 +00:00
entry->child = sd_alloc_ctl_cpu_table(i);
sched: domain sysctl fixes: use for_each_online_cpu() init_sched_domain_sysctl was walking cpus 0-n and referencing per_cpu variables. If the cpus_possible mask is not contigious this will result in a crash referencing unallocated data. If the online mask is not contigious then we would show offline cpus and miss online ones. Signed-off-by: Milton Miller <miltonm@bga.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 15:00:19 +00:00
entry++;
[PATCH] sched: debug feature - make the sched-domains tree runtime-tweakable debugging feature: make the sched-domains tree runtime-tweakable. Signed-off-by: Andrew Morton <akpm@linux-foundation.org> [ mingo@elte.hu: made it depend on CONFIG_SCHED_DEBUG & small updates ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-26 11:40:43 +00:00
}
sched: fix sched_domain sysctl registration again commit 029190c515f15f512ac85de8fc686d4dbd0ae731 (cpuset sched_load_balance flag) was not tested SCHED_DEBUG enabled as committed as it dereferences NULL when used and it reordered the sysctl registration to cause it to never show any domains or their tunables. Fixes: 1) restore arch_init_sched_domains ordering we can't walk the domains before we build them presently we register cpus with empty directories (no domain directories or files). 2) make unregister_sched_domain_sysctl do nothing when already unregistered detach_destroy_domains is now called one set of cpus at a time unregister_syctl dereferences NULL if called with a null. While the the function would always dereference null if called twice, in the previous code it was always called once and then was followed a register. So only the hidden bug of the sysctl_root_table not being allocated followed by an attempt to free it would have shown the error. 3) always call unregister and register in partition_sched_domains The code is "smart" about unregistering only needed domains. Since we aren't guaranteed any calls to unregister, always unregister. Without calling register on the way out we will not have a table or any sysctl tree. 4) warn if register is called without unregistering The previous table memory is lost, leaving pointers to the later freed memory in sysctl and leaking the memory of the tables. Before this patch on a 2-core 4-thread box compiled for SMT and NUMA, the domains appear empty (there are actually 3 levels per cpu). And as soon as two domains a null pointer is dereferenced (unreliable in this case is stack garbage): bu19a:~# ls -R /proc/sys/kernel/sched_domain/ /proc/sys/kernel/sched_domain/: cpu0 cpu1 cpu2 cpu3 /proc/sys/kernel/sched_domain/cpu0: /proc/sys/kernel/sched_domain/cpu1: /proc/sys/kernel/sched_domain/cpu2: /proc/sys/kernel/sched_domain/cpu3: bu19a:~# mkdir /dev/cpuset bu19a:~# mount -tcpuset cpuset /dev/cpuset/ bu19a:~# cd /dev/cpuset/ bu19a:/dev/cpuset# echo 0 > sched_load_balance bu19a:/dev/cpuset# mkdir one bu19a:/dev/cpuset# echo 1 > one/cpus bu19a:/dev/cpuset# echo 0 > one/sched_load_balance Unable to handle kernel paging request for data at address 0x00000018 Faulting instruction address: 0xc00000000006b608 NIP: c00000000006b608 LR: c00000000006b604 CTR: 0000000000000000 REGS: c000000018d973f0 TRAP: 0300 Not tainted (2.6.23-bml) MSR: 9000000000009032 <EE,ME,IR,DR> CR: 28242442 XER: 00000000 DAR: 0000000000000018, DSISR: 0000000040000000 TASK = c00000001912e340[1987] 'bash' THREAD: c000000018d94000 CPU: 2 .. NIP [c00000000006b608] .unregister_sysctl_table+0x38/0x110 LR [c00000000006b604] .unregister_sysctl_table+0x34/0x110 Call Trace: [c000000018d97670] [c000000007017270] 0xc000000007017270 (unreliable) [c000000018d97720] [c000000000058710] .detach_destroy_domains+0x30/0xb0 [c000000018d977b0] [c00000000005cf1c] .partition_sched_domains+0x1bc/0x230 [c000000018d97870] [c00000000009fdc4] .rebuild_sched_domains+0xb4/0x4c0 [c000000018d97970] [c0000000000a02e8] .update_flag+0x118/0x170 [c000000018d97a80] [c0000000000a1768] .cpuset_common_file_write+0x568/0x820 [c000000018d97c00] [c00000000009d95c] .cgroup_file_write+0x7c/0x180 [c000000018d97cf0] [c0000000000e76b8] .vfs_write+0xe8/0x1b0 [c000000018d97d90] [c0000000000e810c] .sys_write+0x4c/0x90 [c000000018d97e30] [c00000000000852c] syscall_exit+0x0/0x40 Signed-off-by: Milton Miller <miltonm@bga.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-24 16:23:48 +00:00
WARN_ON(sd_sysctl_header);
[PATCH] sched: debug feature - make the sched-domains tree runtime-tweakable debugging feature: make the sched-domains tree runtime-tweakable. Signed-off-by: Andrew Morton <akpm@linux-foundation.org> [ mingo@elte.hu: made it depend on CONFIG_SCHED_DEBUG & small updates ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-26 11:40:43 +00:00
sd_sysctl_header = register_sysctl_table(sd_ctl_root);
}
sched: domain sysctl fixes: unregister the sysctl table before domains Unregister and free the sysctl table before destroying domains, then rebuild and register after creating the new domains. This prevents the sysctl table from pointing to freed memory for root to write. Signed-off-by: Milton Miller <miltonm@bga.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 15:00:19 +00:00
sched: fix sched_domain sysctl registration again commit 029190c515f15f512ac85de8fc686d4dbd0ae731 (cpuset sched_load_balance flag) was not tested SCHED_DEBUG enabled as committed as it dereferences NULL when used and it reordered the sysctl registration to cause it to never show any domains or their tunables. Fixes: 1) restore arch_init_sched_domains ordering we can't walk the domains before we build them presently we register cpus with empty directories (no domain directories or files). 2) make unregister_sched_domain_sysctl do nothing when already unregistered detach_destroy_domains is now called one set of cpus at a time unregister_syctl dereferences NULL if called with a null. While the the function would always dereference null if called twice, in the previous code it was always called once and then was followed a register. So only the hidden bug of the sysctl_root_table not being allocated followed by an attempt to free it would have shown the error. 3) always call unregister and register in partition_sched_domains The code is "smart" about unregistering only needed domains. Since we aren't guaranteed any calls to unregister, always unregister. Without calling register on the way out we will not have a table or any sysctl tree. 4) warn if register is called without unregistering The previous table memory is lost, leaving pointers to the later freed memory in sysctl and leaking the memory of the tables. Before this patch on a 2-core 4-thread box compiled for SMT and NUMA, the domains appear empty (there are actually 3 levels per cpu). And as soon as two domains a null pointer is dereferenced (unreliable in this case is stack garbage): bu19a:~# ls -R /proc/sys/kernel/sched_domain/ /proc/sys/kernel/sched_domain/: cpu0 cpu1 cpu2 cpu3 /proc/sys/kernel/sched_domain/cpu0: /proc/sys/kernel/sched_domain/cpu1: /proc/sys/kernel/sched_domain/cpu2: /proc/sys/kernel/sched_domain/cpu3: bu19a:~# mkdir /dev/cpuset bu19a:~# mount -tcpuset cpuset /dev/cpuset/ bu19a:~# cd /dev/cpuset/ bu19a:/dev/cpuset# echo 0 > sched_load_balance bu19a:/dev/cpuset# mkdir one bu19a:/dev/cpuset# echo 1 > one/cpus bu19a:/dev/cpuset# echo 0 > one/sched_load_balance Unable to handle kernel paging request for data at address 0x00000018 Faulting instruction address: 0xc00000000006b608 NIP: c00000000006b608 LR: c00000000006b604 CTR: 0000000000000000 REGS: c000000018d973f0 TRAP: 0300 Not tainted (2.6.23-bml) MSR: 9000000000009032 <EE,ME,IR,DR> CR: 28242442 XER: 00000000 DAR: 0000000000000018, DSISR: 0000000040000000 TASK = c00000001912e340[1987] 'bash' THREAD: c000000018d94000 CPU: 2 .. NIP [c00000000006b608] .unregister_sysctl_table+0x38/0x110 LR [c00000000006b604] .unregister_sysctl_table+0x34/0x110 Call Trace: [c000000018d97670] [c000000007017270] 0xc000000007017270 (unreliable) [c000000018d97720] [c000000000058710] .detach_destroy_domains+0x30/0xb0 [c000000018d977b0] [c00000000005cf1c] .partition_sched_domains+0x1bc/0x230 [c000000018d97870] [c00000000009fdc4] .rebuild_sched_domains+0xb4/0x4c0 [c000000018d97970] [c0000000000a02e8] .update_flag+0x118/0x170 [c000000018d97a80] [c0000000000a1768] .cpuset_common_file_write+0x568/0x820 [c000000018d97c00] [c00000000009d95c] .cgroup_file_write+0x7c/0x180 [c000000018d97cf0] [c0000000000e76b8] .vfs_write+0xe8/0x1b0 [c000000018d97d90] [c0000000000e810c] .sys_write+0x4c/0x90 [c000000018d97e30] [c00000000000852c] syscall_exit+0x0/0x40 Signed-off-by: Milton Miller <miltonm@bga.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-24 16:23:48 +00:00
/* may be called multiple times per register */
sched: domain sysctl fixes: unregister the sysctl table before domains Unregister and free the sysctl table before destroying domains, then rebuild and register after creating the new domains. This prevents the sysctl table from pointing to freed memory for root to write. Signed-off-by: Milton Miller <miltonm@bga.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 15:00:19 +00:00
static void unregister_sched_domain_sysctl(void)
{
sched: fix sched_domain sysctl registration again commit 029190c515f15f512ac85de8fc686d4dbd0ae731 (cpuset sched_load_balance flag) was not tested SCHED_DEBUG enabled as committed as it dereferences NULL when used and it reordered the sysctl registration to cause it to never show any domains or their tunables. Fixes: 1) restore arch_init_sched_domains ordering we can't walk the domains before we build them presently we register cpus with empty directories (no domain directories or files). 2) make unregister_sched_domain_sysctl do nothing when already unregistered detach_destroy_domains is now called one set of cpus at a time unregister_syctl dereferences NULL if called with a null. While the the function would always dereference null if called twice, in the previous code it was always called once and then was followed a register. So only the hidden bug of the sysctl_root_table not being allocated followed by an attempt to free it would have shown the error. 3) always call unregister and register in partition_sched_domains The code is "smart" about unregistering only needed domains. Since we aren't guaranteed any calls to unregister, always unregister. Without calling register on the way out we will not have a table or any sysctl tree. 4) warn if register is called without unregistering The previous table memory is lost, leaving pointers to the later freed memory in sysctl and leaking the memory of the tables. Before this patch on a 2-core 4-thread box compiled for SMT and NUMA, the domains appear empty (there are actually 3 levels per cpu). And as soon as two domains a null pointer is dereferenced (unreliable in this case is stack garbage): bu19a:~# ls -R /proc/sys/kernel/sched_domain/ /proc/sys/kernel/sched_domain/: cpu0 cpu1 cpu2 cpu3 /proc/sys/kernel/sched_domain/cpu0: /proc/sys/kernel/sched_domain/cpu1: /proc/sys/kernel/sched_domain/cpu2: /proc/sys/kernel/sched_domain/cpu3: bu19a:~# mkdir /dev/cpuset bu19a:~# mount -tcpuset cpuset /dev/cpuset/ bu19a:~# cd /dev/cpuset/ bu19a:/dev/cpuset# echo 0 > sched_load_balance bu19a:/dev/cpuset# mkdir one bu19a:/dev/cpuset# echo 1 > one/cpus bu19a:/dev/cpuset# echo 0 > one/sched_load_balance Unable to handle kernel paging request for data at address 0x00000018 Faulting instruction address: 0xc00000000006b608 NIP: c00000000006b608 LR: c00000000006b604 CTR: 0000000000000000 REGS: c000000018d973f0 TRAP: 0300 Not tainted (2.6.23-bml) MSR: 9000000000009032 <EE,ME,IR,DR> CR: 28242442 XER: 00000000 DAR: 0000000000000018, DSISR: 0000000040000000 TASK = c00000001912e340[1987] 'bash' THREAD: c000000018d94000 CPU: 2 .. NIP [c00000000006b608] .unregister_sysctl_table+0x38/0x110 LR [c00000000006b604] .unregister_sysctl_table+0x34/0x110 Call Trace: [c000000018d97670] [c000000007017270] 0xc000000007017270 (unreliable) [c000000018d97720] [c000000000058710] .detach_destroy_domains+0x30/0xb0 [c000000018d977b0] [c00000000005cf1c] .partition_sched_domains+0x1bc/0x230 [c000000018d97870] [c00000000009fdc4] .rebuild_sched_domains+0xb4/0x4c0 [c000000018d97970] [c0000000000a02e8] .update_flag+0x118/0x170 [c000000018d97a80] [c0000000000a1768] .cpuset_common_file_write+0x568/0x820 [c000000018d97c00] [c00000000009d95c] .cgroup_file_write+0x7c/0x180 [c000000018d97cf0] [c0000000000e76b8] .vfs_write+0xe8/0x1b0 [c000000018d97d90] [c0000000000e810c] .sys_write+0x4c/0x90 [c000000018d97e30] [c00000000000852c] syscall_exit+0x0/0x40 Signed-off-by: Milton Miller <miltonm@bga.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-24 16:23:48 +00:00
if (sd_sysctl_header)
unregister_sysctl_table(sd_sysctl_header);
sched: domain sysctl fixes: unregister the sysctl table before domains Unregister and free the sysctl table before destroying domains, then rebuild and register after creating the new domains. This prevents the sysctl table from pointing to freed memory for root to write. Signed-off-by: Milton Miller <miltonm@bga.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 15:00:19 +00:00
sd_sysctl_header = NULL;
sched: fix sched_domain sysctl registration again commit 029190c515f15f512ac85de8fc686d4dbd0ae731 (cpuset sched_load_balance flag) was not tested SCHED_DEBUG enabled as committed as it dereferences NULL when used and it reordered the sysctl registration to cause it to never show any domains or their tunables. Fixes: 1) restore arch_init_sched_domains ordering we can't walk the domains before we build them presently we register cpus with empty directories (no domain directories or files). 2) make unregister_sched_domain_sysctl do nothing when already unregistered detach_destroy_domains is now called one set of cpus at a time unregister_syctl dereferences NULL if called with a null. While the the function would always dereference null if called twice, in the previous code it was always called once and then was followed a register. So only the hidden bug of the sysctl_root_table not being allocated followed by an attempt to free it would have shown the error. 3) always call unregister and register in partition_sched_domains The code is "smart" about unregistering only needed domains. Since we aren't guaranteed any calls to unregister, always unregister. Without calling register on the way out we will not have a table or any sysctl tree. 4) warn if register is called without unregistering The previous table memory is lost, leaving pointers to the later freed memory in sysctl and leaking the memory of the tables. Before this patch on a 2-core 4-thread box compiled for SMT and NUMA, the domains appear empty (there are actually 3 levels per cpu). And as soon as two domains a null pointer is dereferenced (unreliable in this case is stack garbage): bu19a:~# ls -R /proc/sys/kernel/sched_domain/ /proc/sys/kernel/sched_domain/: cpu0 cpu1 cpu2 cpu3 /proc/sys/kernel/sched_domain/cpu0: /proc/sys/kernel/sched_domain/cpu1: /proc/sys/kernel/sched_domain/cpu2: /proc/sys/kernel/sched_domain/cpu3: bu19a:~# mkdir /dev/cpuset bu19a:~# mount -tcpuset cpuset /dev/cpuset/ bu19a:~# cd /dev/cpuset/ bu19a:/dev/cpuset# echo 0 > sched_load_balance bu19a:/dev/cpuset# mkdir one bu19a:/dev/cpuset# echo 1 > one/cpus bu19a:/dev/cpuset# echo 0 > one/sched_load_balance Unable to handle kernel paging request for data at address 0x00000018 Faulting instruction address: 0xc00000000006b608 NIP: c00000000006b608 LR: c00000000006b604 CTR: 0000000000000000 REGS: c000000018d973f0 TRAP: 0300 Not tainted (2.6.23-bml) MSR: 9000000000009032 <EE,ME,IR,DR> CR: 28242442 XER: 00000000 DAR: 0000000000000018, DSISR: 0000000040000000 TASK = c00000001912e340[1987] 'bash' THREAD: c000000018d94000 CPU: 2 .. NIP [c00000000006b608] .unregister_sysctl_table+0x38/0x110 LR [c00000000006b604] .unregister_sysctl_table+0x34/0x110 Call Trace: [c000000018d97670] [c000000007017270] 0xc000000007017270 (unreliable) [c000000018d97720] [c000000000058710] .detach_destroy_domains+0x30/0xb0 [c000000018d977b0] [c00000000005cf1c] .partition_sched_domains+0x1bc/0x230 [c000000018d97870] [c00000000009fdc4] .rebuild_sched_domains+0xb4/0x4c0 [c000000018d97970] [c0000000000a02e8] .update_flag+0x118/0x170 [c000000018d97a80] [c0000000000a1768] .cpuset_common_file_write+0x568/0x820 [c000000018d97c00] [c00000000009d95c] .cgroup_file_write+0x7c/0x180 [c000000018d97cf0] [c0000000000e76b8] .vfs_write+0xe8/0x1b0 [c000000018d97d90] [c0000000000e810c] .sys_write+0x4c/0x90 [c000000018d97e30] [c00000000000852c] syscall_exit+0x0/0x40 Signed-off-by: Milton Miller <miltonm@bga.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-24 16:23:48 +00:00
if (sd_ctl_dir[0].child)
sd_free_ctl_entry(&sd_ctl_dir[0].child);
sched: domain sysctl fixes: unregister the sysctl table before domains Unregister and free the sysctl table before destroying domains, then rebuild and register after creating the new domains. This prevents the sysctl table from pointing to freed memory for root to write. Signed-off-by: Milton Miller <miltonm@bga.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 15:00:19 +00:00
}
[PATCH] sched: debug feature - make the sched-domains tree runtime-tweakable debugging feature: make the sched-domains tree runtime-tweakable. Signed-off-by: Andrew Morton <akpm@linux-foundation.org> [ mingo@elte.hu: made it depend on CONFIG_SCHED_DEBUG & small updates ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-26 11:40:43 +00:00
#else
sched: domain sysctl fixes: unregister the sysctl table before domains Unregister and free the sysctl table before destroying domains, then rebuild and register after creating the new domains. This prevents the sysctl table from pointing to freed memory for root to write. Signed-off-by: Milton Miller <miltonm@bga.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 15:00:19 +00:00
static void register_sched_domain_sysctl(void)
{
}
static void unregister_sched_domain_sysctl(void)
[PATCH] sched: debug feature - make the sched-domains tree runtime-tweakable debugging feature: make the sched-domains tree runtime-tweakable. Signed-off-by: Andrew Morton <akpm@linux-foundation.org> [ mingo@elte.hu: made it depend on CONFIG_SCHED_DEBUG & small updates ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-26 11:40:43 +00:00
{
}
#endif
sched: fix cpupri hotplug support The RT folks over at RedHat found an issue w.r.t. hotplug support which was traced to problems with the cpupri infrastructure in the scheduler: https://bugzilla.redhat.com/show_bug.cgi?id=449676 This bug affects 23-rt12+, 24-rtX, 25-rtX, and sched-devel. This patch applies to 25.4-rt4, though it should trivially apply to most cpupri enabled kernels mentioned above. It turned out that the issue was that offline cpus could get inadvertently registered with cpupri so that they were erroneously selected during migration decisions. The end result would be an OOPS as the offline cpu had tasks routed to it. This patch generalizes the old join/leave domain interface into an online/offline interface, and adjusts the root-domain/hotplug code to utilize it. I was able to easily reproduce the issue prior to this patch, and am no longer able to reproduce it after this patch. I can offline cpus indefinately and everything seems to be in working order. Thanks to Arnaldo (acme), Thomas, and Peter for doing the legwork to point me in the right direction. Also thank you to Peter for reviewing the early iterations of this patch. Signed-off-by: Gregory Haskins <ghaskins@novell.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-06-04 19:04:05 +00:00
static void set_rq_online(struct rq *rq)
{
if (!rq->online) {
const struct sched_class *class;
sched: convert struct root_domain to cpumask_var_t. Impact: (future) size reduction for large NR_CPUS. Dynamically allocating cpumasks (when CONFIG_CPUMASK_OFFSTACK) saves space for small nr_cpu_ids but big CONFIG_NR_CPUS. cpumask_var_t is just a struct cpumask for !CONFIG_CPUMASK_OFFSTACK. def_root_domain is static, and so its masks are initialized with alloc_bootmem_cpumask_var. After that, alloc_cpumask_var is used. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-24 16:05:05 +00:00
cpumask_set_cpu(rq->cpu, rq->rd->online);
sched: fix cpupri hotplug support The RT folks over at RedHat found an issue w.r.t. hotplug support which was traced to problems with the cpupri infrastructure in the scheduler: https://bugzilla.redhat.com/show_bug.cgi?id=449676 This bug affects 23-rt12+, 24-rtX, 25-rtX, and sched-devel. This patch applies to 25.4-rt4, though it should trivially apply to most cpupri enabled kernels mentioned above. It turned out that the issue was that offline cpus could get inadvertently registered with cpupri so that they were erroneously selected during migration decisions. The end result would be an OOPS as the offline cpu had tasks routed to it. This patch generalizes the old join/leave domain interface into an online/offline interface, and adjusts the root-domain/hotplug code to utilize it. I was able to easily reproduce the issue prior to this patch, and am no longer able to reproduce it after this patch. I can offline cpus indefinately and everything seems to be in working order. Thanks to Arnaldo (acme), Thomas, and Peter for doing the legwork to point me in the right direction. Also thank you to Peter for reviewing the early iterations of this patch. Signed-off-by: Gregory Haskins <ghaskins@novell.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-06-04 19:04:05 +00:00
rq->online = 1;
for_each_class(class) {
if (class->rq_online)
class->rq_online(rq);
}
}
}
static void set_rq_offline(struct rq *rq)
{
if (rq->online) {
const struct sched_class *class;
for_each_class(class) {
if (class->rq_offline)
class->rq_offline(rq);
}
sched: convert struct root_domain to cpumask_var_t. Impact: (future) size reduction for large NR_CPUS. Dynamically allocating cpumasks (when CONFIG_CPUMASK_OFFSTACK) saves space for small nr_cpu_ids but big CONFIG_NR_CPUS. cpumask_var_t is just a struct cpumask for !CONFIG_CPUMASK_OFFSTACK. def_root_domain is static, and so its masks are initialized with alloc_bootmem_cpumask_var. After that, alloc_cpumask_var is used. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-24 16:05:05 +00:00
cpumask_clear_cpu(rq->cpu, rq->rd->online);
sched: fix cpupri hotplug support The RT folks over at RedHat found an issue w.r.t. hotplug support which was traced to problems with the cpupri infrastructure in the scheduler: https://bugzilla.redhat.com/show_bug.cgi?id=449676 This bug affects 23-rt12+, 24-rtX, 25-rtX, and sched-devel. This patch applies to 25.4-rt4, though it should trivially apply to most cpupri enabled kernels mentioned above. It turned out that the issue was that offline cpus could get inadvertently registered with cpupri so that they were erroneously selected during migration decisions. The end result would be an OOPS as the offline cpu had tasks routed to it. This patch generalizes the old join/leave domain interface into an online/offline interface, and adjusts the root-domain/hotplug code to utilize it. I was able to easily reproduce the issue prior to this patch, and am no longer able to reproduce it after this patch. I can offline cpus indefinately and everything seems to be in working order. Thanks to Arnaldo (acme), Thomas, and Peter for doing the legwork to point me in the right direction. Also thank you to Peter for reviewing the early iterations of this patch. Signed-off-by: Gregory Haskins <ghaskins@novell.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-06-04 19:04:05 +00:00
rq->online = 0;
}
}
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
/*
* migration_call - callback that gets triggered when a CPU is added.
* Here we can start up the necessary migration thread for the new CPU.
*/
[PATCH] sched: clean up fallout of recent changes Clean up some of the impact of recent (and not so recent) scheduler changes: - turning macros into nice inline functions - sanitizing and unifying variable definitions - whitespace, style consistency, 80-lines, comment correctness, spelling and curly braces police Due to the macro hell and variable placement simplifications there's even 26 bytes of .text saved: text data bss dec hex filename 25510 4153 192 29855 749f sched.o.before 25484 4153 192 29829 7485 sched.o.after [akpm@osdl.org: build fix] Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-03 07:25:40 +00:00
static int __cpuinit
migration_call(struct notifier_block *nfb, unsigned long action, void *hcpu)
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
{
[PATCH] sched: clean up fallout of recent changes Clean up some of the impact of recent (and not so recent) scheduler changes: - turning macros into nice inline functions - sanitizing and unifying variable definitions - whitespace, style consistency, 80-lines, comment correctness, spelling and curly braces police Due to the macro hell and variable placement simplifications there's even 26 bytes of .text saved: text data bss dec hex filename 25510 4153 192 29855 749f sched.o.before 25484 4153 192 29829 7485 sched.o.after [akpm@osdl.org: build fix] Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-03 07:25:40 +00:00
int cpu = (long)hcpu;
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
unsigned long flags;
sched: replace migration_thread with cpu_stop Currently migration_thread is serving three purposes - migration pusher, context to execute active_load_balance() and forced context switcher for expedited RCU synchronize_sched. All three roles are hardcoded into migration_thread() and determining which job is scheduled is slightly messy. This patch kills migration_thread and replaces all three uses with cpu_stop. The three different roles of migration_thread() are splitted into three separate cpu_stop callbacks - migration_cpu_stop(), active_load_balance_cpu_stop() and synchronize_sched_expedited_cpu_stop() - and each use case now simply asks cpu_stop to execute the callback as necessary. synchronize_sched_expedited() was implemented with private preallocated resources and custom multi-cpu queueing and waiting logic, both of which are provided by cpu_stop. synchronize_sched_expedited_count is made atomic and all other shared resources along with the mutex are dropped. synchronize_sched_expedited() also implemented a check to detect cases where not all the callback got executed on their assigned cpus and fall back to synchronize_sched(). If called with cpu hotplug blocked, cpu_stop already guarantees that and the condition cannot happen; otherwise, stop_machine() would break. However, this patch preserves the paranoid check using a cpumask to record on which cpus the stopper ran so that it can serve as a bisection point if something actually goes wrong theree. Because the internal execution state is no longer visible, rcu_expedited_torture_stats() is removed. This patch also renames cpu_stop threads to from "stopper/%d" to "migration/%d". The names of these threads ultimately don't matter and there's no reason to make unnecessary userland visible changes. With this patch applied, stop_machine() and sched now share the same resources. stop_machine() is faster without wasting any resources and sched migration users are much cleaner. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Dipankar Sarma <dipankar@in.ibm.com> Cc: Josh Triplett <josh@freedesktop.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Dimitri Sivanich <sivanich@sgi.com>
2010-05-06 16:49:21 +00:00
struct rq *rq = cpu_rq(cpu);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
sched: Simplify cpu-hot-unplug task migration While discussing the need for sched_idle_next(), Oleg remarked that since try_to_wake_up() ensures sleeping tasks will end up running on a sane cpu, we can do away with migrate_live_tasks(). If we then extend the existing hack of migrating current from CPU_DYING to migrating the full rq worth of tasks from CPU_DYING, the need for the sched_idle_next() abomination disappears as well, since idle will be the only possible thread left after the migration thread stops. This greatly simplifies the hot-unplug task migration path, as can be seen from the resulting code reduction (and about half the new lines are comments). Suggested-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1289851597.2109.547.camel@laptop> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-13 18:32:29 +00:00
switch (action & ~CPU_TASKS_FROZEN) {
Eliminate lock_cpu_hotplug in kernel/schedc Eliminate lock_cpu_hotplug from kernel/sched.c and use sched_hotcpu_mutex instead to postpone a hotplug event. In the migration_call hotcpu callback function, take sched_hotcpu_mutex while handling the event CPU_LOCK_ACQUIRE and release it while handling CPU_LOCK_RELEASE event. [akpm@linux-foundation.org: fix deadlock] Signed-off-by: Gautham R Shenoy <ego@in.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-09 09:34:04 +00:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
case CPU_UP_PREPARE:
sched: fix load average accounting vs. cpu hotplug The new load average code clears rq->calc_load_active on CPU_ONLINE. That's wrong as the new onlined CPU might have got a scheduler tick already and accounted the delta to the stale value of the time we offlined the CPU. Clear the value when we cleanup the dead CPU instead. Also move the update of the calc_load_update time for the newly online CPU to CPU_UP_PREPARE to avoid that the CPU plays catch up with the stale update time value. Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2009-07-17 12:15:46 +00:00
rq->calc_load_update = calc_load_update;
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
break;
[PATCH] sched: clean up fallout of recent changes Clean up some of the impact of recent (and not so recent) scheduler changes: - turning macros into nice inline functions - sanitizing and unifying variable definitions - whitespace, style consistency, 80-lines, comment correctness, spelling and curly braces police Due to the macro hell and variable placement simplifications there's even 26 bytes of .text saved: text data bss dec hex filename 25510 4153 192 29855 749f sched.o.before 25484 4153 192 29829 7485 sched.o.after [akpm@osdl.org: build fix] Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-03 07:25:40 +00:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
case CPU_ONLINE:
Revert "cpu hotplug: adjust root-domain->online span in response to hotplug event" This reverts commit 393d94d98b19089ec172566e23557997931b137e. Lets fix this right. Signed-off-by: Gregory Haskins <ghaskins@novell.com> Cc: Gautham R Shenoy <ego@in.ibm.com> Cc: "Siddha, Suresh B" <suresh.b.siddha@intel.com> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-03-10 20:52:41 +00:00
/* Update our root-domain */
sched: Convert rq->lock to raw_spinlock Convert locks which cannot be sleeping locks in preempt-rt to raw_spinlocks. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Ingo Molnar <mingo@elte.hu>
2009-11-17 13:28:38 +00:00
raw_spin_lock_irqsave(&rq->lock, flags);
Revert "cpu hotplug: adjust root-domain->online span in response to hotplug event" This reverts commit 393d94d98b19089ec172566e23557997931b137e. Lets fix this right. Signed-off-by: Gregory Haskins <ghaskins@novell.com> Cc: Gautham R Shenoy <ego@in.ibm.com> Cc: "Siddha, Suresh B" <suresh.b.siddha@intel.com> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-03-10 20:52:41 +00:00
if (rq->rd) {
sched: convert struct root_domain to cpumask_var_t. Impact: (future) size reduction for large NR_CPUS. Dynamically allocating cpumasks (when CONFIG_CPUMASK_OFFSTACK) saves space for small nr_cpu_ids but big CONFIG_NR_CPUS. cpumask_var_t is just a struct cpumask for !CONFIG_CPUMASK_OFFSTACK. def_root_domain is static, and so its masks are initialized with alloc_bootmem_cpumask_var. After that, alloc_cpumask_var is used. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-24 16:05:05 +00:00
BUG_ON(!cpumask_test_cpu(cpu, rq->rd->span));
sched: fix cpupri hotplug support The RT folks over at RedHat found an issue w.r.t. hotplug support which was traced to problems with the cpupri infrastructure in the scheduler: https://bugzilla.redhat.com/show_bug.cgi?id=449676 This bug affects 23-rt12+, 24-rtX, 25-rtX, and sched-devel. This patch applies to 25.4-rt4, though it should trivially apply to most cpupri enabled kernels mentioned above. It turned out that the issue was that offline cpus could get inadvertently registered with cpupri so that they were erroneously selected during migration decisions. The end result would be an OOPS as the offline cpu had tasks routed to it. This patch generalizes the old join/leave domain interface into an online/offline interface, and adjusts the root-domain/hotplug code to utilize it. I was able to easily reproduce the issue prior to this patch, and am no longer able to reproduce it after this patch. I can offline cpus indefinately and everything seems to be in working order. Thanks to Arnaldo (acme), Thomas, and Peter for doing the legwork to point me in the right direction. Also thank you to Peter for reviewing the early iterations of this patch. Signed-off-by: Gregory Haskins <ghaskins@novell.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-06-04 19:04:05 +00:00
set_rq_online(rq);
Revert "cpu hotplug: adjust root-domain->online span in response to hotplug event" This reverts commit 393d94d98b19089ec172566e23557997931b137e. Lets fix this right. Signed-off-by: Gregory Haskins <ghaskins@novell.com> Cc: Gautham R Shenoy <ego@in.ibm.com> Cc: "Siddha, Suresh B" <suresh.b.siddha@intel.com> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-03-10 20:52:41 +00:00
}
sched: Convert rq->lock to raw_spinlock Convert locks which cannot be sleeping locks in preempt-rt to raw_spinlocks. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Ingo Molnar <mingo@elte.hu>
2009-11-17 13:28:38 +00:00
raw_spin_unlock_irqrestore(&rq->lock, flags);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
break;
[PATCH] sched: clean up fallout of recent changes Clean up some of the impact of recent (and not so recent) scheduler changes: - turning macros into nice inline functions - sanitizing and unifying variable definitions - whitespace, style consistency, 80-lines, comment correctness, spelling and curly braces police Due to the macro hell and variable placement simplifications there's even 26 bytes of .text saved: text data bss dec hex filename 25510 4153 192 29855 749f sched.o.before 25484 4153 192 29829 7485 sched.o.after [akpm@osdl.org: build fix] Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-03 07:25:40 +00:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
#ifdef CONFIG_HOTPLUG_CPU
keep rd->online and cpu_online_map in sync It is possible to allow the root-domain cache of online cpus to become out of sync with the global cpu_online_map. This is because we currently trigger removal of cpus too early in the notifier chain. Other DOWN_PREPARE handlers may in fact run and reconfigure the root-domain topology, thereby stomping on our own offline handling. The end result is that rd->online may become out of sync with cpu_online_map, which results in potential task misrouting. So change the offline handling to be more tightly coupled with the global offline process by triggering on CPU_DYING intead of CPU_DOWN_PREPARE. Signed-off-by: Gregory Haskins <ghaskins@novell.com> Cc: Gautham R Shenoy <ego@in.ibm.com> Cc: "Siddha, Suresh B" <suresh.b.siddha@intel.com> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-03-10 21:59:11 +00:00
case CPU_DYING:
sched: Move the second half of ttwu() to the remote cpu Now that we've removed the rq->lock requirement from the first part of ttwu() and can compute placement without holding any rq->lock, ensure we execute the second half of ttwu() on the actual cpu we want the task to run on. This avoids having to take rq->lock and doing the task enqueue remotely, saving lots on cacheline transfers. As measured using: http://oss.oracle.com/~mason/sembench.c $ for i in /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor ; do echo performance > $i; done $ echo 4096 32000 64 128 > /proc/sys/kernel/sem $ ./sembench -t 2048 -w 1900 -o 0 unpatched: run time 30 seconds 647278 worker burns per second patched: run time 30 seconds 816715 worker burns per second Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110405152729.515897185@chello.nl
2011-04-05 15:23:58 +00:00
sched_ttwu_pending();
sched: add sched-domain roots We add the notion of a root-domain which will be used later to rescope global variables to per-domain variables. Each exclusive cpuset essentially defines an island domain by fully partitioning the member cpus from any other cpuset. However, we currently still maintain some policy/state as global variables which transcend all cpusets. Consider, for instance, rt-overload state. Whenever a new exclusive cpuset is created, we also create a new root-domain object and move each cpu member to the root-domain's span. By default the system creates a single root-domain with all cpus as members (mimicking the global state we have today). We add some plumbing for storing class specific data in our root-domain. Whenever a RQ is switching root-domains (because of repartitioning) we give each sched_class the opportunity to remove any state from its old domain and add state to the new one. This logic doesn't have any clients yet but it will later in the series. Signed-off-by: Gregory Haskins <ghaskins@novell.com> CC: Christoph Lameter <clameter@sgi.com> CC: Paul Jackson <pj@sgi.com> CC: Simon Derr <simon.derr@bull.net> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:18 +00:00
/* Update our root-domain */
sched: Convert rq->lock to raw_spinlock Convert locks which cannot be sleeping locks in preempt-rt to raw_spinlocks. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Ingo Molnar <mingo@elte.hu>
2009-11-17 13:28:38 +00:00
raw_spin_lock_irqsave(&rq->lock, flags);
sched: add sched-domain roots We add the notion of a root-domain which will be used later to rescope global variables to per-domain variables. Each exclusive cpuset essentially defines an island domain by fully partitioning the member cpus from any other cpuset. However, we currently still maintain some policy/state as global variables which transcend all cpusets. Consider, for instance, rt-overload state. Whenever a new exclusive cpuset is created, we also create a new root-domain object and move each cpu member to the root-domain's span. By default the system creates a single root-domain with all cpus as members (mimicking the global state we have today). We add some plumbing for storing class specific data in our root-domain. Whenever a RQ is switching root-domains (because of repartitioning) we give each sched_class the opportunity to remove any state from its old domain and add state to the new one. This logic doesn't have any clients yet but it will later in the series. Signed-off-by: Gregory Haskins <ghaskins@novell.com> CC: Christoph Lameter <clameter@sgi.com> CC: Paul Jackson <pj@sgi.com> CC: Simon Derr <simon.derr@bull.net> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:18 +00:00
if (rq->rd) {
sched: convert struct root_domain to cpumask_var_t. Impact: (future) size reduction for large NR_CPUS. Dynamically allocating cpumasks (when CONFIG_CPUMASK_OFFSTACK) saves space for small nr_cpu_ids but big CONFIG_NR_CPUS. cpumask_var_t is just a struct cpumask for !CONFIG_CPUMASK_OFFSTACK. def_root_domain is static, and so its masks are initialized with alloc_bootmem_cpumask_var. After that, alloc_cpumask_var is used. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-24 16:05:05 +00:00
BUG_ON(!cpumask_test_cpu(cpu, rq->rd->span));
sched: fix cpupri hotplug support The RT folks over at RedHat found an issue w.r.t. hotplug support which was traced to problems with the cpupri infrastructure in the scheduler: https://bugzilla.redhat.com/show_bug.cgi?id=449676 This bug affects 23-rt12+, 24-rtX, 25-rtX, and sched-devel. This patch applies to 25.4-rt4, though it should trivially apply to most cpupri enabled kernels mentioned above. It turned out that the issue was that offline cpus could get inadvertently registered with cpupri so that they were erroneously selected during migration decisions. The end result would be an OOPS as the offline cpu had tasks routed to it. This patch generalizes the old join/leave domain interface into an online/offline interface, and adjusts the root-domain/hotplug code to utilize it. I was able to easily reproduce the issue prior to this patch, and am no longer able to reproduce it after this patch. I can offline cpus indefinately and everything seems to be in working order. Thanks to Arnaldo (acme), Thomas, and Peter for doing the legwork to point me in the right direction. Also thank you to Peter for reviewing the early iterations of this patch. Signed-off-by: Gregory Haskins <ghaskins@novell.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-06-04 19:04:05 +00:00
set_rq_offline(rq);
sched: add sched-domain roots We add the notion of a root-domain which will be used later to rescope global variables to per-domain variables. Each exclusive cpuset essentially defines an island domain by fully partitioning the member cpus from any other cpuset. However, we currently still maintain some policy/state as global variables which transcend all cpusets. Consider, for instance, rt-overload state. Whenever a new exclusive cpuset is created, we also create a new root-domain object and move each cpu member to the root-domain's span. By default the system creates a single root-domain with all cpus as members (mimicking the global state we have today). We add some plumbing for storing class specific data in our root-domain. Whenever a RQ is switching root-domains (because of repartitioning) we give each sched_class the opportunity to remove any state from its old domain and add state to the new one. This logic doesn't have any clients yet but it will later in the series. Signed-off-by: Gregory Haskins <ghaskins@novell.com> CC: Christoph Lameter <clameter@sgi.com> CC: Paul Jackson <pj@sgi.com> CC: Simon Derr <simon.derr@bull.net> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:18 +00:00
}
sched: Simplify cpu-hot-unplug task migration While discussing the need for sched_idle_next(), Oleg remarked that since try_to_wake_up() ensures sleeping tasks will end up running on a sane cpu, we can do away with migrate_live_tasks(). If we then extend the existing hack of migrating current from CPU_DYING to migrating the full rq worth of tasks from CPU_DYING, the need for the sched_idle_next() abomination disappears as well, since idle will be the only possible thread left after the migration thread stops. This greatly simplifies the hot-unplug task migration path, as can be seen from the resulting code reduction (and about half the new lines are comments). Suggested-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1289851597.2109.547.camel@laptop> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-13 18:32:29 +00:00
migrate_tasks(cpu);
BUG_ON(rq->nr_running != 1); /* the migration thread */
sched: Convert rq->lock to raw_spinlock Convert locks which cannot be sleeping locks in preempt-rt to raw_spinlocks. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Ingo Molnar <mingo@elte.hu>
2009-11-17 13:28:38 +00:00
raw_spin_unlock_irqrestore(&rq->lock, flags);
sched: Simplify cpu-hot-unplug task migration While discussing the need for sched_idle_next(), Oleg remarked that since try_to_wake_up() ensures sleeping tasks will end up running on a sane cpu, we can do away with migrate_live_tasks(). If we then extend the existing hack of migrating current from CPU_DYING to migrating the full rq worth of tasks from CPU_DYING, the need for the sched_idle_next() abomination disappears as well, since idle will be the only possible thread left after the migration thread stops. This greatly simplifies the hot-unplug task migration path, as can be seen from the resulting code reduction (and about half the new lines are comments). Suggested-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1289851597.2109.547.camel@laptop> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-13 18:32:29 +00:00
migrate_nr_uninterruptible(rq);
calc_global_load_remove(rq);
sched: add sched-domain roots We add the notion of a root-domain which will be used later to rescope global variables to per-domain variables. Each exclusive cpuset essentially defines an island domain by fully partitioning the member cpus from any other cpuset. However, we currently still maintain some policy/state as global variables which transcend all cpusets. Consider, for instance, rt-overload state. Whenever a new exclusive cpuset is created, we also create a new root-domain object and move each cpu member to the root-domain's span. By default the system creates a single root-domain with all cpus as members (mimicking the global state we have today). We add some plumbing for storing class specific data in our root-domain. Whenever a RQ is switching root-domains (because of repartitioning) we give each sched_class the opportunity to remove any state from its old domain and add state to the new one. This logic doesn't have any clients yet but it will later in the series. Signed-off-by: Gregory Haskins <ghaskins@novell.com> CC: Christoph Lameter <clameter@sgi.com> CC: Paul Jackson <pj@sgi.com> CC: Simon Derr <simon.derr@bull.net> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:18 +00:00
break;
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
#endif
}
sched: Clean up rebalance_domains() load-balance interval calculation Instead of the possible multiple-evaluation of num_online_cpus() in rebalance_domains() that Linus reported, avoid it altogether in the normal case since it's implemented with a Hamming weight function over a cpu bitmask which can be darn expensive for those with big iron. This also makes it cleaner, smaller and documents the code. Reported-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1301991265.2225.12.camel@twins> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-05 08:14:25 +00:00
update_max_interval();
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
return NOTIFY_OK;
}
perf_counter: Initialize per-cpu context earlier on cpu up This arranges for perf_counter's notifier for cpu hotplug operations to be called earlier than the migration notifier in sched.c by increasing its priority to 20, compared to the 10 for the migration notifier. The reason for doing this is that a subsequent commit to convert the cpu migration counter to use the generic swcounter infrastructure will add a call into the perf_counter subsystem when tasks get migrated. Therefore the perf_counter subsystem needs a chance to initialize its per-cpu data for the new cpu before it can get called from the migration code. This also adds a comment to the migration notifier noting that its priority needs to be lower than that of the perf_counter notifier. Signed-off-by: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <18981.1900.792795.836858@cargo.ozlabs.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-06-02 11:05:16 +00:00
/*
* Register at high priority so that task migration (migrate_all_tasks)
* happens before everything else. This has to be lower priority than
perf: Do the big rename: Performance Counters -> Performance Events Bye-bye Performance Counters, welcome Performance Events! In the past few months the perfcounters subsystem has grown out its initial role of counting hardware events, and has become (and is becoming) a much broader generic event enumeration, reporting, logging, monitoring, analysis facility. Naming its core object 'perf_counter' and naming the subsystem 'perfcounters' has become more and more of a misnomer. With pending code like hw-breakpoints support the 'counter' name is less and less appropriate. All in one, we've decided to rename the subsystem to 'performance events' and to propagate this rename through all fields, variables and API names. (in an ABI compatible fashion) The word 'event' is also a bit shorter than 'counter' - which makes it slightly more convenient to write/handle as well. Thanks goes to Stephane Eranian who first observed this misnomer and suggested a rename. User-space tooling and ABI compatibility is not affected - this patch should be function-invariant. (Also, defconfigs were not touched to keep the size down.) This patch has been generated via the following script: FILES=$(find * -type f | grep -vE 'oprofile|[^K]config') sed -i \ -e 's/PERF_EVENT_/PERF_RECORD_/g' \ -e 's/PERF_COUNTER/PERF_EVENT/g' \ -e 's/perf_counter/perf_event/g' \ -e 's/nb_counters/nb_events/g' \ -e 's/swcounter/swevent/g' \ -e 's/tpcounter_event/tp_event/g' \ $FILES for N in $(find . -name perf_counter.[ch]); do M=$(echo $N | sed 's/perf_counter/perf_event/g') mv $N $M done FILES=$(find . -name perf_event.*) sed -i \ -e 's/COUNTER_MASK/REG_MASK/g' \ -e 's/COUNTER/EVENT/g' \ -e 's/\<event\>/event_id/g' \ -e 's/counter/event/g' \ -e 's/Counter/Event/g' \ $FILES ... to keep it as correct as possible. This script can also be used by anyone who has pending perfcounters patches - it converts a Linux kernel tree over to the new naming. We tried to time this change to the point in time where the amount of pending patches is the smallest: the end of the merge window. Namespace clashes were fixed up in a preparatory patch - and some stylistic fallout will be fixed up in a subsequent patch. ( NOTE: 'counters' are still the proper terminology when we deal with hardware registers - and these sed scripts are a bit over-eager in renaming them. I've undone some of that, but in case there's something left where 'counter' would be better than 'event' we can undo that on an individual basis instead of touching an otherwise nicely automated patch. ) Suggested-by: Stephane Eranian <eranian@google.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Paul Mackerras <paulus@samba.org> Reviewed-by: Arjan van de Ven <arjan@linux.intel.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: David Howells <dhowells@redhat.com> Cc: Kyle McMartin <kyle@mcmartin.ca> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: <linux-arch@vger.kernel.org> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-09-21 10:02:48 +00:00
* the notifier in the perf_event subsystem, though.
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
*/
[PATCH] cpu hotplug: make cpu_notifier related notifier calls __cpuinit only Make notifier_calls associated with cpu_notifier as __cpuinit. __cpuinit makes sure that the function is init time only unless CONFIG_HOTPLUG_CPU is defined. [akpm@osdl.org: section fix] Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com> Cc: Ashok Raj <ashok.raj@intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 09:54:10 +00:00
static struct notifier_block __cpuinitdata migration_notifier = {
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
.notifier_call = migration_call,
sched: define and use CPU_PRI_* enums for cpu notifier priorities Instead of hardcoding priority 10 and 20 in sched and perf, collect them into CPU_PRI_* enums. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Paul Mackerras <paulus@samba.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
2010-06-08 19:40:36 +00:00
.priority = CPU_PRI_MIGRATION,
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
};
sched: adjust when cpu_active and cpuset configurations are updated during cpu on/offlining Currently, when a cpu goes down, cpu_active is cleared before CPU_DOWN_PREPARE starts and cpuset configuration is updated from a default priority cpu notifier. When a cpu is coming up, it's set before CPU_ONLINE but cpuset configuration again is updated from the same cpu notifier. For cpu notifiers, this presents an inconsistent state. Threads which a CPU_DOWN_PREPARE notifier expects to be bound to the CPU can be migrated to other cpus because the cpu is no more inactive. Fix it by updating cpu_active in the highest priority cpu notifier and cpuset configuration in the second highest when a cpu is coming up. Down path is updated similarly. This guarantees that all other cpu notifiers see consistent cpu_active and cpuset configuration. cpuset_track_online_cpus() notifier is converted to cpuset_update_active_cpus() which just updates the configuration and now called from cpuset_cpu_[in]active() notifiers registered from sched_init_smp(). If cpuset is disabled, cpuset_update_active_cpus() degenerates into partition_sched_domains() making separate notifier for !CONFIG_CPUSETS unnecessary. This problem is triggered by cmwq. During CPU_DOWN_PREPARE, hotplug callback creates a kthread and kthread_bind()s it to the target cpu, and the thread is expected to run on that cpu. * Ingo's test discovered __cpuinit/exit markups were incorrect. Fixed. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Ingo Molnar <mingo@elte.hu> Cc: Paul Menage <menage@google.com>
2010-06-08 19:40:36 +00:00
static int __cpuinit sched_cpu_active(struct notifier_block *nfb,
unsigned long action, void *hcpu)
{
switch (action & ~CPU_TASKS_FROZEN) {
case CPU_ONLINE:
case CPU_DOWN_FAILED:
set_cpu_active((long)hcpu, true);
return NOTIFY_OK;
default:
return NOTIFY_DONE;
}
}
static int __cpuinit sched_cpu_inactive(struct notifier_block *nfb,
unsigned long action, void *hcpu)
{
switch (action & ~CPU_TASKS_FROZEN) {
case CPU_DOWN_PREPARE:
set_cpu_active((long)hcpu, false);
return NOTIFY_OK;
default:
return NOTIFY_DONE;
}
}
Full conversion to early_initcall() interface, remove old interface A previous patch added the early_initcall(), to allow a cleaner hooking of pre-SMP initcalls. Now we remove the older interface, converting all existing users to the new one. [akpm@linux-foundation.org: cleanups] [akpm@linux-foundation.org: build fix] [kosaki.motohiro@jp.fujitsu.com: warning fix] [kosaki.motohiro@jp.fujitsu.com: warning fix] Signed-off-by: Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro> Cc: Tom Zanussi <tzanussi@gmail.com> Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-26 02:45:11 +00:00
static int __init migration_init(void)
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
{
void *cpu = (void *)(long)smp_processor_id();
[PATCH] check return value of cpu_callback Spawing ksoftirqd, migration, or watchdog, and calling init_timers_cpu() may fail with small memory. If it happens in initcalls, kernel NULL pointer dereference happens later. This patch makes crash happen immediately in such cases. It seems a bit better than getting kernel NULL pointer dereference later. Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Akinobu Mita <mita@miraclelinux.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-29 09:00:22 +00:00
int err;
[PATCH] sched: clean up fallout of recent changes Clean up some of the impact of recent (and not so recent) scheduler changes: - turning macros into nice inline functions - sanitizing and unifying variable definitions - whitespace, style consistency, 80-lines, comment correctness, spelling and curly braces police Due to the macro hell and variable placement simplifications there's even 26 bytes of .text saved: text data bss dec hex filename 25510 4153 192 29855 749f sched.o.before 25484 4153 192 29829 7485 sched.o.after [akpm@osdl.org: build fix] Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-03 07:25:40 +00:00
sched: adjust when cpu_active and cpuset configurations are updated during cpu on/offlining Currently, when a cpu goes down, cpu_active is cleared before CPU_DOWN_PREPARE starts and cpuset configuration is updated from a default priority cpu notifier. When a cpu is coming up, it's set before CPU_ONLINE but cpuset configuration again is updated from the same cpu notifier. For cpu notifiers, this presents an inconsistent state. Threads which a CPU_DOWN_PREPARE notifier expects to be bound to the CPU can be migrated to other cpus because the cpu is no more inactive. Fix it by updating cpu_active in the highest priority cpu notifier and cpuset configuration in the second highest when a cpu is coming up. Down path is updated similarly. This guarantees that all other cpu notifiers see consistent cpu_active and cpuset configuration. cpuset_track_online_cpus() notifier is converted to cpuset_update_active_cpus() which just updates the configuration and now called from cpuset_cpu_[in]active() notifiers registered from sched_init_smp(). If cpuset is disabled, cpuset_update_active_cpus() degenerates into partition_sched_domains() making separate notifier for !CONFIG_CPUSETS unnecessary. This problem is triggered by cmwq. During CPU_DOWN_PREPARE, hotplug callback creates a kthread and kthread_bind()s it to the target cpu, and the thread is expected to run on that cpu. * Ingo's test discovered __cpuinit/exit markups were incorrect. Fixed. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Ingo Molnar <mingo@elte.hu> Cc: Paul Menage <menage@google.com>
2010-06-08 19:40:36 +00:00
/* Initialize migration for the boot CPU */
[PATCH] check return value of cpu_callback Spawing ksoftirqd, migration, or watchdog, and calling init_timers_cpu() may fail with small memory. If it happens in initcalls, kernel NULL pointer dereference happens later. This patch makes crash happen immediately in such cases. It seems a bit better than getting kernel NULL pointer dereference later. Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Akinobu Mita <mita@miraclelinux.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-29 09:00:22 +00:00
err = migration_call(&migration_notifier, CPU_UP_PREPARE, cpu);
BUG_ON(err == NOTIFY_BAD);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
migration_call(&migration_notifier, CPU_ONLINE, cpu);
register_cpu_notifier(&migration_notifier);
Full conversion to early_initcall() interface, remove old interface A previous patch added the early_initcall(), to allow a cleaner hooking of pre-SMP initcalls. Now we remove the older interface, converting all existing users to the new one. [akpm@linux-foundation.org: cleanups] [akpm@linux-foundation.org: build fix] [kosaki.motohiro@jp.fujitsu.com: warning fix] [kosaki.motohiro@jp.fujitsu.com: warning fix] Signed-off-by: Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro> Cc: Tom Zanussi <tzanussi@gmail.com> Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-26 02:45:11 +00:00
sched: adjust when cpu_active and cpuset configurations are updated during cpu on/offlining Currently, when a cpu goes down, cpu_active is cleared before CPU_DOWN_PREPARE starts and cpuset configuration is updated from a default priority cpu notifier. When a cpu is coming up, it's set before CPU_ONLINE but cpuset configuration again is updated from the same cpu notifier. For cpu notifiers, this presents an inconsistent state. Threads which a CPU_DOWN_PREPARE notifier expects to be bound to the CPU can be migrated to other cpus because the cpu is no more inactive. Fix it by updating cpu_active in the highest priority cpu notifier and cpuset configuration in the second highest when a cpu is coming up. Down path is updated similarly. This guarantees that all other cpu notifiers see consistent cpu_active and cpuset configuration. cpuset_track_online_cpus() notifier is converted to cpuset_update_active_cpus() which just updates the configuration and now called from cpuset_cpu_[in]active() notifiers registered from sched_init_smp(). If cpuset is disabled, cpuset_update_active_cpus() degenerates into partition_sched_domains() making separate notifier for !CONFIG_CPUSETS unnecessary. This problem is triggered by cmwq. During CPU_DOWN_PREPARE, hotplug callback creates a kthread and kthread_bind()s it to the target cpu, and the thread is expected to run on that cpu. * Ingo's test discovered __cpuinit/exit markups were incorrect. Fixed. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Ingo Molnar <mingo@elte.hu> Cc: Paul Menage <menage@google.com>
2010-06-08 19:40:36 +00:00
/* Register cpu active notifiers */
cpu_notifier(sched_cpu_active, CPU_PRI_SCHED_ACTIVE);
cpu_notifier(sched_cpu_inactive, CPU_PRI_SCHED_INACTIVE);
sched: Fix return value of migration_init() migration_init() returns the return value of the hotplug notifier. In the success case this is NOTIFY_OK which is 1. initcall_debug evaluates that as an error code because init calls are expected to return 0 on success. Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2009-07-21 07:54:05 +00:00
return 0;
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
}
Full conversion to early_initcall() interface, remove old interface A previous patch added the early_initcall(), to allow a cleaner hooking of pre-SMP initcalls. Now we remove the older interface, converting all existing users to the new one. [akpm@linux-foundation.org: cleanups] [akpm@linux-foundation.org: build fix] [kosaki.motohiro@jp.fujitsu.com: warning fix] [kosaki.motohiro@jp.fujitsu.com: warning fix] Signed-off-by: Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro> Cc: Tom Zanussi <tzanussi@gmail.com> Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-26 02:45:11 +00:00
early_initcall(migration_init);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
#endif
#ifdef CONFIG_SMP
Safer nr_node_ids and nr_node_ids determination and initial values The nr_cpu_ids value is currently only calculated in smp_init. However, it may be needed before (SLUB needs it on kmem_cache_init!) and other kernel components may also want to allocate dynamically sized per cpu array before smp_init. So move the determination of possible cpus into sched_init() where we already loop over all possible cpus early in boot. Also initialize both nr_node_ids and nr_cpu_ids with the highest value they could take. If we have accidental users before these values are determined then the current valud of 0 may cause too small per cpu and per node arrays to be allocated. If it is set to the maximum possible then we only waste some memory for early boot users. Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-06 21:48:58 +00:00
sched: Avoid allocations in sched_domain_debug() Since we're all serialized by sched_domains_mutex we can use sched_domains_tmpmask and avoid having to do allocations. This means we can use sched_domains_debug() for cpu_attach_domain() again. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.664347467@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:09:58 +00:00
static cpumask_var_t sched_domains_tmpmask; /* sched_domains_mutex */
sched: run sched_domain_debug() if CONFIG_SCHED_DEBUG=y run sched_domain_debug() if CONFIG_SCHED_DEBUG=y, instead of relying on the hand-crafted SCHED_DOMAIN_DEBUG switch. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 15:00:13 +00:00
#ifdef CONFIG_SCHED_DEBUG
sched: clean up sched_domain_debug() clean up sched_domain_debug(). this also shrinks the code a bit: text data bss dec hex filename 50474 4306 480 55260 d7dc sched.o.before 50404 4306 480 55190 d796 sched.o.after Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-24 16:23:48 +00:00
sched: Limit the number of scheduler debug messages Remove the verbose scheduler debug messages unless kernel parameter "sched_debug" set. /proc/sched_debug unchanged. Signed-off-by: Mike Travis <travis@sgi.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Roland Dreier <rdreier@cisco.com> Cc: Randy Dunlap <rdunlap@xenotime.net> Cc: Tejun Heo <tj@kernel.org> Cc: Andi Kleen <andi@firstfloor.org> Cc: Greg Kroah-Hartman <gregkh@suse.de> Cc: Yinghai Lu <yhlu.kernel@gmail.com> Cc: David Rientjes <rientjes@google.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Cc: Jack Steiner <steiner@sgi.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> LKML-Reference: <20091118002221.489305000@alcatraz.americas.sgi.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-11-18 00:22:15 +00:00
static __read_mostly int sched_domain_debug_enabled;
static int __init sched_domain_debug_setup(char *str)
{
sched_domain_debug_enabled = 1;
return 0;
}
early_param("sched_debug", sched_domain_debug_setup);
cpumask: reduce stack usage in SD_x_INIT initializers * Remove empty cpumask_t (and all non-zero/non-null) variables in SD_*_INIT macros. Use memset(0) to clear. Also, don't inline the initializer functions to save on stack space in build_sched_domains(). * Merge change to include/linux/topology.h that uses the new node_to_cpumask_ptr function in the nr_cpus_node macro into this patch. Depends on: [mm-patch]: asm-generic-add-node_to_cpumask_ptr-macro.patch [sched-devel]: sched: add new set_cpus_allowed_ptr function Cc: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Mike Travis <travis@sgi.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-05 01:11:11 +00:00
static int sched_domain_debug_one(struct sched_domain *sd, int cpu, int level,
sched: convert remaining old-style cpumask operators Impact: Trivial API conversion NR_CPUS -> nr_cpu_ids cpumask_t -> struct cpumask sizeof(cpumask_t) -> cpumask_size() cpumask_a = cpumask_b -> cpumask_copy(&cpumask_a, &cpumask_b) cpu_set() -> cpumask_set_cpu() first_cpu() -> cpumask_first() cpumask_of_cpu() -> cpumask_of() cpus_* -> cpumask_* There are some FIXMEs where we all archs to complete infrastructure (patches have been sent): cpu_coregroup_map -> cpu_coregroup_mask node_to_cpumask* -> cpumask_of_node There is also one FIXME where we pass an array of cpumasks to partition_sched_domains(): this implies knowing the definition of 'struct cpumask' and the size of a cpumask. This will be fixed in a future patch. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-24 16:05:14 +00:00
struct cpumask *groupmask)
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
{
sched: clean up sched_domain_debug() clean up sched_domain_debug(). this also shrinks the code a bit: text data bss dec hex filename 50474 4306 480 55260 d7dc sched.o.before 50404 4306 480 55190 d796 sched.o.after Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-24 16:23:48 +00:00
struct sched_group *group = sd->groups;
sched: remove fixed NR_CPUS sized arrays in kernel_sched_c * Change fixed size arrays to per_cpu variables or dynamically allocated arrays in sched_init() and sched_init_smp(). (1) static struct sched_entity *init_sched_entity_p[NR_CPUS]; (1) static struct cfs_rq *init_cfs_rq_p[NR_CPUS]; (1) static struct sched_rt_entity *init_sched_rt_entity_p[NR_CPUS]; (1) static struct rt_rq *init_rt_rq_p[NR_CPUS]; static struct sched_group **sched_group_nodes_bycpu[NR_CPUS]; (1) - these arrays are allocated via alloc_bootmem_low() * Change sched_domain_debug_one() to use cpulist_scnprintf instead of cpumask_scnprintf. This reduces the output buffer required and improves readability when large NR_CPU count machines arrive. * In sched_create_group() we allocate new arrays based on nr_cpu_ids. Signed-off-by: Mike Travis <travis@sgi.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-05 01:11:04 +00:00
char str[256];
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
Merge ../linux-2.6-x86 Conflicts: arch/x86/kernel/io_apic.c kernel/sched.c kernel/sched_stats.h
2008-12-13 11:25:51 +00:00
cpulist_scnprintf(str, sizeof(str), sched_domain_span(sd));
sched: convert remaining old-style cpumask operators Impact: Trivial API conversion NR_CPUS -> nr_cpu_ids cpumask_t -> struct cpumask sizeof(cpumask_t) -> cpumask_size() cpumask_a = cpumask_b -> cpumask_copy(&cpumask_a, &cpumask_b) cpu_set() -> cpumask_set_cpu() first_cpu() -> cpumask_first() cpumask_of_cpu() -> cpumask_of() cpus_* -> cpumask_* There are some FIXMEs where we all archs to complete infrastructure (patches have been sent): cpu_coregroup_map -> cpu_coregroup_mask node_to_cpumask* -> cpumask_of_node There is also one FIXME where we pass an array of cpumasks to partition_sched_domains(): this implies knowing the definition of 'struct cpumask' and the size of a cpumask. This will be fixed in a future patch. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-24 16:05:14 +00:00
cpumask_clear(groupmask);
sched: clean up sched_domain_debug() clean up sched_domain_debug(). this also shrinks the code a bit: text data bss dec hex filename 50474 4306 480 55260 d7dc sched.o.before 50404 4306 480 55190 d796 sched.o.after Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-24 16:23:48 +00:00
printk(KERN_DEBUG "%*s domain %d: ", level, "", level);
if (!(sd->flags & SD_LOAD_BALANCE)) {
sched: Restore printk sanity Revert the braindead pr_* crap. (Commit 663997d "sched: Use pr_fmt() and pr_<level>()") It's dumb and causes stupid "sched: " strings all over the place. Signed-off-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Mike Galbraith <efault@gmx.de> Cc: Joe Perches <joe@perches.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> LKML-Reference: <1261315437.4314.6.camel@laptop> [ i dont mind the pr_*() patterns that much - but Peter dislikes them with a vengence. ] [ - v2: remove spurious diffstat from changelog :-/ ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-20 13:23:57 +00:00
printk("does not load-balance\n");
sched: clean up sched_domain_debug() clean up sched_domain_debug(). this also shrinks the code a bit: text data bss dec hex filename 50474 4306 480 55260 d7dc sched.o.before 50404 4306 480 55190 d796 sched.o.after Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-24 16:23:48 +00:00
if (sd->parent)
sched: Restore printk sanity Revert the braindead pr_* crap. (Commit 663997d "sched: Use pr_fmt() and pr_<level>()") It's dumb and causes stupid "sched: " strings all over the place. Signed-off-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Mike Galbraith <efault@gmx.de> Cc: Joe Perches <joe@perches.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> LKML-Reference: <1261315437.4314.6.camel@laptop> [ i dont mind the pr_*() patterns that much - but Peter dislikes them with a vengence. ] [ - v2: remove spurious diffstat from changelog :-/ ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-20 13:23:57 +00:00
printk(KERN_ERR "ERROR: !SD_LOAD_BALANCE domain"
" has parent");
sched: clean up sched_domain_debug() clean up sched_domain_debug(). this also shrinks the code a bit: text data bss dec hex filename 50474 4306 480 55260 d7dc sched.o.before 50404 4306 480 55190 d796 sched.o.after Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-24 16:23:48 +00:00
return -1;
[PATCH] sched: null domains Fix the last 2 places that directly access a runqueue's sched-domain and assume it cannot be NULL. That allows the use of NULL for domain, instead of a dummy domain, to signify no balancing is to happen. No functional changes. Signed-off-by: Nick Piggin <nickpiggin@yahoo.com.au> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-25 21:57:24 +00:00
}
sched: Restore printk sanity Revert the braindead pr_* crap. (Commit 663997d "sched: Use pr_fmt() and pr_<level>()") It's dumb and causes stupid "sched: " strings all over the place. Signed-off-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Mike Galbraith <efault@gmx.de> Cc: Joe Perches <joe@perches.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> LKML-Reference: <1261315437.4314.6.camel@laptop> [ i dont mind the pr_*() patterns that much - but Peter dislikes them with a vengence. ] [ - v2: remove spurious diffstat from changelog :-/ ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-20 13:23:57 +00:00
printk(KERN_CONT "span %s level %s\n", str, sd->name);
sched: clean up sched_domain_debug() clean up sched_domain_debug(). this also shrinks the code a bit: text data bss dec hex filename 50474 4306 480 55260 d7dc sched.o.before 50404 4306 480 55190 d796 sched.o.after Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-24 16:23:48 +00:00
sched: wrap sched_group and sched_domain cpumask accesses. Impact: trivial wrap of member accesses This eases the transition in the next patch. We also get rid of a temporary cpumask in find_idlest_cpu() thanks to for_each_cpu_and, and sched_balance_self() due to getting weight before setting sd to NULL. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-24 16:05:04 +00:00
if (!cpumask_test_cpu(cpu, sched_domain_span(sd))) {
sched: Restore printk sanity Revert the braindead pr_* crap. (Commit 663997d "sched: Use pr_fmt() and pr_<level>()") It's dumb and causes stupid "sched: " strings all over the place. Signed-off-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Mike Galbraith <efault@gmx.de> Cc: Joe Perches <joe@perches.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> LKML-Reference: <1261315437.4314.6.camel@laptop> [ i dont mind the pr_*() patterns that much - but Peter dislikes them with a vengence. ] [ - v2: remove spurious diffstat from changelog :-/ ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-20 13:23:57 +00:00
printk(KERN_ERR "ERROR: domain->span does not contain "
"CPU%d\n", cpu);
sched: clean up sched_domain_debug() clean up sched_domain_debug(). this also shrinks the code a bit: text data bss dec hex filename 50474 4306 480 55260 d7dc sched.o.before 50404 4306 480 55190 d796 sched.o.after Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-24 16:23:48 +00:00
}
sched: wrap sched_group and sched_domain cpumask accesses. Impact: trivial wrap of member accesses This eases the transition in the next patch. We also get rid of a temporary cpumask in find_idlest_cpu() thanks to for_each_cpu_and, and sched_balance_self() due to getting weight before setting sd to NULL. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-24 16:05:04 +00:00
if (!cpumask_test_cpu(cpu, sched_group_cpus(group))) {
sched: Restore printk sanity Revert the braindead pr_* crap. (Commit 663997d "sched: Use pr_fmt() and pr_<level>()") It's dumb and causes stupid "sched: " strings all over the place. Signed-off-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Mike Galbraith <efault@gmx.de> Cc: Joe Perches <joe@perches.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> LKML-Reference: <1261315437.4314.6.camel@laptop> [ i dont mind the pr_*() patterns that much - but Peter dislikes them with a vengence. ] [ - v2: remove spurious diffstat from changelog :-/ ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-20 13:23:57 +00:00
printk(KERN_ERR "ERROR: domain->groups does not contain"
" CPU%d\n", cpu);
sched: clean up sched_domain_debug() clean up sched_domain_debug(). this also shrinks the code a bit: text data bss dec hex filename 50474 4306 480 55260 d7dc sched.o.before 50404 4306 480 55190 d796 sched.o.after Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-24 16:23:48 +00:00
}
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
sched: clean up sched_domain_debug() clean up sched_domain_debug(). this also shrinks the code a bit: text data bss dec hex filename 50474 4306 480 55260 d7dc sched.o.before 50404 4306 480 55190 d796 sched.o.after Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-24 16:23:48 +00:00
printk(KERN_DEBUG "%*s groups:", level + 1, "");
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
do {
sched: clean up sched_domain_debug() clean up sched_domain_debug(). this also shrinks the code a bit: text data bss dec hex filename 50474 4306 480 55260 d7dc sched.o.before 50404 4306 480 55190 d796 sched.o.after Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-24 16:23:48 +00:00
if (!group) {
sched: Restore printk sanity Revert the braindead pr_* crap. (Commit 663997d "sched: Use pr_fmt() and pr_<level>()") It's dumb and causes stupid "sched: " strings all over the place. Signed-off-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Mike Galbraith <efault@gmx.de> Cc: Joe Perches <joe@perches.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> LKML-Reference: <1261315437.4314.6.camel@laptop> [ i dont mind the pr_*() patterns that much - but Peter dislikes them with a vengence. ] [ - v2: remove spurious diffstat from changelog :-/ ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-20 13:23:57 +00:00
printk("\n");
printk(KERN_ERR "ERROR: group is NULL\n");
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
break;
}
sched: Break out cpu_power from the sched_group structure In order to prepare for non-unique sched_groups per domain, we need to carry the cpu_power elsewhere, so put a level of indirection in. Reported-and-tested-by: Anton Blanchard <anton@samba.org> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/n/tip-qkho2byuhe4482fuknss40ad@git.kernel.org Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-14 11:00:06 +00:00
if (!group->sgp->power) {
sched: Restore printk sanity Revert the braindead pr_* crap. (Commit 663997d "sched: Use pr_fmt() and pr_<level>()") It's dumb and causes stupid "sched: " strings all over the place. Signed-off-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Mike Galbraith <efault@gmx.de> Cc: Joe Perches <joe@perches.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> LKML-Reference: <1261315437.4314.6.camel@laptop> [ i dont mind the pr_*() patterns that much - but Peter dislikes them with a vengence. ] [ - v2: remove spurious diffstat from changelog :-/ ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-20 13:23:57 +00:00
printk(KERN_CONT "\n");
printk(KERN_ERR "ERROR: domain->cpu_power not "
"set\n");
sched: clean up sched_domain_debug() clean up sched_domain_debug(). this also shrinks the code a bit: text data bss dec hex filename 50474 4306 480 55260 d7dc sched.o.before 50404 4306 480 55190 d796 sched.o.after Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-24 16:23:48 +00:00
break;
}
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
sched: wrap sched_group and sched_domain cpumask accesses. Impact: trivial wrap of member accesses This eases the transition in the next patch. We also get rid of a temporary cpumask in find_idlest_cpu() thanks to for_each_cpu_and, and sched_balance_self() due to getting weight before setting sd to NULL. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-24 16:05:04 +00:00
if (!cpumask_weight(sched_group_cpus(group))) {
sched: Restore printk sanity Revert the braindead pr_* crap. (Commit 663997d "sched: Use pr_fmt() and pr_<level>()") It's dumb and causes stupid "sched: " strings all over the place. Signed-off-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Mike Galbraith <efault@gmx.de> Cc: Joe Perches <joe@perches.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> LKML-Reference: <1261315437.4314.6.camel@laptop> [ i dont mind the pr_*() patterns that much - but Peter dislikes them with a vengence. ] [ - v2: remove spurious diffstat from changelog :-/ ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-20 13:23:57 +00:00
printk(KERN_CONT "\n");
printk(KERN_ERR "ERROR: empty group\n");
sched: clean up sched_domain_debug() clean up sched_domain_debug(). this also shrinks the code a bit: text data bss dec hex filename 50474 4306 480 55260 d7dc sched.o.before 50404 4306 480 55190 d796 sched.o.after Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-24 16:23:48 +00:00
break;
}
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
sched: wrap sched_group and sched_domain cpumask accesses. Impact: trivial wrap of member accesses This eases the transition in the next patch. We also get rid of a temporary cpumask in find_idlest_cpu() thanks to for_each_cpu_and, and sched_balance_self() due to getting weight before setting sd to NULL. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-24 16:05:04 +00:00
if (cpumask_intersects(groupmask, sched_group_cpus(group))) {
sched: Restore printk sanity Revert the braindead pr_* crap. (Commit 663997d "sched: Use pr_fmt() and pr_<level>()") It's dumb and causes stupid "sched: " strings all over the place. Signed-off-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Mike Galbraith <efault@gmx.de> Cc: Joe Perches <joe@perches.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> LKML-Reference: <1261315437.4314.6.camel@laptop> [ i dont mind the pr_*() patterns that much - but Peter dislikes them with a vengence. ] [ - v2: remove spurious diffstat from changelog :-/ ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-20 13:23:57 +00:00
printk(KERN_CONT "\n");
printk(KERN_ERR "ERROR: repeated CPUs\n");
sched: clean up sched_domain_debug() clean up sched_domain_debug(). this also shrinks the code a bit: text data bss dec hex filename 50474 4306 480 55260 d7dc sched.o.before 50404 4306 480 55190 d796 sched.o.after Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-24 16:23:48 +00:00
break;
}
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
sched: wrap sched_group and sched_domain cpumask accesses. Impact: trivial wrap of member accesses This eases the transition in the next patch. We also get rid of a temporary cpumask in find_idlest_cpu() thanks to for_each_cpu_and, and sched_balance_self() due to getting weight before setting sd to NULL. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-24 16:05:04 +00:00
cpumask_or(groupmask, groupmask, sched_group_cpus(group));
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
Merge ../linux-2.6-x86 Conflicts: arch/x86/kernel/io_apic.c kernel/sched.c kernel/sched_stats.h
2008-12-13 11:25:51 +00:00
cpulist_scnprintf(str, sizeof(str), sched_group_cpus(group));
sched: Avoid printing sched_group::__cpu_power for default case Commit 46e0bb9c12f4 ("sched: Print sched_group::__cpu_power in sched_domain_debug") produces a messy dmesg output while attempting to print the sched_group::__cpu_power for each group in the sched_domain hierarchy. Fix this by avoid printing the __cpu_power for default cases. (i.e, __cpu_power == SCHED_LOAD_SCALE). [ Impact: reduce syslog clutter ] Reported-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Gautham R Shenoy <ego@in.ibm.com> Fixed-by: Tony Luck <tony.luck@intel.com> Cc: a.p.zijlstra@chello.nl LKML-Reference: <20090414033936.GA534@in.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-14 03:39:36 +00:00
sched: Restore printk sanity Revert the braindead pr_* crap. (Commit 663997d "sched: Use pr_fmt() and pr_<level>()") It's dumb and causes stupid "sched: " strings all over the place. Signed-off-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Mike Galbraith <efault@gmx.de> Cc: Joe Perches <joe@perches.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> LKML-Reference: <1261315437.4314.6.camel@laptop> [ i dont mind the pr_*() patterns that much - but Peter dislikes them with a vengence. ] [ - v2: remove spurious diffstat from changelog :-/ ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-20 13:23:57 +00:00
printk(KERN_CONT " %s", str);
sched: Break out cpu_power from the sched_group structure In order to prepare for non-unique sched_groups per domain, we need to carry the cpu_power elsewhere, so put a level of indirection in. Reported-and-tested-by: Anton Blanchard <anton@samba.org> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/n/tip-qkho2byuhe4482fuknss40ad@git.kernel.org Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-14 11:00:06 +00:00
if (group->sgp->power != SCHED_POWER_SCALE) {
sched: Restore printk sanity Revert the braindead pr_* crap. (Commit 663997d "sched: Use pr_fmt() and pr_<level>()") It's dumb and causes stupid "sched: " strings all over the place. Signed-off-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Mike Galbraith <efault@gmx.de> Cc: Joe Perches <joe@perches.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> LKML-Reference: <1261315437.4314.6.camel@laptop> [ i dont mind the pr_*() patterns that much - but Peter dislikes them with a vengence. ] [ - v2: remove spurious diffstat from changelog :-/ ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-20 13:23:57 +00:00
printk(KERN_CONT " (cpu_power = %d)",
sched: Break out cpu_power from the sched_group structure In order to prepare for non-unique sched_groups per domain, we need to carry the cpu_power elsewhere, so put a level of indirection in. Reported-and-tested-by: Anton Blanchard <anton@samba.org> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/n/tip-qkho2byuhe4482fuknss40ad@git.kernel.org Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-14 11:00:06 +00:00
group->sgp->power);
sched: Avoid printing sched_group::__cpu_power for default case Commit 46e0bb9c12f4 ("sched: Print sched_group::__cpu_power in sched_domain_debug") produces a messy dmesg output while attempting to print the sched_group::__cpu_power for each group in the sched_domain hierarchy. Fix this by avoid printing the __cpu_power for default cases. (i.e, __cpu_power == SCHED_LOAD_SCALE). [ Impact: reduce syslog clutter ] Reported-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Gautham R Shenoy <ego@in.ibm.com> Fixed-by: Tony Luck <tony.luck@intel.com> Cc: a.p.zijlstra@chello.nl LKML-Reference: <20090414033936.GA534@in.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-14 03:39:36 +00:00
}
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
sched: clean up sched_domain_debug() clean up sched_domain_debug(). this also shrinks the code a bit: text data bss dec hex filename 50474 4306 480 55260 d7dc sched.o.before 50404 4306 480 55190 d796 sched.o.after Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-24 16:23:48 +00:00
group = group->next;
} while (group != sd->groups);
sched: Restore printk sanity Revert the braindead pr_* crap. (Commit 663997d "sched: Use pr_fmt() and pr_<level>()") It's dumb and causes stupid "sched: " strings all over the place. Signed-off-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Mike Galbraith <efault@gmx.de> Cc: Joe Perches <joe@perches.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> LKML-Reference: <1261315437.4314.6.camel@laptop> [ i dont mind the pr_*() patterns that much - but Peter dislikes them with a vengence. ] [ - v2: remove spurious diffstat from changelog :-/ ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-20 13:23:57 +00:00
printk(KERN_CONT "\n");
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
sched: wrap sched_group and sched_domain cpumask accesses. Impact: trivial wrap of member accesses This eases the transition in the next patch. We also get rid of a temporary cpumask in find_idlest_cpu() thanks to for_each_cpu_and, and sched_balance_self() due to getting weight before setting sd to NULL. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-24 16:05:04 +00:00
if (!cpumask_equal(sched_domain_span(sd), groupmask))
sched: Restore printk sanity Revert the braindead pr_* crap. (Commit 663997d "sched: Use pr_fmt() and pr_<level>()") It's dumb and causes stupid "sched: " strings all over the place. Signed-off-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Mike Galbraith <efault@gmx.de> Cc: Joe Perches <joe@perches.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> LKML-Reference: <1261315437.4314.6.camel@laptop> [ i dont mind the pr_*() patterns that much - but Peter dislikes them with a vengence. ] [ - v2: remove spurious diffstat from changelog :-/ ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-20 13:23:57 +00:00
printk(KERN_ERR "ERROR: groups don't span domain->span\n");
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
sched: wrap sched_group and sched_domain cpumask accesses. Impact: trivial wrap of member accesses This eases the transition in the next patch. We also get rid of a temporary cpumask in find_idlest_cpu() thanks to for_each_cpu_and, and sched_balance_self() due to getting weight before setting sd to NULL. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-24 16:05:04 +00:00
if (sd->parent &&
!cpumask_subset(groupmask, sched_domain_span(sd->parent)))
sched: Restore printk sanity Revert the braindead pr_* crap. (Commit 663997d "sched: Use pr_fmt() and pr_<level>()") It's dumb and causes stupid "sched: " strings all over the place. Signed-off-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Mike Galbraith <efault@gmx.de> Cc: Joe Perches <joe@perches.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> LKML-Reference: <1261315437.4314.6.camel@laptop> [ i dont mind the pr_*() patterns that much - but Peter dislikes them with a vengence. ] [ - v2: remove spurious diffstat from changelog :-/ ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-20 13:23:57 +00:00
printk(KERN_ERR "ERROR: parent span is not a superset "
"of domain->span\n");
sched: clean up sched_domain_debug() clean up sched_domain_debug(). this also shrinks the code a bit: text data bss dec hex filename 50474 4306 480 55260 d7dc sched.o.before 50404 4306 480 55190 d796 sched.o.after Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-24 16:23:48 +00:00
return 0;
}
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
sched: clean up sched_domain_debug() clean up sched_domain_debug(). this also shrinks the code a bit: text data bss dec hex filename 50474 4306 480 55260 d7dc sched.o.before 50404 4306 480 55190 d796 sched.o.after Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-24 16:23:48 +00:00
static void sched_domain_debug(struct sched_domain *sd, int cpu)
{
int level = 0;
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
sched: Limit the number of scheduler debug messages Remove the verbose scheduler debug messages unless kernel parameter "sched_debug" set. /proc/sched_debug unchanged. Signed-off-by: Mike Travis <travis@sgi.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Roland Dreier <rdreier@cisco.com> Cc: Randy Dunlap <rdunlap@xenotime.net> Cc: Tejun Heo <tj@kernel.org> Cc: Andi Kleen <andi@firstfloor.org> Cc: Greg Kroah-Hartman <gregkh@suse.de> Cc: Yinghai Lu <yhlu.kernel@gmail.com> Cc: David Rientjes <rientjes@google.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Cc: Jack Steiner <steiner@sgi.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> LKML-Reference: <20091118002221.489305000@alcatraz.americas.sgi.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-11-18 00:22:15 +00:00
if (!sched_domain_debug_enabled)
return;
sched: clean up sched_domain_debug() clean up sched_domain_debug(). this also shrinks the code a bit: text data bss dec hex filename 50474 4306 480 55260 d7dc sched.o.before 50404 4306 480 55190 d796 sched.o.after Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-24 16:23:48 +00:00
if (!sd) {
printk(KERN_DEBUG "CPU%d attaching NULL sched-domain.\n", cpu);
return;
}
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
sched: clean up sched_domain_debug() clean up sched_domain_debug(). this also shrinks the code a bit: text data bss dec hex filename 50474 4306 480 55260 d7dc sched.o.before 50404 4306 480 55190 d796 sched.o.after Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-24 16:23:48 +00:00
printk(KERN_DEBUG "CPU%d attaching sched-domain:\n", cpu);
for (;;) {
sched: Avoid allocations in sched_domain_debug() Since we're all serialized by sched_domains_mutex we can use sched_domains_tmpmask and avoid having to do allocations. This means we can use sched_domains_debug() for cpu_attach_domain() again. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.664347467@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:09:58 +00:00
if (sched_domain_debug_one(sd, cpu, level, sched_domains_tmpmask))
sched: clean up sched_domain_debug() clean up sched_domain_debug(). this also shrinks the code a bit: text data bss dec hex filename 50474 4306 480 55260 d7dc sched.o.before 50404 4306 480 55190 d796 sched.o.after Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-24 16:23:48 +00:00
break;
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
level++;
sd = sd->parent;
[PATCH] kernel/sched.c: whitespace cleanups [akpm@osdl.org: additional cleanups] Signed-off-by: Miguel Ojeda Sandonis <maxextreme@gmail.com> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 10:20:38 +00:00
if (!sd)
sched: clean up sched_domain_debug() clean up sched_domain_debug(). this also shrinks the code a bit: text data bss dec hex filename 50474 4306 480 55260 d7dc sched.o.before 50404 4306 480 55190 d796 sched.o.after Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-24 16:23:48 +00:00
break;
}
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
}
sched: add comments for ifdefs in sched.c make sched.c easier to read. Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-30 12:23:45 +00:00
#else /* !CONFIG_SCHED_DEBUG */
[PATCH] sched: clean up fallout of recent changes Clean up some of the impact of recent (and not so recent) scheduler changes: - turning macros into nice inline functions - sanitizing and unifying variable definitions - whitespace, style consistency, 80-lines, comment correctness, spelling and curly braces police Due to the macro hell and variable placement simplifications there's even 26 bytes of .text saved: text data bss dec hex filename 25510 4153 192 29855 749f sched.o.before 25484 4153 192 29829 7485 sched.o.after [akpm@osdl.org: build fix] Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-03 07:25:40 +00:00
# define sched_domain_debug(sd, cpu) do { } while (0)
sched: add comments for ifdefs in sched.c make sched.c easier to read. Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-30 12:23:45 +00:00
#endif /* CONFIG_SCHED_DEBUG */
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
[PATCH] Dynamic sched domains: sched changes The following patches add dynamic sched domains functionality that was extensively discussed on lkml and lse-tech. I would like to see this added to -mm o The main advantage with this feature is that it ensures that the scheduler load balacing code only balances against the cpus that are in the sched domain as defined by an exclusive cpuset and not all of the cpus in the system. This removes any overhead due to load balancing code trying to pull tasks outside of the cpu exclusive cpuset only to be prevented by the tasks' cpus_allowed mask. o cpu exclusive cpusets are useful for servers running orthogonal workloads such as RT applications requiring low latency and HPC applications that are throughput sensitive o It provides a new API partition_sched_domains in sched.c that makes dynamic sched domains possible. o cpu_exclusive cpusets sets are now associated with a sched domain. Which means that the users can dynamically modify the sched domains through the cpuset file system interface o ia64 sched domain code has been updated to support this feature as well o Currently, this does not support hotplug. (However some of my tests indicate hotplug+preempt is currently broken) o I have tested it extensively on x86. o This should have very minimal impact on performance as none of the fast paths are affected Signed-off-by: Dinakar Guniguntala <dino@in.ibm.com> Acked-by: Paul Jackson <pj@sgi.com> Acked-by: Nick Piggin <nickpiggin@yahoo.com.au> Acked-by: Matthew Dobson <colpatch@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-25 21:57:33 +00:00
static int sd_degenerate(struct sched_domain *sd)
[PATCH] sched: remove degenerate domains Remove degenerate scheduler domains during the sched-domain init. For example on x86_64, we always have NUMA configured in. On Intel EM64T systems, top most sched domain will be of NUMA and with only one sched_group in it. With fork/exec balances(recent Nick's fixes in -mm tree), we always endup taking wrong decisions because of this topmost domain (as it contains only one group and find_idlest_group always returns NULL). We will endup loading HT package completely first, letting active load balance kickin and correct it. In general, this patch also makes sense with out recent Nick's fixes in -mm. From: Nick Piggin <nickpiggin@yahoo.com.au> Modified to account for more than just sched_groups when scanning for degenerate domains by Nick Piggin. And allow a runqueue's sd to go NULL rather than keep a single degenerate domain around (this happens when you run with maxcpus=1). Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Signed-off-by: Nick Piggin <nickpiggin@yahoo.com.au> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-25 21:57:25 +00:00
{
sched: wrap sched_group and sched_domain cpumask accesses. Impact: trivial wrap of member accesses This eases the transition in the next patch. We also get rid of a temporary cpumask in find_idlest_cpu() thanks to for_each_cpu_and, and sched_balance_self() due to getting weight before setting sd to NULL. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-24 16:05:04 +00:00
if (cpumask_weight(sched_domain_span(sd)) == 1)
[PATCH] sched: remove degenerate domains Remove degenerate scheduler domains during the sched-domain init. For example on x86_64, we always have NUMA configured in. On Intel EM64T systems, top most sched domain will be of NUMA and with only one sched_group in it. With fork/exec balances(recent Nick's fixes in -mm tree), we always endup taking wrong decisions because of this topmost domain (as it contains only one group and find_idlest_group always returns NULL). We will endup loading HT package completely first, letting active load balance kickin and correct it. In general, this patch also makes sense with out recent Nick's fixes in -mm. From: Nick Piggin <nickpiggin@yahoo.com.au> Modified to account for more than just sched_groups when scanning for degenerate domains by Nick Piggin. And allow a runqueue's sd to go NULL rather than keep a single degenerate domain around (this happens when you run with maxcpus=1). Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Signed-off-by: Nick Piggin <nickpiggin@yahoo.com.au> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-25 21:57:25 +00:00
return 1;
/* Following flags need at least 2 groups */
if (sd->flags & (SD_LOAD_BALANCE |
SD_BALANCE_NEWIDLE |
SD_BALANCE_FORK |
[PATCH] sched: cleanup sched_group cpu_power setup Up to now sched group's cpu_power for each sched domain is initialized independently. This made the setup code ugly as the new sched domains are getting added. Make the sched group cpu_power setup code generic, by using domain child field and new domain flag in sched_domain. For most of the sched domains(except NUMA), sched group's cpu_power is now computed generically using the domain properties of itself and of the child domain. sched groups in NUMA domains are setup little differently and hence they don't use this generic mechanism. Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Acked-by: Ingo Molnar <mingo@elte.hu> Acked-by: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Paul Jackson <pj@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-03 08:14:09 +00:00
SD_BALANCE_EXEC |
SD_SHARE_CPUPOWER |
SD_SHARE_PKG_RESOURCES)) {
[PATCH] sched: remove degenerate domains Remove degenerate scheduler domains during the sched-domain init. For example on x86_64, we always have NUMA configured in. On Intel EM64T systems, top most sched domain will be of NUMA and with only one sched_group in it. With fork/exec balances(recent Nick's fixes in -mm tree), we always endup taking wrong decisions because of this topmost domain (as it contains only one group and find_idlest_group always returns NULL). We will endup loading HT package completely first, letting active load balance kickin and correct it. In general, this patch also makes sense with out recent Nick's fixes in -mm. From: Nick Piggin <nickpiggin@yahoo.com.au> Modified to account for more than just sched_groups when scanning for degenerate domains by Nick Piggin. And allow a runqueue's sd to go NULL rather than keep a single degenerate domain around (this happens when you run with maxcpus=1). Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Signed-off-by: Nick Piggin <nickpiggin@yahoo.com.au> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-25 21:57:25 +00:00
if (sd->groups != sd->groups->next)
return 0;
}
/* Following flags don't use groups */
sched: Merge select_task_rq_fair() and sched_balance_self() The problem with wake_idle() is that is doesn't respect things like cpu_power, which means it doesn't deal well with SMT nor the recent RT interaction. To cure this, it needs to do what sched_balance_self() does, which leads to the possibility of merging select_task_rq_fair() and sched_balance_self(). Modify sched_balance_self() to: - update_shares() when walking up the domain tree, (it only called it for the top domain, but it should have done this anyway), which allows us to remove this ugly bit from try_to_wake_up(). - do wake_affine() on the smallest domain that contains both this (the waking) and the prev (the wakee) cpu for WAKE invocations. Then use the top-down balance steps it had to replace wake_idle(). This leads to the dissapearance of SD_WAKE_BALANCE and SD_WAKE_IDLE_FAR, with SD_WAKE_IDLE replaced with SD_BALANCE_WAKE. SD_WAKE_AFFINE needs SD_BALANCE_WAKE to be effective. Touch all topology bits to replace the old with new SD flags -- platforms might need re-tuning, enabling SD_BALANCE_WAKE conditionally on a NUMA distance seems like a good additional feature, magny-core and small nehalem systems would want this enabled, systems with slow interconnects would not. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-09-10 11:50:02 +00:00
if (sd->flags & (SD_WAKE_AFFINE))
[PATCH] sched: remove degenerate domains Remove degenerate scheduler domains during the sched-domain init. For example on x86_64, we always have NUMA configured in. On Intel EM64T systems, top most sched domain will be of NUMA and with only one sched_group in it. With fork/exec balances(recent Nick's fixes in -mm tree), we always endup taking wrong decisions because of this topmost domain (as it contains only one group and find_idlest_group always returns NULL). We will endup loading HT package completely first, letting active load balance kickin and correct it. In general, this patch also makes sense with out recent Nick's fixes in -mm. From: Nick Piggin <nickpiggin@yahoo.com.au> Modified to account for more than just sched_groups when scanning for degenerate domains by Nick Piggin. And allow a runqueue's sd to go NULL rather than keep a single degenerate domain around (this happens when you run with maxcpus=1). Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Signed-off-by: Nick Piggin <nickpiggin@yahoo.com.au> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-25 21:57:25 +00:00
return 0;
return 1;
}
[PATCH] sched: clean up fallout of recent changes Clean up some of the impact of recent (and not so recent) scheduler changes: - turning macros into nice inline functions - sanitizing and unifying variable definitions - whitespace, style consistency, 80-lines, comment correctness, spelling and curly braces police Due to the macro hell and variable placement simplifications there's even 26 bytes of .text saved: text data bss dec hex filename 25510 4153 192 29855 749f sched.o.before 25484 4153 192 29829 7485 sched.o.after [akpm@osdl.org: build fix] Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-03 07:25:40 +00:00
static int
sd_parent_degenerate(struct sched_domain *sd, struct sched_domain *parent)
[PATCH] sched: remove degenerate domains Remove degenerate scheduler domains during the sched-domain init. For example on x86_64, we always have NUMA configured in. On Intel EM64T systems, top most sched domain will be of NUMA and with only one sched_group in it. With fork/exec balances(recent Nick's fixes in -mm tree), we always endup taking wrong decisions because of this topmost domain (as it contains only one group and find_idlest_group always returns NULL). We will endup loading HT package completely first, letting active load balance kickin and correct it. In general, this patch also makes sense with out recent Nick's fixes in -mm. From: Nick Piggin <nickpiggin@yahoo.com.au> Modified to account for more than just sched_groups when scanning for degenerate domains by Nick Piggin. And allow a runqueue's sd to go NULL rather than keep a single degenerate domain around (this happens when you run with maxcpus=1). Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Signed-off-by: Nick Piggin <nickpiggin@yahoo.com.au> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-25 21:57:25 +00:00
{
unsigned long cflags = sd->flags, pflags = parent->flags;
if (sd_degenerate(parent))
return 1;
sched: wrap sched_group and sched_domain cpumask accesses. Impact: trivial wrap of member accesses This eases the transition in the next patch. We also get rid of a temporary cpumask in find_idlest_cpu() thanks to for_each_cpu_and, and sched_balance_self() due to getting weight before setting sd to NULL. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-24 16:05:04 +00:00
if (!cpumask_equal(sched_domain_span(sd), sched_domain_span(parent)))
[PATCH] sched: remove degenerate domains Remove degenerate scheduler domains during the sched-domain init. For example on x86_64, we always have NUMA configured in. On Intel EM64T systems, top most sched domain will be of NUMA and with only one sched_group in it. With fork/exec balances(recent Nick's fixes in -mm tree), we always endup taking wrong decisions because of this topmost domain (as it contains only one group and find_idlest_group always returns NULL). We will endup loading HT package completely first, letting active load balance kickin and correct it. In general, this patch also makes sense with out recent Nick's fixes in -mm. From: Nick Piggin <nickpiggin@yahoo.com.au> Modified to account for more than just sched_groups when scanning for degenerate domains by Nick Piggin. And allow a runqueue's sd to go NULL rather than keep a single degenerate domain around (this happens when you run with maxcpus=1). Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Signed-off-by: Nick Piggin <nickpiggin@yahoo.com.au> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-25 21:57:25 +00:00
return 0;
/* Flags needing groups don't count if only 1 group in parent */
if (parent->groups == parent->groups->next) {
pflags &= ~(SD_LOAD_BALANCE |
SD_BALANCE_NEWIDLE |
SD_BALANCE_FORK |
[PATCH] sched: cleanup sched_group cpu_power setup Up to now sched group's cpu_power for each sched domain is initialized independently. This made the setup code ugly as the new sched domains are getting added. Make the sched group cpu_power setup code generic, by using domain child field and new domain flag in sched_domain. For most of the sched domains(except NUMA), sched group's cpu_power is now computed generically using the domain properties of itself and of the child domain. sched groups in NUMA domains are setup little differently and hence they don't use this generic mechanism. Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Acked-by: Ingo Molnar <mingo@elte.hu> Acked-by: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Paul Jackson <pj@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-03 08:14:09 +00:00
SD_BALANCE_EXEC |
SD_SHARE_CPUPOWER |
SD_SHARE_PKG_RESOURCES);
sched: fix sd_parent_degenerate on non-numa smp machine Impact: optimize the sched domains tree some more The addition of SD_SERIALIZE flag added to SD_NODE_INIT prevented top level dummy numa sched_domain to be properly degenerated on non-numa smp machine. The reason is that in sd_parent_degenerate(), it found that the child and parent does not have comon sched_domain flags due to SD_SERIALIZE. However, for non-numa smp box, the top level is a dummy with a single sched_group. Filter out SD_SERIALIZE if it is on non-numa machine to properly degenerate top level node sched_domain. this will cut back some of the sd domain walk in the load balancer code. Signed-off-by: Ken Chen <kenchen@google.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-08 02:47:37 +00:00
if (nr_node_ids == 1)
pflags &= ~SD_SERIALIZE;
[PATCH] sched: remove degenerate domains Remove degenerate scheduler domains during the sched-domain init. For example on x86_64, we always have NUMA configured in. On Intel EM64T systems, top most sched domain will be of NUMA and with only one sched_group in it. With fork/exec balances(recent Nick's fixes in -mm tree), we always endup taking wrong decisions because of this topmost domain (as it contains only one group and find_idlest_group always returns NULL). We will endup loading HT package completely first, letting active load balance kickin and correct it. In general, this patch also makes sense with out recent Nick's fixes in -mm. From: Nick Piggin <nickpiggin@yahoo.com.au> Modified to account for more than just sched_groups when scanning for degenerate domains by Nick Piggin. And allow a runqueue's sd to go NULL rather than keep a single degenerate domain around (this happens when you run with maxcpus=1). Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Signed-off-by: Nick Piggin <nickpiggin@yahoo.com.au> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-25 21:57:25 +00:00
}
if (~cflags & pflags)
return 0;
return 1;
}
sched: Dynamically allocate sched_domain/sched_group data-structures Instead of relying on static allocations for the sched_domain and sched_group trees, dynamically allocate and RCU free them. Allocating this dynamically also allows for some build_sched_groups() simplification since we can now (like with other simplifications) rely on the sched_domain tree instead of hard-coded knowledge. One tricky to note is that detach_destroy_domains() needs to hold rcu_read_lock() over the entire tear-down, per-cpu is not sufficient since that can lead to partial sched_group existance (could possibly be solved by doing the tear-down backwards but this is much more robust). A concequence of the above is that we can no longer print the sched_domain debug stuff from cpu_attach_domain() since that might now run with preemption disabled (due to classic RCU etc.) and sched_domain_debug() does some GFP_KERNEL allocations. Another thing to note is that we now fully rely on normal RCU and not RCU-sched, this is because with the new and exiting RCU flavours we grew over the years BH doesn't necessarily hold off RCU-sched grace periods (-rt is known to break this). This would in fact already cause us grief since we do sched_domain/sched_group iterations from softirq context. This patch is somewhat larger than I would like it to be, but I didn't find any means of shrinking/splitting this. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.245307941@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:09:50 +00:00
static void free_rootdomain(struct rcu_head *rcu)
sched: convert struct root_domain to cpumask_var_t. Impact: (future) size reduction for large NR_CPUS. Dynamically allocating cpumasks (when CONFIG_CPUMASK_OFFSTACK) saves space for small nr_cpu_ids but big CONFIG_NR_CPUS. cpumask_var_t is just a struct cpumask for !CONFIG_CPUMASK_OFFSTACK. def_root_domain is static, and so its masks are initialized with alloc_bootmem_cpumask_var. After that, alloc_cpumask_var is used. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-24 16:05:05 +00:00
{
sched: Dynamically allocate sched_domain/sched_group data-structures Instead of relying on static allocations for the sched_domain and sched_group trees, dynamically allocate and RCU free them. Allocating this dynamically also allows for some build_sched_groups() simplification since we can now (like with other simplifications) rely on the sched_domain tree instead of hard-coded knowledge. One tricky to note is that detach_destroy_domains() needs to hold rcu_read_lock() over the entire tear-down, per-cpu is not sufficient since that can lead to partial sched_group existance (could possibly be solved by doing the tear-down backwards but this is much more robust). A concequence of the above is that we can no longer print the sched_domain debug stuff from cpu_attach_domain() since that might now run with preemption disabled (due to classic RCU etc.) and sched_domain_debug() does some GFP_KERNEL allocations. Another thing to note is that we now fully rely on normal RCU and not RCU-sched, this is because with the new and exiting RCU flavours we grew over the years BH doesn't necessarily hold off RCU-sched grace periods (-rt is known to break this). This would in fact already cause us grief since we do sched_domain/sched_group iterations from softirq context. This patch is somewhat larger than I would like it to be, but I didn't find any means of shrinking/splitting this. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.245307941@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:09:50 +00:00
struct root_domain *rd = container_of(rcu, struct root_domain, rcu);
sched: Sched_rt_periodic_timer vs cpu hotplug Heiko reported a case where a timer interrupt managed to reference a root_domain structure that was already freed by a concurrent hot-un-plug operation. Solve this like the regular sched_domain stuff is also synchronized, by adding a synchronize_sched() stmt to the free path, this ensures that a root_domain stays present for any atomic section that could have observed it. Reported-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Gregory Haskins <ghaskins@novell.com> Cc: Siddha Suresh B <suresh.b.siddha@intel.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> LKML-Reference: <1258363873.26714.83.camel@laptop> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-11-16 09:28:09 +00:00
sched: convert struct cpupri_vec cpumask_var_t. Impact: stack usage reduction, (future) size reduction for large NR_CPUS. Dynamically allocating cpumasks (when CONFIG_CPUMASK_OFFSTACK) saves space for small nr_cpu_ids but big CONFIG_NR_CPUS. The fact cpupro_init is called both before and after the slab is available makes for an ugly parameter unfortunately. We also use cpumask_any_and to get rid of a temporary in cpupri_find. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-24 16:05:13 +00:00
cpupri_cleanup(&rd->cpupri);
sched: convert struct root_domain to cpumask_var_t. Impact: (future) size reduction for large NR_CPUS. Dynamically allocating cpumasks (when CONFIG_CPUMASK_OFFSTACK) saves space for small nr_cpu_ids but big CONFIG_NR_CPUS. cpumask_var_t is just a struct cpumask for !CONFIG_CPUMASK_OFFSTACK. def_root_domain is static, and so its masks are initialized with alloc_bootmem_cpumask_var. After that, alloc_cpumask_var is used. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-24 16:05:05 +00:00
free_cpumask_var(rd->rto_mask);
free_cpumask_var(rd->online);
free_cpumask_var(rd->span);
kfree(rd);
}
sched: add sched-domain roots We add the notion of a root-domain which will be used later to rescope global variables to per-domain variables. Each exclusive cpuset essentially defines an island domain by fully partitioning the member cpus from any other cpuset. However, we currently still maintain some policy/state as global variables which transcend all cpusets. Consider, for instance, rt-overload state. Whenever a new exclusive cpuset is created, we also create a new root-domain object and move each cpu member to the root-domain's span. By default the system creates a single root-domain with all cpus as members (mimicking the global state we have today). We add some plumbing for storing class specific data in our root-domain. Whenever a RQ is switching root-domains (because of repartitioning) we give each sched_class the opportunity to remove any state from its old domain and add state to the new one. This logic doesn't have any clients yet but it will later in the series. Signed-off-by: Gregory Haskins <ghaskins@novell.com> CC: Christoph Lameter <clameter@sgi.com> CC: Paul Jackson <pj@sgi.com> CC: Simon Derr <simon.derr@bull.net> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:18 +00:00
static void rq_attach_root(struct rq *rq, struct root_domain *rd)
{
sched: cpu hotplug fix rq_attach_root() does a kfree() with the runqueue lock held. That's not a very wise move, fix it. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-12 10:35:40 +00:00
struct root_domain *old_rd = NULL;
sched: add sched-domain roots We add the notion of a root-domain which will be used later to rescope global variables to per-domain variables. Each exclusive cpuset essentially defines an island domain by fully partitioning the member cpus from any other cpuset. However, we currently still maintain some policy/state as global variables which transcend all cpusets. Consider, for instance, rt-overload state. Whenever a new exclusive cpuset is created, we also create a new root-domain object and move each cpu member to the root-domain's span. By default the system creates a single root-domain with all cpus as members (mimicking the global state we have today). We add some plumbing for storing class specific data in our root-domain. Whenever a RQ is switching root-domains (because of repartitioning) we give each sched_class the opportunity to remove any state from its old domain and add state to the new one. This logic doesn't have any clients yet but it will later in the series. Signed-off-by: Gregory Haskins <ghaskins@novell.com> CC: Christoph Lameter <clameter@sgi.com> CC: Paul Jackson <pj@sgi.com> CC: Simon Derr <simon.derr@bull.net> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:18 +00:00
unsigned long flags;
sched: Convert rq->lock to raw_spinlock Convert locks which cannot be sleeping locks in preempt-rt to raw_spinlocks. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Ingo Molnar <mingo@elte.hu>
2009-11-17 13:28:38 +00:00
raw_spin_lock_irqsave(&rq->lock, flags);
sched: add sched-domain roots We add the notion of a root-domain which will be used later to rescope global variables to per-domain variables. Each exclusive cpuset essentially defines an island domain by fully partitioning the member cpus from any other cpuset. However, we currently still maintain some policy/state as global variables which transcend all cpusets. Consider, for instance, rt-overload state. Whenever a new exclusive cpuset is created, we also create a new root-domain object and move each cpu member to the root-domain's span. By default the system creates a single root-domain with all cpus as members (mimicking the global state we have today). We add some plumbing for storing class specific data in our root-domain. Whenever a RQ is switching root-domains (because of repartitioning) we give each sched_class the opportunity to remove any state from its old domain and add state to the new one. This logic doesn't have any clients yet but it will later in the series. Signed-off-by: Gregory Haskins <ghaskins@novell.com> CC: Christoph Lameter <clameter@sgi.com> CC: Paul Jackson <pj@sgi.com> CC: Simon Derr <simon.derr@bull.net> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:18 +00:00
if (rq->rd) {
sched: cpu hotplug fix rq_attach_root() does a kfree() with the runqueue lock held. That's not a very wise move, fix it. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-12 10:35:40 +00:00
old_rd = rq->rd;
sched: add sched-domain roots We add the notion of a root-domain which will be used later to rescope global variables to per-domain variables. Each exclusive cpuset essentially defines an island domain by fully partitioning the member cpus from any other cpuset. However, we currently still maintain some policy/state as global variables which transcend all cpusets. Consider, for instance, rt-overload state. Whenever a new exclusive cpuset is created, we also create a new root-domain object and move each cpu member to the root-domain's span. By default the system creates a single root-domain with all cpus as members (mimicking the global state we have today). We add some plumbing for storing class specific data in our root-domain. Whenever a RQ is switching root-domains (because of repartitioning) we give each sched_class the opportunity to remove any state from its old domain and add state to the new one. This logic doesn't have any clients yet but it will later in the series. Signed-off-by: Gregory Haskins <ghaskins@novell.com> CC: Christoph Lameter <clameter@sgi.com> CC: Paul Jackson <pj@sgi.com> CC: Simon Derr <simon.derr@bull.net> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:18 +00:00
sched: convert struct root_domain to cpumask_var_t. Impact: (future) size reduction for large NR_CPUS. Dynamically allocating cpumasks (when CONFIG_CPUMASK_OFFSTACK) saves space for small nr_cpu_ids but big CONFIG_NR_CPUS. cpumask_var_t is just a struct cpumask for !CONFIG_CPUMASK_OFFSTACK. def_root_domain is static, and so its masks are initialized with alloc_bootmem_cpumask_var. After that, alloc_cpumask_var is used. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-24 16:05:05 +00:00
if (cpumask_test_cpu(rq->cpu, old_rd->online))
sched: fix cpupri hotplug support The RT folks over at RedHat found an issue w.r.t. hotplug support which was traced to problems with the cpupri infrastructure in the scheduler: https://bugzilla.redhat.com/show_bug.cgi?id=449676 This bug affects 23-rt12+, 24-rtX, 25-rtX, and sched-devel. This patch applies to 25.4-rt4, though it should trivially apply to most cpupri enabled kernels mentioned above. It turned out that the issue was that offline cpus could get inadvertently registered with cpupri so that they were erroneously selected during migration decisions. The end result would be an OOPS as the offline cpu had tasks routed to it. This patch generalizes the old join/leave domain interface into an online/offline interface, and adjusts the root-domain/hotplug code to utilize it. I was able to easily reproduce the issue prior to this patch, and am no longer able to reproduce it after this patch. I can offline cpus indefinately and everything seems to be in working order. Thanks to Arnaldo (acme), Thomas, and Peter for doing the legwork to point me in the right direction. Also thank you to Peter for reviewing the early iterations of this patch. Signed-off-by: Gregory Haskins <ghaskins@novell.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-06-04 19:04:05 +00:00
set_rq_offline(rq);
sched: add sched-domain roots We add the notion of a root-domain which will be used later to rescope global variables to per-domain variables. Each exclusive cpuset essentially defines an island domain by fully partitioning the member cpus from any other cpuset. However, we currently still maintain some policy/state as global variables which transcend all cpusets. Consider, for instance, rt-overload state. Whenever a new exclusive cpuset is created, we also create a new root-domain object and move each cpu member to the root-domain's span. By default the system creates a single root-domain with all cpus as members (mimicking the global state we have today). We add some plumbing for storing class specific data in our root-domain. Whenever a RQ is switching root-domains (because of repartitioning) we give each sched_class the opportunity to remove any state from its old domain and add state to the new one. This logic doesn't have any clients yet but it will later in the series. Signed-off-by: Gregory Haskins <ghaskins@novell.com> CC: Christoph Lameter <clameter@sgi.com> CC: Paul Jackson <pj@sgi.com> CC: Simon Derr <simon.derr@bull.net> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:18 +00:00
sched: convert struct root_domain to cpumask_var_t. Impact: (future) size reduction for large NR_CPUS. Dynamically allocating cpumasks (when CONFIG_CPUMASK_OFFSTACK) saves space for small nr_cpu_ids but big CONFIG_NR_CPUS. cpumask_var_t is just a struct cpumask for !CONFIG_CPUMASK_OFFSTACK. def_root_domain is static, and so its masks are initialized with alloc_bootmem_cpumask_var. After that, alloc_cpumask_var is used. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-24 16:05:05 +00:00
cpumask_clear_cpu(rq->cpu, old_rd->span);
sched: dynamically update the root-domain span/online maps The baseline code statically builds the span maps when the domain is formed. Previous attempts at dynamically updating the maps caused a suspend-to-ram regression, which should now be fixed. Signed-off-by: Gregory Haskins <ghaskins@novell.com> CC: Gautham R Shenoy <ego@in.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:26 +00:00
sched: cpu hotplug fix rq_attach_root() does a kfree() with the runqueue lock held. That's not a very wise move, fix it. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-12 10:35:40 +00:00
/*
* If we dont want to free the old_rt yet then
* set old_rd to NULL to skip the freeing later
* in this function:
*/
if (!atomic_dec_and_test(&old_rd->refcount))
old_rd = NULL;
sched: add sched-domain roots We add the notion of a root-domain which will be used later to rescope global variables to per-domain variables. Each exclusive cpuset essentially defines an island domain by fully partitioning the member cpus from any other cpuset. However, we currently still maintain some policy/state as global variables which transcend all cpusets. Consider, for instance, rt-overload state. Whenever a new exclusive cpuset is created, we also create a new root-domain object and move each cpu member to the root-domain's span. By default the system creates a single root-domain with all cpus as members (mimicking the global state we have today). We add some plumbing for storing class specific data in our root-domain. Whenever a RQ is switching root-domains (because of repartitioning) we give each sched_class the opportunity to remove any state from its old domain and add state to the new one. This logic doesn't have any clients yet but it will later in the series. Signed-off-by: Gregory Haskins <ghaskins@novell.com> CC: Christoph Lameter <clameter@sgi.com> CC: Paul Jackson <pj@sgi.com> CC: Simon Derr <simon.derr@bull.net> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:18 +00:00
}
atomic_inc(&rd->refcount);
rq->rd = rd;
sched: convert struct root_domain to cpumask_var_t. Impact: (future) size reduction for large NR_CPUS. Dynamically allocating cpumasks (when CONFIG_CPUMASK_OFFSTACK) saves space for small nr_cpu_ids but big CONFIG_NR_CPUS. cpumask_var_t is just a struct cpumask for !CONFIG_CPUMASK_OFFSTACK. def_root_domain is static, and so its masks are initialized with alloc_bootmem_cpumask_var. After that, alloc_cpumask_var is used. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-24 16:05:05 +00:00
cpumask_set_cpu(rq->cpu, rd->span);
sched: Fully integrate cpus_active_map and root-domain code Reflect "active" cpus in the rq->rd->online field, instead of the online_map. The motivation is that things that use the root-domain code (such as cpupri) only care about cpus classified as "active" anyway. By synchronizing the root-domain state with the active map, we allow several optimizations. For instance, we can remove an extra cpumask_and from the scheduler hotpath by utilizing rq->rd->online (since it is now a cached version of cpu_active_map & rq->rd->span). Signed-off-by: Gregory Haskins <ghaskins@novell.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Max Krasnyansky <maxk@qualcomm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20090730145723.25226.24493.stgit@dev.haskins.net> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-07-30 14:57:23 +00:00
if (cpumask_test_cpu(rq->cpu, cpu_active_mask))
sched: fix cpupri hotplug support The RT folks over at RedHat found an issue w.r.t. hotplug support which was traced to problems with the cpupri infrastructure in the scheduler: https://bugzilla.redhat.com/show_bug.cgi?id=449676 This bug affects 23-rt12+, 24-rtX, 25-rtX, and sched-devel. This patch applies to 25.4-rt4, though it should trivially apply to most cpupri enabled kernels mentioned above. It turned out that the issue was that offline cpus could get inadvertently registered with cpupri so that they were erroneously selected during migration decisions. The end result would be an OOPS as the offline cpu had tasks routed to it. This patch generalizes the old join/leave domain interface into an online/offline interface, and adjusts the root-domain/hotplug code to utilize it. I was able to easily reproduce the issue prior to this patch, and am no longer able to reproduce it after this patch. I can offline cpus indefinately and everything seems to be in working order. Thanks to Arnaldo (acme), Thomas, and Peter for doing the legwork to point me in the right direction. Also thank you to Peter for reviewing the early iterations of this patch. Signed-off-by: Gregory Haskins <ghaskins@novell.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-06-04 19:04:05 +00:00
set_rq_online(rq);
sched: add sched-domain roots We add the notion of a root-domain which will be used later to rescope global variables to per-domain variables. Each exclusive cpuset essentially defines an island domain by fully partitioning the member cpus from any other cpuset. However, we currently still maintain some policy/state as global variables which transcend all cpusets. Consider, for instance, rt-overload state. Whenever a new exclusive cpuset is created, we also create a new root-domain object and move each cpu member to the root-domain's span. By default the system creates a single root-domain with all cpus as members (mimicking the global state we have today). We add some plumbing for storing class specific data in our root-domain. Whenever a RQ is switching root-domains (because of repartitioning) we give each sched_class the opportunity to remove any state from its old domain and add state to the new one. This logic doesn't have any clients yet but it will later in the series. Signed-off-by: Gregory Haskins <ghaskins@novell.com> CC: Christoph Lameter <clameter@sgi.com> CC: Paul Jackson <pj@sgi.com> CC: Simon Derr <simon.derr@bull.net> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:18 +00:00
sched: Convert rq->lock to raw_spinlock Convert locks which cannot be sleeping locks in preempt-rt to raw_spinlocks. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Ingo Molnar <mingo@elte.hu>
2009-11-17 13:28:38 +00:00
raw_spin_unlock_irqrestore(&rq->lock, flags);
sched: cpu hotplug fix rq_attach_root() does a kfree() with the runqueue lock held. That's not a very wise move, fix it. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-12 10:35:40 +00:00
if (old_rd)
sched: Dynamically allocate sched_domain/sched_group data-structures Instead of relying on static allocations for the sched_domain and sched_group trees, dynamically allocate and RCU free them. Allocating this dynamically also allows for some build_sched_groups() simplification since we can now (like with other simplifications) rely on the sched_domain tree instead of hard-coded knowledge. One tricky to note is that detach_destroy_domains() needs to hold rcu_read_lock() over the entire tear-down, per-cpu is not sufficient since that can lead to partial sched_group existance (could possibly be solved by doing the tear-down backwards but this is much more robust). A concequence of the above is that we can no longer print the sched_domain debug stuff from cpu_attach_domain() since that might now run with preemption disabled (due to classic RCU etc.) and sched_domain_debug() does some GFP_KERNEL allocations. Another thing to note is that we now fully rely on normal RCU and not RCU-sched, this is because with the new and exiting RCU flavours we grew over the years BH doesn't necessarily hold off RCU-sched grace periods (-rt is known to break this). This would in fact already cause us grief since we do sched_domain/sched_group iterations from softirq context. This patch is somewhat larger than I would like it to be, but I didn't find any means of shrinking/splitting this. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.245307941@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:09:50 +00:00
call_rcu_sched(&old_rd->rcu, free_rootdomain);
sched: add sched-domain roots We add the notion of a root-domain which will be used later to rescope global variables to per-domain variables. Each exclusive cpuset essentially defines an island domain by fully partitioning the member cpus from any other cpuset. However, we currently still maintain some policy/state as global variables which transcend all cpusets. Consider, for instance, rt-overload state. Whenever a new exclusive cpuset is created, we also create a new root-domain object and move each cpu member to the root-domain's span. By default the system creates a single root-domain with all cpus as members (mimicking the global state we have today). We add some plumbing for storing class specific data in our root-domain. Whenever a RQ is switching root-domains (because of repartitioning) we give each sched_class the opportunity to remove any state from its old domain and add state to the new one. This logic doesn't have any clients yet but it will later in the series. Signed-off-by: Gregory Haskins <ghaskins@novell.com> CC: Christoph Lameter <clameter@sgi.com> CC: Paul Jackson <pj@sgi.com> CC: Simon Derr <simon.derr@bull.net> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:18 +00:00
}
sched: No need for bootmem special cases As of commit dcce284 ("mm: Extend gfp masking to the page allocator") and commit 7e85ee0 ("slab,slub: don't enable interrupts during early boot"), the slab allocator makes sure we don't attempt to sleep during boot. Therefore, remove bootmem special cases from the scheduler and use plain GFP_KERNEL instead. Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1279225102-2572-1-git-send-email-penberg@cs.helsinki.fi> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-07-15 20:18:22 +00:00
static int init_rootdomain(struct root_domain *rd)
sched: add sched-domain roots We add the notion of a root-domain which will be used later to rescope global variables to per-domain variables. Each exclusive cpuset essentially defines an island domain by fully partitioning the member cpus from any other cpuset. However, we currently still maintain some policy/state as global variables which transcend all cpusets. Consider, for instance, rt-overload state. Whenever a new exclusive cpuset is created, we also create a new root-domain object and move each cpu member to the root-domain's span. By default the system creates a single root-domain with all cpus as members (mimicking the global state we have today). We add some plumbing for storing class specific data in our root-domain. Whenever a RQ is switching root-domains (because of repartitioning) we give each sched_class the opportunity to remove any state from its old domain and add state to the new one. This logic doesn't have any clients yet but it will later in the series. Signed-off-by: Gregory Haskins <ghaskins@novell.com> CC: Christoph Lameter <clameter@sgi.com> CC: Paul Jackson <pj@sgi.com> CC: Simon Derr <simon.derr@bull.net> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:18 +00:00
{
memset(rd, 0, sizeof(*rd));
sched: No need for bootmem special cases As of commit dcce284 ("mm: Extend gfp masking to the page allocator") and commit 7e85ee0 ("slab,slub: don't enable interrupts during early boot"), the slab allocator makes sure we don't attempt to sleep during boot. Therefore, remove bootmem special cases from the scheduler and use plain GFP_KERNEL instead. Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1279225102-2572-1-git-send-email-penberg@cs.helsinki.fi> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-07-15 20:18:22 +00:00
if (!alloc_cpumask_var(&rd->span, GFP_KERNEL))
sched: fix double kfree in failure path It's not the responsibility of init_rootdomain() to free root_domain allocated by alloc_rootdomain(). Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Reviewed-by: Pekka Enberg <penberg@cs.helsinki.fi> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-06 09:39:06 +00:00
goto out;
sched: No need for bootmem special cases As of commit dcce284 ("mm: Extend gfp masking to the page allocator") and commit 7e85ee0 ("slab,slub: don't enable interrupts during early boot"), the slab allocator makes sure we don't attempt to sleep during boot. Therefore, remove bootmem special cases from the scheduler and use plain GFP_KERNEL instead. Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1279225102-2572-1-git-send-email-penberg@cs.helsinki.fi> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-07-15 20:18:22 +00:00
if (!alloc_cpumask_var(&rd->online, GFP_KERNEL))
sched: convert struct root_domain to cpumask_var_t. Impact: (future) size reduction for large NR_CPUS. Dynamically allocating cpumasks (when CONFIG_CPUMASK_OFFSTACK) saves space for small nr_cpu_ids but big CONFIG_NR_CPUS. cpumask_var_t is just a struct cpumask for !CONFIG_CPUMASK_OFFSTACK. def_root_domain is static, and so its masks are initialized with alloc_bootmem_cpumask_var. After that, alloc_cpumask_var is used. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-24 16:05:05 +00:00
goto free_span;
sched: No need for bootmem special cases As of commit dcce284 ("mm: Extend gfp masking to the page allocator") and commit 7e85ee0 ("slab,slub: don't enable interrupts during early boot"), the slab allocator makes sure we don't attempt to sleep during boot. Therefore, remove bootmem special cases from the scheduler and use plain GFP_KERNEL instead. Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1279225102-2572-1-git-send-email-penberg@cs.helsinki.fi> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-07-15 20:18:22 +00:00
if (!alloc_cpumask_var(&rd->rto_mask, GFP_KERNEL))
sched: convert struct root_domain to cpumask_var_t. Impact: (future) size reduction for large NR_CPUS. Dynamically allocating cpumasks (when CONFIG_CPUMASK_OFFSTACK) saves space for small nr_cpu_ids but big CONFIG_NR_CPUS. cpumask_var_t is just a struct cpumask for !CONFIG_CPUMASK_OFFSTACK. def_root_domain is static, and so its masks are initialized with alloc_bootmem_cpumask_var. After that, alloc_cpumask_var is used. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-24 16:05:05 +00:00
goto free_online;
sched: use a 2-d bitmap for searching lowest-pri CPU The current code use a linear algorithm which causes scaling issues on larger SMP machines. This patch replaces that algorithm with a 2-dimensional bitmap to reduce latencies in the wake-up path. Signed-off-by: Gregory Haskins <ghaskins@novell.com> Acked-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-12 19:21:01 +00:00
sched: No need for bootmem special cases As of commit dcce284 ("mm: Extend gfp masking to the page allocator") and commit 7e85ee0 ("slab,slub: don't enable interrupts during early boot"), the slab allocator makes sure we don't attempt to sleep during boot. Therefore, remove bootmem special cases from the scheduler and use plain GFP_KERNEL instead. Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1279225102-2572-1-git-send-email-penberg@cs.helsinki.fi> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-07-15 20:18:22 +00:00
if (cpupri_init(&rd->cpupri) != 0)
sched: convert struct cpupri_vec cpumask_var_t. Impact: stack usage reduction, (future) size reduction for large NR_CPUS. Dynamically allocating cpumasks (when CONFIG_CPUMASK_OFFSTACK) saves space for small nr_cpu_ids but big CONFIG_NR_CPUS. The fact cpupro_init is called both before and after the slab is available makes for an ugly parameter unfortunately. We also use cpumask_any_and to get rid of a temporary in cpupri_find. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-24 16:05:13 +00:00
goto free_rto_mask;
sched: convert struct root_domain to cpumask_var_t. Impact: (future) size reduction for large NR_CPUS. Dynamically allocating cpumasks (when CONFIG_CPUMASK_OFFSTACK) saves space for small nr_cpu_ids but big CONFIG_NR_CPUS. cpumask_var_t is just a struct cpumask for !CONFIG_CPUMASK_OFFSTACK. def_root_domain is static, and so its masks are initialized with alloc_bootmem_cpumask_var. After that, alloc_cpumask_var is used. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-24 16:05:05 +00:00
return 0;
sched: use a 2-d bitmap for searching lowest-pri CPU The current code use a linear algorithm which causes scaling issues on larger SMP machines. This patch replaces that algorithm with a 2-dimensional bitmap to reduce latencies in the wake-up path. Signed-off-by: Gregory Haskins <ghaskins@novell.com> Acked-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-12 19:21:01 +00:00
sched: convert struct cpupri_vec cpumask_var_t. Impact: stack usage reduction, (future) size reduction for large NR_CPUS. Dynamically allocating cpumasks (when CONFIG_CPUMASK_OFFSTACK) saves space for small nr_cpu_ids but big CONFIG_NR_CPUS. The fact cpupro_init is called both before and after the slab is available makes for an ugly parameter unfortunately. We also use cpumask_any_and to get rid of a temporary in cpupri_find. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-24 16:05:13 +00:00
free_rto_mask:
free_cpumask_var(rd->rto_mask);
sched: convert struct root_domain to cpumask_var_t. Impact: (future) size reduction for large NR_CPUS. Dynamically allocating cpumasks (when CONFIG_CPUMASK_OFFSTACK) saves space for small nr_cpu_ids but big CONFIG_NR_CPUS. cpumask_var_t is just a struct cpumask for !CONFIG_CPUMASK_OFFSTACK. def_root_domain is static, and so its masks are initialized with alloc_bootmem_cpumask_var. After that, alloc_cpumask_var is used. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-24 16:05:05 +00:00
free_online:
free_cpumask_var(rd->online);
free_span:
free_cpumask_var(rd->span);
sched: fix double kfree in failure path It's not the responsibility of init_rootdomain() to free root_domain allocated by alloc_rootdomain(). Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Reviewed-by: Pekka Enberg <penberg@cs.helsinki.fi> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-06 09:39:06 +00:00
out:
sched: convert struct root_domain to cpumask_var_t. Impact: (future) size reduction for large NR_CPUS. Dynamically allocating cpumasks (when CONFIG_CPUMASK_OFFSTACK) saves space for small nr_cpu_ids but big CONFIG_NR_CPUS. cpumask_var_t is just a struct cpumask for !CONFIG_CPUMASK_OFFSTACK. def_root_domain is static, and so its masks are initialized with alloc_bootmem_cpumask_var. After that, alloc_cpumask_var is used. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-24 16:05:05 +00:00
return -ENOMEM;
sched: add sched-domain roots We add the notion of a root-domain which will be used later to rescope global variables to per-domain variables. Each exclusive cpuset essentially defines an island domain by fully partitioning the member cpus from any other cpuset. However, we currently still maintain some policy/state as global variables which transcend all cpusets. Consider, for instance, rt-overload state. Whenever a new exclusive cpuset is created, we also create a new root-domain object and move each cpu member to the root-domain's span. By default the system creates a single root-domain with all cpus as members (mimicking the global state we have today). We add some plumbing for storing class specific data in our root-domain. Whenever a RQ is switching root-domains (because of repartitioning) we give each sched_class the opportunity to remove any state from its old domain and add state to the new one. This logic doesn't have any clients yet but it will later in the series. Signed-off-by: Gregory Haskins <ghaskins@novell.com> CC: Christoph Lameter <clameter@sgi.com> CC: Paul Jackson <pj@sgi.com> CC: Simon Derr <simon.derr@bull.net> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:18 +00:00
}
static void init_defrootdomain(void)
{
sched: No need for bootmem special cases As of commit dcce284 ("mm: Extend gfp masking to the page allocator") and commit 7e85ee0 ("slab,slub: don't enable interrupts during early boot"), the slab allocator makes sure we don't attempt to sleep during boot. Therefore, remove bootmem special cases from the scheduler and use plain GFP_KERNEL instead. Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1279225102-2572-1-git-send-email-penberg@cs.helsinki.fi> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-07-15 20:18:22 +00:00
init_rootdomain(&def_root_domain);
sched: convert struct root_domain to cpumask_var_t. Impact: (future) size reduction for large NR_CPUS. Dynamically allocating cpumasks (when CONFIG_CPUMASK_OFFSTACK) saves space for small nr_cpu_ids but big CONFIG_NR_CPUS. cpumask_var_t is just a struct cpumask for !CONFIG_CPUMASK_OFFSTACK. def_root_domain is static, and so its masks are initialized with alloc_bootmem_cpumask_var. After that, alloc_cpumask_var is used. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-24 16:05:05 +00:00
sched: add sched-domain roots We add the notion of a root-domain which will be used later to rescope global variables to per-domain variables. Each exclusive cpuset essentially defines an island domain by fully partitioning the member cpus from any other cpuset. However, we currently still maintain some policy/state as global variables which transcend all cpusets. Consider, for instance, rt-overload state. Whenever a new exclusive cpuset is created, we also create a new root-domain object and move each cpu member to the root-domain's span. By default the system creates a single root-domain with all cpus as members (mimicking the global state we have today). We add some plumbing for storing class specific data in our root-domain. Whenever a RQ is switching root-domains (because of repartitioning) we give each sched_class the opportunity to remove any state from its old domain and add state to the new one. This logic doesn't have any clients yet but it will later in the series. Signed-off-by: Gregory Haskins <ghaskins@novell.com> CC: Christoph Lameter <clameter@sgi.com> CC: Paul Jackson <pj@sgi.com> CC: Simon Derr <simon.derr@bull.net> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:18 +00:00
atomic_set(&def_root_domain.refcount, 1);
}
sched: dynamically update the root-domain span/online maps The baseline code statically builds the span maps when the domain is formed. Previous attempts at dynamically updating the maps caused a suspend-to-ram regression, which should now be fixed. Signed-off-by: Gregory Haskins <ghaskins@novell.com> CC: Gautham R Shenoy <ego@in.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:26 +00:00
static struct root_domain *alloc_rootdomain(void)
sched: add sched-domain roots We add the notion of a root-domain which will be used later to rescope global variables to per-domain variables. Each exclusive cpuset essentially defines an island domain by fully partitioning the member cpus from any other cpuset. However, we currently still maintain some policy/state as global variables which transcend all cpusets. Consider, for instance, rt-overload state. Whenever a new exclusive cpuset is created, we also create a new root-domain object and move each cpu member to the root-domain's span. By default the system creates a single root-domain with all cpus as members (mimicking the global state we have today). We add some plumbing for storing class specific data in our root-domain. Whenever a RQ is switching root-domains (because of repartitioning) we give each sched_class the opportunity to remove any state from its old domain and add state to the new one. This logic doesn't have any clients yet but it will later in the series. Signed-off-by: Gregory Haskins <ghaskins@novell.com> CC: Christoph Lameter <clameter@sgi.com> CC: Paul Jackson <pj@sgi.com> CC: Simon Derr <simon.derr@bull.net> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:18 +00:00
{
struct root_domain *rd;
rd = kmalloc(sizeof(*rd), GFP_KERNEL);
if (!rd)
return NULL;
sched: No need for bootmem special cases As of commit dcce284 ("mm: Extend gfp masking to the page allocator") and commit 7e85ee0 ("slab,slub: don't enable interrupts during early boot"), the slab allocator makes sure we don't attempt to sleep during boot. Therefore, remove bootmem special cases from the scheduler and use plain GFP_KERNEL instead. Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1279225102-2572-1-git-send-email-penberg@cs.helsinki.fi> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-07-15 20:18:22 +00:00
if (init_rootdomain(rd) != 0) {
sched: convert struct root_domain to cpumask_var_t. Impact: (future) size reduction for large NR_CPUS. Dynamically allocating cpumasks (when CONFIG_CPUMASK_OFFSTACK) saves space for small nr_cpu_ids but big CONFIG_NR_CPUS. cpumask_var_t is just a struct cpumask for !CONFIG_CPUMASK_OFFSTACK. def_root_domain is static, and so its masks are initialized with alloc_bootmem_cpumask_var. After that, alloc_cpumask_var is used. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-24 16:05:05 +00:00
kfree(rd);
return NULL;
}
sched: add sched-domain roots We add the notion of a root-domain which will be used later to rescope global variables to per-domain variables. Each exclusive cpuset essentially defines an island domain by fully partitioning the member cpus from any other cpuset. However, we currently still maintain some policy/state as global variables which transcend all cpusets. Consider, for instance, rt-overload state. Whenever a new exclusive cpuset is created, we also create a new root-domain object and move each cpu member to the root-domain's span. By default the system creates a single root-domain with all cpus as members (mimicking the global state we have today). We add some plumbing for storing class specific data in our root-domain. Whenever a RQ is switching root-domains (because of repartitioning) we give each sched_class the opportunity to remove any state from its old domain and add state to the new one. This logic doesn't have any clients yet but it will later in the series. Signed-off-by: Gregory Haskins <ghaskins@novell.com> CC: Christoph Lameter <clameter@sgi.com> CC: Paul Jackson <pj@sgi.com> CC: Simon Derr <simon.derr@bull.net> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:18 +00:00
return rd;
}
sched: Allow for overlapping sched_domain spans Allow for sched_domain spans that overlap by giving such domains their own sched_group list instead of sharing the sched_groups amongst each-other. This is needed for machines with more than 16 nodes, because sched_domain_node_span() will generate a node mask from the 16 nearest nodes without regard if these masks have any overlap. Currently sched_domains have a sched_group that maps to their child sched_domain span, and since there is no overlap we share the sched_group between the sched_domains of the various CPUs. If however there is overlap, we would need to link the sched_group list in different ways for each cpu, and hence sharing isn't possible. In order to solve this, allocate private sched_groups for each CPU's sched_domain but have the sched_groups share a sched_group_power structure such that we can uniquely track the power. Reported-and-tested-by: Anton Blanchard <anton@samba.org> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/n/tip-08bxqw9wis3qti9u5inifh3y@git.kernel.org Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-15 08:35:52 +00:00
static void free_sched_groups(struct sched_group *sg, int free_sgp)
{
struct sched_group *tmp, *first;
if (!sg)
return;
first = sg;
do {
tmp = sg->next;
if (free_sgp && atomic_dec_and_test(&sg->sgp->ref))
kfree(sg->sgp);
kfree(sg);
sg = tmp;
} while (sg != first);
}
sched: Dynamically allocate sched_domain/sched_group data-structures Instead of relying on static allocations for the sched_domain and sched_group trees, dynamically allocate and RCU free them. Allocating this dynamically also allows for some build_sched_groups() simplification since we can now (like with other simplifications) rely on the sched_domain tree instead of hard-coded knowledge. One tricky to note is that detach_destroy_domains() needs to hold rcu_read_lock() over the entire tear-down, per-cpu is not sufficient since that can lead to partial sched_group existance (could possibly be solved by doing the tear-down backwards but this is much more robust). A concequence of the above is that we can no longer print the sched_domain debug stuff from cpu_attach_domain() since that might now run with preemption disabled (due to classic RCU etc.) and sched_domain_debug() does some GFP_KERNEL allocations. Another thing to note is that we now fully rely on normal RCU and not RCU-sched, this is because with the new and exiting RCU flavours we grew over the years BH doesn't necessarily hold off RCU-sched grace periods (-rt is known to break this). This would in fact already cause us grief since we do sched_domain/sched_group iterations from softirq context. This patch is somewhat larger than I would like it to be, but I didn't find any means of shrinking/splitting this. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.245307941@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:09:50 +00:00
static void free_sched_domain(struct rcu_head *rcu)
{
struct sched_domain *sd = container_of(rcu, struct sched_domain, rcu);
sched: Allow for overlapping sched_domain spans Allow for sched_domain spans that overlap by giving such domains their own sched_group list instead of sharing the sched_groups amongst each-other. This is needed for machines with more than 16 nodes, because sched_domain_node_span() will generate a node mask from the 16 nearest nodes without regard if these masks have any overlap. Currently sched_domains have a sched_group that maps to their child sched_domain span, and since there is no overlap we share the sched_group between the sched_domains of the various CPUs. If however there is overlap, we would need to link the sched_group list in different ways for each cpu, and hence sharing isn't possible. In order to solve this, allocate private sched_groups for each CPU's sched_domain but have the sched_groups share a sched_group_power structure such that we can uniquely track the power. Reported-and-tested-by: Anton Blanchard <anton@samba.org> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/n/tip-08bxqw9wis3qti9u5inifh3y@git.kernel.org Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-15 08:35:52 +00:00
/*
* If its an overlapping domain it has private groups, iterate and
* nuke them all.
*/
if (sd->flags & SD_OVERLAP) {
free_sched_groups(sd->groups, 1);
} else if (atomic_dec_and_test(&sd->groups->ref)) {
sched: Break out cpu_power from the sched_group structure In order to prepare for non-unique sched_groups per domain, we need to carry the cpu_power elsewhere, so put a level of indirection in. Reported-and-tested-by: Anton Blanchard <anton@samba.org> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/n/tip-qkho2byuhe4482fuknss40ad@git.kernel.org Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-14 11:00:06 +00:00
kfree(sd->groups->sgp);
sched: Dynamically allocate sched_domain/sched_group data-structures Instead of relying on static allocations for the sched_domain and sched_group trees, dynamically allocate and RCU free them. Allocating this dynamically also allows for some build_sched_groups() simplification since we can now (like with other simplifications) rely on the sched_domain tree instead of hard-coded knowledge. One tricky to note is that detach_destroy_domains() needs to hold rcu_read_lock() over the entire tear-down, per-cpu is not sufficient since that can lead to partial sched_group existance (could possibly be solved by doing the tear-down backwards but this is much more robust). A concequence of the above is that we can no longer print the sched_domain debug stuff from cpu_attach_domain() since that might now run with preemption disabled (due to classic RCU etc.) and sched_domain_debug() does some GFP_KERNEL allocations. Another thing to note is that we now fully rely on normal RCU and not RCU-sched, this is because with the new and exiting RCU flavours we grew over the years BH doesn't necessarily hold off RCU-sched grace periods (-rt is known to break this). This would in fact already cause us grief since we do sched_domain/sched_group iterations from softirq context. This patch is somewhat larger than I would like it to be, but I didn't find any means of shrinking/splitting this. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.245307941@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:09:50 +00:00
kfree(sd->groups);
sched: Break out cpu_power from the sched_group structure In order to prepare for non-unique sched_groups per domain, we need to carry the cpu_power elsewhere, so put a level of indirection in. Reported-and-tested-by: Anton Blanchard <anton@samba.org> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/n/tip-qkho2byuhe4482fuknss40ad@git.kernel.org Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-14 11:00:06 +00:00
}
sched: Dynamically allocate sched_domain/sched_group data-structures Instead of relying on static allocations for the sched_domain and sched_group trees, dynamically allocate and RCU free them. Allocating this dynamically also allows for some build_sched_groups() simplification since we can now (like with other simplifications) rely on the sched_domain tree instead of hard-coded knowledge. One tricky to note is that detach_destroy_domains() needs to hold rcu_read_lock() over the entire tear-down, per-cpu is not sufficient since that can lead to partial sched_group existance (could possibly be solved by doing the tear-down backwards but this is much more robust). A concequence of the above is that we can no longer print the sched_domain debug stuff from cpu_attach_domain() since that might now run with preemption disabled (due to classic RCU etc.) and sched_domain_debug() does some GFP_KERNEL allocations. Another thing to note is that we now fully rely on normal RCU and not RCU-sched, this is because with the new and exiting RCU flavours we grew over the years BH doesn't necessarily hold off RCU-sched grace periods (-rt is known to break this). This would in fact already cause us grief since we do sched_domain/sched_group iterations from softirq context. This patch is somewhat larger than I would like it to be, but I didn't find any means of shrinking/splitting this. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.245307941@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:09:50 +00:00
kfree(sd);
}
static void destroy_sched_domain(struct sched_domain *sd, int cpu)
{
call_rcu(&sd->rcu, free_sched_domain);
}
static void destroy_sched_domains(struct sched_domain *sd, int cpu)
{
for (; sd; sd = sd->parent)
destroy_sched_domain(sd, cpu);
}
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
/*
sched: style cleanup, #2 style cleanup of various changes that were done recently. no code changed: text data bss dec hex filename 26399 2578 48 29025 7161 sched.o.before 26399 2578 48 29025 7161 sched.o.after Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:19 +00:00
* Attach the domain 'sd' to 'cpu' as its base domain. Callers must
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
* hold the hotplug lock.
*/
sched: style cleanup, #2 style cleanup of various changes that were done recently. no code changed: text data bss dec hex filename 26399 2578 48 29025 7161 sched.o.before 26399 2578 48 29025 7161 sched.o.after Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:19 +00:00
static void
cpu_attach_domain(struct sched_domain *sd, struct root_domain *rd, int cpu)
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
{
[PATCH] sched: cleanup, convert sched.c-internal typedefs to struct convert: - runqueue_t to 'struct rq' - prio_array_t to 'struct prio_array' - migration_req_t to 'struct migration_req' I was the one who added these but they are both against the kernel coding style and also were used inconsistently at places. So just get rid of them at once, now that we are flushing the scheduler patch-queue anyway. Conversion was mostly scripted, the result was reviewed and all secondary whitespace and style impact (if any) was fixed up by hand. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-03 07:25:42 +00:00
struct rq *rq = cpu_rq(cpu);
[PATCH] sched: remove degenerate domains Remove degenerate scheduler domains during the sched-domain init. For example on x86_64, we always have NUMA configured in. On Intel EM64T systems, top most sched domain will be of NUMA and with only one sched_group in it. With fork/exec balances(recent Nick's fixes in -mm tree), we always endup taking wrong decisions because of this topmost domain (as it contains only one group and find_idlest_group always returns NULL). We will endup loading HT package completely first, letting active load balance kickin and correct it. In general, this patch also makes sense with out recent Nick's fixes in -mm. From: Nick Piggin <nickpiggin@yahoo.com.au> Modified to account for more than just sched_groups when scanning for degenerate domains by Nick Piggin. And allow a runqueue's sd to go NULL rather than keep a single degenerate domain around (this happens when you run with maxcpus=1). Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Signed-off-by: Nick Piggin <nickpiggin@yahoo.com.au> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-25 21:57:25 +00:00
struct sched_domain *tmp;
/* Remove the sched domains which do not contribute to scheduling. */
sched: fix a bug in sched domain degenerate Impact: re-add incorrectly eliminated sched domain layers (1) on i386 with SCHED_SMT and SCHED_MC enabled # mount -t cgroup -o cpuset xxx /mnt # echo 0 > /mnt/cpuset.sched_load_balance # mkdir /mnt/0 # echo 0 > /mnt/0/cpuset.cpus # dmesg CPU0 attaching sched-domain: domain 0: span 0 level CPU groups: 0 (2) on i386 with SCHED_MC enabled but SCHED_SMT disabled # same with (1) # dmesg CPU0 attaching NULL sched-domain. The bug is that some sched domains may be skipped unintentionally when degenerating (optimizing) sched domains. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-06 01:45:16 +00:00
for (tmp = sd; tmp; ) {
[PATCH] sched: remove degenerate domains Remove degenerate scheduler domains during the sched-domain init. For example on x86_64, we always have NUMA configured in. On Intel EM64T systems, top most sched domain will be of NUMA and with only one sched_group in it. With fork/exec balances(recent Nick's fixes in -mm tree), we always endup taking wrong decisions because of this topmost domain (as it contains only one group and find_idlest_group always returns NULL). We will endup loading HT package completely first, letting active load balance kickin and correct it. In general, this patch also makes sense with out recent Nick's fixes in -mm. From: Nick Piggin <nickpiggin@yahoo.com.au> Modified to account for more than just sched_groups when scanning for degenerate domains by Nick Piggin. And allow a runqueue's sd to go NULL rather than keep a single degenerate domain around (this happens when you run with maxcpus=1). Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Signed-off-by: Nick Piggin <nickpiggin@yahoo.com.au> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-25 21:57:25 +00:00
struct sched_domain *parent = tmp->parent;
if (!parent)
break;
sched: fix a bug in sched domain degenerate Impact: re-add incorrectly eliminated sched domain layers (1) on i386 with SCHED_SMT and SCHED_MC enabled # mount -t cgroup -o cpuset xxx /mnt # echo 0 > /mnt/cpuset.sched_load_balance # mkdir /mnt/0 # echo 0 > /mnt/0/cpuset.cpus # dmesg CPU0 attaching sched-domain: domain 0: span 0 level CPU groups: 0 (2) on i386 with SCHED_MC enabled but SCHED_SMT disabled # same with (1) # dmesg CPU0 attaching NULL sched-domain. The bug is that some sched domains may be skipped unintentionally when degenerating (optimizing) sched domains. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-06 01:45:16 +00:00
[PATCH] sched: introduce child field in sched_domain Introduce the child field in sched_domain struct and use it in sched_balance_self(). We will also use this field in cleaning up the sched group cpu_power setup(done in a different patch) code. Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Acked-by: Ingo Molnar <mingo@elte.hu> Acked-by: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Paul Jackson <pj@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-03 08:14:08 +00:00
if (sd_parent_degenerate(tmp, parent)) {
[PATCH] sched: remove degenerate domains Remove degenerate scheduler domains during the sched-domain init. For example on x86_64, we always have NUMA configured in. On Intel EM64T systems, top most sched domain will be of NUMA and with only one sched_group in it. With fork/exec balances(recent Nick's fixes in -mm tree), we always endup taking wrong decisions because of this topmost domain (as it contains only one group and find_idlest_group always returns NULL). We will endup loading HT package completely first, letting active load balance kickin and correct it. In general, this patch also makes sense with out recent Nick's fixes in -mm. From: Nick Piggin <nickpiggin@yahoo.com.au> Modified to account for more than just sched_groups when scanning for degenerate domains by Nick Piggin. And allow a runqueue's sd to go NULL rather than keep a single degenerate domain around (this happens when you run with maxcpus=1). Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Signed-off-by: Nick Piggin <nickpiggin@yahoo.com.au> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-25 21:57:25 +00:00
tmp->parent = parent->parent;
[PATCH] sched: introduce child field in sched_domain Introduce the child field in sched_domain struct and use it in sched_balance_self(). We will also use this field in cleaning up the sched group cpu_power setup(done in a different patch) code. Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Acked-by: Ingo Molnar <mingo@elte.hu> Acked-by: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Paul Jackson <pj@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-03 08:14:08 +00:00
if (parent->parent)
parent->parent->child = tmp;
sched: Dynamically allocate sched_domain/sched_group data-structures Instead of relying on static allocations for the sched_domain and sched_group trees, dynamically allocate and RCU free them. Allocating this dynamically also allows for some build_sched_groups() simplification since we can now (like with other simplifications) rely on the sched_domain tree instead of hard-coded knowledge. One tricky to note is that detach_destroy_domains() needs to hold rcu_read_lock() over the entire tear-down, per-cpu is not sufficient since that can lead to partial sched_group existance (could possibly be solved by doing the tear-down backwards but this is much more robust). A concequence of the above is that we can no longer print the sched_domain debug stuff from cpu_attach_domain() since that might now run with preemption disabled (due to classic RCU etc.) and sched_domain_debug() does some GFP_KERNEL allocations. Another thing to note is that we now fully rely on normal RCU and not RCU-sched, this is because with the new and exiting RCU flavours we grew over the years BH doesn't necessarily hold off RCU-sched grace periods (-rt is known to break this). This would in fact already cause us grief since we do sched_domain/sched_group iterations from softirq context. This patch is somewhat larger than I would like it to be, but I didn't find any means of shrinking/splitting this. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.245307941@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:09:50 +00:00
destroy_sched_domain(parent, cpu);
sched: fix a bug in sched domain degenerate Impact: re-add incorrectly eliminated sched domain layers (1) on i386 with SCHED_SMT and SCHED_MC enabled # mount -t cgroup -o cpuset xxx /mnt # echo 0 > /mnt/cpuset.sched_load_balance # mkdir /mnt/0 # echo 0 > /mnt/0/cpuset.cpus # dmesg CPU0 attaching sched-domain: domain 0: span 0 level CPU groups: 0 (2) on i386 with SCHED_MC enabled but SCHED_SMT disabled # same with (1) # dmesg CPU0 attaching NULL sched-domain. The bug is that some sched domains may be skipped unintentionally when degenerating (optimizing) sched domains. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-06 01:45:16 +00:00
} else
tmp = tmp->parent;
[PATCH] sched: remove degenerate domains Remove degenerate scheduler domains during the sched-domain init. For example on x86_64, we always have NUMA configured in. On Intel EM64T systems, top most sched domain will be of NUMA and with only one sched_group in it. With fork/exec balances(recent Nick's fixes in -mm tree), we always endup taking wrong decisions because of this topmost domain (as it contains only one group and find_idlest_group always returns NULL). We will endup loading HT package completely first, letting active load balance kickin and correct it. In general, this patch also makes sense with out recent Nick's fixes in -mm. From: Nick Piggin <nickpiggin@yahoo.com.au> Modified to account for more than just sched_groups when scanning for degenerate domains by Nick Piggin. And allow a runqueue's sd to go NULL rather than keep a single degenerate domain around (this happens when you run with maxcpus=1). Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Signed-off-by: Nick Piggin <nickpiggin@yahoo.com.au> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-25 21:57:25 +00:00
}
[PATCH] sched: introduce child field in sched_domain Introduce the child field in sched_domain struct and use it in sched_balance_self(). We will also use this field in cleaning up the sched group cpu_power setup(done in a different patch) code. Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Acked-by: Ingo Molnar <mingo@elte.hu> Acked-by: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Paul Jackson <pj@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-03 08:14:08 +00:00
if (sd && sd_degenerate(sd)) {
sched: Dynamically allocate sched_domain/sched_group data-structures Instead of relying on static allocations for the sched_domain and sched_group trees, dynamically allocate and RCU free them. Allocating this dynamically also allows for some build_sched_groups() simplification since we can now (like with other simplifications) rely on the sched_domain tree instead of hard-coded knowledge. One tricky to note is that detach_destroy_domains() needs to hold rcu_read_lock() over the entire tear-down, per-cpu is not sufficient since that can lead to partial sched_group existance (could possibly be solved by doing the tear-down backwards but this is much more robust). A concequence of the above is that we can no longer print the sched_domain debug stuff from cpu_attach_domain() since that might now run with preemption disabled (due to classic RCU etc.) and sched_domain_debug() does some GFP_KERNEL allocations. Another thing to note is that we now fully rely on normal RCU and not RCU-sched, this is because with the new and exiting RCU flavours we grew over the years BH doesn't necessarily hold off RCU-sched grace periods (-rt is known to break this). This would in fact already cause us grief since we do sched_domain/sched_group iterations from softirq context. This patch is somewhat larger than I would like it to be, but I didn't find any means of shrinking/splitting this. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.245307941@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:09:50 +00:00
tmp = sd;
[PATCH] sched: remove degenerate domains Remove degenerate scheduler domains during the sched-domain init. For example on x86_64, we always have NUMA configured in. On Intel EM64T systems, top most sched domain will be of NUMA and with only one sched_group in it. With fork/exec balances(recent Nick's fixes in -mm tree), we always endup taking wrong decisions because of this topmost domain (as it contains only one group and find_idlest_group always returns NULL). We will endup loading HT package completely first, letting active load balance kickin and correct it. In general, this patch also makes sense with out recent Nick's fixes in -mm. From: Nick Piggin <nickpiggin@yahoo.com.au> Modified to account for more than just sched_groups when scanning for degenerate domains by Nick Piggin. And allow a runqueue's sd to go NULL rather than keep a single degenerate domain around (this happens when you run with maxcpus=1). Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Signed-off-by: Nick Piggin <nickpiggin@yahoo.com.au> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-25 21:57:25 +00:00
sd = sd->parent;
sched: Dynamically allocate sched_domain/sched_group data-structures Instead of relying on static allocations for the sched_domain and sched_group trees, dynamically allocate and RCU free them. Allocating this dynamically also allows for some build_sched_groups() simplification since we can now (like with other simplifications) rely on the sched_domain tree instead of hard-coded knowledge. One tricky to note is that detach_destroy_domains() needs to hold rcu_read_lock() over the entire tear-down, per-cpu is not sufficient since that can lead to partial sched_group existance (could possibly be solved by doing the tear-down backwards but this is much more robust). A concequence of the above is that we can no longer print the sched_domain debug stuff from cpu_attach_domain() since that might now run with preemption disabled (due to classic RCU etc.) and sched_domain_debug() does some GFP_KERNEL allocations. Another thing to note is that we now fully rely on normal RCU and not RCU-sched, this is because with the new and exiting RCU flavours we grew over the years BH doesn't necessarily hold off RCU-sched grace periods (-rt is known to break this). This would in fact already cause us grief since we do sched_domain/sched_group iterations from softirq context. This patch is somewhat larger than I would like it to be, but I didn't find any means of shrinking/splitting this. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.245307941@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:09:50 +00:00
destroy_sched_domain(tmp, cpu);
[PATCH] sched: introduce child field in sched_domain Introduce the child field in sched_domain struct and use it in sched_balance_self(). We will also use this field in cleaning up the sched group cpu_power setup(done in a different patch) code. Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Acked-by: Ingo Molnar <mingo@elte.hu> Acked-by: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Paul Jackson <pj@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-03 08:14:08 +00:00
if (sd)
sd->child = NULL;
}
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
sched: Avoid allocations in sched_domain_debug() Since we're all serialized by sched_domains_mutex we can use sched_domains_tmpmask and avoid having to do allocations. This means we can use sched_domains_debug() for cpu_attach_domain() again. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.664347467@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:09:58 +00:00
sched_domain_debug(sd, cpu);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
sched: add sched-domain roots We add the notion of a root-domain which will be used later to rescope global variables to per-domain variables. Each exclusive cpuset essentially defines an island domain by fully partitioning the member cpus from any other cpuset. However, we currently still maintain some policy/state as global variables which transcend all cpusets. Consider, for instance, rt-overload state. Whenever a new exclusive cpuset is created, we also create a new root-domain object and move each cpu member to the root-domain's span. By default the system creates a single root-domain with all cpus as members (mimicking the global state we have today). We add some plumbing for storing class specific data in our root-domain. Whenever a RQ is switching root-domains (because of repartitioning) we give each sched_class the opportunity to remove any state from its old domain and add state to the new one. This logic doesn't have any clients yet but it will later in the series. Signed-off-by: Gregory Haskins <ghaskins@novell.com> CC: Christoph Lameter <clameter@sgi.com> CC: Paul Jackson <pj@sgi.com> CC: Simon Derr <simon.derr@bull.net> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:18 +00:00
rq_attach_root(rq, rd);
sched: Dynamically allocate sched_domain/sched_group data-structures Instead of relying on static allocations for the sched_domain and sched_group trees, dynamically allocate and RCU free them. Allocating this dynamically also allows for some build_sched_groups() simplification since we can now (like with other simplifications) rely on the sched_domain tree instead of hard-coded knowledge. One tricky to note is that detach_destroy_domains() needs to hold rcu_read_lock() over the entire tear-down, per-cpu is not sufficient since that can lead to partial sched_group existance (could possibly be solved by doing the tear-down backwards but this is much more robust). A concequence of the above is that we can no longer print the sched_domain debug stuff from cpu_attach_domain() since that might now run with preemption disabled (due to classic RCU etc.) and sched_domain_debug() does some GFP_KERNEL allocations. Another thing to note is that we now fully rely on normal RCU and not RCU-sched, this is because with the new and exiting RCU flavours we grew over the years BH doesn't necessarily hold off RCU-sched grace periods (-rt is known to break this). This would in fact already cause us grief since we do sched_domain/sched_group iterations from softirq context. This patch is somewhat larger than I would like it to be, but I didn't find any means of shrinking/splitting this. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.245307941@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:09:50 +00:00
tmp = rq->sd;
[PATCH] sched: RCU domains One of the problems with the multilevel balance-on-fork/exec is that it needs to jump through hoops to satisfy sched-domain's locking semantics (that is, you may traverse your own domain when not preemptable, and you may traverse others' domains when holding their runqueue lock). balance-on-exec had to potentially migrate between more than one CPU before finding a final CPU to migrate to, and balance-on-fork needed to potentially take multiple runqueue locks. So bite the bullet and make sched-domains go completely RCU. This actually simplifies the code quite a bit. From: Ingo Molnar <mingo@elte.hu> schedstats RCU fix, and a nice comment on for_each_domain, from Ingo. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Nick Piggin <nickpiggin@yahoo.com.au> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-25 21:57:27 +00:00
rcu_assign_pointer(rq->sd, sd);
sched: Dynamically allocate sched_domain/sched_group data-structures Instead of relying on static allocations for the sched_domain and sched_group trees, dynamically allocate and RCU free them. Allocating this dynamically also allows for some build_sched_groups() simplification since we can now (like with other simplifications) rely on the sched_domain tree instead of hard-coded knowledge. One tricky to note is that detach_destroy_domains() needs to hold rcu_read_lock() over the entire tear-down, per-cpu is not sufficient since that can lead to partial sched_group existance (could possibly be solved by doing the tear-down backwards but this is much more robust). A concequence of the above is that we can no longer print the sched_domain debug stuff from cpu_attach_domain() since that might now run with preemption disabled (due to classic RCU etc.) and sched_domain_debug() does some GFP_KERNEL allocations. Another thing to note is that we now fully rely on normal RCU and not RCU-sched, this is because with the new and exiting RCU flavours we grew over the years BH doesn't necessarily hold off RCU-sched grace periods (-rt is known to break this). This would in fact already cause us grief since we do sched_domain/sched_group iterations from softirq context. This patch is somewhat larger than I would like it to be, but I didn't find any means of shrinking/splitting this. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.245307941@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:09:50 +00:00
destroy_sched_domains(tmp, cpu);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
}
/* cpus with isolated domains */
sched: convert cpu_isolated_map to cpumask_var_t. Impact: stack usage reduction, (future) size reduction, cleanup Dynamically allocating cpumasks (when CONFIG_CPUMASK_OFFSTACK) saves space for small nr_cpu_ids but big CONFIG_NR_CPUS. cpumask_var_t is just a struct cpumask for !CONFIG_CPUMASK_OFFSTACK. We can also use cpulist_parse() instead of doing it manually in isolated_cpu_setup. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-24 16:05:12 +00:00
static cpumask_var_t cpu_isolated_map;
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
/* Setup the mask of cpus configured for isolated domains */
static int __init isolated_cpu_setup(char *str)
{
sched: Fix isolcpus boot option Anton Blanchard wrote: > We allocate and zero cpu_isolated_map after the isolcpus > __setup option has run. This means cpu_isolated_map always > ends up empty and if CPUMASK_OFFSTACK is enabled we write to a > cpumask that hasn't been allocated. I introduced this regression in 49557e620339cb13 (sched: Fix boot crash by zalloc()ing most of the cpu masks). Use the bootmem allocator if they set isolcpus=, otherwise allocate and zero like normal. Reported-by: Anton Blanchard <anton@samba.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: peterz@infradead.org Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: <stable@kernel.org> LKML-Reference: <200912021409.17013.rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu> Tested-by: Anton Blanchard <anton@samba.org>
2009-12-02 03:39:16 +00:00
alloc_bootmem_cpumask_var(&cpu_isolated_map);
Merge ../linux-2.6-x86 Conflicts: arch/x86/kernel/io_apic.c kernel/sched.c kernel/sched_stats.h
2008-12-13 11:25:51 +00:00
cpulist_parse(str, cpu_isolated_map);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
return 1;
}
sched: style cleanup fix up __setup() style bug - noticed via checkpatch.pl. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 15:00:13 +00:00
__setup("isolcpus=", isolated_cpu_setup);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
[PATCH] cpusets: Move the ia64 domain setup code to the generic code Signed-off-by: John Hawkes <hawkes@sgi.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-06 22:18:14 +00:00
#define SD_NODES_PER_DOMAIN 16
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
[PATCH] cpusets: Move the ia64 domain setup code to the generic code Signed-off-by: John Hawkes <hawkes@sgi.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-06 22:18:14 +00:00
#ifdef CONFIG_NUMA
[PATCH] scheduler cache-hot-autodetect ) From: Ingo Molnar <mingo@elte.hu> This is the latest version of the scheduler cache-hot-auto-tune patch. The first problem was that detection time scaled with O(N^2), which is unacceptable on larger SMP and NUMA systems. To solve this: - I've added a 'domain distance' function, which is used to cache measurement results. Each distance is only measured once. This means that e.g. on NUMA distances of 0, 1 and 2 might be measured, on HT distances 0 and 1, and on SMP distance 0 is measured. The code walks the domain tree to determine the distance, so it automatically follows whatever hierarchy an architecture sets up. This cuts down on the boot time significantly and removes the O(N^2) limit. The only assumption is that migration costs can be expressed as a function of domain distance - this covers the overwhelming majority of existing systems, and is a good guess even for more assymetric systems. [ People hacking systems that have assymetries that break this assumption (e.g. different CPU speeds) should experiment a bit with the cpu_distance() function. Adding a ->migration_distance factor to the domain structure would be one possible solution - but lets first see the problem systems, if they exist at all. Lets not overdesign. ] Another problem was that only a single cache-size was used for measuring the cost of migration, and most architectures didnt set that variable up. Furthermore, a single cache-size does not fit NUMA hierarchies with L3 caches and does not fit HT setups, where different CPUs will often have different 'effective cache sizes'. To solve this problem: - Instead of relying on a single cache-size provided by the platform and sticking to it, the code now auto-detects the 'effective migration cost' between two measured CPUs, via iterating through a wide range of cachesizes. The code searches for the maximum migration cost, which occurs when the working set of the test-workload falls just below the 'effective cache size'. I.e. real-life optimized search is done for the maximum migration cost, between two real CPUs. This, amongst other things, has the positive effect hat if e.g. two CPUs share a L2/L3 cache, a different (and accurate) migration cost will be found than between two CPUs on the same system that dont share any caches. (The reliable measurement of migration costs is tricky - see the source for details.) Furthermore i've added various boot-time options to override/tune migration behavior. Firstly, there's a blanket override for autodetection: migration_cost=1000,2000,3000 will override the depth 0/1/2 values with 1msec/2msec/3msec values. Secondly, there's a global factor that can be used to increase (or decrease) the autodetected values: migration_factor=120 will increase the autodetected values by 20%. This option is useful to tune things in a workload-dependent way - e.g. if a workload is cache-insensitive then CPU utilization can be maximized by specifying migration_factor=0. I've tested the autodetection code quite extensively on x86, on 3 P3/Xeon/2MB, and the autodetected values look pretty good: Dual Celeron (128K L2 cache): --------------------- migration cost matrix (max_cache_size: 131072, cpu: 467 MHz): --------------------- [00] [01] [00]: - 1.7(1) [01]: 1.7(1) - --------------------- cacheflush times [2]: 0.0 (0) 1.7 (1784008) --------------------- Here the slow memory subsystem dominates system performance, and even though caches are small, the migration cost is 1.7 msecs. Dual HT P4 (512K L2 cache): --------------------- migration cost matrix (max_cache_size: 524288, cpu: 2379 MHz): --------------------- [00] [01] [02] [03] [00]: - 0.4(1) 0.0(0) 0.4(1) [01]: 0.4(1) - 0.4(1) 0.0(0) [02]: 0.0(0) 0.4(1) - 0.4(1) [03]: 0.4(1) 0.0(0) 0.4(1) - --------------------- cacheflush times [2]: 0.0 (33900) 0.4 (448514) --------------------- Here it can be seen that there is no migration cost between two HT siblings (CPU#0/2 and CPU#1/3 are separate physical CPUs). A fast memory system makes inter-physical-CPU migration pretty cheap: 0.4 msecs. 8-way P3/Xeon [2MB L2 cache]: --------------------- migration cost matrix (max_cache_size: 2097152, cpu: 700 MHz): --------------------- [00] [01] [02] [03] [04] [05] [06] [07] [00]: - 19.2(1) 19.2(1) 19.2(1) 19.2(1) 19.2(1) 19.2(1) 19.2(1) [01]: 19.2(1) - 19.2(1) 19.2(1) 19.2(1) 19.2(1) 19.2(1) 19.2(1) [02]: 19.2(1) 19.2(1) - 19.2(1) 19.2(1) 19.2(1) 19.2(1) 19.2(1) [03]: 19.2(1) 19.2(1) 19.2(1) - 19.2(1) 19.2(1) 19.2(1) 19.2(1) [04]: 19.2(1) 19.2(1) 19.2(1) 19.2(1) - 19.2(1) 19.2(1) 19.2(1) [05]: 19.2(1) 19.2(1) 19.2(1) 19.2(1) 19.2(1) - 19.2(1) 19.2(1) [06]: 19.2(1) 19.2(1) 19.2(1) 19.2(1) 19.2(1) 19.2(1) - 19.2(1) [07]: 19.2(1) 19.2(1) 19.2(1) 19.2(1) 19.2(1) 19.2(1) 19.2(1) - --------------------- cacheflush times [2]: 0.0 (0) 19.2 (19281756) --------------------- This one has huge caches and a relatively slow memory subsystem - so the migration cost is 19 msecs. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Ashok Raj <ashok.raj@intel.com> Signed-off-by: Ken Chen <kenneth.w.chen@intel.com> Cc: <wilder@us.ibm.com> Signed-off-by: John Hawkes <hawkes@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-12 09:05:30 +00:00
[PATCH] cpusets: Move the ia64 domain setup code to the generic code Signed-off-by: John Hawkes <hawkes@sgi.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-06 22:18:14 +00:00
/**
* find_next_best_node - find the next node to include in a sched_domain
* @node: node whose sched_domain we're building
* @used_nodes: nodes already in the sched_domain
*
sched: style cleanups style cleanup of various changes that were done recently. no code changed: text data bss dec hex filename 23680 2542 28 26250 668a sched.o.before 23680 2542 28 26250 668a sched.o.after Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-12-05 14:46:09 +00:00
* Find the next node to include in a given scheduling domain. Simply
[PATCH] cpusets: Move the ia64 domain setup code to the generic code Signed-off-by: John Hawkes <hawkes@sgi.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-06 22:18:14 +00:00
* finds the closest node not already in the @used_nodes map.
*
* Should use nodemask_t.
*/
nodemask: use new node_to_cpumask_ptr function * Use new node_to_cpumask_ptr. This creates a pointer to the cpumask for a given node. This definition is in mm patch: asm-generic-add-node_to_cpumask_ptr-macro.patch * Use new set_cpus_allowed_ptr function. Depends on: [mm-patch]: asm-generic-add-node_to_cpumask_ptr-macro.patch [sched-devel]: sched: add new set_cpus_allowed_ptr function [x86/latest]: x86: add cpus_scnprintf function Cc: Greg Kroah-Hartman <gregkh@suse.de> Cc: Greg Banks <gnb@melbourne.sgi.com> Cc: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Mike Travis <travis@sgi.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-05 01:11:10 +00:00
static int find_next_best_node(int node, nodemask_t *used_nodes)
[PATCH] cpusets: Move the ia64 domain setup code to the generic code Signed-off-by: John Hawkes <hawkes@sgi.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-06 22:18:14 +00:00
{
sched: Shorten the construction of the span cpu mask of sched domain For a given node, when constructing the cpumask for its sched_domain to span, if there is no best node available after searching, further efforts could be saved, based on small change in the return value of find_next_best_node(). Signed-off-by: Hillf Danton <dhillf@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Yong Zhang <yong.zhang0@gmail.com> Link: http://lkml.kernel.org/r/BANLkTi%3DqPWxRAa6%2BdT3ohEP6Z%3D0v%2Be4EXA@mail.gmail.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-05-05 12:53:20 +00:00
int i, n, val, min_val, best_node = -1;
[PATCH] cpusets: Move the ia64 domain setup code to the generic code Signed-off-by: John Hawkes <hawkes@sgi.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-06 22:18:14 +00:00
min_val = INT_MAX;
sched, numa: replace MAX_NUMNODES with nr_node_ids in kernel/sched.c * Replace usages of MAX_NUMNODES with nr_node_ids in kernel/sched.c, where appropriate. This saves some allocated space as well as many wasted cycles going through node entries that are non-existent. Signed-off-by: Mike Travis <travis@sgi.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-05-12 19:21:12 +00:00
for (i = 0; i < nr_node_ids; i++) {
[PATCH] cpusets: Move the ia64 domain setup code to the generic code Signed-off-by: John Hawkes <hawkes@sgi.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-06 22:18:14 +00:00
/* Start at @node */
sched, numa: replace MAX_NUMNODES with nr_node_ids in kernel/sched.c * Replace usages of MAX_NUMNODES with nr_node_ids in kernel/sched.c, where appropriate. This saves some allocated space as well as many wasted cycles going through node entries that are non-existent. Signed-off-by: Mike Travis <travis@sgi.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-05-12 19:21:12 +00:00
n = (node + i) % nr_node_ids;
[PATCH] cpusets: Move the ia64 domain setup code to the generic code Signed-off-by: John Hawkes <hawkes@sgi.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-06 22:18:14 +00:00
if (!nr_cpus_node(n))
continue;
/* Skip already used nodes */
nodemask: use new node_to_cpumask_ptr function * Use new node_to_cpumask_ptr. This creates a pointer to the cpumask for a given node. This definition is in mm patch: asm-generic-add-node_to_cpumask_ptr-macro.patch * Use new set_cpus_allowed_ptr function. Depends on: [mm-patch]: asm-generic-add-node_to_cpumask_ptr-macro.patch [sched-devel]: sched: add new set_cpus_allowed_ptr function [x86/latest]: x86: add cpus_scnprintf function Cc: Greg Kroah-Hartman <gregkh@suse.de> Cc: Greg Banks <gnb@melbourne.sgi.com> Cc: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Mike Travis <travis@sgi.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-05 01:11:10 +00:00
if (node_isset(n, *used_nodes))
[PATCH] cpusets: Move the ia64 domain setup code to the generic code Signed-off-by: John Hawkes <hawkes@sgi.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-06 22:18:14 +00:00
continue;
/* Simple min distance search */
val = node_distance(node, n);
if (val < min_val) {
min_val = val;
best_node = n;
}
}
sched: Shorten the construction of the span cpu mask of sched domain For a given node, when constructing the cpumask for its sched_domain to span, if there is no best node available after searching, further efforts could be saved, based on small change in the return value of find_next_best_node(). Signed-off-by: Hillf Danton <dhillf@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Yong Zhang <yong.zhang0@gmail.com> Link: http://lkml.kernel.org/r/BANLkTi%3DqPWxRAa6%2BdT3ohEP6Z%3D0v%2Be4EXA@mail.gmail.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-05-05 12:53:20 +00:00
if (best_node != -1)
node_set(best_node, *used_nodes);
[PATCH] cpusets: Move the ia64 domain setup code to the generic code Signed-off-by: John Hawkes <hawkes@sgi.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-06 22:18:14 +00:00
return best_node;
}
/**
* sched_domain_node_span - get a cpumask for a node's sched_domain
* @node: node whose cpumask we're constructing
kernel-doc: fix sched.c missing parameter Add missing kernel-doc in kernel/sched.c: Warning(linux-2.6.25-git3//kernel/sched.c:7044): No description found for parameter 'span' Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-22 17:07:22 +00:00
* @span: resulting cpumask
[PATCH] cpusets: Move the ia64 domain setup code to the generic code Signed-off-by: John Hawkes <hawkes@sgi.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-06 22:18:14 +00:00
*
sched: style cleanups style cleanup of various changes that were done recently. no code changed: text data bss dec hex filename 23680 2542 28 26250 668a sched.o.before 23680 2542 28 26250 668a sched.o.after Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-12-05 14:46:09 +00:00
* Given a node, construct a good cpumask for its sched_domain to span. It
[PATCH] cpusets: Move the ia64 domain setup code to the generic code Signed-off-by: John Hawkes <hawkes@sgi.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-06 22:18:14 +00:00
* should be one that prevents unnecessary balancing, but also spreads tasks
* out optimally.
*/
sched: convert remaining old-style cpumask operators Impact: Trivial API conversion NR_CPUS -> nr_cpu_ids cpumask_t -> struct cpumask sizeof(cpumask_t) -> cpumask_size() cpumask_a = cpumask_b -> cpumask_copy(&cpumask_a, &cpumask_b) cpu_set() -> cpumask_set_cpu() first_cpu() -> cpumask_first() cpumask_of_cpu() -> cpumask_of() cpus_* -> cpumask_* There are some FIXMEs where we all archs to complete infrastructure (patches have been sent): cpu_coregroup_map -> cpu_coregroup_mask node_to_cpumask* -> cpumask_of_node There is also one FIXME where we pass an array of cpumasks to partition_sched_domains(): this implies knowing the definition of 'struct cpumask' and the size of a cpumask. This will be fixed in a future patch. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-24 16:05:14 +00:00
static void sched_domain_node_span(int node, struct cpumask *span)
[PATCH] cpusets: Move the ia64 domain setup code to the generic code Signed-off-by: John Hawkes <hawkes@sgi.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-06 22:18:14 +00:00
{
nodemask: use new node_to_cpumask_ptr function * Use new node_to_cpumask_ptr. This creates a pointer to the cpumask for a given node. This definition is in mm patch: asm-generic-add-node_to_cpumask_ptr-macro.patch * Use new set_cpus_allowed_ptr function. Depends on: [mm-patch]: asm-generic-add-node_to_cpumask_ptr-macro.patch [sched-devel]: sched: add new set_cpus_allowed_ptr function [x86/latest]: x86: add cpus_scnprintf function Cc: Greg Kroah-Hartman <gregkh@suse.de> Cc: Greg Banks <gnb@melbourne.sgi.com> Cc: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Mike Travis <travis@sgi.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-05 01:11:10 +00:00
nodemask_t used_nodes;
[PATCH] sched: clean up fallout of recent changes Clean up some of the impact of recent (and not so recent) scheduler changes: - turning macros into nice inline functions - sanitizing and unifying variable definitions - whitespace, style consistency, 80-lines, comment correctness, spelling and curly braces police Due to the macro hell and variable placement simplifications there's even 26 bytes of .text saved: text data bss dec hex filename 25510 4153 192 29855 749f sched.o.before 25484 4153 192 29829 7485 sched.o.after [akpm@osdl.org: build fix] Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-03 07:25:40 +00:00
int i;
[PATCH] cpusets: Move the ia64 domain setup code to the generic code Signed-off-by: John Hawkes <hawkes@sgi.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-06 22:18:14 +00:00
sched: put back some stack hog changes that were undone in kernel/sched.c Impact: prevents panic from stack overflow on numa-capable machines. Some of the "removal of stack hogs" changes in kernel/sched.c by using node_to_cpumask_ptr were undone by the early cpumask API updates, and causes a panic due to stack overflow. This patch undoes those changes by using cpumask_of_node() which returns a 'const struct cpumask *'. In addition, cpu_coregoup_map is replaced with cpu_coregroup_mask further reducing stack usage. (Both of these updates removed 9 FIXME's!) Also: Pick up some remaining changes from the old 'cpumask_t' functions to the new 'struct cpumask *' functions. Optimize memory traffic by allocating each percpu local_cpu_mask on the same node as the referring cpu. Signed-off-by: Mike Travis <travis@sgi.com> Acked-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-01 02:08:45 +00:00
cpumask_clear(span);
nodemask: use new node_to_cpumask_ptr function * Use new node_to_cpumask_ptr. This creates a pointer to the cpumask for a given node. This definition is in mm patch: asm-generic-add-node_to_cpumask_ptr-macro.patch * Use new set_cpus_allowed_ptr function. Depends on: [mm-patch]: asm-generic-add-node_to_cpumask_ptr-macro.patch [sched-devel]: sched: add new set_cpus_allowed_ptr function [x86/latest]: x86: add cpus_scnprintf function Cc: Greg Kroah-Hartman <gregkh@suse.de> Cc: Greg Banks <gnb@melbourne.sgi.com> Cc: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Mike Travis <travis@sgi.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-05 01:11:10 +00:00
nodes_clear(used_nodes);
[PATCH] cpusets: Move the ia64 domain setup code to the generic code Signed-off-by: John Hawkes <hawkes@sgi.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-06 22:18:14 +00:00
sched: put back some stack hog changes that were undone in kernel/sched.c Impact: prevents panic from stack overflow on numa-capable machines. Some of the "removal of stack hogs" changes in kernel/sched.c by using node_to_cpumask_ptr were undone by the early cpumask API updates, and causes a panic due to stack overflow. This patch undoes those changes by using cpumask_of_node() which returns a 'const struct cpumask *'. In addition, cpu_coregoup_map is replaced with cpu_coregroup_mask further reducing stack usage. (Both of these updates removed 9 FIXME's!) Also: Pick up some remaining changes from the old 'cpumask_t' functions to the new 'struct cpumask *' functions. Optimize memory traffic by allocating each percpu local_cpu_mask on the same node as the referring cpu. Signed-off-by: Mike Travis <travis@sgi.com> Acked-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-01 02:08:45 +00:00
cpumask_or(span, span, cpumask_of_node(node));
nodemask: use new node_to_cpumask_ptr function * Use new node_to_cpumask_ptr. This creates a pointer to the cpumask for a given node. This definition is in mm patch: asm-generic-add-node_to_cpumask_ptr-macro.patch * Use new set_cpus_allowed_ptr function. Depends on: [mm-patch]: asm-generic-add-node_to_cpumask_ptr-macro.patch [sched-devel]: sched: add new set_cpus_allowed_ptr function [x86/latest]: x86: add cpus_scnprintf function Cc: Greg Kroah-Hartman <gregkh@suse.de> Cc: Greg Banks <gnb@melbourne.sgi.com> Cc: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Mike Travis <travis@sgi.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-05 01:11:10 +00:00
node_set(node, used_nodes);
[PATCH] cpusets: Move the ia64 domain setup code to the generic code Signed-off-by: John Hawkes <hawkes@sgi.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-06 22:18:14 +00:00
for (i = 1; i < SD_NODES_PER_DOMAIN; i++) {
nodemask: use new node_to_cpumask_ptr function * Use new node_to_cpumask_ptr. This creates a pointer to the cpumask for a given node. This definition is in mm patch: asm-generic-add-node_to_cpumask_ptr-macro.patch * Use new set_cpus_allowed_ptr function. Depends on: [mm-patch]: asm-generic-add-node_to_cpumask_ptr-macro.patch [sched-devel]: sched: add new set_cpus_allowed_ptr function [x86/latest]: x86: add cpus_scnprintf function Cc: Greg Kroah-Hartman <gregkh@suse.de> Cc: Greg Banks <gnb@melbourne.sgi.com> Cc: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Mike Travis <travis@sgi.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-05 01:11:10 +00:00
int next_node = find_next_best_node(node, &used_nodes);
sched: Shorten the construction of the span cpu mask of sched domain For a given node, when constructing the cpumask for its sched_domain to span, if there is no best node available after searching, further efforts could be saved, based on small change in the return value of find_next_best_node(). Signed-off-by: Hillf Danton <dhillf@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Yong Zhang <yong.zhang0@gmail.com> Link: http://lkml.kernel.org/r/BANLkTi%3DqPWxRAa6%2BdT3ohEP6Z%3D0v%2Be4EXA@mail.gmail.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-05-05 12:53:20 +00:00
if (next_node < 0)
break;
sched: put back some stack hog changes that were undone in kernel/sched.c Impact: prevents panic from stack overflow on numa-capable machines. Some of the "removal of stack hogs" changes in kernel/sched.c by using node_to_cpumask_ptr were undone by the early cpumask API updates, and causes a panic due to stack overflow. This patch undoes those changes by using cpumask_of_node() which returns a 'const struct cpumask *'. In addition, cpu_coregoup_map is replaced with cpu_coregroup_mask further reducing stack usage. (Both of these updates removed 9 FIXME's!) Also: Pick up some remaining changes from the old 'cpumask_t' functions to the new 'struct cpumask *' functions. Optimize memory traffic by allocating each percpu local_cpu_mask on the same node as the referring cpu. Signed-off-by: Mike Travis <travis@sgi.com> Acked-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-01 02:08:45 +00:00
cpumask_or(span, span, cpumask_of_node(next_node));
[PATCH] cpusets: Move the ia64 domain setup code to the generic code Signed-off-by: John Hawkes <hawkes@sgi.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-06 22:18:14 +00:00
}
}
sched: Create proper cpu_$DOM_mask() functions In order to unify the sched domain creation more, create proper cpu_$DOM_mask() functions for those domains that didn't already have one. Use the sched_domains_tmpmask for the weird NUMA domain span. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.717702108@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:09:59 +00:00
static const struct cpumask *cpu_node_mask(int cpu)
{
lockdep_assert_held(&sched_domains_mutex);
sched_domain_node_span(cpu_to_node(cpu), sched_domains_tmpmask);
return sched_domains_tmpmask;
}
sched: Unify the sched_domain build functions Since all the __build_$DOM_sched_domain() functions do pretty much the same thing, unify them. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.826347257@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:10:01 +00:00
static const struct cpumask *cpu_allnodes_mask(int cpu)
{
return cpu_possible_mask;
}
sched: add comments for ifdefs in sched.c make sched.c easier to read. Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-30 12:23:45 +00:00
#endif /* CONFIG_NUMA */
[PATCH] cpusets: Move the ia64 domain setup code to the generic code Signed-off-by: John Hawkes <hawkes@sgi.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-06 22:18:14 +00:00
sched: Create proper cpu_$DOM_mask() functions In order to unify the sched domain creation more, create proper cpu_$DOM_mask() functions for those domains that didn't already have one. Use the sched_domains_tmpmask for the weird NUMA domain span. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.717702108@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:09:59 +00:00
static const struct cpumask *cpu_cpu_mask(int cpu)
{
return cpumask_of_node(cpu_to_node(cpu));
}
[PATCH] sched: mc/smt power savings sched policy sysfs entries 'sched_mc_power_savings' and 'sched_smt_power_savings' in /sys/devices/system/cpu/ control the MC/SMT power savings policy for the scheduler. Based on the values (1-enable, 0-disable) for these controls, sched groups cpu power will be determined for different domains. When power savings policy is enabled and under light load conditions, scheduler will minimize the physical packages/cpu cores carrying the load and thus conserving power(with a perf impact based on the workload characteristics... see OLS 2005 CMP kernel scheduler paper for more details..) Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Con Kolivas <kernel@kolivas.org> Cc: "Chen, Kenneth W" <kenneth.w.chen@intel.com> Cc: "David S. Miller" <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 09:54:42 +00:00
int sched_smt_power_savings = 0, sched_mc_power_savings = 0;
[PATCH] sched: clean up fallout of recent changes Clean up some of the impact of recent (and not so recent) scheduler changes: - turning macros into nice inline functions - sanitizing and unifying variable definitions - whitespace, style consistency, 80-lines, comment correctness, spelling and curly braces police Due to the macro hell and variable placement simplifications there's even 26 bytes of .text saved: text data bss dec hex filename 25510 4153 192 29855 749f sched.o.before 25484 4153 192 29829 7485 sched.o.after [akpm@osdl.org: build fix] Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-03 07:25:40 +00:00
sched: Dynamically allocate sched_domain/sched_group data-structures Instead of relying on static allocations for the sched_domain and sched_group trees, dynamically allocate and RCU free them. Allocating this dynamically also allows for some build_sched_groups() simplification since we can now (like with other simplifications) rely on the sched_domain tree instead of hard-coded knowledge. One tricky to note is that detach_destroy_domains() needs to hold rcu_read_lock() over the entire tear-down, per-cpu is not sufficient since that can lead to partial sched_group existance (could possibly be solved by doing the tear-down backwards but this is much more robust). A concequence of the above is that we can no longer print the sched_domain debug stuff from cpu_attach_domain() since that might now run with preemption disabled (due to classic RCU etc.) and sched_domain_debug() does some GFP_KERNEL allocations. Another thing to note is that we now fully rely on normal RCU and not RCU-sched, this is because with the new and exiting RCU flavours we grew over the years BH doesn't necessarily hold off RCU-sched grace periods (-rt is known to break this). This would in fact already cause us grief since we do sched_domain/sched_group iterations from softirq context. This patch is somewhat larger than I would like it to be, but I didn't find any means of shrinking/splitting this. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.245307941@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:09:50 +00:00
struct sd_data {
struct sched_domain **__percpu sd;
struct sched_group **__percpu sg;
sched: Break out cpu_power from the sched_group structure In order to prepare for non-unique sched_groups per domain, we need to carry the cpu_power elsewhere, so put a level of indirection in. Reported-and-tested-by: Anton Blanchard <anton@samba.org> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/n/tip-qkho2byuhe4482fuknss40ad@git.kernel.org Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-14 11:00:06 +00:00
struct sched_group_power **__percpu sgp;
sched: Dynamically allocate sched_domain/sched_group data-structures Instead of relying on static allocations for the sched_domain and sched_group trees, dynamically allocate and RCU free them. Allocating this dynamically also allows for some build_sched_groups() simplification since we can now (like with other simplifications) rely on the sched_domain tree instead of hard-coded knowledge. One tricky to note is that detach_destroy_domains() needs to hold rcu_read_lock() over the entire tear-down, per-cpu is not sufficient since that can lead to partial sched_group existance (could possibly be solved by doing the tear-down backwards but this is much more robust). A concequence of the above is that we can no longer print the sched_domain debug stuff from cpu_attach_domain() since that might now run with preemption disabled (due to classic RCU etc.) and sched_domain_debug() does some GFP_KERNEL allocations. Another thing to note is that we now fully rely on normal RCU and not RCU-sched, this is because with the new and exiting RCU flavours we grew over the years BH doesn't necessarily hold off RCU-sched grace periods (-rt is known to break this). This would in fact already cause us grief since we do sched_domain/sched_group iterations from softirq context. This patch is somewhat larger than I would like it to be, but I didn't find any means of shrinking/splitting this. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.245307941@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:09:50 +00:00
};
sched: Use structure to store local data in __build_sched_domains Signed-off-by: Andreas Herrmann <andreas.herrmann3@amd.com> Cc: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <20090818105152.GB29515@alberich.amd.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-08-18 10:51:52 +00:00
struct s_data {
sched: Simplify finding the lowest sched_domain Instead of relying on knowing the build order and various CONFIG_ flags simply remember the bottom most sched_domain when we created the domain hierarchy. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.134511046@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:09:48 +00:00
struct sched_domain ** __percpu sd;
sched: Use structure to store local data in __build_sched_domains Signed-off-by: Andreas Herrmann <andreas.herrmann3@amd.com> Cc: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <20090818105152.GB29515@alberich.amd.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-08-18 10:51:52 +00:00
struct root_domain *rd;
};
sched: Separate out allocation/free/goto-hell from __build_sched_domains Signed-off-by: Andreas Herrmann <andreas.herrmann3@amd.com> Cc: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <20090818105300.GC29515@alberich.amd.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-08-18 10:53:00 +00:00
enum s_alloc {
sa_rootdomain,
sched: Simplify finding the lowest sched_domain Instead of relying on knowing the build order and various CONFIG_ flags simply remember the bottom most sched_domain when we created the domain hierarchy. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.134511046@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:09:48 +00:00
sa_sd,
sched: Dynamically allocate sched_domain/sched_group data-structures Instead of relying on static allocations for the sched_domain and sched_group trees, dynamically allocate and RCU free them. Allocating this dynamically also allows for some build_sched_groups() simplification since we can now (like with other simplifications) rely on the sched_domain tree instead of hard-coded knowledge. One tricky to note is that detach_destroy_domains() needs to hold rcu_read_lock() over the entire tear-down, per-cpu is not sufficient since that can lead to partial sched_group existance (could possibly be solved by doing the tear-down backwards but this is much more robust). A concequence of the above is that we can no longer print the sched_domain debug stuff from cpu_attach_domain() since that might now run with preemption disabled (due to classic RCU etc.) and sched_domain_debug() does some GFP_KERNEL allocations. Another thing to note is that we now fully rely on normal RCU and not RCU-sched, this is because with the new and exiting RCU flavours we grew over the years BH doesn't necessarily hold off RCU-sched grace periods (-rt is known to break this). This would in fact already cause us grief since we do sched_domain/sched_group iterations from softirq context. This patch is somewhat larger than I would like it to be, but I didn't find any means of shrinking/splitting this. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.245307941@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:09:50 +00:00
sa_sd_storage,
sched: Separate out allocation/free/goto-hell from __build_sched_domains Signed-off-by: Andreas Herrmann <andreas.herrmann3@amd.com> Cc: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <20090818105300.GC29515@alberich.amd.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-08-18 10:53:00 +00:00
sa_none,
};
sched: Move sched domain storage into the topology list In order to remove the last dependency on the statid domain levels, move the sd_data storage into the topology structure. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.924926412@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:10:03 +00:00
struct sched_domain_topology_level;
typedef struct sched_domain *(*sched_domain_init_f)(struct sched_domain_topology_level *tl, int cpu);
sched: Stuff the sched_domain creation in a data-structure In order to make the topology contruction fully dynamic, remove the still hard-coded list of possible domains and stick them in a data-structure. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.770335383@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:10:00 +00:00
typedef const struct cpumask *(*sched_domain_mask_f)(int cpu);
sched: Allow for overlapping sched_domain spans Allow for sched_domain spans that overlap by giving such domains their own sched_group list instead of sharing the sched_groups amongst each-other. This is needed for machines with more than 16 nodes, because sched_domain_node_span() will generate a node mask from the 16 nearest nodes without regard if these masks have any overlap. Currently sched_domains have a sched_group that maps to their child sched_domain span, and since there is no overlap we share the sched_group between the sched_domains of the various CPUs. If however there is overlap, we would need to link the sched_group list in different ways for each cpu, and hence sharing isn't possible. In order to solve this, allocate private sched_groups for each CPU's sched_domain but have the sched_groups share a sched_group_power structure such that we can uniquely track the power. Reported-and-tested-by: Anton Blanchard <anton@samba.org> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/n/tip-08bxqw9wis3qti9u5inifh3y@git.kernel.org Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-15 08:35:52 +00:00
#define SDTL_OVERLAP 0x01
sched: Stuff the sched_domain creation in a data-structure In order to make the topology contruction fully dynamic, remove the still hard-coded list of possible domains and stick them in a data-structure. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.770335383@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:10:00 +00:00
struct sched_domain_topology_level {
sched: Unify the sched_domain build functions Since all the __build_$DOM_sched_domain() functions do pretty much the same thing, unify them. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.826347257@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:10:01 +00:00
sched_domain_init_f init;
sched_domain_mask_f mask;
sched: Allow for overlapping sched_domain spans Allow for sched_domain spans that overlap by giving such domains their own sched_group list instead of sharing the sched_groups amongst each-other. This is needed for machines with more than 16 nodes, because sched_domain_node_span() will generate a node mask from the 16 nearest nodes without regard if these masks have any overlap. Currently sched_domains have a sched_group that maps to their child sched_domain span, and since there is no overlap we share the sched_group between the sched_domains of the various CPUs. If however there is overlap, we would need to link the sched_group list in different ways for each cpu, and hence sharing isn't possible. In order to solve this, allocate private sched_groups for each CPU's sched_domain but have the sched_groups share a sched_group_power structure such that we can uniquely track the power. Reported-and-tested-by: Anton Blanchard <anton@samba.org> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/n/tip-08bxqw9wis3qti9u5inifh3y@git.kernel.org Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-15 08:35:52 +00:00
int flags;
sched: Move sched domain storage into the topology list In order to remove the last dependency on the statid domain levels, move the sd_data storage into the topology structure. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.924926412@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:10:03 +00:00
struct sd_data data;
sched: Stuff the sched_domain creation in a data-structure In order to make the topology contruction fully dynamic, remove the still hard-coded list of possible domains and stick them in a data-structure. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.770335383@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:10:00 +00:00
};
sched: Allow for overlapping sched_domain spans Allow for sched_domain spans that overlap by giving such domains their own sched_group list instead of sharing the sched_groups amongst each-other. This is needed for machines with more than 16 nodes, because sched_domain_node_span() will generate a node mask from the 16 nearest nodes without regard if these masks have any overlap. Currently sched_domains have a sched_group that maps to their child sched_domain span, and since there is no overlap we share the sched_group between the sched_domains of the various CPUs. If however there is overlap, we would need to link the sched_group list in different ways for each cpu, and hence sharing isn't possible. In order to solve this, allocate private sched_groups for each CPU's sched_domain but have the sched_groups share a sched_group_power structure such that we can uniquely track the power. Reported-and-tested-by: Anton Blanchard <anton@samba.org> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/n/tip-08bxqw9wis3qti9u5inifh3y@git.kernel.org Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-15 08:35:52 +00:00
static int
build_overlap_sched_groups(struct sched_domain *sd, int cpu)
{
struct sched_group *first = NULL, *last = NULL, *groups = NULL, *sg;
const struct cpumask *span = sched_domain_span(sd);
struct cpumask *covered = sched_domains_tmpmask;
struct sd_data *sdd = sd->private;
struct sched_domain *child;
int i;
cpumask_clear(covered);
for_each_cpu(i, span) {
struct cpumask *sg_span;
if (cpumask_test_cpu(i, covered))
continue;
sg = kzalloc_node(sizeof(struct sched_group) + cpumask_size(),
GFP_KERNEL, cpu_to_node(i));
if (!sg)
goto fail;
sg_span = sched_group_cpus(sg);
child = *per_cpu_ptr(sdd->sd, i);
if (child->child) {
child = child->child;
cpumask_copy(sg_span, sched_domain_span(child));
} else
cpumask_set_cpu(i, sg_span);
cpumask_or(covered, covered, sg_span);
sg->sgp = *per_cpu_ptr(sdd->sgp, cpumask_first(sg_span));
atomic_inc(&sg->sgp->ref);
if (cpumask_test_cpu(cpu, sg_span))
groups = sg;
if (!first)
first = sg;
if (last)
last->next = sg;
last = sg;
last->next = first;
}
sd->groups = groups;
return 0;
fail:
free_sched_groups(first, 0);
return -ENOMEM;
}
sched: Dynamically allocate sched_domain/sched_group data-structures Instead of relying on static allocations for the sched_domain and sched_group trees, dynamically allocate and RCU free them. Allocating this dynamically also allows for some build_sched_groups() simplification since we can now (like with other simplifications) rely on the sched_domain tree instead of hard-coded knowledge. One tricky to note is that detach_destroy_domains() needs to hold rcu_read_lock() over the entire tear-down, per-cpu is not sufficient since that can lead to partial sched_group existance (could possibly be solved by doing the tear-down backwards but this is much more robust). A concequence of the above is that we can no longer print the sched_domain debug stuff from cpu_attach_domain() since that might now run with preemption disabled (due to classic RCU etc.) and sched_domain_debug() does some GFP_KERNEL allocations. Another thing to note is that we now fully rely on normal RCU and not RCU-sched, this is because with the new and exiting RCU flavours we grew over the years BH doesn't necessarily hold off RCU-sched grace periods (-rt is known to break this). This would in fact already cause us grief since we do sched_domain/sched_group iterations from softirq context. This patch is somewhat larger than I would like it to be, but I didn't find any means of shrinking/splitting this. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.245307941@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:09:50 +00:00
static int get_group(int cpu, struct sd_data *sdd, struct sched_group **sg)
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
{
sched: Dynamically allocate sched_domain/sched_group data-structures Instead of relying on static allocations for the sched_domain and sched_group trees, dynamically allocate and RCU free them. Allocating this dynamically also allows for some build_sched_groups() simplification since we can now (like with other simplifications) rely on the sched_domain tree instead of hard-coded knowledge. One tricky to note is that detach_destroy_domains() needs to hold rcu_read_lock() over the entire tear-down, per-cpu is not sufficient since that can lead to partial sched_group existance (could possibly be solved by doing the tear-down backwards but this is much more robust). A concequence of the above is that we can no longer print the sched_domain debug stuff from cpu_attach_domain() since that might now run with preemption disabled (due to classic RCU etc.) and sched_domain_debug() does some GFP_KERNEL allocations. Another thing to note is that we now fully rely on normal RCU and not RCU-sched, this is because with the new and exiting RCU flavours we grew over the years BH doesn't necessarily hold off RCU-sched grace periods (-rt is known to break this). This would in fact already cause us grief since we do sched_domain/sched_group iterations from softirq context. This patch is somewhat larger than I would like it to be, but I didn't find any means of shrinking/splitting this. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.245307941@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:09:50 +00:00
struct sched_domain *sd = *per_cpu_ptr(sdd->sd, cpu);
struct sched_domain *child = sd->child;
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
sched: Dynamically allocate sched_domain/sched_group data-structures Instead of relying on static allocations for the sched_domain and sched_group trees, dynamically allocate and RCU free them. Allocating this dynamically also allows for some build_sched_groups() simplification since we can now (like with other simplifications) rely on the sched_domain tree instead of hard-coded knowledge. One tricky to note is that detach_destroy_domains() needs to hold rcu_read_lock() over the entire tear-down, per-cpu is not sufficient since that can lead to partial sched_group existance (could possibly be solved by doing the tear-down backwards but this is much more robust). A concequence of the above is that we can no longer print the sched_domain debug stuff from cpu_attach_domain() since that might now run with preemption disabled (due to classic RCU etc.) and sched_domain_debug() does some GFP_KERNEL allocations. Another thing to note is that we now fully rely on normal RCU and not RCU-sched, this is because with the new and exiting RCU flavours we grew over the years BH doesn't necessarily hold off RCU-sched grace periods (-rt is known to break this). This would in fact already cause us grief since we do sched_domain/sched_group iterations from softirq context. This patch is somewhat larger than I would like it to be, but I didn't find any means of shrinking/splitting this. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.245307941@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:09:50 +00:00
if (child)
cpu = cpumask_first(sched_domain_span(child));
[PATCH] sched: new sched domain for representing multi-core Add a new sched domain for representing multi-core with shared caches between cores. Consider a dual package system, each package containing two cores and with last level cache shared between cores with in a package. If there are two runnable processes, with this appended patch those two processes will be scheduled on different packages. On such systems, with this patch we have observed 8% perf improvement with specJBB(2 warehouse) benchmark and 35% improvement with CFP2000 rate(with 2 users). This new domain will come into play only on multi-core systems with shared caches. On other systems, this sched domain will be removed by domain degeneration code. This new domain can be also used for implementing power savings policy (see OLS 2005 CMP kernel scheduler paper for more details.. I will post another patch for power savings policy soon) Most of the arch/* file changes are for cpu_coregroup_map() implementation. Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-27 09:15:22 +00:00
sched: Break out cpu_power from the sched_group structure In order to prepare for non-unique sched_groups per domain, we need to carry the cpu_power elsewhere, so put a level of indirection in. Reported-and-tested-by: Anton Blanchard <anton@samba.org> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/n/tip-qkho2byuhe4482fuknss40ad@git.kernel.org Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-14 11:00:06 +00:00
if (sg) {
sched: Dynamically allocate sched_domain/sched_group data-structures Instead of relying on static allocations for the sched_domain and sched_group trees, dynamically allocate and RCU free them. Allocating this dynamically also allows for some build_sched_groups() simplification since we can now (like with other simplifications) rely on the sched_domain tree instead of hard-coded knowledge. One tricky to note is that detach_destroy_domains() needs to hold rcu_read_lock() over the entire tear-down, per-cpu is not sufficient since that can lead to partial sched_group existance (could possibly be solved by doing the tear-down backwards but this is much more robust). A concequence of the above is that we can no longer print the sched_domain debug stuff from cpu_attach_domain() since that might now run with preemption disabled (due to classic RCU etc.) and sched_domain_debug() does some GFP_KERNEL allocations. Another thing to note is that we now fully rely on normal RCU and not RCU-sched, this is because with the new and exiting RCU flavours we grew over the years BH doesn't necessarily hold off RCU-sched grace periods (-rt is known to break this). This would in fact already cause us grief since we do sched_domain/sched_group iterations from softirq context. This patch is somewhat larger than I would like it to be, but I didn't find any means of shrinking/splitting this. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.245307941@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:09:50 +00:00
*sg = *per_cpu_ptr(sdd->sg, cpu);
sched: Break out cpu_power from the sched_group structure In order to prepare for non-unique sched_groups per domain, we need to carry the cpu_power elsewhere, so put a level of indirection in. Reported-and-tested-by: Anton Blanchard <anton@samba.org> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/n/tip-qkho2byuhe4482fuknss40ad@git.kernel.org Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-14 11:00:06 +00:00
(*sg)->sgp = *per_cpu_ptr(sdd->sgp, cpu);
sched: Allow for overlapping sched_domain spans Allow for sched_domain spans that overlap by giving such domains their own sched_group list instead of sharing the sched_groups amongst each-other. This is needed for machines with more than 16 nodes, because sched_domain_node_span() will generate a node mask from the 16 nearest nodes without regard if these masks have any overlap. Currently sched_domains have a sched_group that maps to their child sched_domain span, and since there is no overlap we share the sched_group between the sched_domains of the various CPUs. If however there is overlap, we would need to link the sched_group list in different ways for each cpu, and hence sharing isn't possible. In order to solve this, allocate private sched_groups for each CPU's sched_domain but have the sched_groups share a sched_group_power structure such that we can uniquely track the power. Reported-and-tested-by: Anton Blanchard <anton@samba.org> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/n/tip-08bxqw9wis3qti9u5inifh3y@git.kernel.org Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-15 08:35:52 +00:00
atomic_set(&(*sg)->sgp->ref, 1); /* for claim_allocations */
sched: Break out cpu_power from the sched_group structure In order to prepare for non-unique sched_groups per domain, we need to carry the cpu_power elsewhere, so put a level of indirection in. Reported-and-tested-by: Anton Blanchard <anton@samba.org> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/n/tip-qkho2byuhe4482fuknss40ad@git.kernel.org Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-14 11:00:06 +00:00
}
sched: Dynamically allocate sched_domain/sched_group data-structures Instead of relying on static allocations for the sched_domain and sched_group trees, dynamically allocate and RCU free them. Allocating this dynamically also allows for some build_sched_groups() simplification since we can now (like with other simplifications) rely on the sched_domain tree instead of hard-coded knowledge. One tricky to note is that detach_destroy_domains() needs to hold rcu_read_lock() over the entire tear-down, per-cpu is not sufficient since that can lead to partial sched_group existance (could possibly be solved by doing the tear-down backwards but this is much more robust). A concequence of the above is that we can no longer print the sched_domain debug stuff from cpu_attach_domain() since that might now run with preemption disabled (due to classic RCU etc.) and sched_domain_debug() does some GFP_KERNEL allocations. Another thing to note is that we now fully rely on normal RCU and not RCU-sched, this is because with the new and exiting RCU flavours we grew over the years BH doesn't necessarily hold off RCU-sched grace periods (-rt is known to break this). This would in fact already cause us grief since we do sched_domain/sched_group iterations from softirq context. This patch is somewhat larger than I would like it to be, but I didn't find any means of shrinking/splitting this. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.245307941@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:09:50 +00:00
return cpu;
[PATCH] sched: new sched domain for representing multi-core Add a new sched domain for representing multi-core with shared caches between cores. Consider a dual package system, each package containing two cores and with last level cache shared between cores with in a package. If there are two runnable processes, with this appended patch those two processes will be scheduled on different packages. On such systems, with this patch we have observed 8% perf improvement with specJBB(2 warehouse) benchmark and 35% improvement with CFP2000 rate(with 2 users). This new domain will come into play only on multi-core systems with shared caches. On other systems, this sched domain will be removed by domain degeneration code. This new domain can be also used for implementing power savings policy (see OLS 2005 CMP kernel scheduler paper for more details.. I will post another patch for power savings policy soon) Most of the arch/* file changes are for cpu_coregroup_map() implementation. Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-27 09:15:22 +00:00
}
sched: Add book scheduling domain On top of the SMT and MC scheduling domains this adds the BOOK scheduling domain. This is useful for NUMA like machines which do not have an interface which tells which piece of memory is attached to which node or where the hardware performs striping. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20100831082844.253053798@de.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-08-31 08:28:16 +00:00
/*
sched: Dynamically allocate sched_domain/sched_group data-structures Instead of relying on static allocations for the sched_domain and sched_group trees, dynamically allocate and RCU free them. Allocating this dynamically also allows for some build_sched_groups() simplification since we can now (like with other simplifications) rely on the sched_domain tree instead of hard-coded knowledge. One tricky to note is that detach_destroy_domains() needs to hold rcu_read_lock() over the entire tear-down, per-cpu is not sufficient since that can lead to partial sched_group existance (could possibly be solved by doing the tear-down backwards but this is much more robust). A concequence of the above is that we can no longer print the sched_domain debug stuff from cpu_attach_domain() since that might now run with preemption disabled (due to classic RCU etc.) and sched_domain_debug() does some GFP_KERNEL allocations. Another thing to note is that we now fully rely on normal RCU and not RCU-sched, this is because with the new and exiting RCU flavours we grew over the years BH doesn't necessarily hold off RCU-sched grace periods (-rt is known to break this). This would in fact already cause us grief since we do sched_domain/sched_group iterations from softirq context. This patch is somewhat larger than I would like it to be, but I didn't find any means of shrinking/splitting this. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.245307941@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:09:50 +00:00
* build_sched_groups will build a circular linked list of the groups
* covered by the given span, and will set each group's ->cpumask correctly,
* and ->cpu_power to 0.
sched: Allow for overlapping sched_domain spans Allow for sched_domain spans that overlap by giving such domains their own sched_group list instead of sharing the sched_groups amongst each-other. This is needed for machines with more than 16 nodes, because sched_domain_node_span() will generate a node mask from the 16 nearest nodes without regard if these masks have any overlap. Currently sched_domains have a sched_group that maps to their child sched_domain span, and since there is no overlap we share the sched_group between the sched_domains of the various CPUs. If however there is overlap, we would need to link the sched_group list in different ways for each cpu, and hence sharing isn't possible. In order to solve this, allocate private sched_groups for each CPU's sched_domain but have the sched_groups share a sched_group_power structure such that we can uniquely track the power. Reported-and-tested-by: Anton Blanchard <anton@samba.org> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/n/tip-08bxqw9wis3qti9u5inifh3y@git.kernel.org Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-15 08:35:52 +00:00
*
* Assumes the sched_domain tree is fully constructed
sched: Add book scheduling domain On top of the SMT and MC scheduling domains this adds the BOOK scheduling domain. This is useful for NUMA like machines which do not have an interface which tells which piece of memory is attached to which node or where the hardware performs striping. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20100831082844.253053798@de.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-08-31 08:28:16 +00:00
*/
sched: Allow for overlapping sched_domain spans Allow for sched_domain spans that overlap by giving such domains their own sched_group list instead of sharing the sched_groups amongst each-other. This is needed for machines with more than 16 nodes, because sched_domain_node_span() will generate a node mask from the 16 nearest nodes without regard if these masks have any overlap. Currently sched_domains have a sched_group that maps to their child sched_domain span, and since there is no overlap we share the sched_group between the sched_domains of the various CPUs. If however there is overlap, we would need to link the sched_group list in different ways for each cpu, and hence sharing isn't possible. In order to solve this, allocate private sched_groups for each CPU's sched_domain but have the sched_groups share a sched_group_power structure such that we can uniquely track the power. Reported-and-tested-by: Anton Blanchard <anton@samba.org> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/n/tip-08bxqw9wis3qti9u5inifh3y@git.kernel.org Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-15 08:35:52 +00:00
static int
build_sched_groups(struct sched_domain *sd, int cpu)
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
{
sched: Dynamically allocate sched_domain/sched_group data-structures Instead of relying on static allocations for the sched_domain and sched_group trees, dynamically allocate and RCU free them. Allocating this dynamically also allows for some build_sched_groups() simplification since we can now (like with other simplifications) rely on the sched_domain tree instead of hard-coded knowledge. One tricky to note is that detach_destroy_domains() needs to hold rcu_read_lock() over the entire tear-down, per-cpu is not sufficient since that can lead to partial sched_group existance (could possibly be solved by doing the tear-down backwards but this is much more robust). A concequence of the above is that we can no longer print the sched_domain debug stuff from cpu_attach_domain() since that might now run with preemption disabled (due to classic RCU etc.) and sched_domain_debug() does some GFP_KERNEL allocations. Another thing to note is that we now fully rely on normal RCU and not RCU-sched, this is because with the new and exiting RCU flavours we grew over the years BH doesn't necessarily hold off RCU-sched grace periods (-rt is known to break this). This would in fact already cause us grief since we do sched_domain/sched_group iterations from softirq context. This patch is somewhat larger than I would like it to be, but I didn't find any means of shrinking/splitting this. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.245307941@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:09:50 +00:00
struct sched_group *first = NULL, *last = NULL;
struct sd_data *sdd = sd->private;
const struct cpumask *span = sched_domain_span(sd);
sched: Create persistent sched_domains_tmpmask Since sched domain creation is fully serialized by the sched_domains_mutex we can create a single persistent tmpmask to use during domain creation. This removes the need for s_data::send_covered. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.607287405@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:09:57 +00:00
struct cpumask *covered;
sched: Dynamically allocate sched_domain/sched_group data-structures Instead of relying on static allocations for the sched_domain and sched_group trees, dynamically allocate and RCU free them. Allocating this dynamically also allows for some build_sched_groups() simplification since we can now (like with other simplifications) rely on the sched_domain tree instead of hard-coded knowledge. One tricky to note is that detach_destroy_domains() needs to hold rcu_read_lock() over the entire tear-down, per-cpu is not sufficient since that can lead to partial sched_group existance (could possibly be solved by doing the tear-down backwards but this is much more robust). A concequence of the above is that we can no longer print the sched_domain debug stuff from cpu_attach_domain() since that might now run with preemption disabled (due to classic RCU etc.) and sched_domain_debug() does some GFP_KERNEL allocations. Another thing to note is that we now fully rely on normal RCU and not RCU-sched, this is because with the new and exiting RCU flavours we grew over the years BH doesn't necessarily hold off RCU-sched grace periods (-rt is known to break this). This would in fact already cause us grief since we do sched_domain/sched_group iterations from softirq context. This patch is somewhat larger than I would like it to be, but I didn't find any means of shrinking/splitting this. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.245307941@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:09:50 +00:00
int i;
[PATCH] cpusets: Move the ia64 domain setup code to the generic code Signed-off-by: John Hawkes <hawkes@sgi.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-06 22:18:14 +00:00
sched: Allow for overlapping sched_domain spans Allow for sched_domain spans that overlap by giving such domains their own sched_group list instead of sharing the sched_groups amongst each-other. This is needed for machines with more than 16 nodes, because sched_domain_node_span() will generate a node mask from the 16 nearest nodes without regard if these masks have any overlap. Currently sched_domains have a sched_group that maps to their child sched_domain span, and since there is no overlap we share the sched_group between the sched_domains of the various CPUs. If however there is overlap, we would need to link the sched_group list in different ways for each cpu, and hence sharing isn't possible. In order to solve this, allocate private sched_groups for each CPU's sched_domain but have the sched_groups share a sched_group_power structure such that we can uniquely track the power. Reported-and-tested-by: Anton Blanchard <anton@samba.org> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/n/tip-08bxqw9wis3qti9u5inifh3y@git.kernel.org Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-15 08:35:52 +00:00
get_group(cpu, sdd, &sd->groups);
atomic_inc(&sd->groups->ref);
if (cpu != cpumask_first(sched_domain_span(sd)))
return 0;
sched: Create persistent sched_domains_tmpmask Since sched domain creation is fully serialized by the sched_domains_mutex we can create a single persistent tmpmask to use during domain creation. This removes the need for s_data::send_covered. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.607287405@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:09:57 +00:00
lockdep_assert_held(&sched_domains_mutex);
covered = sched_domains_tmpmask;
sched: Dynamically allocate sched_domain/sched_group data-structures Instead of relying on static allocations for the sched_domain and sched_group trees, dynamically allocate and RCU free them. Allocating this dynamically also allows for some build_sched_groups() simplification since we can now (like with other simplifications) rely on the sched_domain tree instead of hard-coded knowledge. One tricky to note is that detach_destroy_domains() needs to hold rcu_read_lock() over the entire tear-down, per-cpu is not sufficient since that can lead to partial sched_group existance (could possibly be solved by doing the tear-down backwards but this is much more robust). A concequence of the above is that we can no longer print the sched_domain debug stuff from cpu_attach_domain() since that might now run with preemption disabled (due to classic RCU etc.) and sched_domain_debug() does some GFP_KERNEL allocations. Another thing to note is that we now fully rely on normal RCU and not RCU-sched, this is because with the new and exiting RCU flavours we grew over the years BH doesn't necessarily hold off RCU-sched grace periods (-rt is known to break this). This would in fact already cause us grief since we do sched_domain/sched_group iterations from softirq context. This patch is somewhat larger than I would like it to be, but I didn't find any means of shrinking/splitting this. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.245307941@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:09:50 +00:00
cpumask_clear(covered);
[PATCH] ched domain: move sched group allocations to percpu area Move the sched group allocations to percpu area. This will minimize cross node memory references and also cleans up the sched groups allocation for allnodes sched domain. Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Acked-by: Ingo Molnar <mingo@elte.hu> Acked-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 10:20:07 +00:00
sched: Dynamically allocate sched_domain/sched_group data-structures Instead of relying on static allocations for the sched_domain and sched_group trees, dynamically allocate and RCU free them. Allocating this dynamically also allows for some build_sched_groups() simplification since we can now (like with other simplifications) rely on the sched_domain tree instead of hard-coded knowledge. One tricky to note is that detach_destroy_domains() needs to hold rcu_read_lock() over the entire tear-down, per-cpu is not sufficient since that can lead to partial sched_group existance (could possibly be solved by doing the tear-down backwards but this is much more robust). A concequence of the above is that we can no longer print the sched_domain debug stuff from cpu_attach_domain() since that might now run with preemption disabled (due to classic RCU etc.) and sched_domain_debug() does some GFP_KERNEL allocations. Another thing to note is that we now fully rely on normal RCU and not RCU-sched, this is because with the new and exiting RCU flavours we grew over the years BH doesn't necessarily hold off RCU-sched grace periods (-rt is known to break this). This would in fact already cause us grief since we do sched_domain/sched_group iterations from softirq context. This patch is somewhat larger than I would like it to be, but I didn't find any means of shrinking/splitting this. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.245307941@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:09:50 +00:00
for_each_cpu(i, span) {
struct sched_group *sg;
int group = get_group(i, sdd, &sg);
int j;
[PATCH] ched domain: move sched group allocations to percpu area Move the sched group allocations to percpu area. This will minimize cross node memory references and also cleans up the sched groups allocation for allnodes sched domain. Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Acked-by: Ingo Molnar <mingo@elte.hu> Acked-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 10:20:07 +00:00
sched: Dynamically allocate sched_domain/sched_group data-structures Instead of relying on static allocations for the sched_domain and sched_group trees, dynamically allocate and RCU free them. Allocating this dynamically also allows for some build_sched_groups() simplification since we can now (like with other simplifications) rely on the sched_domain tree instead of hard-coded knowledge. One tricky to note is that detach_destroy_domains() needs to hold rcu_read_lock() over the entire tear-down, per-cpu is not sufficient since that can lead to partial sched_group existance (could possibly be solved by doing the tear-down backwards but this is much more robust). A concequence of the above is that we can no longer print the sched_domain debug stuff from cpu_attach_domain() since that might now run with preemption disabled (due to classic RCU etc.) and sched_domain_debug() does some GFP_KERNEL allocations. Another thing to note is that we now fully rely on normal RCU and not RCU-sched, this is because with the new and exiting RCU flavours we grew over the years BH doesn't necessarily hold off RCU-sched grace periods (-rt is known to break this). This would in fact already cause us grief since we do sched_domain/sched_group iterations from softirq context. This patch is somewhat larger than I would like it to be, but I didn't find any means of shrinking/splitting this. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.245307941@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:09:50 +00:00
if (cpumask_test_cpu(i, covered))
continue;
[PATCH] ched domain: move sched group allocations to percpu area Move the sched group allocations to percpu area. This will minimize cross node memory references and also cleans up the sched groups allocation for allnodes sched domain. Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Acked-by: Ingo Molnar <mingo@elte.hu> Acked-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 10:20:07 +00:00
sched: Dynamically allocate sched_domain/sched_group data-structures Instead of relying on static allocations for the sched_domain and sched_group trees, dynamically allocate and RCU free them. Allocating this dynamically also allows for some build_sched_groups() simplification since we can now (like with other simplifications) rely on the sched_domain tree instead of hard-coded knowledge. One tricky to note is that detach_destroy_domains() needs to hold rcu_read_lock() over the entire tear-down, per-cpu is not sufficient since that can lead to partial sched_group existance (could possibly be solved by doing the tear-down backwards but this is much more robust). A concequence of the above is that we can no longer print the sched_domain debug stuff from cpu_attach_domain() since that might now run with preemption disabled (due to classic RCU etc.) and sched_domain_debug() does some GFP_KERNEL allocations. Another thing to note is that we now fully rely on normal RCU and not RCU-sched, this is because with the new and exiting RCU flavours we grew over the years BH doesn't necessarily hold off RCU-sched grace periods (-rt is known to break this). This would in fact already cause us grief since we do sched_domain/sched_group iterations from softirq context. This patch is somewhat larger than I would like it to be, but I didn't find any means of shrinking/splitting this. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.245307941@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:09:50 +00:00
cpumask_clear(sched_group_cpus(sg));
sched: Break out cpu_power from the sched_group structure In order to prepare for non-unique sched_groups per domain, we need to carry the cpu_power elsewhere, so put a level of indirection in. Reported-and-tested-by: Anton Blanchard <anton@samba.org> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/n/tip-qkho2byuhe4482fuknss40ad@git.kernel.org Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-14 11:00:06 +00:00
sg->sgp->power = 0;
sched: Separate out build of NUMA sched groups from __build_sched_domains ... to further strip down __build_sched_domains(). Signed-off-by: Andreas Herrmann <andreas.herrmann3@amd.com> Cc: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <20090818110111.GL29515@alberich.amd.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-08-18 11:01:11 +00:00
sched: Dynamically allocate sched_domain/sched_group data-structures Instead of relying on static allocations for the sched_domain and sched_group trees, dynamically allocate and RCU free them. Allocating this dynamically also allows for some build_sched_groups() simplification since we can now (like with other simplifications) rely on the sched_domain tree instead of hard-coded knowledge. One tricky to note is that detach_destroy_domains() needs to hold rcu_read_lock() over the entire tear-down, per-cpu is not sufficient since that can lead to partial sched_group existance (could possibly be solved by doing the tear-down backwards but this is much more robust). A concequence of the above is that we can no longer print the sched_domain debug stuff from cpu_attach_domain() since that might now run with preemption disabled (due to classic RCU etc.) and sched_domain_debug() does some GFP_KERNEL allocations. Another thing to note is that we now fully rely on normal RCU and not RCU-sched, this is because with the new and exiting RCU flavours we grew over the years BH doesn't necessarily hold off RCU-sched grace periods (-rt is known to break this). This would in fact already cause us grief since we do sched_domain/sched_group iterations from softirq context. This patch is somewhat larger than I would like it to be, but I didn't find any means of shrinking/splitting this. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.245307941@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:09:50 +00:00
for_each_cpu(j, span) {
if (get_group(j, sdd, NULL) != group)
continue;
sched: Separate out build of NUMA sched groups from __build_sched_domains ... to further strip down __build_sched_domains(). Signed-off-by: Andreas Herrmann <andreas.herrmann3@amd.com> Cc: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <20090818110111.GL29515@alberich.amd.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-08-18 11:01:11 +00:00
sched: Dynamically allocate sched_domain/sched_group data-structures Instead of relying on static allocations for the sched_domain and sched_group trees, dynamically allocate and RCU free them. Allocating this dynamically also allows for some build_sched_groups() simplification since we can now (like with other simplifications) rely on the sched_domain tree instead of hard-coded knowledge. One tricky to note is that detach_destroy_domains() needs to hold rcu_read_lock() over the entire tear-down, per-cpu is not sufficient since that can lead to partial sched_group existance (could possibly be solved by doing the tear-down backwards but this is much more robust). A concequence of the above is that we can no longer print the sched_domain debug stuff from cpu_attach_domain() since that might now run with preemption disabled (due to classic RCU etc.) and sched_domain_debug() does some GFP_KERNEL allocations. Another thing to note is that we now fully rely on normal RCU and not RCU-sched, this is because with the new and exiting RCU flavours we grew over the years BH doesn't necessarily hold off RCU-sched grace periods (-rt is known to break this). This would in fact already cause us grief since we do sched_domain/sched_group iterations from softirq context. This patch is somewhat larger than I would like it to be, but I didn't find any means of shrinking/splitting this. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.245307941@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:09:50 +00:00
cpumask_set_cpu(j, covered);
cpumask_set_cpu(j, sched_group_cpus(sg));
}
sched: Separate out build of NUMA sched groups from __build_sched_domains ... to further strip down __build_sched_domains(). Signed-off-by: Andreas Herrmann <andreas.herrmann3@amd.com> Cc: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <20090818110111.GL29515@alberich.amd.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-08-18 11:01:11 +00:00
sched: Dynamically allocate sched_domain/sched_group data-structures Instead of relying on static allocations for the sched_domain and sched_group trees, dynamically allocate and RCU free them. Allocating this dynamically also allows for some build_sched_groups() simplification since we can now (like with other simplifications) rely on the sched_domain tree instead of hard-coded knowledge. One tricky to note is that detach_destroy_domains() needs to hold rcu_read_lock() over the entire tear-down, per-cpu is not sufficient since that can lead to partial sched_group existance (could possibly be solved by doing the tear-down backwards but this is much more robust). A concequence of the above is that we can no longer print the sched_domain debug stuff from cpu_attach_domain() since that might now run with preemption disabled (due to classic RCU etc.) and sched_domain_debug() does some GFP_KERNEL allocations. Another thing to note is that we now fully rely on normal RCU and not RCU-sched, this is because with the new and exiting RCU flavours we grew over the years BH doesn't necessarily hold off RCU-sched grace periods (-rt is known to break this). This would in fact already cause us grief since we do sched_domain/sched_group iterations from softirq context. This patch is somewhat larger than I would like it to be, but I didn't find any means of shrinking/splitting this. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.245307941@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:09:50 +00:00
if (!first)
first = sg;
if (last)
last->next = sg;
last = sg;
}
last->next = first;
sched: Allow for overlapping sched_domain spans Allow for sched_domain spans that overlap by giving such domains their own sched_group list instead of sharing the sched_groups amongst each-other. This is needed for machines with more than 16 nodes, because sched_domain_node_span() will generate a node mask from the 16 nearest nodes without regard if these masks have any overlap. Currently sched_domains have a sched_group that maps to their child sched_domain span, and since there is no overlap we share the sched_group between the sched_domains of the various CPUs. If however there is overlap, we would need to link the sched_group list in different ways for each cpu, and hence sharing isn't possible. In order to solve this, allocate private sched_groups for each CPU's sched_domain but have the sched_groups share a sched_group_power structure such that we can uniquely track the power. Reported-and-tested-by: Anton Blanchard <anton@samba.org> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/n/tip-08bxqw9wis3qti9u5inifh3y@git.kernel.org Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-15 08:35:52 +00:00
return 0;
sched: Separate out build of NUMA sched groups from __build_sched_domains ... to further strip down __build_sched_domains(). Signed-off-by: Andreas Herrmann <andreas.herrmann3@amd.com> Cc: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <20090818110111.GL29515@alberich.amd.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-08-18 11:01:11 +00:00
}
[PATCH] sched_domain: handle kmalloc failure Try to handle mem allocation failures in build_sched_domains by bailing out and cleaning up thus-far allocated memory. The patch has a direct consequence that we disable load balancing completely (even at sibling level) upon *any* memory allocation failure. [Lee.Schermerhorn@hp.com: bugfix] Signed-off-by: Srivatsa Vaddagir <vatsa@in.ibm.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Ingo Molnar <mingo@elte.hu> Cc: "Siddha, Suresh B" <suresh.b.siddha@intel.com> Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 09:54:38 +00:00
[PATCH] sched: cleanup sched_group cpu_power setup Up to now sched group's cpu_power for each sched domain is initialized independently. This made the setup code ugly as the new sched domains are getting added. Make the sched group cpu_power setup code generic, by using domain child field and new domain flag in sched_domain. For most of the sched domains(except NUMA), sched group's cpu_power is now computed generically using the domain properties of itself and of the child domain. sched groups in NUMA domains are setup little differently and hence they don't use this generic mechanism. Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Acked-by: Ingo Molnar <mingo@elte.hu> Acked-by: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Paul Jackson <pj@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-03 08:14:09 +00:00
/*
* Initialize sched groups cpu_power.
*
* cpu_power indicates the capacity of sched group, which is used while
* distributing the load between different sched groups in a sched domain.
* Typically cpu_power for all the groups in a sched domain will be same unless
* there are asymmetries in the topology. If there are asymmetries, group
* having more cpu_power will pickup more load compared to the group having
* less cpu_power.
*/
static void init_sched_groups_power(int cpu, struct sched_domain *sd)
{
sched: Allow for overlapping sched_domain spans Allow for sched_domain spans that overlap by giving such domains their own sched_group list instead of sharing the sched_groups amongst each-other. This is needed for machines with more than 16 nodes, because sched_domain_node_span() will generate a node mask from the 16 nearest nodes without regard if these masks have any overlap. Currently sched_domains have a sched_group that maps to their child sched_domain span, and since there is no overlap we share the sched_group between the sched_domains of the various CPUs. If however there is overlap, we would need to link the sched_group list in different ways for each cpu, and hence sharing isn't possible. In order to solve this, allocate private sched_groups for each CPU's sched_domain but have the sched_groups share a sched_group_power structure such that we can uniquely track the power. Reported-and-tested-by: Anton Blanchard <anton@samba.org> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/n/tip-08bxqw9wis3qti9u5inifh3y@git.kernel.org Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-15 08:35:52 +00:00
struct sched_group *sg = sd->groups;
[PATCH] sched: cleanup sched_group cpu_power setup Up to now sched group's cpu_power for each sched domain is initialized independently. This made the setup code ugly as the new sched domains are getting added. Make the sched group cpu_power setup code generic, by using domain child field and new domain flag in sched_domain. For most of the sched domains(except NUMA), sched group's cpu_power is now computed generically using the domain properties of itself and of the child domain. sched groups in NUMA domains are setup little differently and hence they don't use this generic mechanism. Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Acked-by: Ingo Molnar <mingo@elte.hu> Acked-by: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Paul Jackson <pj@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-03 08:14:09 +00:00
sched: Allow for overlapping sched_domain spans Allow for sched_domain spans that overlap by giving such domains their own sched_group list instead of sharing the sched_groups amongst each-other. This is needed for machines with more than 16 nodes, because sched_domain_node_span() will generate a node mask from the 16 nearest nodes without regard if these masks have any overlap. Currently sched_domains have a sched_group that maps to their child sched_domain span, and since there is no overlap we share the sched_group between the sched_domains of the various CPUs. If however there is overlap, we would need to link the sched_group list in different ways for each cpu, and hence sharing isn't possible. In order to solve this, allocate private sched_groups for each CPU's sched_domain but have the sched_groups share a sched_group_power structure such that we can uniquely track the power. Reported-and-tested-by: Anton Blanchard <anton@samba.org> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/n/tip-08bxqw9wis3qti9u5inifh3y@git.kernel.org Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-15 08:35:52 +00:00
WARN_ON(!sd || !sg);
do {
sg->group_weight = cpumask_weight(sched_group_cpus(sg));
sg = sg->next;
} while (sg != sd->groups);
[PATCH] sched: cleanup sched_group cpu_power setup Up to now sched group's cpu_power for each sched domain is initialized independently. This made the setup code ugly as the new sched domains are getting added. Make the sched group cpu_power setup code generic, by using domain child field and new domain flag in sched_domain. For most of the sched domains(except NUMA), sched group's cpu_power is now computed generically using the domain properties of itself and of the child domain. sched groups in NUMA domains are setup little differently and hence they don't use this generic mechanism. Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Acked-by: Ingo Molnar <mingo@elte.hu> Acked-by: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Paul Jackson <pj@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-03 08:14:09 +00:00
sched: Allow for overlapping sched_domain spans Allow for sched_domain spans that overlap by giving such domains their own sched_group list instead of sharing the sched_groups amongst each-other. This is needed for machines with more than 16 nodes, because sched_domain_node_span() will generate a node mask from the 16 nearest nodes without regard if these masks have any overlap. Currently sched_domains have a sched_group that maps to their child sched_domain span, and since there is no overlap we share the sched_group between the sched_domains of the various CPUs. If however there is overlap, we would need to link the sched_group list in different ways for each cpu, and hence sharing isn't possible. In order to solve this, allocate private sched_groups for each CPU's sched_domain but have the sched_groups share a sched_group_power structure such that we can uniquely track the power. Reported-and-tested-by: Anton Blanchard <anton@samba.org> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/n/tip-08bxqw9wis3qti9u5inifh3y@git.kernel.org Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-15 08:35:52 +00:00
if (cpu != group_first_cpu(sg))
return;
sched: Use group weight, idle cpu metrics to fix imbalances during idle Currently we consider a sched domain to be well balanced when the imbalance is less than the domain's imablance_pct. As the number of cores and threads are increasing, current values of imbalance_pct (for example 25% for a NUMA domain) are not enough to detect imbalances like: a) On a WSM-EP system (two sockets, each having 6 cores and 12 logical threads), 24 cpu-hogging tasks get scheduled as 13 on one socket and 11 on another socket. Leading to an idle HT cpu. b) On a hypothetial 2 socket NHM-EX system (each socket having 8 cores and 16 logical threads), 16 cpu-hogging tasks can get scheduled as 9 on one socket and 7 on another socket. Leaving one core in a socket idle whereas in another socket we have a core having both its HT siblings busy. While this issue can be fixed by decreasing the domain's imbalance_pct (by making it a function of number of logical cpus in the domain), it can potentially cause more task migrations across sched groups in an overloaded case. Fix this by using imbalance_pct only during newly_idle and busy load balancing. And during idle load balancing, check if there is an imbalance in number of idle cpu's across the busiest and this sched_group or if the busiest group has more tasks than its weight that the idle cpu in this_group can pull. Reported-by: Nikhil Rao <ncrao@google.com> Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1284760952.2676.11.camel@sbsiddha-MOBL3.sc.intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-09-17 22:02:32 +00:00
sched: Simplify ->cpu_power initialization The code in update_group_power() does what init_sched_groups_power() does and more, so remove the special init_ code and call the generic code instead. Also move the sd->span_weight initialization because update_group_power() needs it. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122941.875856012@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:09:43 +00:00
update_group_power(sd, cpu);
[PATCH] sched: cleanup sched_group cpu_power setup Up to now sched group's cpu_power for each sched domain is initialized independently. This made the setup code ugly as the new sched domains are getting added. Make the sched group cpu_power setup code generic, by using domain child field and new domain flag in sched_domain. For most of the sched domains(except NUMA), sched group's cpu_power is now computed generically using the domain properties of itself and of the child domain. sched groups in NUMA domains are setup little differently and hence they don't use this generic mechanism. Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Acked-by: Ingo Molnar <mingo@elte.hu> Acked-by: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Paul Jackson <pj@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-03 08:14:09 +00:00
}
cpumask: reduce stack usage in SD_x_INIT initializers * Remove empty cpumask_t (and all non-zero/non-null) variables in SD_*_INIT macros. Use memset(0) to clear. Also, don't inline the initializer functions to save on stack space in build_sched_domains(). * Merge change to include/linux/topology.h that uses the new node_to_cpumask_ptr function in the nr_cpus_node macro into this patch. Depends on: [mm-patch]: asm-generic-add-node_to_cpumask_ptr-macro.patch [sched-devel]: sched: add new set_cpus_allowed_ptr function Cc: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Mike Travis <travis@sgi.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-05 01:11:11 +00:00
/*
* Initializers for schedule domains
* Non-inlined to reduce accumulated stack pressure in build_sched_domains()
*/
sched debug: add name to sched_domain sysctl entries add /proc/sys/kernel/sched_domain/cpu0/domain0/name, to make it easier to see which specific scheduler domain remained at that entry. Since we process the scheduler domain tree and simplify it, it's not always immediately clear during debugging which domain came from where. depends on CONFIG_SCHED_DEBUG=y. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-09 09:35:51 +00:00
#ifdef CONFIG_SCHED_DEBUG
# define SD_INIT_NAME(sd, type) sd->name = #type
#else
# define SD_INIT_NAME(sd, type) do { } while (0)
#endif
sched: Move sched domain storage into the topology list In order to remove the last dependency on the statid domain levels, move the sd_data storage into the topology structure. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.924926412@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:10:03 +00:00
#define SD_INIT_FUNC(type) \
static noinline struct sched_domain * \
sd_init_##type(struct sched_domain_topology_level *tl, int cpu) \
{ \
struct sched_domain *sd = *per_cpu_ptr(tl->data.sd, cpu); \
*sd = SD_##type##_INIT; \
SD_INIT_NAME(sd, type); \
sd->private = &tl->data; \
return sd; \
cpumask: reduce stack usage in SD_x_INIT initializers * Remove empty cpumask_t (and all non-zero/non-null) variables in SD_*_INIT macros. Use memset(0) to clear. Also, don't inline the initializer functions to save on stack space in build_sched_domains(). * Merge change to include/linux/topology.h that uses the new node_to_cpumask_ptr function in the nr_cpus_node macro into this patch. Depends on: [mm-patch]: asm-generic-add-node_to_cpumask_ptr-macro.patch [sched-devel]: sched: add new set_cpus_allowed_ptr function Cc: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Mike Travis <travis@sgi.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-05 01:11:11 +00:00
}
SD_INIT_FUNC(CPU)
#ifdef CONFIG_NUMA
SD_INIT_FUNC(ALLNODES)
SD_INIT_FUNC(NODE)
#endif
#ifdef CONFIG_SCHED_SMT
SD_INIT_FUNC(SIBLING)
#endif
#ifdef CONFIG_SCHED_MC
SD_INIT_FUNC(MC)
#endif
sched: Add book scheduling domain On top of the SMT and MC scheduling domains this adds the BOOK scheduling domain. This is useful for NUMA like machines which do not have an interface which tells which piece of memory is attached to which node or where the hardware performs striping. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20100831082844.253053798@de.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-08-31 08:28:16 +00:00
#ifdef CONFIG_SCHED_BOOK
SD_INIT_FUNC(BOOK)
#endif
cpumask: reduce stack usage in SD_x_INIT initializers * Remove empty cpumask_t (and all non-zero/non-null) variables in SD_*_INIT macros. Use memset(0) to clear. Also, don't inline the initializer functions to save on stack space in build_sched_domains(). * Merge change to include/linux/topology.h that uses the new node_to_cpumask_ptr function in the nr_cpus_node macro into this patch. Depends on: [mm-patch]: asm-generic-add-node_to_cpumask_ptr-macro.patch [sched-devel]: sched: add new set_cpus_allowed_ptr function Cc: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Mike Travis <travis@sgi.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-05 01:11:11 +00:00
sched, cpuset: customize sched domains, core [rebased for sched-devel/latest] - Add a new cpuset file, having levels: sched_relax_domain_level - Modify partition_sched_domains() and build_sched_domains() to take attributes parameter passed from cpuset. - Fill newidle_idx for node domains which currently unused but might be required if sched_relax_domain_level become higher. - We can change the default level by boot option 'relax_domain_level='. Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-15 05:04:23 +00:00
static int default_relax_domain_level = -1;
sched: Dynamic sched_domain::level Remove the SD_LV_ enum and use dynamic level assignments. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.969433965@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:10:04 +00:00
int sched_domain_level_max;
sched, cpuset: customize sched domains, core [rebased for sched-devel/latest] - Add a new cpuset file, having levels: sched_relax_domain_level - Modify partition_sched_domains() and build_sched_domains() to take attributes parameter passed from cpuset. - Fill newidle_idx for node domains which currently unused but might be required if sched_relax_domain_level become higher. - We can change the default level by boot option 'relax_domain_level='. Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-15 05:04:23 +00:00
static int __init setup_relax_domain_level(char *str)
{
cpuset: limit the input of cpuset.sched_relax_domain_level We allow the inputs to be [-1 ... SD_LV_MAX), and return -EINVAL for inputs outside this range. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Acked-by: Paul Menage <menage@google.com> Acked-by: Paul Jackson <pj@sgi.com> Acked-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-13 02:27:17 +00:00
unsigned long val;
val = simple_strtoul(str, NULL, 0);
sched: Dynamic sched_domain::level Remove the SD_LV_ enum and use dynamic level assignments. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.969433965@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:10:04 +00:00
if (val < sched_domain_level_max)
cpuset: limit the input of cpuset.sched_relax_domain_level We allow the inputs to be [-1 ... SD_LV_MAX), and return -EINVAL for inputs outside this range. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Acked-by: Paul Menage <menage@google.com> Acked-by: Paul Jackson <pj@sgi.com> Acked-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-13 02:27:17 +00:00
default_relax_domain_level = val;
sched, cpuset: customize sched domains, core [rebased for sched-devel/latest] - Add a new cpuset file, having levels: sched_relax_domain_level - Modify partition_sched_domains() and build_sched_domains() to take attributes parameter passed from cpuset. - Fill newidle_idx for node domains which currently unused but might be required if sched_relax_domain_level become higher. - We can change the default level by boot option 'relax_domain_level='. Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-15 05:04:23 +00:00
return 1;
}
__setup("relax_domain_level=", setup_relax_domain_level);
static void set_domain_attribute(struct sched_domain *sd,
struct sched_domain_attr *attr)
{
int request;
if (!attr || attr->relax_domain_level < 0) {
if (default_relax_domain_level < 0)
return;
else
request = default_relax_domain_level;
} else
request = attr->relax_domain_level;
if (request < sd->level) {
/* turn off idle balance on this domain */
sched: Merge select_task_rq_fair() and sched_balance_self() The problem with wake_idle() is that is doesn't respect things like cpu_power, which means it doesn't deal well with SMT nor the recent RT interaction. To cure this, it needs to do what sched_balance_self() does, which leads to the possibility of merging select_task_rq_fair() and sched_balance_self(). Modify sched_balance_self() to: - update_shares() when walking up the domain tree, (it only called it for the top domain, but it should have done this anyway), which allows us to remove this ugly bit from try_to_wake_up(). - do wake_affine() on the smallest domain that contains both this (the waking) and the prev (the wakee) cpu for WAKE invocations. Then use the top-down balance steps it had to replace wake_idle(). This leads to the dissapearance of SD_WAKE_BALANCE and SD_WAKE_IDLE_FAR, with SD_WAKE_IDLE replaced with SD_BALANCE_WAKE. SD_WAKE_AFFINE needs SD_BALANCE_WAKE to be effective. Touch all topology bits to replace the old with new SD flags -- platforms might need re-tuning, enabling SD_BALANCE_WAKE conditionally on a NUMA distance seems like a good additional feature, magny-core and small nehalem systems would want this enabled, systems with slow interconnects would not. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-09-10 11:50:02 +00:00
sd->flags &= ~(SD_BALANCE_WAKE|SD_BALANCE_NEWIDLE);
sched, cpuset: customize sched domains, core [rebased for sched-devel/latest] - Add a new cpuset file, having levels: sched_relax_domain_level - Modify partition_sched_domains() and build_sched_domains() to take attributes parameter passed from cpuset. - Fill newidle_idx for node domains which currently unused but might be required if sched_relax_domain_level become higher. - We can change the default level by boot option 'relax_domain_level='. Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-15 05:04:23 +00:00
} else {
/* turn on idle balance on this domain */
sched: Merge select_task_rq_fair() and sched_balance_self() The problem with wake_idle() is that is doesn't respect things like cpu_power, which means it doesn't deal well with SMT nor the recent RT interaction. To cure this, it needs to do what sched_balance_self() does, which leads to the possibility of merging select_task_rq_fair() and sched_balance_self(). Modify sched_balance_self() to: - update_shares() when walking up the domain tree, (it only called it for the top domain, but it should have done this anyway), which allows us to remove this ugly bit from try_to_wake_up(). - do wake_affine() on the smallest domain that contains both this (the waking) and the prev (the wakee) cpu for WAKE invocations. Then use the top-down balance steps it had to replace wake_idle(). This leads to the dissapearance of SD_WAKE_BALANCE and SD_WAKE_IDLE_FAR, with SD_WAKE_IDLE replaced with SD_BALANCE_WAKE. SD_WAKE_AFFINE needs SD_BALANCE_WAKE to be effective. Touch all topology bits to replace the old with new SD flags -- platforms might need re-tuning, enabling SD_BALANCE_WAKE conditionally on a NUMA distance seems like a good additional feature, magny-core and small nehalem systems would want this enabled, systems with slow interconnects would not. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-09-10 11:50:02 +00:00
sd->flags |= (SD_BALANCE_WAKE|SD_BALANCE_NEWIDLE);
sched, cpuset: customize sched domains, core [rebased for sched-devel/latest] - Add a new cpuset file, having levels: sched_relax_domain_level - Modify partition_sched_domains() and build_sched_domains() to take attributes parameter passed from cpuset. - Fill newidle_idx for node domains which currently unused but might be required if sched_relax_domain_level become higher. - We can change the default level by boot option 'relax_domain_level='. Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-15 05:04:23 +00:00
}
}
sched: Move sched domain storage into the topology list In order to remove the last dependency on the statid domain levels, move the sd_data storage into the topology structure. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.924926412@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:10:03 +00:00
static void __sdt_free(const struct cpumask *cpu_map);
static int __sdt_alloc(const struct cpumask *cpu_map);
sched: Separate out allocation/free/goto-hell from __build_sched_domains Signed-off-by: Andreas Herrmann <andreas.herrmann3@amd.com> Cc: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <20090818105300.GC29515@alberich.amd.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-08-18 10:53:00 +00:00
static void __free_domain_allocs(struct s_data *d, enum s_alloc what,
const struct cpumask *cpu_map)
{
switch (what) {
case sa_rootdomain:
sched: Simplify the free path some If we check the root_domain reference count we can see if its been used or not, use this observation to simplify some of the return paths. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.298339503@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:09:51 +00:00
if (!atomic_read(&d->rd->refcount))
free_rootdomain(&d->rd->rcu); /* fall through */
sched: Simplify finding the lowest sched_domain Instead of relying on knowing the build order and various CONFIG_ flags simply remember the bottom most sched_domain when we created the domain hierarchy. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.134511046@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:09:48 +00:00
case sa_sd:
free_percpu(d->sd); /* fall through */
sched: Dynamically allocate sched_domain/sched_group data-structures Instead of relying on static allocations for the sched_domain and sched_group trees, dynamically allocate and RCU free them. Allocating this dynamically also allows for some build_sched_groups() simplification since we can now (like with other simplifications) rely on the sched_domain tree instead of hard-coded knowledge. One tricky to note is that detach_destroy_domains() needs to hold rcu_read_lock() over the entire tear-down, per-cpu is not sufficient since that can lead to partial sched_group existance (could possibly be solved by doing the tear-down backwards but this is much more robust). A concequence of the above is that we can no longer print the sched_domain debug stuff from cpu_attach_domain() since that might now run with preemption disabled (due to classic RCU etc.) and sched_domain_debug() does some GFP_KERNEL allocations. Another thing to note is that we now fully rely on normal RCU and not RCU-sched, this is because with the new and exiting RCU flavours we grew over the years BH doesn't necessarily hold off RCU-sched grace periods (-rt is known to break this). This would in fact already cause us grief since we do sched_domain/sched_group iterations from softirq context. This patch is somewhat larger than I would like it to be, but I didn't find any means of shrinking/splitting this. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.245307941@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:09:50 +00:00
case sa_sd_storage:
sched: Move sched domain storage into the topology list In order to remove the last dependency on the statid domain levels, move the sd_data storage into the topology structure. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.924926412@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:10:03 +00:00
__sdt_free(cpu_map); /* fall through */
sched: Separate out allocation/free/goto-hell from __build_sched_domains Signed-off-by: Andreas Herrmann <andreas.herrmann3@amd.com> Cc: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <20090818105300.GC29515@alberich.amd.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-08-18 10:53:00 +00:00
case sa_none:
break;
}
}
sched: get rid of boutique sched.c allocations, use cpumask_var_t. Impact: use new general API Using lots of allocs rather than one big alloc is less efficient, but who cares for this setup function? Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Mike Travis <travis@sgi.com> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-24 16:05:03 +00:00
sched: Separate out allocation/free/goto-hell from __build_sched_domains Signed-off-by: Andreas Herrmann <andreas.herrmann3@amd.com> Cc: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <20090818105300.GC29515@alberich.amd.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-08-18 10:53:00 +00:00
static enum s_alloc __visit_domain_allocation_hell(struct s_data *d,
const struct cpumask *cpu_map)
{
sched: Dynamically allocate sched_domain/sched_group data-structures Instead of relying on static allocations for the sched_domain and sched_group trees, dynamically allocate and RCU free them. Allocating this dynamically also allows for some build_sched_groups() simplification since we can now (like with other simplifications) rely on the sched_domain tree instead of hard-coded knowledge. One tricky to note is that detach_destroy_domains() needs to hold rcu_read_lock() over the entire tear-down, per-cpu is not sufficient since that can lead to partial sched_group existance (could possibly be solved by doing the tear-down backwards but this is much more robust). A concequence of the above is that we can no longer print the sched_domain debug stuff from cpu_attach_domain() since that might now run with preemption disabled (due to classic RCU etc.) and sched_domain_debug() does some GFP_KERNEL allocations. Another thing to note is that we now fully rely on normal RCU and not RCU-sched, this is because with the new and exiting RCU flavours we grew over the years BH doesn't necessarily hold off RCU-sched grace periods (-rt is known to break this). This would in fact already cause us grief since we do sched_domain/sched_group iterations from softirq context. This patch is somewhat larger than I would like it to be, but I didn't find any means of shrinking/splitting this. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.245307941@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:09:50 +00:00
memset(d, 0, sizeof(*d));
sched: Move sched domain storage into the topology list In order to remove the last dependency on the statid domain levels, move the sd_data storage into the topology structure. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.924926412@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:10:03 +00:00
if (__sdt_alloc(cpu_map))
return sa_sd_storage;
sched: Dynamically allocate sched_domain/sched_group data-structures Instead of relying on static allocations for the sched_domain and sched_group trees, dynamically allocate and RCU free them. Allocating this dynamically also allows for some build_sched_groups() simplification since we can now (like with other simplifications) rely on the sched_domain tree instead of hard-coded knowledge. One tricky to note is that detach_destroy_domains() needs to hold rcu_read_lock() over the entire tear-down, per-cpu is not sufficient since that can lead to partial sched_group existance (could possibly be solved by doing the tear-down backwards but this is much more robust). A concequence of the above is that we can no longer print the sched_domain debug stuff from cpu_attach_domain() since that might now run with preemption disabled (due to classic RCU etc.) and sched_domain_debug() does some GFP_KERNEL allocations. Another thing to note is that we now fully rely on normal RCU and not RCU-sched, this is because with the new and exiting RCU flavours we grew over the years BH doesn't necessarily hold off RCU-sched grace periods (-rt is known to break this). This would in fact already cause us grief since we do sched_domain/sched_group iterations from softirq context. This patch is somewhat larger than I would like it to be, but I didn't find any means of shrinking/splitting this. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.245307941@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:09:50 +00:00
d->sd = alloc_percpu(struct sched_domain *);
if (!d->sd)
return sa_sd_storage;
sched: Separate out allocation/free/goto-hell from __build_sched_domains Signed-off-by: Andreas Herrmann <andreas.herrmann3@amd.com> Cc: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <20090818105300.GC29515@alberich.amd.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-08-18 10:53:00 +00:00
d->rd = alloc_rootdomain();
sched: Dynamically allocate sched_domain/sched_group data-structures Instead of relying on static allocations for the sched_domain and sched_group trees, dynamically allocate and RCU free them. Allocating this dynamically also allows for some build_sched_groups() simplification since we can now (like with other simplifications) rely on the sched_domain tree instead of hard-coded knowledge. One tricky to note is that detach_destroy_domains() needs to hold rcu_read_lock() over the entire tear-down, per-cpu is not sufficient since that can lead to partial sched_group existance (could possibly be solved by doing the tear-down backwards but this is much more robust). A concequence of the above is that we can no longer print the sched_domain debug stuff from cpu_attach_domain() since that might now run with preemption disabled (due to classic RCU etc.) and sched_domain_debug() does some GFP_KERNEL allocations. Another thing to note is that we now fully rely on normal RCU and not RCU-sched, this is because with the new and exiting RCU flavours we grew over the years BH doesn't necessarily hold off RCU-sched grace periods (-rt is known to break this). This would in fact already cause us grief since we do sched_domain/sched_group iterations from softirq context. This patch is somewhat larger than I would like it to be, but I didn't find any means of shrinking/splitting this. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.245307941@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:09:50 +00:00
if (!d->rd)
sched: Simplify finding the lowest sched_domain Instead of relying on knowing the build order and various CONFIG_ flags simply remember the bottom most sched_domain when we created the domain hierarchy. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.134511046@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:09:48 +00:00
return sa_sd;
sched: Separate out allocation/free/goto-hell from __build_sched_domains Signed-off-by: Andreas Herrmann <andreas.herrmann3@amd.com> Cc: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <20090818105300.GC29515@alberich.amd.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-08-18 10:53:00 +00:00
return sa_rootdomain;
}
sched: add sched-domain roots We add the notion of a root-domain which will be used later to rescope global variables to per-domain variables. Each exclusive cpuset essentially defines an island domain by fully partitioning the member cpus from any other cpuset. However, we currently still maintain some policy/state as global variables which transcend all cpusets. Consider, for instance, rt-overload state. Whenever a new exclusive cpuset is created, we also create a new root-domain object and move each cpu member to the root-domain's span. By default the system creates a single root-domain with all cpus as members (mimicking the global state we have today). We add some plumbing for storing class specific data in our root-domain. Whenever a RQ is switching root-domains (because of repartitioning) we give each sched_class the opportunity to remove any state from its old domain and add state to the new one. This logic doesn't have any clients yet but it will later in the series. Signed-off-by: Gregory Haskins <ghaskins@novell.com> CC: Christoph Lameter <clameter@sgi.com> CC: Paul Jackson <pj@sgi.com> CC: Simon Derr <simon.derr@bull.net> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:18 +00:00
sched: Dynamically allocate sched_domain/sched_group data-structures Instead of relying on static allocations for the sched_domain and sched_group trees, dynamically allocate and RCU free them. Allocating this dynamically also allows for some build_sched_groups() simplification since we can now (like with other simplifications) rely on the sched_domain tree instead of hard-coded knowledge. One tricky to note is that detach_destroy_domains() needs to hold rcu_read_lock() over the entire tear-down, per-cpu is not sufficient since that can lead to partial sched_group existance (could possibly be solved by doing the tear-down backwards but this is much more robust). A concequence of the above is that we can no longer print the sched_domain debug stuff from cpu_attach_domain() since that might now run with preemption disabled (due to classic RCU etc.) and sched_domain_debug() does some GFP_KERNEL allocations. Another thing to note is that we now fully rely on normal RCU and not RCU-sched, this is because with the new and exiting RCU flavours we grew over the years BH doesn't necessarily hold off RCU-sched grace periods (-rt is known to break this). This would in fact already cause us grief since we do sched_domain/sched_group iterations from softirq context. This patch is somewhat larger than I would like it to be, but I didn't find any means of shrinking/splitting this. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.245307941@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:09:50 +00:00
/*
* NULL the sd_data elements we've used to build the sched_domain and
* sched_group structure so that the subsequent __free_domain_allocs()
* will not free the data we're using.
*/
static void claim_allocations(int cpu, struct sched_domain *sd)
{
struct sd_data *sdd = sd->private;
WARN_ON_ONCE(*per_cpu_ptr(sdd->sd, cpu) != sd);
*per_cpu_ptr(sdd->sd, cpu) = NULL;
sched: Allow for overlapping sched_domain spans Allow for sched_domain spans that overlap by giving such domains their own sched_group list instead of sharing the sched_groups amongst each-other. This is needed for machines with more than 16 nodes, because sched_domain_node_span() will generate a node mask from the 16 nearest nodes without regard if these masks have any overlap. Currently sched_domains have a sched_group that maps to their child sched_domain span, and since there is no overlap we share the sched_group between the sched_domains of the various CPUs. If however there is overlap, we would need to link the sched_group list in different ways for each cpu, and hence sharing isn't possible. In order to solve this, allocate private sched_groups for each CPU's sched_domain but have the sched_groups share a sched_group_power structure such that we can uniquely track the power. Reported-and-tested-by: Anton Blanchard <anton@samba.org> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/n/tip-08bxqw9wis3qti9u5inifh3y@git.kernel.org Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-15 08:35:52 +00:00
if (atomic_read(&(*per_cpu_ptr(sdd->sg, cpu))->ref))
sched: Dynamically allocate sched_domain/sched_group data-structures Instead of relying on static allocations for the sched_domain and sched_group trees, dynamically allocate and RCU free them. Allocating this dynamically also allows for some build_sched_groups() simplification since we can now (like with other simplifications) rely on the sched_domain tree instead of hard-coded knowledge. One tricky to note is that detach_destroy_domains() needs to hold rcu_read_lock() over the entire tear-down, per-cpu is not sufficient since that can lead to partial sched_group existance (could possibly be solved by doing the tear-down backwards but this is much more robust). A concequence of the above is that we can no longer print the sched_domain debug stuff from cpu_attach_domain() since that might now run with preemption disabled (due to classic RCU etc.) and sched_domain_debug() does some GFP_KERNEL allocations. Another thing to note is that we now fully rely on normal RCU and not RCU-sched, this is because with the new and exiting RCU flavours we grew over the years BH doesn't necessarily hold off RCU-sched grace periods (-rt is known to break this). This would in fact already cause us grief since we do sched_domain/sched_group iterations from softirq context. This patch is somewhat larger than I would like it to be, but I didn't find any means of shrinking/splitting this. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.245307941@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:09:50 +00:00
*per_cpu_ptr(sdd->sg, cpu) = NULL;
sched: Allow for overlapping sched_domain spans Allow for sched_domain spans that overlap by giving such domains their own sched_group list instead of sharing the sched_groups amongst each-other. This is needed for machines with more than 16 nodes, because sched_domain_node_span() will generate a node mask from the 16 nearest nodes without regard if these masks have any overlap. Currently sched_domains have a sched_group that maps to their child sched_domain span, and since there is no overlap we share the sched_group between the sched_domains of the various CPUs. If however there is overlap, we would need to link the sched_group list in different ways for each cpu, and hence sharing isn't possible. In order to solve this, allocate private sched_groups for each CPU's sched_domain but have the sched_groups share a sched_group_power structure such that we can uniquely track the power. Reported-and-tested-by: Anton Blanchard <anton@samba.org> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/n/tip-08bxqw9wis3qti9u5inifh3y@git.kernel.org Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-15 08:35:52 +00:00
if (atomic_read(&(*per_cpu_ptr(sdd->sgp, cpu))->ref))
sched: Break out cpu_power from the sched_group structure In order to prepare for non-unique sched_groups per domain, we need to carry the cpu_power elsewhere, so put a level of indirection in. Reported-and-tested-by: Anton Blanchard <anton@samba.org> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/n/tip-qkho2byuhe4482fuknss40ad@git.kernel.org Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-14 11:00:06 +00:00
*per_cpu_ptr(sdd->sgp, cpu) = NULL;
sched: Dynamically allocate sched_domain/sched_group data-structures Instead of relying on static allocations for the sched_domain and sched_group trees, dynamically allocate and RCU free them. Allocating this dynamically also allows for some build_sched_groups() simplification since we can now (like with other simplifications) rely on the sched_domain tree instead of hard-coded knowledge. One tricky to note is that detach_destroy_domains() needs to hold rcu_read_lock() over the entire tear-down, per-cpu is not sufficient since that can lead to partial sched_group existance (could possibly be solved by doing the tear-down backwards but this is much more robust). A concequence of the above is that we can no longer print the sched_domain debug stuff from cpu_attach_domain() since that might now run with preemption disabled (due to classic RCU etc.) and sched_domain_debug() does some GFP_KERNEL allocations. Another thing to note is that we now fully rely on normal RCU and not RCU-sched, this is because with the new and exiting RCU flavours we grew over the years BH doesn't necessarily hold off RCU-sched grace periods (-rt is known to break this). This would in fact already cause us grief since we do sched_domain/sched_group iterations from softirq context. This patch is somewhat larger than I would like it to be, but I didn't find any means of shrinking/splitting this. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.245307941@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:09:50 +00:00
}
sched: Unify the sched_domain build functions Since all the __build_$DOM_sched_domain() functions do pretty much the same thing, unify them. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.826347257@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:10:01 +00:00
#ifdef CONFIG_SCHED_SMT
static const struct cpumask *cpu_smt_mask(int cpu)
sched: Separate out build of NUMA sched domain from __build_sched_domains ... to further strip down __build_sched_domains(). Signed-off-by: Andreas Herrmann <andreas.herrmann3@amd.com> Cc: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <20090818105406.GD29515@alberich.amd.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-08-18 10:54:06 +00:00
{
sched: Unify the sched_domain build functions Since all the __build_$DOM_sched_domain() functions do pretty much the same thing, unify them. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.826347257@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:10:01 +00:00
return topology_thread_cpumask(cpu);
sched: Simplify NODE/ALLNODES domain creation Don't treat ALLNODES/NODE different for difference's sake. Simply always create the ALLNODES domain and let the sd_degenerate() checks kill it when its redundant. This simplifies the code flow. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.455464579@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:09:54 +00:00
}
sched: Unify the sched_domain build functions Since all the __build_$DOM_sched_domain() functions do pretty much the same thing, unify them. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.826347257@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:10:01 +00:00
#endif
sched: Separate out build of NUMA sched domain from __build_sched_domains ... to further strip down __build_sched_domains(). Signed-off-by: Andreas Herrmann <andreas.herrmann3@amd.com> Cc: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <20090818105406.GD29515@alberich.amd.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-08-18 10:54:06 +00:00
sched: Reverse the topology list In order to get rid of static sched_domain::level assignments, reverse the topology iteration. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.876506131@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:10:02 +00:00
/*
* Topology list, bottom-up.
*/
sched: Unify the sched_domain build functions Since all the __build_$DOM_sched_domain() functions do pretty much the same thing, unify them. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.826347257@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:10:01 +00:00
static struct sched_domain_topology_level default_topology[] = {
sched: Reverse the topology list In order to get rid of static sched_domain::level assignments, reverse the topology iteration. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.876506131@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:10:02 +00:00
#ifdef CONFIG_SCHED_SMT
{ sd_init_SIBLING, cpu_smt_mask, },
sched: Add book scheduling domain On top of the SMT and MC scheduling domains this adds the BOOK scheduling domain. This is useful for NUMA like machines which do not have an interface which tells which piece of memory is attached to which node or where the hardware performs striping. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20100831082844.253053798@de.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-08-31 08:28:16 +00:00
#endif
[PATCH] sched: new sched domain for representing multi-core Add a new sched domain for representing multi-core with shared caches between cores. Consider a dual package system, each package containing two cores and with last level cache shared between cores with in a package. If there are two runnable processes, with this appended patch those two processes will be scheduled on different packages. On such systems, with this patch we have observed 8% perf improvement with specJBB(2 warehouse) benchmark and 35% improvement with CFP2000 rate(with 2 users). This new domain will come into play only on multi-core systems with shared caches. On other systems, this sched domain will be removed by domain degeneration code. This new domain can be also used for implementing power savings policy (see OLS 2005 CMP kernel scheduler paper for more details.. I will post another patch for power savings policy soon) Most of the arch/* file changes are for cpu_coregroup_map() implementation. Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-27 09:15:22 +00:00
#ifdef CONFIG_SCHED_MC
sched: Unify the sched_domain build functions Since all the __build_$DOM_sched_domain() functions do pretty much the same thing, unify them. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.826347257@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:10:01 +00:00
{ sd_init_MC, cpu_coregroup_mask, },
[PATCH] sched: new sched domain for representing multi-core Add a new sched domain for representing multi-core with shared caches between cores. Consider a dual package system, each package containing two cores and with last level cache shared between cores with in a package. If there are two runnable processes, with this appended patch those two processes will be scheduled on different packages. On such systems, with this patch we have observed 8% perf improvement with specJBB(2 warehouse) benchmark and 35% improvement with CFP2000 rate(with 2 users). This new domain will come into play only on multi-core systems with shared caches. On other systems, this sched domain will be removed by domain degeneration code. This new domain can be also used for implementing power savings policy (see OLS 2005 CMP kernel scheduler paper for more details.. I will post another patch for power savings policy soon) Most of the arch/* file changes are for cpu_coregroup_map() implementation. Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-27 09:15:22 +00:00
#endif
sched: Reverse the topology list In order to get rid of static sched_domain::level assignments, reverse the topology iteration. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.876506131@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:10:02 +00:00
#ifdef CONFIG_SCHED_BOOK
{ sd_init_BOOK, cpu_book_mask, },
#endif
{ sd_init_CPU, cpu_cpu_mask, },
#ifdef CONFIG_NUMA
sched: Allow for overlapping sched_domain spans Allow for sched_domain spans that overlap by giving such domains their own sched_group list instead of sharing the sched_groups amongst each-other. This is needed for machines with more than 16 nodes, because sched_domain_node_span() will generate a node mask from the 16 nearest nodes without regard if these masks have any overlap. Currently sched_domains have a sched_group that maps to their child sched_domain span, and since there is no overlap we share the sched_group between the sched_domains of the various CPUs. If however there is overlap, we would need to link the sched_group list in different ways for each cpu, and hence sharing isn't possible. In order to solve this, allocate private sched_groups for each CPU's sched_domain but have the sched_groups share a sched_group_power structure such that we can uniquely track the power. Reported-and-tested-by: Anton Blanchard <anton@samba.org> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/n/tip-08bxqw9wis3qti9u5inifh3y@git.kernel.org Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-15 08:35:52 +00:00
{ sd_init_NODE, cpu_node_mask, SDTL_OVERLAP, },
sched: Reverse the topology list In order to get rid of static sched_domain::level assignments, reverse the topology iteration. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.876506131@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:10:02 +00:00
{ sd_init_ALLNODES, cpu_allnodes_mask, },
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
#endif
sched: Stuff the sched_domain creation in a data-structure In order to make the topology contruction fully dynamic, remove the still hard-coded list of possible domains and stick them in a data-structure. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.770335383@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:10:00 +00:00
{ NULL, },
};
static struct sched_domain_topology_level *sched_domain_topology = default_topology;
sched: Move sched domain storage into the topology list In order to remove the last dependency on the statid domain levels, move the sd_data storage into the topology structure. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.924926412@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:10:03 +00:00
static int __sdt_alloc(const struct cpumask *cpu_map)
{
struct sched_domain_topology_level *tl;
int j;
for (tl = sched_domain_topology; tl->init; tl++) {
struct sd_data *sdd = &tl->data;
sdd->sd = alloc_percpu(struct sched_domain *);
if (!sdd->sd)
return -ENOMEM;
sdd->sg = alloc_percpu(struct sched_group *);
if (!sdd->sg)
return -ENOMEM;
sched: Break out cpu_power from the sched_group structure In order to prepare for non-unique sched_groups per domain, we need to carry the cpu_power elsewhere, so put a level of indirection in. Reported-and-tested-by: Anton Blanchard <anton@samba.org> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/n/tip-qkho2byuhe4482fuknss40ad@git.kernel.org Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-14 11:00:06 +00:00
sdd->sgp = alloc_percpu(struct sched_group_power *);
if (!sdd->sgp)
return -ENOMEM;
sched: Move sched domain storage into the topology list In order to remove the last dependency on the statid domain levels, move the sd_data storage into the topology structure. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.924926412@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:10:03 +00:00
for_each_cpu(j, cpu_map) {
struct sched_domain *sd;
struct sched_group *sg;
sched: Break out cpu_power from the sched_group structure In order to prepare for non-unique sched_groups per domain, we need to carry the cpu_power elsewhere, so put a level of indirection in. Reported-and-tested-by: Anton Blanchard <anton@samba.org> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/n/tip-qkho2byuhe4482fuknss40ad@git.kernel.org Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-14 11:00:06 +00:00
struct sched_group_power *sgp;
sched: Move sched domain storage into the topology list In order to remove the last dependency on the statid domain levels, move the sd_data storage into the topology structure. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.924926412@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:10:03 +00:00
sd = kzalloc_node(sizeof(struct sched_domain) + cpumask_size(),
GFP_KERNEL, cpu_to_node(j));
if (!sd)
return -ENOMEM;
*per_cpu_ptr(sdd->sd, j) = sd;
sg = kzalloc_node(sizeof(struct sched_group) + cpumask_size(),
GFP_KERNEL, cpu_to_node(j));
if (!sg)
return -ENOMEM;
*per_cpu_ptr(sdd->sg, j) = sg;
sched: Break out cpu_power from the sched_group structure In order to prepare for non-unique sched_groups per domain, we need to carry the cpu_power elsewhere, so put a level of indirection in. Reported-and-tested-by: Anton Blanchard <anton@samba.org> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/n/tip-qkho2byuhe4482fuknss40ad@git.kernel.org Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-14 11:00:06 +00:00
sgp = kzalloc_node(sizeof(struct sched_group_power),
GFP_KERNEL, cpu_to_node(j));
if (!sgp)
return -ENOMEM;
*per_cpu_ptr(sdd->sgp, j) = sgp;
sched: Move sched domain storage into the topology list In order to remove the last dependency on the statid domain levels, move the sd_data storage into the topology structure. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.924926412@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:10:03 +00:00
}
}
return 0;
}
static void __sdt_free(const struct cpumask *cpu_map)
{
struct sched_domain_topology_level *tl;
int j;
for (tl = sched_domain_topology; tl->init; tl++) {
struct sd_data *sdd = &tl->data;
for_each_cpu(j, cpu_map) {
sched: Allow for overlapping sched_domain spans Allow for sched_domain spans that overlap by giving such domains their own sched_group list instead of sharing the sched_groups amongst each-other. This is needed for machines with more than 16 nodes, because sched_domain_node_span() will generate a node mask from the 16 nearest nodes without regard if these masks have any overlap. Currently sched_domains have a sched_group that maps to their child sched_domain span, and since there is no overlap we share the sched_group between the sched_domains of the various CPUs. If however there is overlap, we would need to link the sched_group list in different ways for each cpu, and hence sharing isn't possible. In order to solve this, allocate private sched_groups for each CPU's sched_domain but have the sched_groups share a sched_group_power structure such that we can uniquely track the power. Reported-and-tested-by: Anton Blanchard <anton@samba.org> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/n/tip-08bxqw9wis3qti9u5inifh3y@git.kernel.org Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-15 08:35:52 +00:00
struct sched_domain *sd = *per_cpu_ptr(sdd->sd, j);
if (sd && (sd->flags & SD_OVERLAP))
free_sched_groups(sd->groups, 0);
sched: Move sched domain storage into the topology list In order to remove the last dependency on the statid domain levels, move the sd_data storage into the topology structure. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.924926412@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:10:03 +00:00
kfree(*per_cpu_ptr(sdd->sg, j));
sched: Break out cpu_power from the sched_group structure In order to prepare for non-unique sched_groups per domain, we need to carry the cpu_power elsewhere, so put a level of indirection in. Reported-and-tested-by: Anton Blanchard <anton@samba.org> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/n/tip-qkho2byuhe4482fuknss40ad@git.kernel.org Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-14 11:00:06 +00:00
kfree(*per_cpu_ptr(sdd->sgp, j));
sched: Move sched domain storage into the topology list In order to remove the last dependency on the statid domain levels, move the sd_data storage into the topology structure. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.924926412@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:10:03 +00:00
}
free_percpu(sdd->sd);
free_percpu(sdd->sg);
sched: Break out cpu_power from the sched_group structure In order to prepare for non-unique sched_groups per domain, we need to carry the cpu_power elsewhere, so put a level of indirection in. Reported-and-tested-by: Anton Blanchard <anton@samba.org> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/n/tip-qkho2byuhe4482fuknss40ad@git.kernel.org Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-14 11:00:06 +00:00
free_percpu(sdd->sgp);
sched: Move sched domain storage into the topology list In order to remove the last dependency on the statid domain levels, move the sd_data storage into the topology structure. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.924926412@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:10:03 +00:00
}
}
sched: Unify the sched_domain build functions Since all the __build_$DOM_sched_domain() functions do pretty much the same thing, unify them. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.826347257@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:10:01 +00:00
struct sched_domain *build_sched_domain(struct sched_domain_topology_level *tl,
struct s_data *d, const struct cpumask *cpu_map,
sched: Reverse the topology list In order to get rid of static sched_domain::level assignments, reverse the topology iteration. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.876506131@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:10:02 +00:00
struct sched_domain_attr *attr, struct sched_domain *child,
sched: Unify the sched_domain build functions Since all the __build_$DOM_sched_domain() functions do pretty much the same thing, unify them. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.826347257@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:10:01 +00:00
int cpu)
{
sched: Move sched domain storage into the topology list In order to remove the last dependency on the statid domain levels, move the sd_data storage into the topology structure. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.924926412@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:10:03 +00:00
struct sched_domain *sd = tl->init(tl, cpu);
sched: Unify the sched_domain build functions Since all the __build_$DOM_sched_domain() functions do pretty much the same thing, unify them. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.826347257@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:10:01 +00:00
if (!sd)
sched: Reverse the topology list In order to get rid of static sched_domain::level assignments, reverse the topology iteration. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.876506131@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:10:02 +00:00
return child;
sched: Unify the sched_domain build functions Since all the __build_$DOM_sched_domain() functions do pretty much the same thing, unify them. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.826347257@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:10:01 +00:00
set_domain_attribute(sd, attr);
cpumask_and(sched_domain_span(sd), cpu_map, tl->mask(cpu));
sched: Dynamic sched_domain::level Remove the SD_LV_ enum and use dynamic level assignments. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.969433965@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:10:04 +00:00
if (child) {
sd->level = child->level + 1;
sched_domain_level_max = max(sched_domain_level_max, sd->level);
sched: Reverse the topology list In order to get rid of static sched_domain::level assignments, reverse the topology iteration. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.876506131@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:10:02 +00:00
child->parent = sd;
sched: Dynamic sched_domain::level Remove the SD_LV_ enum and use dynamic level assignments. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.969433965@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:10:04 +00:00
}
sched: Reverse the topology list In order to get rid of static sched_domain::level assignments, reverse the topology iteration. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.876506131@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:10:02 +00:00
sd->child = child;
sched: Unify the sched_domain build functions Since all the __build_$DOM_sched_domain() functions do pretty much the same thing, unify them. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.826347257@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:10:01 +00:00
return sd;
}
sched: Separate out allocation/free/goto-hell from __build_sched_domains Signed-off-by: Andreas Herrmann <andreas.herrmann3@amd.com> Cc: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <20090818105300.GC29515@alberich.amd.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-08-18 10:53:00 +00:00
/*
* Build sched domains for a given set of cpus and attach the sched domains
* to the individual cpus
*/
sched: Dynamically allocate sched_domain/sched_group data-structures Instead of relying on static allocations for the sched_domain and sched_group trees, dynamically allocate and RCU free them. Allocating this dynamically also allows for some build_sched_groups() simplification since we can now (like with other simplifications) rely on the sched_domain tree instead of hard-coded knowledge. One tricky to note is that detach_destroy_domains() needs to hold rcu_read_lock() over the entire tear-down, per-cpu is not sufficient since that can lead to partial sched_group existance (could possibly be solved by doing the tear-down backwards but this is much more robust). A concequence of the above is that we can no longer print the sched_domain debug stuff from cpu_attach_domain() since that might now run with preemption disabled (due to classic RCU etc.) and sched_domain_debug() does some GFP_KERNEL allocations. Another thing to note is that we now fully rely on normal RCU and not RCU-sched, this is because with the new and exiting RCU flavours we grew over the years BH doesn't necessarily hold off RCU-sched grace periods (-rt is known to break this). This would in fact already cause us grief since we do sched_domain/sched_group iterations from softirq context. This patch is somewhat larger than I would like it to be, but I didn't find any means of shrinking/splitting this. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.245307941@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:09:50 +00:00
static int build_sched_domains(const struct cpumask *cpu_map,
struct sched_domain_attr *attr)
sched: Separate out allocation/free/goto-hell from __build_sched_domains Signed-off-by: Andreas Herrmann <andreas.herrmann3@amd.com> Cc: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <20090818105300.GC29515@alberich.amd.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-08-18 10:53:00 +00:00
{
enum s_alloc alloc_state = sa_none;
sched: Dynamically allocate sched_domain/sched_group data-structures Instead of relying on static allocations for the sched_domain and sched_group trees, dynamically allocate and RCU free them. Allocating this dynamically also allows for some build_sched_groups() simplification since we can now (like with other simplifications) rely on the sched_domain tree instead of hard-coded knowledge. One tricky to note is that detach_destroy_domains() needs to hold rcu_read_lock() over the entire tear-down, per-cpu is not sufficient since that can lead to partial sched_group existance (could possibly be solved by doing the tear-down backwards but this is much more robust). A concequence of the above is that we can no longer print the sched_domain debug stuff from cpu_attach_domain() since that might now run with preemption disabled (due to classic RCU etc.) and sched_domain_debug() does some GFP_KERNEL allocations. Another thing to note is that we now fully rely on normal RCU and not RCU-sched, this is because with the new and exiting RCU flavours we grew over the years BH doesn't necessarily hold off RCU-sched grace periods (-rt is known to break this). This would in fact already cause us grief since we do sched_domain/sched_group iterations from softirq context. This patch is somewhat larger than I would like it to be, but I didn't find any means of shrinking/splitting this. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.245307941@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:09:50 +00:00
struct sched_domain *sd;
sched: Separate out allocation/free/goto-hell from __build_sched_domains Signed-off-by: Andreas Herrmann <andreas.herrmann3@amd.com> Cc: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <20090818105300.GC29515@alberich.amd.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-08-18 10:53:00 +00:00
struct s_data d;
sched: Simplify the free path some If we check the root_domain reference count we can see if its been used or not, use this observation to simplify some of the return paths. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.298339503@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:09:51 +00:00
int i, ret = -ENOMEM;
[PATCH] cpusets: Move the ia64 domain setup code to the generic code Signed-off-by: John Hawkes <hawkes@sgi.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-06 22:18:14 +00:00
sched: Separate out allocation/free/goto-hell from __build_sched_domains Signed-off-by: Andreas Herrmann <andreas.herrmann3@amd.com> Cc: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <20090818105300.GC29515@alberich.amd.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-08-18 10:53:00 +00:00
alloc_state = __visit_domain_allocation_hell(&d, cpu_map);
if (alloc_state != sa_rootdomain)
goto error;
[PATCH] cpusets: Move the ia64 domain setup code to the generic code Signed-off-by: John Hawkes <hawkes@sgi.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-06 22:18:14 +00:00
sched: Dynamically allocate sched_domain/sched_group data-structures Instead of relying on static allocations for the sched_domain and sched_group trees, dynamically allocate and RCU free them. Allocating this dynamically also allows for some build_sched_groups() simplification since we can now (like with other simplifications) rely on the sched_domain tree instead of hard-coded knowledge. One tricky to note is that detach_destroy_domains() needs to hold rcu_read_lock() over the entire tear-down, per-cpu is not sufficient since that can lead to partial sched_group existance (could possibly be solved by doing the tear-down backwards but this is much more robust). A concequence of the above is that we can no longer print the sched_domain debug stuff from cpu_attach_domain() since that might now run with preemption disabled (due to classic RCU etc.) and sched_domain_debug() does some GFP_KERNEL allocations. Another thing to note is that we now fully rely on normal RCU and not RCU-sched, this is because with the new and exiting RCU flavours we grew over the years BH doesn't necessarily hold off RCU-sched grace periods (-rt is known to break this). This would in fact already cause us grief since we do sched_domain/sched_group iterations from softirq context. This patch is somewhat larger than I would like it to be, but I didn't find any means of shrinking/splitting this. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.245307941@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:09:50 +00:00
/* Set up domains for cpus specified by the cpu_map. */
sched: convert sched.c from for_each_cpu_mask to for_each_cpu. Impact: trivial API conversion This is a simple conversion, but note that for_each_cpu() terminates with i >= nr_cpu_ids, not i == NR_CPUS like for_each_cpu_mask() did. I don't convert all of them: sd->span changes in a later patch, so change those iterators there rather than here. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-24 16:05:02 +00:00
for_each_cpu(i, cpu_map) {
sched: Stuff the sched_domain creation in a data-structure In order to make the topology contruction fully dynamic, remove the still hard-coded list of possible domains and stick them in a data-structure. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.770335383@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:10:00 +00:00
struct sched_domain_topology_level *tl;
sched: Simplify NODE/ALLNODES domain creation Don't treat ALLNODES/NODE different for difference's sake. Simply always create the ALLNODES domain and let the sd_degenerate() checks kill it when its redundant. This simplifies the code flow. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.455464579@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:09:54 +00:00
sd = NULL;
sched: Allow for overlapping sched_domain spans Allow for sched_domain spans that overlap by giving such domains their own sched_group list instead of sharing the sched_groups amongst each-other. This is needed for machines with more than 16 nodes, because sched_domain_node_span() will generate a node mask from the 16 nearest nodes without regard if these masks have any overlap. Currently sched_domains have a sched_group that maps to their child sched_domain span, and since there is no overlap we share the sched_group between the sched_domains of the various CPUs. If however there is overlap, we would need to link the sched_group list in different ways for each cpu, and hence sharing isn't possible. In order to solve this, allocate private sched_groups for each CPU's sched_domain but have the sched_groups share a sched_group_power structure such that we can uniquely track the power. Reported-and-tested-by: Anton Blanchard <anton@samba.org> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/n/tip-08bxqw9wis3qti9u5inifh3y@git.kernel.org Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-15 08:35:52 +00:00
for (tl = sched_domain_topology; tl->init; tl++) {
sched: Unify the sched_domain build functions Since all the __build_$DOM_sched_domain() functions do pretty much the same thing, unify them. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.826347257@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:10:01 +00:00
sd = build_sched_domain(tl, &d, cpu_map, attr, sd, i);
sched: Allow for overlapping sched_domain spans Allow for sched_domain spans that overlap by giving such domains their own sched_group list instead of sharing the sched_groups amongst each-other. This is needed for machines with more than 16 nodes, because sched_domain_node_span() will generate a node mask from the 16 nearest nodes without regard if these masks have any overlap. Currently sched_domains have a sched_group that maps to their child sched_domain span, and since there is no overlap we share the sched_group between the sched_domains of the various CPUs. If however there is overlap, we would need to link the sched_group list in different ways for each cpu, and hence sharing isn't possible. In order to solve this, allocate private sched_groups for each CPU's sched_domain but have the sched_groups share a sched_group_power structure such that we can uniquely track the power. Reported-and-tested-by: Anton Blanchard <anton@samba.org> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/n/tip-08bxqw9wis3qti9u5inifh3y@git.kernel.org Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-15 08:35:52 +00:00
if (tl->flags & SDTL_OVERLAP || sched_feat(FORCE_SD_OVERLAP))
sd->flags |= SD_OVERLAP;
sched: Avoid creating superfluous NUMA domains on non-NUMA systems When creating sched_domains, stop when we've covered the entire target span instead of continuing to create domains, only to later find they're redundant and throw them away again. This avoids single node systems from touching funny NUMA sched_domain creation code and reduces the risks of the new SD_OVERLAP code. Requested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Anton Blanchard <anton@samba.org> Cc: mahesh@linux.vnet.ibm.com Cc: benh@kernel.crashing.org Cc: linuxppc-dev@lists.ozlabs.org Link: http://lkml.kernel.org/r/1311180177.29152.57.camel@twins Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-20 16:42:57 +00:00
if (cpumask_equal(cpu_map, sched_domain_span(sd)))
break;
sched: Allow for overlapping sched_domain spans Allow for sched_domain spans that overlap by giving such domains their own sched_group list instead of sharing the sched_groups amongst each-other. This is needed for machines with more than 16 nodes, because sched_domain_node_span() will generate a node mask from the 16 nearest nodes without regard if these masks have any overlap. Currently sched_domains have a sched_group that maps to their child sched_domain span, and since there is no overlap we share the sched_group between the sched_domains of the various CPUs. If however there is overlap, we would need to link the sched_group list in different ways for each cpu, and hence sharing isn't possible. In order to solve this, allocate private sched_groups for each CPU's sched_domain but have the sched_groups share a sched_group_power structure such that we can uniquely track the power. Reported-and-tested-by: Anton Blanchard <anton@samba.org> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/n/tip-08bxqw9wis3qti9u5inifh3y@git.kernel.org Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-15 08:35:52 +00:00
}
sched: Simplify ->cpu_power initialization The code in update_group_power() does what init_sched_groups_power() does and more, so remove the special init_ code and call the generic code instead. Also move the sd->span_weight initialization because update_group_power() needs it. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122941.875856012@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:09:43 +00:00
sched: Reverse the topology list In order to get rid of static sched_domain::level assignments, reverse the topology iteration. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.876506131@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:10:02 +00:00
while (sd->child)
sd = sd->child;
sched: Simplify finding the lowest sched_domain Instead of relying on knowing the build order and various CONFIG_ flags simply remember the bottom most sched_domain when we created the domain hierarchy. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.134511046@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:09:48 +00:00
*per_cpu_ptr(d.sd, i) = sd;
sched: Dynamically allocate sched_domain/sched_group data-structures Instead of relying on static allocations for the sched_domain and sched_group trees, dynamically allocate and RCU free them. Allocating this dynamically also allows for some build_sched_groups() simplification since we can now (like with other simplifications) rely on the sched_domain tree instead of hard-coded knowledge. One tricky to note is that detach_destroy_domains() needs to hold rcu_read_lock() over the entire tear-down, per-cpu is not sufficient since that can lead to partial sched_group existance (could possibly be solved by doing the tear-down backwards but this is much more robust). A concequence of the above is that we can no longer print the sched_domain debug stuff from cpu_attach_domain() since that might now run with preemption disabled (due to classic RCU etc.) and sched_domain_debug() does some GFP_KERNEL allocations. Another thing to note is that we now fully rely on normal RCU and not RCU-sched, this is because with the new and exiting RCU flavours we grew over the years BH doesn't necessarily hold off RCU-sched grace periods (-rt is known to break this). This would in fact already cause us grief since we do sched_domain/sched_group iterations from softirq context. This patch is somewhat larger than I would like it to be, but I didn't find any means of shrinking/splitting this. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.245307941@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:09:50 +00:00
}
/* Build the groups for the domains */
for_each_cpu(i, cpu_map) {
for (sd = *per_cpu_ptr(d.sd, i); sd; sd = sd->parent) {
sd->span_weight = cpumask_weight(sched_domain_span(sd));
sched: Allow for overlapping sched_domain spans Allow for sched_domain spans that overlap by giving such domains their own sched_group list instead of sharing the sched_groups amongst each-other. This is needed for machines with more than 16 nodes, because sched_domain_node_span() will generate a node mask from the 16 nearest nodes without regard if these masks have any overlap. Currently sched_domains have a sched_group that maps to their child sched_domain span, and since there is no overlap we share the sched_group between the sched_domains of the various CPUs. If however there is overlap, we would need to link the sched_group list in different ways for each cpu, and hence sharing isn't possible. In order to solve this, allocate private sched_groups for each CPU's sched_domain but have the sched_groups share a sched_group_power structure such that we can uniquely track the power. Reported-and-tested-by: Anton Blanchard <anton@samba.org> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/n/tip-08bxqw9wis3qti9u5inifh3y@git.kernel.org Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-15 08:35:52 +00:00
if (sd->flags & SD_OVERLAP) {
if (build_overlap_sched_groups(sd, i))
goto error;
} else {
if (build_sched_groups(sd, i))
goto error;
}
sched: Simplify sched_group creation Instead of calling build_sched_groups() for each possible sched_domain we might have created, note that we can simply iterate the sched_domain tree and call it for each sched_domain present. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.077862519@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:09:47 +00:00
}
sched: Simplify build_sched_groups() Notice that the mask being computed is the same as the domain span we just computed. By using the domain_span we can avoid some mask allocations and computations. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122941.925028189@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:09:44 +00:00
}
[PATCH] cpusets: Move the ia64 domain setup code to the generic code Signed-off-by: John Hawkes <hawkes@sgi.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-06 22:18:14 +00:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
/* Calculate CPU power for physical packages and nodes */
sched: Simplify sched_groups_power initialization Again, instead of relying on knowing the possible domains and their order, simply rely on the sched_domain tree and whatever domains are present in there to initialize the sched_group cpu_power. Note: we need to iterate the CPU mask backwards because of the cpumask_first() condition for iterating up the tree. By iterating the mask backwards we ensure all groups of a domain are set-up before starting on the parent groups that rely on its children to be completely done. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.187335414@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:09:49 +00:00
for (i = nr_cpumask_bits-1; i >= 0; i--) {
if (!cpumask_test_cpu(i, cpu_map))
continue;
[PATCH] cpusets: Move the ia64 domain setup code to the generic code Signed-off-by: John Hawkes <hawkes@sgi.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-06 22:18:14 +00:00
sched: Dynamically allocate sched_domain/sched_group data-structures Instead of relying on static allocations for the sched_domain and sched_group trees, dynamically allocate and RCU free them. Allocating this dynamically also allows for some build_sched_groups() simplification since we can now (like with other simplifications) rely on the sched_domain tree instead of hard-coded knowledge. One tricky to note is that detach_destroy_domains() needs to hold rcu_read_lock() over the entire tear-down, per-cpu is not sufficient since that can lead to partial sched_group existance (could possibly be solved by doing the tear-down backwards but this is much more robust). A concequence of the above is that we can no longer print the sched_domain debug stuff from cpu_attach_domain() since that might now run with preemption disabled (due to classic RCU etc.) and sched_domain_debug() does some GFP_KERNEL allocations. Another thing to note is that we now fully rely on normal RCU and not RCU-sched, this is because with the new and exiting RCU flavours we grew over the years BH doesn't necessarily hold off RCU-sched grace periods (-rt is known to break this). This would in fact already cause us grief since we do sched_domain/sched_group iterations from softirq context. This patch is somewhat larger than I would like it to be, but I didn't find any means of shrinking/splitting this. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.245307941@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:09:50 +00:00
for (sd = *per_cpu_ptr(d.sd, i); sd; sd = sd->parent) {
claim_allocations(i, sd);
sched: Change NODE sched_domain group creation The NODE sched_domain is 'special' in that it allocates sched_groups per CPU, instead of sharing the sched_groups between all CPUs. While this might have some benefits on large NUMA and avoid remote memory accesses when iterating the sched_groups, this does break current code that assumes sched_groups are shared between all sched_domains (since the dynamic cpu_power patches). So refactor the NODE groups to behave like all other groups. (The ALLNODES domain again shared its groups across the CPUs for some reason). If someone does measure a performance decrease due to this change we need to revisit this and come up with another way to have both dynamic cpu_power and NUMA work nice together. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122941.978111700@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:09:45 +00:00
init_sched_groups_power(i, sd);
sched: Dynamically allocate sched_domain/sched_group data-structures Instead of relying on static allocations for the sched_domain and sched_group trees, dynamically allocate and RCU free them. Allocating this dynamically also allows for some build_sched_groups() simplification since we can now (like with other simplifications) rely on the sched_domain tree instead of hard-coded knowledge. One tricky to note is that detach_destroy_domains() needs to hold rcu_read_lock() over the entire tear-down, per-cpu is not sufficient since that can lead to partial sched_group existance (could possibly be solved by doing the tear-down backwards but this is much more robust). A concequence of the above is that we can no longer print the sched_domain debug stuff from cpu_attach_domain() since that might now run with preemption disabled (due to classic RCU etc.) and sched_domain_debug() does some GFP_KERNEL allocations. Another thing to note is that we now fully rely on normal RCU and not RCU-sched, this is because with the new and exiting RCU flavours we grew over the years BH doesn't necessarily hold off RCU-sched grace periods (-rt is known to break this). This would in fact already cause us grief since we do sched_domain/sched_group iterations from softirq context. This patch is somewhat larger than I would like it to be, but I didn't find any means of shrinking/splitting this. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.245307941@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:09:50 +00:00
}
[PATCH] sched: build_sched_domains() fix Use the correct groups while initializing sched groups power for allnodes_domain. This fixes the crash observed while creating exclusive cpusets. Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Reported-and-tested-by: Paul Jackson <pj@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-30 10:02:59 +00:00
}
[PATCH] cpusets: Move the ia64 domain setup code to the generic code Signed-off-by: John Hawkes <hawkes@sgi.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-06 22:18:14 +00:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
/* Attach the domains */
sched: Dynamically allocate sched_domain/sched_group data-structures Instead of relying on static allocations for the sched_domain and sched_group trees, dynamically allocate and RCU free them. Allocating this dynamically also allows for some build_sched_groups() simplification since we can now (like with other simplifications) rely on the sched_domain tree instead of hard-coded knowledge. One tricky to note is that detach_destroy_domains() needs to hold rcu_read_lock() over the entire tear-down, per-cpu is not sufficient since that can lead to partial sched_group existance (could possibly be solved by doing the tear-down backwards but this is much more robust). A concequence of the above is that we can no longer print the sched_domain debug stuff from cpu_attach_domain() since that might now run with preemption disabled (due to classic RCU etc.) and sched_domain_debug() does some GFP_KERNEL allocations. Another thing to note is that we now fully rely on normal RCU and not RCU-sched, this is because with the new and exiting RCU flavours we grew over the years BH doesn't necessarily hold off RCU-sched grace periods (-rt is known to break this). This would in fact already cause us grief since we do sched_domain/sched_group iterations from softirq context. This patch is somewhat larger than I would like it to be, but I didn't find any means of shrinking/splitting this. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.245307941@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:09:50 +00:00
rcu_read_lock();
sched: convert sched.c from for_each_cpu_mask to for_each_cpu. Impact: trivial API conversion This is a simple conversion, but note that for_each_cpu() terminates with i >= nr_cpu_ids, not i == NR_CPUS like for_each_cpu_mask() did. I don't convert all of them: sd->span changes in a later patch, so change those iterators there rather than here. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-24 16:05:02 +00:00
for_each_cpu(i, cpu_map) {
sched: Simplify finding the lowest sched_domain Instead of relying on knowing the build order and various CONFIG_ flags simply remember the bottom most sched_domain when we created the domain hierarchy. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.134511046@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:09:48 +00:00
sd = *per_cpu_ptr(d.sd, i);
sched: Use structure to store local data in __build_sched_domains Signed-off-by: Andreas Herrmann <andreas.herrmann3@amd.com> Cc: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <20090818105152.GB29515@alberich.amd.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-08-18 10:51:52 +00:00
cpu_attach_domain(sd, d.rd, i);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
}
sched: Dynamically allocate sched_domain/sched_group data-structures Instead of relying on static allocations for the sched_domain and sched_group trees, dynamically allocate and RCU free them. Allocating this dynamically also allows for some build_sched_groups() simplification since we can now (like with other simplifications) rely on the sched_domain tree instead of hard-coded knowledge. One tricky to note is that detach_destroy_domains() needs to hold rcu_read_lock() over the entire tear-down, per-cpu is not sufficient since that can lead to partial sched_group existance (could possibly be solved by doing the tear-down backwards but this is much more robust). A concequence of the above is that we can no longer print the sched_domain debug stuff from cpu_attach_domain() since that might now run with preemption disabled (due to classic RCU etc.) and sched_domain_debug() does some GFP_KERNEL allocations. Another thing to note is that we now fully rely on normal RCU and not RCU-sched, this is because with the new and exiting RCU flavours we grew over the years BH doesn't necessarily hold off RCU-sched grace periods (-rt is known to break this). This would in fact already cause us grief since we do sched_domain/sched_group iterations from softirq context. This patch is somewhat larger than I would like it to be, but I didn't find any means of shrinking/splitting this. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.245307941@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:09:50 +00:00
rcu_read_unlock();
[PATCH] sched_domain: handle kmalloc failure Try to handle mem allocation failures in build_sched_domains by bailing out and cleaning up thus-far allocated memory. The patch has a direct consequence that we disable load balancing completely (even at sibling level) upon *any* memory allocation failure. [Lee.Schermerhorn@hp.com: bugfix] Signed-off-by: Srivatsa Vaddagir <vatsa@in.ibm.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Ingo Molnar <mingo@elte.hu> Cc: "Siddha, Suresh B" <suresh.b.siddha@intel.com> Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 09:54:38 +00:00
sched: Simplify the free path some If we check the root_domain reference count we can see if its been used or not, use this observation to simplify some of the return paths. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.298339503@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:09:51 +00:00
ret = 0;
[PATCH] sched_domain: handle kmalloc failure Try to handle mem allocation failures in build_sched_domains by bailing out and cleaning up thus-far allocated memory. The patch has a direct consequence that we disable load balancing completely (even at sibling level) upon *any* memory allocation failure. [Lee.Schermerhorn@hp.com: bugfix] Signed-off-by: Srivatsa Vaddagir <vatsa@in.ibm.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Ingo Molnar <mingo@elte.hu> Cc: "Siddha, Suresh B" <suresh.b.siddha@intel.com> Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 09:54:38 +00:00
error:
sched: Separate out allocation/free/goto-hell from __build_sched_domains Signed-off-by: Andreas Herrmann <andreas.herrmann3@amd.com> Cc: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <20090818105300.GC29515@alberich.amd.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-08-18 10:53:00 +00:00
__free_domain_allocs(&d, alloc_state, cpu_map);
sched: Simplify the free path some If we check the root_domain reference count we can see if its been used or not, use this observation to simplify some of the return paths. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.298339503@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:09:51 +00:00
return ret;
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
}
cpuset sched_load_balance flag Add a new per-cpuset flag called 'sched_load_balance'. When enabled in a cpuset (the default value) it tells the kernel scheduler that the scheduler should provide the normal load balancing on the CPUs in that cpuset, sometimes moving tasks from one CPU to a second CPU if the second CPU is less loaded and if that task is allowed to run there. When disabled (write "0" to the file) then it tells the kernel scheduler that load balancing is not required for the CPUs in that cpuset. Now even if this flag is disabled for some cpuset, the kernel may still have to load balance some or all the CPUs in that cpuset, if some overlapping cpuset has its sched_load_balance flag enabled. If there are some CPUs that are not in any cpuset whose sched_load_balance flag is enabled, the kernel scheduler will not load balance tasks to those CPUs. Moreover the kernel will partition the 'sched domains' (non-overlapping sets of CPUs over which load balancing is attempted) into the finest granularity partition that it can find, while still keeping any two CPUs that are in the same shed_load_balance enabled cpuset in the same element of the partition. This serves two purposes: 1) It provides a mechanism for real time isolation of some CPUs, and 2) it can be used to improve performance on systems with many CPUs by supporting configurations in which load balancing is not done across all CPUs at once, but rather only done in several smaller disjoint sets of CPUs. This mechanism replaces the earlier overloading of the per-cpuset flag 'cpu_exclusive', which overloading was removed in an earlier patch: cpuset-remove-sched-domain-hooks-from-cpusets See further the Documentation and comments in the code itself. [akpm@linux-foundation.org: don't be weird] Signed-off-by: Paul Jackson <pj@sgi.com> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-19 06:40:20 +00:00
cpumask: Partition_sched_domains takes array of cpumask_var_t Currently partition_sched_domains() takes a 'struct cpumask *doms_new' which is a kmalloc'ed array of cpumask_t. You can't have such an array if 'struct cpumask' is undefined, as we plan for CONFIG_CPUMASK_OFFSTACK=y. So, we make this an array of cpumask_var_t instead: this is the same for the CONFIG_CPUMASK_OFFSTACK=n case, but requires multiple allocations for the CONFIG_CPUMASK_OFFSTACK=y case. Hence we add alloc_sched_domains() and free_sched_domains() functions. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <200911031453.40668.rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-11-03 04:23:40 +00:00
static cpumask_var_t *doms_cur; /* current sched domains */
cpuset sched_load_balance flag Add a new per-cpuset flag called 'sched_load_balance'. When enabled in a cpuset (the default value) it tells the kernel scheduler that the scheduler should provide the normal load balancing on the CPUs in that cpuset, sometimes moving tasks from one CPU to a second CPU if the second CPU is less loaded and if that task is allowed to run there. When disabled (write "0" to the file) then it tells the kernel scheduler that load balancing is not required for the CPUs in that cpuset. Now even if this flag is disabled for some cpuset, the kernel may still have to load balance some or all the CPUs in that cpuset, if some overlapping cpuset has its sched_load_balance flag enabled. If there are some CPUs that are not in any cpuset whose sched_load_balance flag is enabled, the kernel scheduler will not load balance tasks to those CPUs. Moreover the kernel will partition the 'sched domains' (non-overlapping sets of CPUs over which load balancing is attempted) into the finest granularity partition that it can find, while still keeping any two CPUs that are in the same shed_load_balance enabled cpuset in the same element of the partition. This serves two purposes: 1) It provides a mechanism for real time isolation of some CPUs, and 2) it can be used to improve performance on systems with many CPUs by supporting configurations in which load balancing is not done across all CPUs at once, but rather only done in several smaller disjoint sets of CPUs. This mechanism replaces the earlier overloading of the per-cpuset flag 'cpu_exclusive', which overloading was removed in an earlier patch: cpuset-remove-sched-domain-hooks-from-cpusets See further the Documentation and comments in the code itself. [akpm@linux-foundation.org: don't be weird] Signed-off-by: Paul Jackson <pj@sgi.com> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-19 06:40:20 +00:00
static int ndoms_cur; /* number of sched domains in 'doms_cur' */
sched: cleanup Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-05-16 15:47:14 +00:00
static struct sched_domain_attr *dattr_cur;
/* attribues of custom domains in 'doms_cur' */
cpuset sched_load_balance flag Add a new per-cpuset flag called 'sched_load_balance'. When enabled in a cpuset (the default value) it tells the kernel scheduler that the scheduler should provide the normal load balancing on the CPUs in that cpuset, sometimes moving tasks from one CPU to a second CPU if the second CPU is less loaded and if that task is allowed to run there. When disabled (write "0" to the file) then it tells the kernel scheduler that load balancing is not required for the CPUs in that cpuset. Now even if this flag is disabled for some cpuset, the kernel may still have to load balance some or all the CPUs in that cpuset, if some overlapping cpuset has its sched_load_balance flag enabled. If there are some CPUs that are not in any cpuset whose sched_load_balance flag is enabled, the kernel scheduler will not load balance tasks to those CPUs. Moreover the kernel will partition the 'sched domains' (non-overlapping sets of CPUs over which load balancing is attempted) into the finest granularity partition that it can find, while still keeping any two CPUs that are in the same shed_load_balance enabled cpuset in the same element of the partition. This serves two purposes: 1) It provides a mechanism for real time isolation of some CPUs, and 2) it can be used to improve performance on systems with many CPUs by supporting configurations in which load balancing is not done across all CPUs at once, but rather only done in several smaller disjoint sets of CPUs. This mechanism replaces the earlier overloading of the per-cpuset flag 'cpu_exclusive', which overloading was removed in an earlier patch: cpuset-remove-sched-domain-hooks-from-cpusets See further the Documentation and comments in the code itself. [akpm@linux-foundation.org: don't be weird] Signed-off-by: Paul Jackson <pj@sgi.com> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-19 06:40:20 +00:00
/*
* Special case: If a kmalloc of a doms_cur partition (array of
sched: convert falback_doms to cpumask_var_t. Impact: (future) size reduction for large NR_CPUS. Dynamically allocating cpumasks (when CONFIG_CPUMASK_OFFSTACK) saves space for small nr_cpu_ids but big CONFIG_NR_CPUS. cpumask_var_t is just a struct cpumask for !CONFIG_CPUMASK_OFFSTACK. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-24 16:05:12 +00:00
* cpumask) fails, then fallback to a single sched domain,
* as determined by the single cpumask fallback_doms.
cpuset sched_load_balance flag Add a new per-cpuset flag called 'sched_load_balance'. When enabled in a cpuset (the default value) it tells the kernel scheduler that the scheduler should provide the normal load balancing on the CPUs in that cpuset, sometimes moving tasks from one CPU to a second CPU if the second CPU is less loaded and if that task is allowed to run there. When disabled (write "0" to the file) then it tells the kernel scheduler that load balancing is not required for the CPUs in that cpuset. Now even if this flag is disabled for some cpuset, the kernel may still have to load balance some or all the CPUs in that cpuset, if some overlapping cpuset has its sched_load_balance flag enabled. If there are some CPUs that are not in any cpuset whose sched_load_balance flag is enabled, the kernel scheduler will not load balance tasks to those CPUs. Moreover the kernel will partition the 'sched domains' (non-overlapping sets of CPUs over which load balancing is attempted) into the finest granularity partition that it can find, while still keeping any two CPUs that are in the same shed_load_balance enabled cpuset in the same element of the partition. This serves two purposes: 1) It provides a mechanism for real time isolation of some CPUs, and 2) it can be used to improve performance on systems with many CPUs by supporting configurations in which load balancing is not done across all CPUs at once, but rather only done in several smaller disjoint sets of CPUs. This mechanism replaces the earlier overloading of the per-cpuset flag 'cpu_exclusive', which overloading was removed in an earlier patch: cpuset-remove-sched-domain-hooks-from-cpusets See further the Documentation and comments in the code itself. [akpm@linux-foundation.org: don't be weird] Signed-off-by: Paul Jackson <pj@sgi.com> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-19 06:40:20 +00:00
*/
sched: convert falback_doms to cpumask_var_t. Impact: (future) size reduction for large NR_CPUS. Dynamically allocating cpumasks (when CONFIG_CPUMASK_OFFSTACK) saves space for small nr_cpu_ids but big CONFIG_NR_CPUS. cpumask_var_t is just a struct cpumask for !CONFIG_CPUMASK_OFFSTACK. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-24 16:05:12 +00:00
static cpumask_var_t fallback_doms;
cpuset sched_load_balance flag Add a new per-cpuset flag called 'sched_load_balance'. When enabled in a cpuset (the default value) it tells the kernel scheduler that the scheduler should provide the normal load balancing on the CPUs in that cpuset, sometimes moving tasks from one CPU to a second CPU if the second CPU is less loaded and if that task is allowed to run there. When disabled (write "0" to the file) then it tells the kernel scheduler that load balancing is not required for the CPUs in that cpuset. Now even if this flag is disabled for some cpuset, the kernel may still have to load balance some or all the CPUs in that cpuset, if some overlapping cpuset has its sched_load_balance flag enabled. If there are some CPUs that are not in any cpuset whose sched_load_balance flag is enabled, the kernel scheduler will not load balance tasks to those CPUs. Moreover the kernel will partition the 'sched domains' (non-overlapping sets of CPUs over which load balancing is attempted) into the finest granularity partition that it can find, while still keeping any two CPUs that are in the same shed_load_balance enabled cpuset in the same element of the partition. This serves two purposes: 1) It provides a mechanism for real time isolation of some CPUs, and 2) it can be used to improve performance on systems with many CPUs by supporting configurations in which load balancing is not done across all CPUs at once, but rather only done in several smaller disjoint sets of CPUs. This mechanism replaces the earlier overloading of the per-cpuset flag 'cpu_exclusive', which overloading was removed in an earlier patch: cpuset-remove-sched-domain-hooks-from-cpusets See further the Documentation and comments in the code itself. [akpm@linux-foundation.org: don't be weird] Signed-off-by: Paul Jackson <pj@sgi.com> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-19 06:40:20 +00:00
sched: let arch_update_cpu_topology indicate if topology changed Change arch_update_cpu_topology so it returns 1 if the cpu topology changed and 0 if it didn't change. This will be useful for the next patch which adds a call to this function in partition_sched_domains. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-09 17:49:50 +00:00
/*
* arch_update_cpu_topology lets virtualized architectures update the
* cpu core maps. It is supposed to return 1 if the topology changed
* or 0 if it stayed the same.
*/
int __attribute__((weak)) arch_update_cpu_topology(void)
sched: add arch_update_cpu_topology hook. Will be called each time the scheduling domains are rebuild. Needed for architectures that don't have a static cpu topology. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-03-12 17:31:59 +00:00
{
sched: let arch_update_cpu_topology indicate if topology changed Change arch_update_cpu_topology so it returns 1 if the cpu topology changed and 0 if it didn't change. This will be useful for the next patch which adds a call to this function in partition_sched_domains. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-09 17:49:50 +00:00
return 0;
sched: add arch_update_cpu_topology hook. Will be called each time the scheduling domains are rebuild. Needed for architectures that don't have a static cpu topology. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-03-12 17:31:59 +00:00
}
cpumask: Partition_sched_domains takes array of cpumask_var_t Currently partition_sched_domains() takes a 'struct cpumask *doms_new' which is a kmalloc'ed array of cpumask_t. You can't have such an array if 'struct cpumask' is undefined, as we plan for CONFIG_CPUMASK_OFFSTACK=y. So, we make this an array of cpumask_var_t instead: this is the same for the CONFIG_CPUMASK_OFFSTACK=n case, but requires multiple allocations for the CONFIG_CPUMASK_OFFSTACK=y case. Hence we add alloc_sched_domains() and free_sched_domains() functions. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <200911031453.40668.rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-11-03 04:23:40 +00:00
cpumask_var_t *alloc_sched_domains(unsigned int ndoms)
{
int i;
cpumask_var_t *doms;
doms = kmalloc(sizeof(*doms) * ndoms, GFP_KERNEL);
if (!doms)
return NULL;
for (i = 0; i < ndoms; i++) {
if (!alloc_cpumask_var(&doms[i], GFP_KERNEL)) {
free_sched_domains(doms, i);
return NULL;
}
}
return doms;
}
void free_sched_domains(cpumask_var_t doms[], unsigned int ndoms)
{
unsigned int i;
for (i = 0; i < ndoms; i++)
free_cpumask_var(doms[i]);
kfree(doms);
}
[PATCH] Dynamic sched domains: sched changes The following patches add dynamic sched domains functionality that was extensively discussed on lkml and lse-tech. I would like to see this added to -mm o The main advantage with this feature is that it ensures that the scheduler load balacing code only balances against the cpus that are in the sched domain as defined by an exclusive cpuset and not all of the cpus in the system. This removes any overhead due to load balancing code trying to pull tasks outside of the cpu exclusive cpuset only to be prevented by the tasks' cpus_allowed mask. o cpu exclusive cpusets are useful for servers running orthogonal workloads such as RT applications requiring low latency and HPC applications that are throughput sensitive o It provides a new API partition_sched_domains in sched.c that makes dynamic sched domains possible. o cpu_exclusive cpusets sets are now associated with a sched domain. Which means that the users can dynamically modify the sched domains through the cpuset file system interface o ia64 sched domain code has been updated to support this feature as well o Currently, this does not support hotplug. (However some of my tests indicate hotplug+preempt is currently broken) o I have tested it extensively on x86. o This should have very minimal impact on performance as none of the fast paths are affected Signed-off-by: Dinakar Guniguntala <dino@in.ibm.com> Acked-by: Paul Jackson <pj@sgi.com> Acked-by: Nick Piggin <nickpiggin@yahoo.com.au> Acked-by: Matthew Dobson <colpatch@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-25 21:57:33 +00:00
/*
sched: style cleanups style cleanup of various changes that were done recently. no code changed: text data bss dec hex filename 23680 2542 28 26250 668a sched.o.before 23680 2542 28 26250 668a sched.o.after Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-12-05 14:46:09 +00:00
* Set up scheduler domains and groups. Callers must hold the hotplug lock.
cpuset sched_load_balance flag Add a new per-cpuset flag called 'sched_load_balance'. When enabled in a cpuset (the default value) it tells the kernel scheduler that the scheduler should provide the normal load balancing on the CPUs in that cpuset, sometimes moving tasks from one CPU to a second CPU if the second CPU is less loaded and if that task is allowed to run there. When disabled (write "0" to the file) then it tells the kernel scheduler that load balancing is not required for the CPUs in that cpuset. Now even if this flag is disabled for some cpuset, the kernel may still have to load balance some or all the CPUs in that cpuset, if some overlapping cpuset has its sched_load_balance flag enabled. If there are some CPUs that are not in any cpuset whose sched_load_balance flag is enabled, the kernel scheduler will not load balance tasks to those CPUs. Moreover the kernel will partition the 'sched domains' (non-overlapping sets of CPUs over which load balancing is attempted) into the finest granularity partition that it can find, while still keeping any two CPUs that are in the same shed_load_balance enabled cpuset in the same element of the partition. This serves two purposes: 1) It provides a mechanism for real time isolation of some CPUs, and 2) it can be used to improve performance on systems with many CPUs by supporting configurations in which load balancing is not done across all CPUs at once, but rather only done in several smaller disjoint sets of CPUs. This mechanism replaces the earlier overloading of the per-cpuset flag 'cpu_exclusive', which overloading was removed in an earlier patch: cpuset-remove-sched-domain-hooks-from-cpusets See further the Documentation and comments in the code itself. [akpm@linux-foundation.org: don't be weird] Signed-off-by: Paul Jackson <pj@sgi.com> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-19 06:40:20 +00:00
* For now this just excludes isolated cpus, but could be used to
* exclude other special cases in the future.
[PATCH] Dynamic sched domains: sched changes The following patches add dynamic sched domains functionality that was extensively discussed on lkml and lse-tech. I would like to see this added to -mm o The main advantage with this feature is that it ensures that the scheduler load balacing code only balances against the cpus that are in the sched domain as defined by an exclusive cpuset and not all of the cpus in the system. This removes any overhead due to load balancing code trying to pull tasks outside of the cpu exclusive cpuset only to be prevented by the tasks' cpus_allowed mask. o cpu exclusive cpusets are useful for servers running orthogonal workloads such as RT applications requiring low latency and HPC applications that are throughput sensitive o It provides a new API partition_sched_domains in sched.c that makes dynamic sched domains possible. o cpu_exclusive cpusets sets are now associated with a sched domain. Which means that the users can dynamically modify the sched domains through the cpuset file system interface o ia64 sched domain code has been updated to support this feature as well o Currently, this does not support hotplug. (However some of my tests indicate hotplug+preempt is currently broken) o I have tested it extensively on x86. o This should have very minimal impact on performance as none of the fast paths are affected Signed-off-by: Dinakar Guniguntala <dino@in.ibm.com> Acked-by: Paul Jackson <pj@sgi.com> Acked-by: Nick Piggin <nickpiggin@yahoo.com.au> Acked-by: Matthew Dobson <colpatch@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-25 21:57:33 +00:00
*/
sched: Remove obsolete arch_ prefixes Non weak static functions clearly are not arch specific, so remove the arch_ prefix. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122941.820460566@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:09:42 +00:00
static int init_sched_domains(const struct cpumask *cpu_map)
[PATCH] Dynamic sched domains: sched changes The following patches add dynamic sched domains functionality that was extensively discussed on lkml and lse-tech. I would like to see this added to -mm o The main advantage with this feature is that it ensures that the scheduler load balacing code only balances against the cpus that are in the sched domain as defined by an exclusive cpuset and not all of the cpus in the system. This removes any overhead due to load balancing code trying to pull tasks outside of the cpu exclusive cpuset only to be prevented by the tasks' cpus_allowed mask. o cpu exclusive cpusets are useful for servers running orthogonal workloads such as RT applications requiring low latency and HPC applications that are throughput sensitive o It provides a new API partition_sched_domains in sched.c that makes dynamic sched domains possible. o cpu_exclusive cpusets sets are now associated with a sched domain. Which means that the users can dynamically modify the sched domains through the cpuset file system interface o ia64 sched domain code has been updated to support this feature as well o Currently, this does not support hotplug. (However some of my tests indicate hotplug+preempt is currently broken) o I have tested it extensively on x86. o This should have very minimal impact on performance as none of the fast paths are affected Signed-off-by: Dinakar Guniguntala <dino@in.ibm.com> Acked-by: Paul Jackson <pj@sgi.com> Acked-by: Nick Piggin <nickpiggin@yahoo.com.au> Acked-by: Matthew Dobson <colpatch@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-25 21:57:33 +00:00
{
sched: fix sched_domain sysctl registration again commit 029190c515f15f512ac85de8fc686d4dbd0ae731 (cpuset sched_load_balance flag) was not tested SCHED_DEBUG enabled as committed as it dereferences NULL when used and it reordered the sysctl registration to cause it to never show any domains or their tunables. Fixes: 1) restore arch_init_sched_domains ordering we can't walk the domains before we build them presently we register cpus with empty directories (no domain directories or files). 2) make unregister_sched_domain_sysctl do nothing when already unregistered detach_destroy_domains is now called one set of cpus at a time unregister_syctl dereferences NULL if called with a null. While the the function would always dereference null if called twice, in the previous code it was always called once and then was followed a register. So only the hidden bug of the sysctl_root_table not being allocated followed by an attempt to free it would have shown the error. 3) always call unregister and register in partition_sched_domains The code is "smart" about unregistering only needed domains. Since we aren't guaranteed any calls to unregister, always unregister. Without calling register on the way out we will not have a table or any sysctl tree. 4) warn if register is called without unregistering The previous table memory is lost, leaving pointers to the later freed memory in sysctl and leaking the memory of the tables. Before this patch on a 2-core 4-thread box compiled for SMT and NUMA, the domains appear empty (there are actually 3 levels per cpu). And as soon as two domains a null pointer is dereferenced (unreliable in this case is stack garbage): bu19a:~# ls -R /proc/sys/kernel/sched_domain/ /proc/sys/kernel/sched_domain/: cpu0 cpu1 cpu2 cpu3 /proc/sys/kernel/sched_domain/cpu0: /proc/sys/kernel/sched_domain/cpu1: /proc/sys/kernel/sched_domain/cpu2: /proc/sys/kernel/sched_domain/cpu3: bu19a:~# mkdir /dev/cpuset bu19a:~# mount -tcpuset cpuset /dev/cpuset/ bu19a:~# cd /dev/cpuset/ bu19a:/dev/cpuset# echo 0 > sched_load_balance bu19a:/dev/cpuset# mkdir one bu19a:/dev/cpuset# echo 1 > one/cpus bu19a:/dev/cpuset# echo 0 > one/sched_load_balance Unable to handle kernel paging request for data at address 0x00000018 Faulting instruction address: 0xc00000000006b608 NIP: c00000000006b608 LR: c00000000006b604 CTR: 0000000000000000 REGS: c000000018d973f0 TRAP: 0300 Not tainted (2.6.23-bml) MSR: 9000000000009032 <EE,ME,IR,DR> CR: 28242442 XER: 00000000 DAR: 0000000000000018, DSISR: 0000000040000000 TASK = c00000001912e340[1987] 'bash' THREAD: c000000018d94000 CPU: 2 .. NIP [c00000000006b608] .unregister_sysctl_table+0x38/0x110 LR [c00000000006b604] .unregister_sysctl_table+0x34/0x110 Call Trace: [c000000018d97670] [c000000007017270] 0xc000000007017270 (unreliable) [c000000018d97720] [c000000000058710] .detach_destroy_domains+0x30/0xb0 [c000000018d977b0] [c00000000005cf1c] .partition_sched_domains+0x1bc/0x230 [c000000018d97870] [c00000000009fdc4] .rebuild_sched_domains+0xb4/0x4c0 [c000000018d97970] [c0000000000a02e8] .update_flag+0x118/0x170 [c000000018d97a80] [c0000000000a1768] .cpuset_common_file_write+0x568/0x820 [c000000018d97c00] [c00000000009d95c] .cgroup_file_write+0x7c/0x180 [c000000018d97cf0] [c0000000000e76b8] .vfs_write+0xe8/0x1b0 [c000000018d97d90] [c0000000000e810c] .sys_write+0x4c/0x90 [c000000018d97e30] [c00000000000852c] syscall_exit+0x0/0x40 Signed-off-by: Milton Miller <miltonm@bga.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-24 16:23:48 +00:00
int err;
sched: add arch_update_cpu_topology hook. Will be called each time the scheduling domains are rebuild. Needed for architectures that don't have a static cpu topology. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-03-12 17:31:59 +00:00
arch_update_cpu_topology();
cpuset sched_load_balance flag Add a new per-cpuset flag called 'sched_load_balance'. When enabled in a cpuset (the default value) it tells the kernel scheduler that the scheduler should provide the normal load balancing on the CPUs in that cpuset, sometimes moving tasks from one CPU to a second CPU if the second CPU is less loaded and if that task is allowed to run there. When disabled (write "0" to the file) then it tells the kernel scheduler that load balancing is not required for the CPUs in that cpuset. Now even if this flag is disabled for some cpuset, the kernel may still have to load balance some or all the CPUs in that cpuset, if some overlapping cpuset has its sched_load_balance flag enabled. If there are some CPUs that are not in any cpuset whose sched_load_balance flag is enabled, the kernel scheduler will not load balance tasks to those CPUs. Moreover the kernel will partition the 'sched domains' (non-overlapping sets of CPUs over which load balancing is attempted) into the finest granularity partition that it can find, while still keeping any two CPUs that are in the same shed_load_balance enabled cpuset in the same element of the partition. This serves two purposes: 1) It provides a mechanism for real time isolation of some CPUs, and 2) it can be used to improve performance on systems with many CPUs by supporting configurations in which load balancing is not done across all CPUs at once, but rather only done in several smaller disjoint sets of CPUs. This mechanism replaces the earlier overloading of the per-cpuset flag 'cpu_exclusive', which overloading was removed in an earlier patch: cpuset-remove-sched-domain-hooks-from-cpusets See further the Documentation and comments in the code itself. [akpm@linux-foundation.org: don't be weird] Signed-off-by: Paul Jackson <pj@sgi.com> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-19 06:40:20 +00:00
ndoms_cur = 1;
cpumask: Partition_sched_domains takes array of cpumask_var_t Currently partition_sched_domains() takes a 'struct cpumask *doms_new' which is a kmalloc'ed array of cpumask_t. You can't have such an array if 'struct cpumask' is undefined, as we plan for CONFIG_CPUMASK_OFFSTACK=y. So, we make this an array of cpumask_var_t instead: this is the same for the CONFIG_CPUMASK_OFFSTACK=n case, but requires multiple allocations for the CONFIG_CPUMASK_OFFSTACK=y case. Hence we add alloc_sched_domains() and free_sched_domains() functions. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <200911031453.40668.rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-11-03 04:23:40 +00:00
doms_cur = alloc_sched_domains(ndoms_cur);
cpuset sched_load_balance flag Add a new per-cpuset flag called 'sched_load_balance'. When enabled in a cpuset (the default value) it tells the kernel scheduler that the scheduler should provide the normal load balancing on the CPUs in that cpuset, sometimes moving tasks from one CPU to a second CPU if the second CPU is less loaded and if that task is allowed to run there. When disabled (write "0" to the file) then it tells the kernel scheduler that load balancing is not required for the CPUs in that cpuset. Now even if this flag is disabled for some cpuset, the kernel may still have to load balance some or all the CPUs in that cpuset, if some overlapping cpuset has its sched_load_balance flag enabled. If there are some CPUs that are not in any cpuset whose sched_load_balance flag is enabled, the kernel scheduler will not load balance tasks to those CPUs. Moreover the kernel will partition the 'sched domains' (non-overlapping sets of CPUs over which load balancing is attempted) into the finest granularity partition that it can find, while still keeping any two CPUs that are in the same shed_load_balance enabled cpuset in the same element of the partition. This serves two purposes: 1) It provides a mechanism for real time isolation of some CPUs, and 2) it can be used to improve performance on systems with many CPUs by supporting configurations in which load balancing is not done across all CPUs at once, but rather only done in several smaller disjoint sets of CPUs. This mechanism replaces the earlier overloading of the per-cpuset flag 'cpu_exclusive', which overloading was removed in an earlier patch: cpuset-remove-sched-domain-hooks-from-cpusets See further the Documentation and comments in the code itself. [akpm@linux-foundation.org: don't be weird] Signed-off-by: Paul Jackson <pj@sgi.com> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-19 06:40:20 +00:00
if (!doms_cur)
cpumask: Partition_sched_domains takes array of cpumask_var_t Currently partition_sched_domains() takes a 'struct cpumask *doms_new' which is a kmalloc'ed array of cpumask_t. You can't have such an array if 'struct cpumask' is undefined, as we plan for CONFIG_CPUMASK_OFFSTACK=y. So, we make this an array of cpumask_var_t instead: this is the same for the CONFIG_CPUMASK_OFFSTACK=n case, but requires multiple allocations for the CONFIG_CPUMASK_OFFSTACK=y case. Hence we add alloc_sched_domains() and free_sched_domains() functions. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <200911031453.40668.rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-11-03 04:23:40 +00:00
doms_cur = &fallback_doms;
cpumask_andnot(doms_cur[0], cpu_map, cpu_isolated_map);
sched, cpuset: customize sched domains, core [rebased for sched-devel/latest] - Add a new cpuset file, having levels: sched_relax_domain_level - Modify partition_sched_domains() and build_sched_domains() to take attributes parameter passed from cpuset. - Fill newidle_idx for node domains which currently unused but might be required if sched_relax_domain_level become higher. - We can change the default level by boot option 'relax_domain_level='. Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-15 05:04:23 +00:00
dattr_cur = NULL;
sched: Dynamically allocate sched_domain/sched_group data-structures Instead of relying on static allocations for the sched_domain and sched_group trees, dynamically allocate and RCU free them. Allocating this dynamically also allows for some build_sched_groups() simplification since we can now (like with other simplifications) rely on the sched_domain tree instead of hard-coded knowledge. One tricky to note is that detach_destroy_domains() needs to hold rcu_read_lock() over the entire tear-down, per-cpu is not sufficient since that can lead to partial sched_group existance (could possibly be solved by doing the tear-down backwards but this is much more robust). A concequence of the above is that we can no longer print the sched_domain debug stuff from cpu_attach_domain() since that might now run with preemption disabled (due to classic RCU etc.) and sched_domain_debug() does some GFP_KERNEL allocations. Another thing to note is that we now fully rely on normal RCU and not RCU-sched, this is because with the new and exiting RCU flavours we grew over the years BH doesn't necessarily hold off RCU-sched grace periods (-rt is known to break this). This would in fact already cause us grief since we do sched_domain/sched_group iterations from softirq context. This patch is somewhat larger than I would like it to be, but I didn't find any means of shrinking/splitting this. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.245307941@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:09:50 +00:00
err = build_sched_domains(doms_cur[0], NULL);
sched: domain sysctl fixes: unregister the sysctl table before domains Unregister and free the sysctl table before destroying domains, then rebuild and register after creating the new domains. This prevents the sysctl table from pointing to freed memory for root to write. Signed-off-by: Milton Miller <miltonm@bga.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 15:00:19 +00:00
register_sched_domain_sysctl();
sched: fix sched_domain sysctl registration again commit 029190c515f15f512ac85de8fc686d4dbd0ae731 (cpuset sched_load_balance flag) was not tested SCHED_DEBUG enabled as committed as it dereferences NULL when used and it reordered the sysctl registration to cause it to never show any domains or their tunables. Fixes: 1) restore arch_init_sched_domains ordering we can't walk the domains before we build them presently we register cpus with empty directories (no domain directories or files). 2) make unregister_sched_domain_sysctl do nothing when already unregistered detach_destroy_domains is now called one set of cpus at a time unregister_syctl dereferences NULL if called with a null. While the the function would always dereference null if called twice, in the previous code it was always called once and then was followed a register. So only the hidden bug of the sysctl_root_table not being allocated followed by an attempt to free it would have shown the error. 3) always call unregister and register in partition_sched_domains The code is "smart" about unregistering only needed domains. Since we aren't guaranteed any calls to unregister, always unregister. Without calling register on the way out we will not have a table or any sysctl tree. 4) warn if register is called without unregistering The previous table memory is lost, leaving pointers to the later freed memory in sysctl and leaking the memory of the tables. Before this patch on a 2-core 4-thread box compiled for SMT and NUMA, the domains appear empty (there are actually 3 levels per cpu). And as soon as two domains a null pointer is dereferenced (unreliable in this case is stack garbage): bu19a:~# ls -R /proc/sys/kernel/sched_domain/ /proc/sys/kernel/sched_domain/: cpu0 cpu1 cpu2 cpu3 /proc/sys/kernel/sched_domain/cpu0: /proc/sys/kernel/sched_domain/cpu1: /proc/sys/kernel/sched_domain/cpu2: /proc/sys/kernel/sched_domain/cpu3: bu19a:~# mkdir /dev/cpuset bu19a:~# mount -tcpuset cpuset /dev/cpuset/ bu19a:~# cd /dev/cpuset/ bu19a:/dev/cpuset# echo 0 > sched_load_balance bu19a:/dev/cpuset# mkdir one bu19a:/dev/cpuset# echo 1 > one/cpus bu19a:/dev/cpuset# echo 0 > one/sched_load_balance Unable to handle kernel paging request for data at address 0x00000018 Faulting instruction address: 0xc00000000006b608 NIP: c00000000006b608 LR: c00000000006b604 CTR: 0000000000000000 REGS: c000000018d973f0 TRAP: 0300 Not tainted (2.6.23-bml) MSR: 9000000000009032 <EE,ME,IR,DR> CR: 28242442 XER: 00000000 DAR: 0000000000000018, DSISR: 0000000040000000 TASK = c00000001912e340[1987] 'bash' THREAD: c000000018d94000 CPU: 2 .. NIP [c00000000006b608] .unregister_sysctl_table+0x38/0x110 LR [c00000000006b604] .unregister_sysctl_table+0x34/0x110 Call Trace: [c000000018d97670] [c000000007017270] 0xc000000007017270 (unreliable) [c000000018d97720] [c000000000058710] .detach_destroy_domains+0x30/0xb0 [c000000018d977b0] [c00000000005cf1c] .partition_sched_domains+0x1bc/0x230 [c000000018d97870] [c00000000009fdc4] .rebuild_sched_domains+0xb4/0x4c0 [c000000018d97970] [c0000000000a02e8] .update_flag+0x118/0x170 [c000000018d97a80] [c0000000000a1768] .cpuset_common_file_write+0x568/0x820 [c000000018d97c00] [c00000000009d95c] .cgroup_file_write+0x7c/0x180 [c000000018d97cf0] [c0000000000e76b8] .vfs_write+0xe8/0x1b0 [c000000018d97d90] [c0000000000e810c] .sys_write+0x4c/0x90 [c000000018d97e30] [c00000000000852c] syscall_exit+0x0/0x40 Signed-off-by: Milton Miller <miltonm@bga.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-24 16:23:48 +00:00
return err;
[PATCH] Dynamic sched domains: sched changes The following patches add dynamic sched domains functionality that was extensively discussed on lkml and lse-tech. I would like to see this added to -mm o The main advantage with this feature is that it ensures that the scheduler load balacing code only balances against the cpus that are in the sched domain as defined by an exclusive cpuset and not all of the cpus in the system. This removes any overhead due to load balancing code trying to pull tasks outside of the cpu exclusive cpuset only to be prevented by the tasks' cpus_allowed mask. o cpu exclusive cpusets are useful for servers running orthogonal workloads such as RT applications requiring low latency and HPC applications that are throughput sensitive o It provides a new API partition_sched_domains in sched.c that makes dynamic sched domains possible. o cpu_exclusive cpusets sets are now associated with a sched domain. Which means that the users can dynamically modify the sched domains through the cpuset file system interface o ia64 sched domain code has been updated to support this feature as well o Currently, this does not support hotplug. (However some of my tests indicate hotplug+preempt is currently broken) o I have tested it extensively on x86. o This should have very minimal impact on performance as none of the fast paths are affected Signed-off-by: Dinakar Guniguntala <dino@in.ibm.com> Acked-by: Paul Jackson <pj@sgi.com> Acked-by: Nick Piggin <nickpiggin@yahoo.com.au> Acked-by: Matthew Dobson <colpatch@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-25 21:57:33 +00:00
}
/*
* Detach sched domains from a group of cpus specified in cpu_map
* These cpus will now be attached to the NULL domain
*/
sched: convert remaining old-style cpumask operators Impact: Trivial API conversion NR_CPUS -> nr_cpu_ids cpumask_t -> struct cpumask sizeof(cpumask_t) -> cpumask_size() cpumask_a = cpumask_b -> cpumask_copy(&cpumask_a, &cpumask_b) cpu_set() -> cpumask_set_cpu() first_cpu() -> cpumask_first() cpumask_of_cpu() -> cpumask_of() cpus_* -> cpumask_* There are some FIXMEs where we all archs to complete infrastructure (patches have been sent): cpu_coregroup_map -> cpu_coregroup_mask node_to_cpumask* -> cpumask_of_node There is also one FIXME where we pass an array of cpumasks to partition_sched_domains(): this implies knowing the definition of 'struct cpumask' and the size of a cpumask. This will be fixed in a future patch. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-24 16:05:14 +00:00
static void detach_destroy_domains(const struct cpumask *cpu_map)
[PATCH] Dynamic sched domains: sched changes The following patches add dynamic sched domains functionality that was extensively discussed on lkml and lse-tech. I would like to see this added to -mm o The main advantage with this feature is that it ensures that the scheduler load balacing code only balances against the cpus that are in the sched domain as defined by an exclusive cpuset and not all of the cpus in the system. This removes any overhead due to load balancing code trying to pull tasks outside of the cpu exclusive cpuset only to be prevented by the tasks' cpus_allowed mask. o cpu exclusive cpusets are useful for servers running orthogonal workloads such as RT applications requiring low latency and HPC applications that are throughput sensitive o It provides a new API partition_sched_domains in sched.c that makes dynamic sched domains possible. o cpu_exclusive cpusets sets are now associated with a sched domain. Which means that the users can dynamically modify the sched domains through the cpuset file system interface o ia64 sched domain code has been updated to support this feature as well o Currently, this does not support hotplug. (However some of my tests indicate hotplug+preempt is currently broken) o I have tested it extensively on x86. o This should have very minimal impact on performance as none of the fast paths are affected Signed-off-by: Dinakar Guniguntala <dino@in.ibm.com> Acked-by: Paul Jackson <pj@sgi.com> Acked-by: Nick Piggin <nickpiggin@yahoo.com.au> Acked-by: Matthew Dobson <colpatch@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-25 21:57:33 +00:00
{
int i;
sched: Dynamically allocate sched_domain/sched_group data-structures Instead of relying on static allocations for the sched_domain and sched_group trees, dynamically allocate and RCU free them. Allocating this dynamically also allows for some build_sched_groups() simplification since we can now (like with other simplifications) rely on the sched_domain tree instead of hard-coded knowledge. One tricky to note is that detach_destroy_domains() needs to hold rcu_read_lock() over the entire tear-down, per-cpu is not sufficient since that can lead to partial sched_group existance (could possibly be solved by doing the tear-down backwards but this is much more robust). A concequence of the above is that we can no longer print the sched_domain debug stuff from cpu_attach_domain() since that might now run with preemption disabled (due to classic RCU etc.) and sched_domain_debug() does some GFP_KERNEL allocations. Another thing to note is that we now fully rely on normal RCU and not RCU-sched, this is because with the new and exiting RCU flavours we grew over the years BH doesn't necessarily hold off RCU-sched grace periods (-rt is known to break this). This would in fact already cause us grief since we do sched_domain/sched_group iterations from softirq context. This patch is somewhat larger than I would like it to be, but I didn't find any means of shrinking/splitting this. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.245307941@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:09:50 +00:00
rcu_read_lock();
sched: convert sched.c from for_each_cpu_mask to for_each_cpu. Impact: trivial API conversion This is a simple conversion, but note that for_each_cpu() terminates with i >= nr_cpu_ids, not i == NR_CPUS like for_each_cpu_mask() did. I don't convert all of them: sd->span changes in a later patch, so change those iterators there rather than here. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-24 16:05:02 +00:00
for_each_cpu(i, cpu_map)
sched: add sched-domain roots We add the notion of a root-domain which will be used later to rescope global variables to per-domain variables. Each exclusive cpuset essentially defines an island domain by fully partitioning the member cpus from any other cpuset. However, we currently still maintain some policy/state as global variables which transcend all cpusets. Consider, for instance, rt-overload state. Whenever a new exclusive cpuset is created, we also create a new root-domain object and move each cpu member to the root-domain's span. By default the system creates a single root-domain with all cpus as members (mimicking the global state we have today). We add some plumbing for storing class specific data in our root-domain. Whenever a RQ is switching root-domains (because of repartitioning) we give each sched_class the opportunity to remove any state from its old domain and add state to the new one. This logic doesn't have any clients yet but it will later in the series. Signed-off-by: Gregory Haskins <ghaskins@novell.com> CC: Christoph Lameter <clameter@sgi.com> CC: Paul Jackson <pj@sgi.com> CC: Simon Derr <simon.derr@bull.net> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:18 +00:00
cpu_attach_domain(NULL, &def_root_domain, i);
sched: Dynamically allocate sched_domain/sched_group data-structures Instead of relying on static allocations for the sched_domain and sched_group trees, dynamically allocate and RCU free them. Allocating this dynamically also allows for some build_sched_groups() simplification since we can now (like with other simplifications) rely on the sched_domain tree instead of hard-coded knowledge. One tricky to note is that detach_destroy_domains() needs to hold rcu_read_lock() over the entire tear-down, per-cpu is not sufficient since that can lead to partial sched_group existance (could possibly be solved by doing the tear-down backwards but this is much more robust). A concequence of the above is that we can no longer print the sched_domain debug stuff from cpu_attach_domain() since that might now run with preemption disabled (due to classic RCU etc.) and sched_domain_debug() does some GFP_KERNEL allocations. Another thing to note is that we now fully rely on normal RCU and not RCU-sched, this is because with the new and exiting RCU flavours we grew over the years BH doesn't necessarily hold off RCU-sched grace periods (-rt is known to break this). This would in fact already cause us grief since we do sched_domain/sched_group iterations from softirq context. This patch is somewhat larger than I would like it to be, but I didn't find any means of shrinking/splitting this. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.245307941@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:09:50 +00:00
rcu_read_unlock();
[PATCH] Dynamic sched domains: sched changes The following patches add dynamic sched domains functionality that was extensively discussed on lkml and lse-tech. I would like to see this added to -mm o The main advantage with this feature is that it ensures that the scheduler load balacing code only balances against the cpus that are in the sched domain as defined by an exclusive cpuset and not all of the cpus in the system. This removes any overhead due to load balancing code trying to pull tasks outside of the cpu exclusive cpuset only to be prevented by the tasks' cpus_allowed mask. o cpu exclusive cpusets are useful for servers running orthogonal workloads such as RT applications requiring low latency and HPC applications that are throughput sensitive o It provides a new API partition_sched_domains in sched.c that makes dynamic sched domains possible. o cpu_exclusive cpusets sets are now associated with a sched domain. Which means that the users can dynamically modify the sched domains through the cpuset file system interface o ia64 sched domain code has been updated to support this feature as well o Currently, this does not support hotplug. (However some of my tests indicate hotplug+preempt is currently broken) o I have tested it extensively on x86. o This should have very minimal impact on performance as none of the fast paths are affected Signed-off-by: Dinakar Guniguntala <dino@in.ibm.com> Acked-by: Paul Jackson <pj@sgi.com> Acked-by: Nick Piggin <nickpiggin@yahoo.com.au> Acked-by: Matthew Dobson <colpatch@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-25 21:57:33 +00:00
}
sched, cpuset: customize sched domains, core [rebased for sched-devel/latest] - Add a new cpuset file, having levels: sched_relax_domain_level - Modify partition_sched_domains() and build_sched_domains() to take attributes parameter passed from cpuset. - Fill newidle_idx for node domains which currently unused but might be required if sched_relax_domain_level become higher. - We can change the default level by boot option 'relax_domain_level='. Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-15 05:04:23 +00:00
/* handle null as "default" */
static int dattrs_equal(struct sched_domain_attr *cur, int idx_cur,
struct sched_domain_attr *new, int idx_new)
{
struct sched_domain_attr tmp;
/* fast path */
if (!new && !cur)
return 1;
tmp = SD_ATTR_INIT;
return !memcmp(cur ? (cur + idx_cur) : &tmp,
new ? (new + idx_new) : &tmp,
sizeof(struct sched_domain_attr));
}
cpuset sched_load_balance flag Add a new per-cpuset flag called 'sched_load_balance'. When enabled in a cpuset (the default value) it tells the kernel scheduler that the scheduler should provide the normal load balancing on the CPUs in that cpuset, sometimes moving tasks from one CPU to a second CPU if the second CPU is less loaded and if that task is allowed to run there. When disabled (write "0" to the file) then it tells the kernel scheduler that load balancing is not required for the CPUs in that cpuset. Now even if this flag is disabled for some cpuset, the kernel may still have to load balance some or all the CPUs in that cpuset, if some overlapping cpuset has its sched_load_balance flag enabled. If there are some CPUs that are not in any cpuset whose sched_load_balance flag is enabled, the kernel scheduler will not load balance tasks to those CPUs. Moreover the kernel will partition the 'sched domains' (non-overlapping sets of CPUs over which load balancing is attempted) into the finest granularity partition that it can find, while still keeping any two CPUs that are in the same shed_load_balance enabled cpuset in the same element of the partition. This serves two purposes: 1) It provides a mechanism for real time isolation of some CPUs, and 2) it can be used to improve performance on systems with many CPUs by supporting configurations in which load balancing is not done across all CPUs at once, but rather only done in several smaller disjoint sets of CPUs. This mechanism replaces the earlier overloading of the per-cpuset flag 'cpu_exclusive', which overloading was removed in an earlier patch: cpuset-remove-sched-domain-hooks-from-cpusets See further the Documentation and comments in the code itself. [akpm@linux-foundation.org: don't be weird] Signed-off-by: Paul Jackson <pj@sgi.com> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-19 06:40:20 +00:00
/*
* Partition sched domains as specified by the 'ndoms_new'
sched: style cleanups style cleanup of various changes that were done recently. no code changed: text data bss dec hex filename 23680 2542 28 26250 668a sched.o.before 23680 2542 28 26250 668a sched.o.after Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-12-05 14:46:09 +00:00
* cpumasks in the array doms_new[] of cpumasks. This compares
cpuset sched_load_balance flag Add a new per-cpuset flag called 'sched_load_balance'. When enabled in a cpuset (the default value) it tells the kernel scheduler that the scheduler should provide the normal load balancing on the CPUs in that cpuset, sometimes moving tasks from one CPU to a second CPU if the second CPU is less loaded and if that task is allowed to run there. When disabled (write "0" to the file) then it tells the kernel scheduler that load balancing is not required for the CPUs in that cpuset. Now even if this flag is disabled for some cpuset, the kernel may still have to load balance some or all the CPUs in that cpuset, if some overlapping cpuset has its sched_load_balance flag enabled. If there are some CPUs that are not in any cpuset whose sched_load_balance flag is enabled, the kernel scheduler will not load balance tasks to those CPUs. Moreover the kernel will partition the 'sched domains' (non-overlapping sets of CPUs over which load balancing is attempted) into the finest granularity partition that it can find, while still keeping any two CPUs that are in the same shed_load_balance enabled cpuset in the same element of the partition. This serves two purposes: 1) It provides a mechanism for real time isolation of some CPUs, and 2) it can be used to improve performance on systems with many CPUs by supporting configurations in which load balancing is not done across all CPUs at once, but rather only done in several smaller disjoint sets of CPUs. This mechanism replaces the earlier overloading of the per-cpuset flag 'cpu_exclusive', which overloading was removed in an earlier patch: cpuset-remove-sched-domain-hooks-from-cpusets See further the Documentation and comments in the code itself. [akpm@linux-foundation.org: don't be weird] Signed-off-by: Paul Jackson <pj@sgi.com> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-19 06:40:20 +00:00
* doms_new[] to the current sched domain partitioning, doms_cur[].
* It destroys each deleted domain and builds each new domain.
*
cpumask: Partition_sched_domains takes array of cpumask_var_t Currently partition_sched_domains() takes a 'struct cpumask *doms_new' which is a kmalloc'ed array of cpumask_t. You can't have such an array if 'struct cpumask' is undefined, as we plan for CONFIG_CPUMASK_OFFSTACK=y. So, we make this an array of cpumask_var_t instead: this is the same for the CONFIG_CPUMASK_OFFSTACK=n case, but requires multiple allocations for the CONFIG_CPUMASK_OFFSTACK=y case. Hence we add alloc_sched_domains() and free_sched_domains() functions. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <200911031453.40668.rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-11-03 04:23:40 +00:00
* 'doms_new' is an array of cpumask_var_t's of length 'ndoms_new'.
sched: style cleanups style cleanup of various changes that were done recently. no code changed: text data bss dec hex filename 23680 2542 28 26250 668a sched.o.before 23680 2542 28 26250 668a sched.o.after Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-12-05 14:46:09 +00:00
* The masks don't intersect (don't overlap.) We should setup one
* sched domain for each mask. CPUs not in any of the cpumasks will
* not be load balanced. If the same cpumask appears both in the
cpuset sched_load_balance flag Add a new per-cpuset flag called 'sched_load_balance'. When enabled in a cpuset (the default value) it tells the kernel scheduler that the scheduler should provide the normal load balancing on the CPUs in that cpuset, sometimes moving tasks from one CPU to a second CPU if the second CPU is less loaded and if that task is allowed to run there. When disabled (write "0" to the file) then it tells the kernel scheduler that load balancing is not required for the CPUs in that cpuset. Now even if this flag is disabled for some cpuset, the kernel may still have to load balance some or all the CPUs in that cpuset, if some overlapping cpuset has its sched_load_balance flag enabled. If there are some CPUs that are not in any cpuset whose sched_load_balance flag is enabled, the kernel scheduler will not load balance tasks to those CPUs. Moreover the kernel will partition the 'sched domains' (non-overlapping sets of CPUs over which load balancing is attempted) into the finest granularity partition that it can find, while still keeping any two CPUs that are in the same shed_load_balance enabled cpuset in the same element of the partition. This serves two purposes: 1) It provides a mechanism for real time isolation of some CPUs, and 2) it can be used to improve performance on systems with many CPUs by supporting configurations in which load balancing is not done across all CPUs at once, but rather only done in several smaller disjoint sets of CPUs. This mechanism replaces the earlier overloading of the per-cpuset flag 'cpu_exclusive', which overloading was removed in an earlier patch: cpuset-remove-sched-domain-hooks-from-cpusets See further the Documentation and comments in the code itself. [akpm@linux-foundation.org: don't be weird] Signed-off-by: Paul Jackson <pj@sgi.com> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-19 06:40:20 +00:00
* current 'doms_cur' domains and in the new 'doms_new', we can leave
* it as it is.
*
cpumask: Partition_sched_domains takes array of cpumask_var_t Currently partition_sched_domains() takes a 'struct cpumask *doms_new' which is a kmalloc'ed array of cpumask_t. You can't have such an array if 'struct cpumask' is undefined, as we plan for CONFIG_CPUMASK_OFFSTACK=y. So, we make this an array of cpumask_var_t instead: this is the same for the CONFIG_CPUMASK_OFFSTACK=n case, but requires multiple allocations for the CONFIG_CPUMASK_OFFSTACK=y case. Hence we add alloc_sched_domains() and free_sched_domains() functions. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <200911031453.40668.rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-11-03 04:23:40 +00:00
* The passed in 'doms_new' should be allocated using
* alloc_sched_domains. This routine takes ownership of it and will
* free_sched_domains it when done with it. If the caller failed the
* alloc call, then it can pass in doms_new == NULL && ndoms_new == 1,
* and partition_sched_domains() will fallback to the single partition
* 'fallback_doms', it also forces the domains to be rebuilt.
cpuset sched_load_balance flag Add a new per-cpuset flag called 'sched_load_balance'. When enabled in a cpuset (the default value) it tells the kernel scheduler that the scheduler should provide the normal load balancing on the CPUs in that cpuset, sometimes moving tasks from one CPU to a second CPU if the second CPU is less loaded and if that task is allowed to run there. When disabled (write "0" to the file) then it tells the kernel scheduler that load balancing is not required for the CPUs in that cpuset. Now even if this flag is disabled for some cpuset, the kernel may still have to load balance some or all the CPUs in that cpuset, if some overlapping cpuset has its sched_load_balance flag enabled. If there are some CPUs that are not in any cpuset whose sched_load_balance flag is enabled, the kernel scheduler will not load balance tasks to those CPUs. Moreover the kernel will partition the 'sched domains' (non-overlapping sets of CPUs over which load balancing is attempted) into the finest granularity partition that it can find, while still keeping any two CPUs that are in the same shed_load_balance enabled cpuset in the same element of the partition. This serves two purposes: 1) It provides a mechanism for real time isolation of some CPUs, and 2) it can be used to improve performance on systems with many CPUs by supporting configurations in which load balancing is not done across all CPUs at once, but rather only done in several smaller disjoint sets of CPUs. This mechanism replaces the earlier overloading of the per-cpuset flag 'cpu_exclusive', which overloading was removed in an earlier patch: cpuset-remove-sched-domain-hooks-from-cpusets See further the Documentation and comments in the code itself. [akpm@linux-foundation.org: don't be weird] Signed-off-by: Paul Jackson <pj@sgi.com> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-19 06:40:20 +00:00
*
sched: convert remaining old-style cpumask operators Impact: Trivial API conversion NR_CPUS -> nr_cpu_ids cpumask_t -> struct cpumask sizeof(cpumask_t) -> cpumask_size() cpumask_a = cpumask_b -> cpumask_copy(&cpumask_a, &cpumask_b) cpu_set() -> cpumask_set_cpu() first_cpu() -> cpumask_first() cpumask_of_cpu() -> cpumask_of() cpus_* -> cpumask_* There are some FIXMEs where we all archs to complete infrastructure (patches have been sent): cpu_coregroup_map -> cpu_coregroup_mask node_to_cpumask* -> cpumask_of_node There is also one FIXME where we pass an array of cpumasks to partition_sched_domains(): this implies knowing the definition of 'struct cpumask' and the size of a cpumask. This will be fixed in a future patch. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-24 16:05:14 +00:00
* If doms_new == NULL it will be replaced with cpu_online_mask.
cpuset: fix regression when failed to generate sched domains Impact: properly rebuild sched-domains on kmalloc() failure When cpuset failed to generate sched domains due to kmalloc() failure, the scheduler should fallback to the single partition 'fallback_doms' and rebuild sched domains, but now it only destroys but not rebuilds sched domains. The regression was introduced by: | commit dfb512ec4834116124da61d6c1ee10fd0aa32bd6 | Author: Max Krasnyansky <maxk@qualcomm.com> | Date: Fri Aug 29 13:11:41 2008 -0700 | | sched: arch_reinit_sched_domains() must destroy domains to force rebuild After the above commit, partition_sched_domains(0, NULL, NULL) will only destroy sched domains and partition_sched_domains(1, NULL, NULL) will create the default sched domain. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Cc: Max Krasnyansky <maxk@qualcomm.com> Cc: <stable@kernel.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-18 06:02:03 +00:00
* ndoms_new == 0 is a special case for destroying existing domains,
* and it will not create the default domain.
sched: arch_reinit_sched_domains() must destroy domains to force rebuild What I realized recently is that calling rebuild_sched_domains() in arch_reinit_sched_domains() by itself is not enough when cpusets are enabled. partition_sched_domains() code is trying to avoid unnecessary domain rebuilds and will not actually rebuild anything if new domain masks match the old ones. What this means is that doing echo 1 > /sys/devices/system/cpu/sched_mc_power_savings on a system with cpusets enabled will not take affect untill something changes in the cpuset setup (ie new sets created or deleted). This patch fixes restore correct behaviour where domains must be rebuilt in order to enable MC powersaving flags. Test on quad-core Core2 box with both CONFIG_CPUSETS and !CONFIG_CPUSETS. Also tested on dual-core Core2 laptop. Lockdep is happy and things are working as expected. Signed-off-by: Max Krasnyansky <maxk@qualcomm.com> Tested-by: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-29 20:11:41 +00:00
*
cpuset sched_load_balance flag Add a new per-cpuset flag called 'sched_load_balance'. When enabled in a cpuset (the default value) it tells the kernel scheduler that the scheduler should provide the normal load balancing on the CPUs in that cpuset, sometimes moving tasks from one CPU to a second CPU if the second CPU is less loaded and if that task is allowed to run there. When disabled (write "0" to the file) then it tells the kernel scheduler that load balancing is not required for the CPUs in that cpuset. Now even if this flag is disabled for some cpuset, the kernel may still have to load balance some or all the CPUs in that cpuset, if some overlapping cpuset has its sched_load_balance flag enabled. If there are some CPUs that are not in any cpuset whose sched_load_balance flag is enabled, the kernel scheduler will not load balance tasks to those CPUs. Moreover the kernel will partition the 'sched domains' (non-overlapping sets of CPUs over which load balancing is attempted) into the finest granularity partition that it can find, while still keeping any two CPUs that are in the same shed_load_balance enabled cpuset in the same element of the partition. This serves two purposes: 1) It provides a mechanism for real time isolation of some CPUs, and 2) it can be used to improve performance on systems with many CPUs by supporting configurations in which load balancing is not done across all CPUs at once, but rather only done in several smaller disjoint sets of CPUs. This mechanism replaces the earlier overloading of the per-cpuset flag 'cpu_exclusive', which overloading was removed in an earlier patch: cpuset-remove-sched-domain-hooks-from-cpusets See further the Documentation and comments in the code itself. [akpm@linux-foundation.org: don't be weird] Signed-off-by: Paul Jackson <pj@sgi.com> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-19 06:40:20 +00:00
* Call with hotplug lock held
*/
cpumask: Partition_sched_domains takes array of cpumask_var_t Currently partition_sched_domains() takes a 'struct cpumask *doms_new' which is a kmalloc'ed array of cpumask_t. You can't have such an array if 'struct cpumask' is undefined, as we plan for CONFIG_CPUMASK_OFFSTACK=y. So, we make this an array of cpumask_var_t instead: this is the same for the CONFIG_CPUMASK_OFFSTACK=n case, but requires multiple allocations for the CONFIG_CPUMASK_OFFSTACK=y case. Hence we add alloc_sched_domains() and free_sched_domains() functions. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <200911031453.40668.rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-11-03 04:23:40 +00:00
void partition_sched_domains(int ndoms_new, cpumask_var_t doms_new[],
sched, cpuset: customize sched domains, core [rebased for sched-devel/latest] - Add a new cpuset file, having levels: sched_relax_domain_level - Modify partition_sched_domains() and build_sched_domains() to take attributes parameter passed from cpuset. - Fill newidle_idx for node domains which currently unused but might be required if sched_relax_domain_level become higher. - We can change the default level by boot option 'relax_domain_level='. Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-15 05:04:23 +00:00
struct sched_domain_attr *dattr_new)
cpuset sched_load_balance flag Add a new per-cpuset flag called 'sched_load_balance'. When enabled in a cpuset (the default value) it tells the kernel scheduler that the scheduler should provide the normal load balancing on the CPUs in that cpuset, sometimes moving tasks from one CPU to a second CPU if the second CPU is less loaded and if that task is allowed to run there. When disabled (write "0" to the file) then it tells the kernel scheduler that load balancing is not required for the CPUs in that cpuset. Now even if this flag is disabled for some cpuset, the kernel may still have to load balance some or all the CPUs in that cpuset, if some overlapping cpuset has its sched_load_balance flag enabled. If there are some CPUs that are not in any cpuset whose sched_load_balance flag is enabled, the kernel scheduler will not load balance tasks to those CPUs. Moreover the kernel will partition the 'sched domains' (non-overlapping sets of CPUs over which load balancing is attempted) into the finest granularity partition that it can find, while still keeping any two CPUs that are in the same shed_load_balance enabled cpuset in the same element of the partition. This serves two purposes: 1) It provides a mechanism for real time isolation of some CPUs, and 2) it can be used to improve performance on systems with many CPUs by supporting configurations in which load balancing is not done across all CPUs at once, but rather only done in several smaller disjoint sets of CPUs. This mechanism replaces the earlier overloading of the per-cpuset flag 'cpu_exclusive', which overloading was removed in an earlier patch: cpuset-remove-sched-domain-hooks-from-cpusets See further the Documentation and comments in the code itself. [akpm@linux-foundation.org: don't be weird] Signed-off-by: Paul Jackson <pj@sgi.com> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-19 06:40:20 +00:00
{
sched: arch_reinit_sched_domains() must destroy domains to force rebuild What I realized recently is that calling rebuild_sched_domains() in arch_reinit_sched_domains() by itself is not enough when cpusets are enabled. partition_sched_domains() code is trying to avoid unnecessary domain rebuilds and will not actually rebuild anything if new domain masks match the old ones. What this means is that doing echo 1 > /sys/devices/system/cpu/sched_mc_power_savings on a system with cpusets enabled will not take affect untill something changes in the cpuset setup (ie new sets created or deleted). This patch fixes restore correct behaviour where domains must be rebuilt in order to enable MC powersaving flags. Test on quad-core Core2 box with both CONFIG_CPUSETS and !CONFIG_CPUSETS. Also tested on dual-core Core2 laptop. Lockdep is happy and things are working as expected. Signed-off-by: Max Krasnyansky <maxk@qualcomm.com> Tested-by: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-29 20:11:41 +00:00
int i, j, n;
sched: add missing arch_update_cpu_topology() call arch_reinit_sched_domains() used to call arch_update_cpu_topology() via arch_init_sched_domains(). This call got lost with e761b7725234276a802322549cee5255305a0930 ("cpu hotplug, sched: Introduce cpu_active_map and redo sched domain managment (take 2)". So we might end up with outdated and missing cpus in the cpu core maps (architecture used to call arch_reinit_sched_domains if cpu topology changed). This adds a call to arch_update_cpu_topology in partition_sched_domains which gets called whenever scheduling domains get updated. Which is what is supposed to happen when cpu topology changes. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-09 17:49:51 +00:00
int new_topology;
cpuset sched_load_balance flag Add a new per-cpuset flag called 'sched_load_balance'. When enabled in a cpuset (the default value) it tells the kernel scheduler that the scheduler should provide the normal load balancing on the CPUs in that cpuset, sometimes moving tasks from one CPU to a second CPU if the second CPU is less loaded and if that task is allowed to run there. When disabled (write "0" to the file) then it tells the kernel scheduler that load balancing is not required for the CPUs in that cpuset. Now even if this flag is disabled for some cpuset, the kernel may still have to load balance some or all the CPUs in that cpuset, if some overlapping cpuset has its sched_load_balance flag enabled. If there are some CPUs that are not in any cpuset whose sched_load_balance flag is enabled, the kernel scheduler will not load balance tasks to those CPUs. Moreover the kernel will partition the 'sched domains' (non-overlapping sets of CPUs over which load balancing is attempted) into the finest granularity partition that it can find, while still keeping any two CPUs that are in the same shed_load_balance enabled cpuset in the same element of the partition. This serves two purposes: 1) It provides a mechanism for real time isolation of some CPUs, and 2) it can be used to improve performance on systems with many CPUs by supporting configurations in which load balancing is not done across all CPUs at once, but rather only done in several smaller disjoint sets of CPUs. This mechanism replaces the earlier overloading of the per-cpuset flag 'cpu_exclusive', which overloading was removed in an earlier patch: cpuset-remove-sched-domain-hooks-from-cpusets See further the Documentation and comments in the code itself. [akpm@linux-foundation.org: don't be weird] Signed-off-by: Paul Jackson <pj@sgi.com> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-19 06:40:20 +00:00
sched: fix missing locking in sched_domains code Concurrent calls to detach_destroy_domains and arch_init_sched_domains were prevented by the old scheduler subsystem cpu hotplug mutex. When this got converted to get_online_cpus() the locking got broken. Unlike before now several processes can concurrently enter the critical sections that were protected by the old lock. So use the already present doms_cur_mutex to protect these sections again. Cc: Gautham R Shenoy <ego@in.ibm.com> Cc: Paul Jackson <pj@sgi.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-28 09:33:07 +00:00
mutex_lock(&sched_domains_mutex);
sched: introduce a mutex and corresponding API to serialize access to doms_curarray doms_cur[] array represents various scheduling domains which are mutually exclusive. Currently cpusets code can modify this array (by calling partition_sched_domains()) as a result of user modifying sched_load_balance flag for various cpusets. This patch introduces a mutex and corresponding API (only when CONFIG_FAIR_GROUP_SCHED is defined) which allows a reader to safely read the doms_cur[] array w/o worrying abt concurrent modifications to the array. The fair group scheduler code (introduced in next patch of this series) makes use of this mutex to walk thr' doms_cur[] array while rebalancing shares of task groups across cpus. Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:00 +00:00
sched: fix sched_domain sysctl registration again commit 029190c515f15f512ac85de8fc686d4dbd0ae731 (cpuset sched_load_balance flag) was not tested SCHED_DEBUG enabled as committed as it dereferences NULL when used and it reordered the sysctl registration to cause it to never show any domains or their tunables. Fixes: 1) restore arch_init_sched_domains ordering we can't walk the domains before we build them presently we register cpus with empty directories (no domain directories or files). 2) make unregister_sched_domain_sysctl do nothing when already unregistered detach_destroy_domains is now called one set of cpus at a time unregister_syctl dereferences NULL if called with a null. While the the function would always dereference null if called twice, in the previous code it was always called once and then was followed a register. So only the hidden bug of the sysctl_root_table not being allocated followed by an attempt to free it would have shown the error. 3) always call unregister and register in partition_sched_domains The code is "smart" about unregistering only needed domains. Since we aren't guaranteed any calls to unregister, always unregister. Without calling register on the way out we will not have a table or any sysctl tree. 4) warn if register is called without unregistering The previous table memory is lost, leaving pointers to the later freed memory in sysctl and leaking the memory of the tables. Before this patch on a 2-core 4-thread box compiled for SMT and NUMA, the domains appear empty (there are actually 3 levels per cpu). And as soon as two domains a null pointer is dereferenced (unreliable in this case is stack garbage): bu19a:~# ls -R /proc/sys/kernel/sched_domain/ /proc/sys/kernel/sched_domain/: cpu0 cpu1 cpu2 cpu3 /proc/sys/kernel/sched_domain/cpu0: /proc/sys/kernel/sched_domain/cpu1: /proc/sys/kernel/sched_domain/cpu2: /proc/sys/kernel/sched_domain/cpu3: bu19a:~# mkdir /dev/cpuset bu19a:~# mount -tcpuset cpuset /dev/cpuset/ bu19a:~# cd /dev/cpuset/ bu19a:/dev/cpuset# echo 0 > sched_load_balance bu19a:/dev/cpuset# mkdir one bu19a:/dev/cpuset# echo 1 > one/cpus bu19a:/dev/cpuset# echo 0 > one/sched_load_balance Unable to handle kernel paging request for data at address 0x00000018 Faulting instruction address: 0xc00000000006b608 NIP: c00000000006b608 LR: c00000000006b604 CTR: 0000000000000000 REGS: c000000018d973f0 TRAP: 0300 Not tainted (2.6.23-bml) MSR: 9000000000009032 <EE,ME,IR,DR> CR: 28242442 XER: 00000000 DAR: 0000000000000018, DSISR: 0000000040000000 TASK = c00000001912e340[1987] 'bash' THREAD: c000000018d94000 CPU: 2 .. NIP [c00000000006b608] .unregister_sysctl_table+0x38/0x110 LR [c00000000006b604] .unregister_sysctl_table+0x34/0x110 Call Trace: [c000000018d97670] [c000000007017270] 0xc000000007017270 (unreliable) [c000000018d97720] [c000000000058710] .detach_destroy_domains+0x30/0xb0 [c000000018d977b0] [c00000000005cf1c] .partition_sched_domains+0x1bc/0x230 [c000000018d97870] [c00000000009fdc4] .rebuild_sched_domains+0xb4/0x4c0 [c000000018d97970] [c0000000000a02e8] .update_flag+0x118/0x170 [c000000018d97a80] [c0000000000a1768] .cpuset_common_file_write+0x568/0x820 [c000000018d97c00] [c00000000009d95c] .cgroup_file_write+0x7c/0x180 [c000000018d97cf0] [c0000000000e76b8] .vfs_write+0xe8/0x1b0 [c000000018d97d90] [c0000000000e810c] .sys_write+0x4c/0x90 [c000000018d97e30] [c00000000000852c] syscall_exit+0x0/0x40 Signed-off-by: Milton Miller <miltonm@bga.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-24 16:23:48 +00:00
/* always unregister in case we don't destroy any domains */
unregister_sched_domain_sysctl();
sched: add missing arch_update_cpu_topology() call arch_reinit_sched_domains() used to call arch_update_cpu_topology() via arch_init_sched_domains(). This call got lost with e761b7725234276a802322549cee5255305a0930 ("cpu hotplug, sched: Introduce cpu_active_map and redo sched domain managment (take 2)". So we might end up with outdated and missing cpus in the cpu core maps (architecture used to call arch_reinit_sched_domains if cpu topology changed). This adds a call to arch_update_cpu_topology in partition_sched_domains which gets called whenever scheduling domains get updated. Which is what is supposed to happen when cpu topology changes. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-09 17:49:51 +00:00
/* Let architecture update cpu core mappings. */
new_topology = arch_update_cpu_topology();
sched: arch_reinit_sched_domains() must destroy domains to force rebuild What I realized recently is that calling rebuild_sched_domains() in arch_reinit_sched_domains() by itself is not enough when cpusets are enabled. partition_sched_domains() code is trying to avoid unnecessary domain rebuilds and will not actually rebuild anything if new domain masks match the old ones. What this means is that doing echo 1 > /sys/devices/system/cpu/sched_mc_power_savings on a system with cpusets enabled will not take affect untill something changes in the cpuset setup (ie new sets created or deleted). This patch fixes restore correct behaviour where domains must be rebuilt in order to enable MC powersaving flags. Test on quad-core Core2 box with both CONFIG_CPUSETS and !CONFIG_CPUSETS. Also tested on dual-core Core2 laptop. Lockdep is happy and things are working as expected. Signed-off-by: Max Krasnyansky <maxk@qualcomm.com> Tested-by: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-29 20:11:41 +00:00
n = doms_new ? ndoms_new : 0;
cpuset sched_load_balance flag Add a new per-cpuset flag called 'sched_load_balance'. When enabled in a cpuset (the default value) it tells the kernel scheduler that the scheduler should provide the normal load balancing on the CPUs in that cpuset, sometimes moving tasks from one CPU to a second CPU if the second CPU is less loaded and if that task is allowed to run there. When disabled (write "0" to the file) then it tells the kernel scheduler that load balancing is not required for the CPUs in that cpuset. Now even if this flag is disabled for some cpuset, the kernel may still have to load balance some or all the CPUs in that cpuset, if some overlapping cpuset has its sched_load_balance flag enabled. If there are some CPUs that are not in any cpuset whose sched_load_balance flag is enabled, the kernel scheduler will not load balance tasks to those CPUs. Moreover the kernel will partition the 'sched domains' (non-overlapping sets of CPUs over which load balancing is attempted) into the finest granularity partition that it can find, while still keeping any two CPUs that are in the same shed_load_balance enabled cpuset in the same element of the partition. This serves two purposes: 1) It provides a mechanism for real time isolation of some CPUs, and 2) it can be used to improve performance on systems with many CPUs by supporting configurations in which load balancing is not done across all CPUs at once, but rather only done in several smaller disjoint sets of CPUs. This mechanism replaces the earlier overloading of the per-cpuset flag 'cpu_exclusive', which overloading was removed in an earlier patch: cpuset-remove-sched-domain-hooks-from-cpusets See further the Documentation and comments in the code itself. [akpm@linux-foundation.org: don't be weird] Signed-off-by: Paul Jackson <pj@sgi.com> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-19 06:40:20 +00:00
/* Destroy deleted domains */
for (i = 0; i < ndoms_cur; i++) {
sched: add missing arch_update_cpu_topology() call arch_reinit_sched_domains() used to call arch_update_cpu_topology() via arch_init_sched_domains(). This call got lost with e761b7725234276a802322549cee5255305a0930 ("cpu hotplug, sched: Introduce cpu_active_map and redo sched domain managment (take 2)". So we might end up with outdated and missing cpus in the cpu core maps (architecture used to call arch_reinit_sched_domains if cpu topology changed). This adds a call to arch_update_cpu_topology in partition_sched_domains which gets called whenever scheduling domains get updated. Which is what is supposed to happen when cpu topology changes. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-09 17:49:51 +00:00
for (j = 0; j < n && !new_topology; j++) {
cpumask: Partition_sched_domains takes array of cpumask_var_t Currently partition_sched_domains() takes a 'struct cpumask *doms_new' which is a kmalloc'ed array of cpumask_t. You can't have such an array if 'struct cpumask' is undefined, as we plan for CONFIG_CPUMASK_OFFSTACK=y. So, we make this an array of cpumask_var_t instead: this is the same for the CONFIG_CPUMASK_OFFSTACK=n case, but requires multiple allocations for the CONFIG_CPUMASK_OFFSTACK=y case. Hence we add alloc_sched_domains() and free_sched_domains() functions. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <200911031453.40668.rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-11-03 04:23:40 +00:00
if (cpumask_equal(doms_cur[i], doms_new[j])
sched, cpuset: customize sched domains, core [rebased for sched-devel/latest] - Add a new cpuset file, having levels: sched_relax_domain_level - Modify partition_sched_domains() and build_sched_domains() to take attributes parameter passed from cpuset. - Fill newidle_idx for node domains which currently unused but might be required if sched_relax_domain_level become higher. - We can change the default level by boot option 'relax_domain_level='. Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-15 05:04:23 +00:00
&& dattrs_equal(dattr_cur, i, dattr_new, j))
cpuset sched_load_balance flag Add a new per-cpuset flag called 'sched_load_balance'. When enabled in a cpuset (the default value) it tells the kernel scheduler that the scheduler should provide the normal load balancing on the CPUs in that cpuset, sometimes moving tasks from one CPU to a second CPU if the second CPU is less loaded and if that task is allowed to run there. When disabled (write "0" to the file) then it tells the kernel scheduler that load balancing is not required for the CPUs in that cpuset. Now even if this flag is disabled for some cpuset, the kernel may still have to load balance some or all the CPUs in that cpuset, if some overlapping cpuset has its sched_load_balance flag enabled. If there are some CPUs that are not in any cpuset whose sched_load_balance flag is enabled, the kernel scheduler will not load balance tasks to those CPUs. Moreover the kernel will partition the 'sched domains' (non-overlapping sets of CPUs over which load balancing is attempted) into the finest granularity partition that it can find, while still keeping any two CPUs that are in the same shed_load_balance enabled cpuset in the same element of the partition. This serves two purposes: 1) It provides a mechanism for real time isolation of some CPUs, and 2) it can be used to improve performance on systems with many CPUs by supporting configurations in which load balancing is not done across all CPUs at once, but rather only done in several smaller disjoint sets of CPUs. This mechanism replaces the earlier overloading of the per-cpuset flag 'cpu_exclusive', which overloading was removed in an earlier patch: cpuset-remove-sched-domain-hooks-from-cpusets See further the Documentation and comments in the code itself. [akpm@linux-foundation.org: don't be weird] Signed-off-by: Paul Jackson <pj@sgi.com> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-19 06:40:20 +00:00
goto match1;
}
/* no match - a current sched domain not in new doms_new[] */
cpumask: Partition_sched_domains takes array of cpumask_var_t Currently partition_sched_domains() takes a 'struct cpumask *doms_new' which is a kmalloc'ed array of cpumask_t. You can't have such an array if 'struct cpumask' is undefined, as we plan for CONFIG_CPUMASK_OFFSTACK=y. So, we make this an array of cpumask_var_t instead: this is the same for the CONFIG_CPUMASK_OFFSTACK=n case, but requires multiple allocations for the CONFIG_CPUMASK_OFFSTACK=y case. Hence we add alloc_sched_domains() and free_sched_domains() functions. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <200911031453.40668.rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-11-03 04:23:40 +00:00
detach_destroy_domains(doms_cur[i]);
cpuset sched_load_balance flag Add a new per-cpuset flag called 'sched_load_balance'. When enabled in a cpuset (the default value) it tells the kernel scheduler that the scheduler should provide the normal load balancing on the CPUs in that cpuset, sometimes moving tasks from one CPU to a second CPU if the second CPU is less loaded and if that task is allowed to run there. When disabled (write "0" to the file) then it tells the kernel scheduler that load balancing is not required for the CPUs in that cpuset. Now even if this flag is disabled for some cpuset, the kernel may still have to load balance some or all the CPUs in that cpuset, if some overlapping cpuset has its sched_load_balance flag enabled. If there are some CPUs that are not in any cpuset whose sched_load_balance flag is enabled, the kernel scheduler will not load balance tasks to those CPUs. Moreover the kernel will partition the 'sched domains' (non-overlapping sets of CPUs over which load balancing is attempted) into the finest granularity partition that it can find, while still keeping any two CPUs that are in the same shed_load_balance enabled cpuset in the same element of the partition. This serves two purposes: 1) It provides a mechanism for real time isolation of some CPUs, and 2) it can be used to improve performance on systems with many CPUs by supporting configurations in which load balancing is not done across all CPUs at once, but rather only done in several smaller disjoint sets of CPUs. This mechanism replaces the earlier overloading of the per-cpuset flag 'cpu_exclusive', which overloading was removed in an earlier patch: cpuset-remove-sched-domain-hooks-from-cpusets See further the Documentation and comments in the code itself. [akpm@linux-foundation.org: don't be weird] Signed-off-by: Paul Jackson <pj@sgi.com> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-19 06:40:20 +00:00
match1:
;
}
cpu hotplug, sched: Introduce cpu_active_map and redo sched domain managment (take 2) This is based on Linus' idea of creating cpu_active_map that prevents scheduler load balancer from migrating tasks to the cpu that is going down. It allows us to simplify domain management code and avoid unecessary domain rebuilds during cpu hotplug event handling. Please ignore the cpusets part for now. It needs some more work in order to avoid crazy lock nesting. Although I did simplfy and unify domain reinitialization logic. We now simply call partition_sched_domains() in all the cases. This means that we're using exact same code paths as in cpusets case and hence the test below cover cpusets too. Cpuset changes to make rebuild_sched_domains() callable from various contexts are in the separate patch (right next after this one). This not only boots but also easily handles while true; do make clean; make -j 8; done and while true; do on-off-cpu 1; done at the same time. (on-off-cpu 1 simple does echo 0/1 > /sys/.../cpu1/online thing). Suprisingly the box (dual-core Core2) is quite usable. In fact I'm typing this on right now in gnome-terminal and things are moving just fine. Also this is running with most of the debug features enabled (lockdep, mutex, etc) no BUG_ONs or lockdep complaints so far. I believe I addressed all of the Dmitry's comments for original Linus' version. I changed both fair and rt balancer to mask out non-active cpus. And replaced cpu_is_offline() with !cpu_active() in the main scheduler code where it made sense (to me). Signed-off-by: Max Krasnyanskiy <maxk@qualcomm.com> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Gregory Haskins <ghaskins@novell.com> Cc: dmitry.adamushko@gmail.com Cc: pj@sgi.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-15 11:43:49 +00:00
if (doms_new == NULL) {
ndoms_cur = 0;
cpumask: Partition_sched_domains takes array of cpumask_var_t Currently partition_sched_domains() takes a 'struct cpumask *doms_new' which is a kmalloc'ed array of cpumask_t. You can't have such an array if 'struct cpumask' is undefined, as we plan for CONFIG_CPUMASK_OFFSTACK=y. So, we make this an array of cpumask_var_t instead: this is the same for the CONFIG_CPUMASK_OFFSTACK=n case, but requires multiple allocations for the CONFIG_CPUMASK_OFFSTACK=y case. Hence we add alloc_sched_domains() and free_sched_domains() functions. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <200911031453.40668.rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-11-03 04:23:40 +00:00
doms_new = &fallback_doms;
sched: Fix balance vs hotplug race Since (e761b77: cpu hotplug, sched: Introduce cpu_active_map and redo sched domain managment) we have cpu_active_mask which is suppose to rule scheduler migration and load-balancing, except it never (fully) did. The particular problem being solved here is a crash in try_to_wake_up() where select_task_rq() ends up selecting an offline cpu because select_task_rq_fair() trusts the sched_domain tree to reflect the current state of affairs, similarly select_task_rq_rt() trusts the root_domain. However, the sched_domains are updated from CPU_DEAD, which is after the cpu is taken offline and after stop_machine is done. Therefore it can race perfectly well with code assuming the domains are right. Cure this by building the domains from cpu_active_mask on CPU_DOWN_PREPARE. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-11-25 12:31:39 +00:00
cpumask_andnot(doms_new[0], cpu_active_mask, cpu_isolated_map);
sched: add sanity check in partition_sched_domains() Impact: cleanup, add debug check It's wrong to make dattr_new = NULL if doms_new == NULL, it introduces memory leak if dattr_new != NULL. Fortunately dattr_new is always NULL in this case. So remove the code and add a sanity check. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-04 08:20:23 +00:00
WARN_ON_ONCE(dattr_new);
cpu hotplug, sched: Introduce cpu_active_map and redo sched domain managment (take 2) This is based on Linus' idea of creating cpu_active_map that prevents scheduler load balancer from migrating tasks to the cpu that is going down. It allows us to simplify domain management code and avoid unecessary domain rebuilds during cpu hotplug event handling. Please ignore the cpusets part for now. It needs some more work in order to avoid crazy lock nesting. Although I did simplfy and unify domain reinitialization logic. We now simply call partition_sched_domains() in all the cases. This means that we're using exact same code paths as in cpusets case and hence the test below cover cpusets too. Cpuset changes to make rebuild_sched_domains() callable from various contexts are in the separate patch (right next after this one). This not only boots but also easily handles while true; do make clean; make -j 8; done and while true; do on-off-cpu 1; done at the same time. (on-off-cpu 1 simple does echo 0/1 > /sys/.../cpu1/online thing). Suprisingly the box (dual-core Core2) is quite usable. In fact I'm typing this on right now in gnome-terminal and things are moving just fine. Also this is running with most of the debug features enabled (lockdep, mutex, etc) no BUG_ONs or lockdep complaints so far. I believe I addressed all of the Dmitry's comments for original Linus' version. I changed both fair and rt balancer to mask out non-active cpus. And replaced cpu_is_offline() with !cpu_active() in the main scheduler code where it made sense (to me). Signed-off-by: Max Krasnyanskiy <maxk@qualcomm.com> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Gregory Haskins <ghaskins@novell.com> Cc: dmitry.adamushko@gmail.com Cc: pj@sgi.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-15 11:43:49 +00:00
}
cpuset sched_load_balance flag Add a new per-cpuset flag called 'sched_load_balance'. When enabled in a cpuset (the default value) it tells the kernel scheduler that the scheduler should provide the normal load balancing on the CPUs in that cpuset, sometimes moving tasks from one CPU to a second CPU if the second CPU is less loaded and if that task is allowed to run there. When disabled (write "0" to the file) then it tells the kernel scheduler that load balancing is not required for the CPUs in that cpuset. Now even if this flag is disabled for some cpuset, the kernel may still have to load balance some or all the CPUs in that cpuset, if some overlapping cpuset has its sched_load_balance flag enabled. If there are some CPUs that are not in any cpuset whose sched_load_balance flag is enabled, the kernel scheduler will not load balance tasks to those CPUs. Moreover the kernel will partition the 'sched domains' (non-overlapping sets of CPUs over which load balancing is attempted) into the finest granularity partition that it can find, while still keeping any two CPUs that are in the same shed_load_balance enabled cpuset in the same element of the partition. This serves two purposes: 1) It provides a mechanism for real time isolation of some CPUs, and 2) it can be used to improve performance on systems with many CPUs by supporting configurations in which load balancing is not done across all CPUs at once, but rather only done in several smaller disjoint sets of CPUs. This mechanism replaces the earlier overloading of the per-cpuset flag 'cpu_exclusive', which overloading was removed in an earlier patch: cpuset-remove-sched-domain-hooks-from-cpusets See further the Documentation and comments in the code itself. [akpm@linux-foundation.org: don't be weird] Signed-off-by: Paul Jackson <pj@sgi.com> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-19 06:40:20 +00:00
/* Build new domains */
for (i = 0; i < ndoms_new; i++) {
sched: add missing arch_update_cpu_topology() call arch_reinit_sched_domains() used to call arch_update_cpu_topology() via arch_init_sched_domains(). This call got lost with e761b7725234276a802322549cee5255305a0930 ("cpu hotplug, sched: Introduce cpu_active_map and redo sched domain managment (take 2)". So we might end up with outdated and missing cpus in the cpu core maps (architecture used to call arch_reinit_sched_domains if cpu topology changed). This adds a call to arch_update_cpu_topology in partition_sched_domains which gets called whenever scheduling domains get updated. Which is what is supposed to happen when cpu topology changes. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-09 17:49:51 +00:00
for (j = 0; j < ndoms_cur && !new_topology; j++) {
cpumask: Partition_sched_domains takes array of cpumask_var_t Currently partition_sched_domains() takes a 'struct cpumask *doms_new' which is a kmalloc'ed array of cpumask_t. You can't have such an array if 'struct cpumask' is undefined, as we plan for CONFIG_CPUMASK_OFFSTACK=y. So, we make this an array of cpumask_var_t instead: this is the same for the CONFIG_CPUMASK_OFFSTACK=n case, but requires multiple allocations for the CONFIG_CPUMASK_OFFSTACK=y case. Hence we add alloc_sched_domains() and free_sched_domains() functions. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <200911031453.40668.rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-11-03 04:23:40 +00:00
if (cpumask_equal(doms_new[i], doms_cur[j])
sched, cpuset: customize sched domains, core [rebased for sched-devel/latest] - Add a new cpuset file, having levels: sched_relax_domain_level - Modify partition_sched_domains() and build_sched_domains() to take attributes parameter passed from cpuset. - Fill newidle_idx for node domains which currently unused but might be required if sched_relax_domain_level become higher. - We can change the default level by boot option 'relax_domain_level='. Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-15 05:04:23 +00:00
&& dattrs_equal(dattr_new, i, dattr_cur, j))
cpuset sched_load_balance flag Add a new per-cpuset flag called 'sched_load_balance'. When enabled in a cpuset (the default value) it tells the kernel scheduler that the scheduler should provide the normal load balancing on the CPUs in that cpuset, sometimes moving tasks from one CPU to a second CPU if the second CPU is less loaded and if that task is allowed to run there. When disabled (write "0" to the file) then it tells the kernel scheduler that load balancing is not required for the CPUs in that cpuset. Now even if this flag is disabled for some cpuset, the kernel may still have to load balance some or all the CPUs in that cpuset, if some overlapping cpuset has its sched_load_balance flag enabled. If there are some CPUs that are not in any cpuset whose sched_load_balance flag is enabled, the kernel scheduler will not load balance tasks to those CPUs. Moreover the kernel will partition the 'sched domains' (non-overlapping sets of CPUs over which load balancing is attempted) into the finest granularity partition that it can find, while still keeping any two CPUs that are in the same shed_load_balance enabled cpuset in the same element of the partition. This serves two purposes: 1) It provides a mechanism for real time isolation of some CPUs, and 2) it can be used to improve performance on systems with many CPUs by supporting configurations in which load balancing is not done across all CPUs at once, but rather only done in several smaller disjoint sets of CPUs. This mechanism replaces the earlier overloading of the per-cpuset flag 'cpu_exclusive', which overloading was removed in an earlier patch: cpuset-remove-sched-domain-hooks-from-cpusets See further the Documentation and comments in the code itself. [akpm@linux-foundation.org: don't be weird] Signed-off-by: Paul Jackson <pj@sgi.com> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-19 06:40:20 +00:00
goto match2;
}
/* no match - add a new doms_new */
sched: Dynamically allocate sched_domain/sched_group data-structures Instead of relying on static allocations for the sched_domain and sched_group trees, dynamically allocate and RCU free them. Allocating this dynamically also allows for some build_sched_groups() simplification since we can now (like with other simplifications) rely on the sched_domain tree instead of hard-coded knowledge. One tricky to note is that detach_destroy_domains() needs to hold rcu_read_lock() over the entire tear-down, per-cpu is not sufficient since that can lead to partial sched_group existance (could possibly be solved by doing the tear-down backwards but this is much more robust). A concequence of the above is that we can no longer print the sched_domain debug stuff from cpu_attach_domain() since that might now run with preemption disabled (due to classic RCU etc.) and sched_domain_debug() does some GFP_KERNEL allocations. Another thing to note is that we now fully rely on normal RCU and not RCU-sched, this is because with the new and exiting RCU flavours we grew over the years BH doesn't necessarily hold off RCU-sched grace periods (-rt is known to break this). This would in fact already cause us grief since we do sched_domain/sched_group iterations from softirq context. This patch is somewhat larger than I would like it to be, but I didn't find any means of shrinking/splitting this. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.245307941@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:09:50 +00:00
build_sched_domains(doms_new[i], dattr_new ? dattr_new + i : NULL);
cpuset sched_load_balance flag Add a new per-cpuset flag called 'sched_load_balance'. When enabled in a cpuset (the default value) it tells the kernel scheduler that the scheduler should provide the normal load balancing on the CPUs in that cpuset, sometimes moving tasks from one CPU to a second CPU if the second CPU is less loaded and if that task is allowed to run there. When disabled (write "0" to the file) then it tells the kernel scheduler that load balancing is not required for the CPUs in that cpuset. Now even if this flag is disabled for some cpuset, the kernel may still have to load balance some or all the CPUs in that cpuset, if some overlapping cpuset has its sched_load_balance flag enabled. If there are some CPUs that are not in any cpuset whose sched_load_balance flag is enabled, the kernel scheduler will not load balance tasks to those CPUs. Moreover the kernel will partition the 'sched domains' (non-overlapping sets of CPUs over which load balancing is attempted) into the finest granularity partition that it can find, while still keeping any two CPUs that are in the same shed_load_balance enabled cpuset in the same element of the partition. This serves two purposes: 1) It provides a mechanism for real time isolation of some CPUs, and 2) it can be used to improve performance on systems with many CPUs by supporting configurations in which load balancing is not done across all CPUs at once, but rather only done in several smaller disjoint sets of CPUs. This mechanism replaces the earlier overloading of the per-cpuset flag 'cpu_exclusive', which overloading was removed in an earlier patch: cpuset-remove-sched-domain-hooks-from-cpusets See further the Documentation and comments in the code itself. [akpm@linux-foundation.org: don't be weird] Signed-off-by: Paul Jackson <pj@sgi.com> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-19 06:40:20 +00:00
match2:
;
}
/* Remember the new sched domains */
cpumask: Partition_sched_domains takes array of cpumask_var_t Currently partition_sched_domains() takes a 'struct cpumask *doms_new' which is a kmalloc'ed array of cpumask_t. You can't have such an array if 'struct cpumask' is undefined, as we plan for CONFIG_CPUMASK_OFFSTACK=y. So, we make this an array of cpumask_var_t instead: this is the same for the CONFIG_CPUMASK_OFFSTACK=n case, but requires multiple allocations for the CONFIG_CPUMASK_OFFSTACK=y case. Hence we add alloc_sched_domains() and free_sched_domains() functions. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <200911031453.40668.rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-11-03 04:23:40 +00:00
if (doms_cur != &fallback_doms)
free_sched_domains(doms_cur, ndoms_cur);
sched, cpuset: customize sched domains, core [rebased for sched-devel/latest] - Add a new cpuset file, having levels: sched_relax_domain_level - Modify partition_sched_domains() and build_sched_domains() to take attributes parameter passed from cpuset. - Fill newidle_idx for node domains which currently unused but might be required if sched_relax_domain_level become higher. - We can change the default level by boot option 'relax_domain_level='. Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-15 05:04:23 +00:00
kfree(dattr_cur); /* kfree(NULL) is safe */
cpuset sched_load_balance flag Add a new per-cpuset flag called 'sched_load_balance'. When enabled in a cpuset (the default value) it tells the kernel scheduler that the scheduler should provide the normal load balancing on the CPUs in that cpuset, sometimes moving tasks from one CPU to a second CPU if the second CPU is less loaded and if that task is allowed to run there. When disabled (write "0" to the file) then it tells the kernel scheduler that load balancing is not required for the CPUs in that cpuset. Now even if this flag is disabled for some cpuset, the kernel may still have to load balance some or all the CPUs in that cpuset, if some overlapping cpuset has its sched_load_balance flag enabled. If there are some CPUs that are not in any cpuset whose sched_load_balance flag is enabled, the kernel scheduler will not load balance tasks to those CPUs. Moreover the kernel will partition the 'sched domains' (non-overlapping sets of CPUs over which load balancing is attempted) into the finest granularity partition that it can find, while still keeping any two CPUs that are in the same shed_load_balance enabled cpuset in the same element of the partition. This serves two purposes: 1) It provides a mechanism for real time isolation of some CPUs, and 2) it can be used to improve performance on systems with many CPUs by supporting configurations in which load balancing is not done across all CPUs at once, but rather only done in several smaller disjoint sets of CPUs. This mechanism replaces the earlier overloading of the per-cpuset flag 'cpu_exclusive', which overloading was removed in an earlier patch: cpuset-remove-sched-domain-hooks-from-cpusets See further the Documentation and comments in the code itself. [akpm@linux-foundation.org: don't be weird] Signed-off-by: Paul Jackson <pj@sgi.com> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-19 06:40:20 +00:00
doms_cur = doms_new;
sched, cpuset: customize sched domains, core [rebased for sched-devel/latest] - Add a new cpuset file, having levels: sched_relax_domain_level - Modify partition_sched_domains() and build_sched_domains() to take attributes parameter passed from cpuset. - Fill newidle_idx for node domains which currently unused but might be required if sched_relax_domain_level become higher. - We can change the default level by boot option 'relax_domain_level='. Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-15 05:04:23 +00:00
dattr_cur = dattr_new;
cpuset sched_load_balance flag Add a new per-cpuset flag called 'sched_load_balance'. When enabled in a cpuset (the default value) it tells the kernel scheduler that the scheduler should provide the normal load balancing on the CPUs in that cpuset, sometimes moving tasks from one CPU to a second CPU if the second CPU is less loaded and if that task is allowed to run there. When disabled (write "0" to the file) then it tells the kernel scheduler that load balancing is not required for the CPUs in that cpuset. Now even if this flag is disabled for some cpuset, the kernel may still have to load balance some or all the CPUs in that cpuset, if some overlapping cpuset has its sched_load_balance flag enabled. If there are some CPUs that are not in any cpuset whose sched_load_balance flag is enabled, the kernel scheduler will not load balance tasks to those CPUs. Moreover the kernel will partition the 'sched domains' (non-overlapping sets of CPUs over which load balancing is attempted) into the finest granularity partition that it can find, while still keeping any two CPUs that are in the same shed_load_balance enabled cpuset in the same element of the partition. This serves two purposes: 1) It provides a mechanism for real time isolation of some CPUs, and 2) it can be used to improve performance on systems with many CPUs by supporting configurations in which load balancing is not done across all CPUs at once, but rather only done in several smaller disjoint sets of CPUs. This mechanism replaces the earlier overloading of the per-cpuset flag 'cpu_exclusive', which overloading was removed in an earlier patch: cpuset-remove-sched-domain-hooks-from-cpusets See further the Documentation and comments in the code itself. [akpm@linux-foundation.org: don't be weird] Signed-off-by: Paul Jackson <pj@sgi.com> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-19 06:40:20 +00:00
ndoms_cur = ndoms_new;
sched: fix sched_domain sysctl registration again commit 029190c515f15f512ac85de8fc686d4dbd0ae731 (cpuset sched_load_balance flag) was not tested SCHED_DEBUG enabled as committed as it dereferences NULL when used and it reordered the sysctl registration to cause it to never show any domains or their tunables. Fixes: 1) restore arch_init_sched_domains ordering we can't walk the domains before we build them presently we register cpus with empty directories (no domain directories or files). 2) make unregister_sched_domain_sysctl do nothing when already unregistered detach_destroy_domains is now called one set of cpus at a time unregister_syctl dereferences NULL if called with a null. While the the function would always dereference null if called twice, in the previous code it was always called once and then was followed a register. So only the hidden bug of the sysctl_root_table not being allocated followed by an attempt to free it would have shown the error. 3) always call unregister and register in partition_sched_domains The code is "smart" about unregistering only needed domains. Since we aren't guaranteed any calls to unregister, always unregister. Without calling register on the way out we will not have a table or any sysctl tree. 4) warn if register is called without unregistering The previous table memory is lost, leaving pointers to the later freed memory in sysctl and leaking the memory of the tables. Before this patch on a 2-core 4-thread box compiled for SMT and NUMA, the domains appear empty (there are actually 3 levels per cpu). And as soon as two domains a null pointer is dereferenced (unreliable in this case is stack garbage): bu19a:~# ls -R /proc/sys/kernel/sched_domain/ /proc/sys/kernel/sched_domain/: cpu0 cpu1 cpu2 cpu3 /proc/sys/kernel/sched_domain/cpu0: /proc/sys/kernel/sched_domain/cpu1: /proc/sys/kernel/sched_domain/cpu2: /proc/sys/kernel/sched_domain/cpu3: bu19a:~# mkdir /dev/cpuset bu19a:~# mount -tcpuset cpuset /dev/cpuset/ bu19a:~# cd /dev/cpuset/ bu19a:/dev/cpuset# echo 0 > sched_load_balance bu19a:/dev/cpuset# mkdir one bu19a:/dev/cpuset# echo 1 > one/cpus bu19a:/dev/cpuset# echo 0 > one/sched_load_balance Unable to handle kernel paging request for data at address 0x00000018 Faulting instruction address: 0xc00000000006b608 NIP: c00000000006b608 LR: c00000000006b604 CTR: 0000000000000000 REGS: c000000018d973f0 TRAP: 0300 Not tainted (2.6.23-bml) MSR: 9000000000009032 <EE,ME,IR,DR> CR: 28242442 XER: 00000000 DAR: 0000000000000018, DSISR: 0000000040000000 TASK = c00000001912e340[1987] 'bash' THREAD: c000000018d94000 CPU: 2 .. NIP [c00000000006b608] .unregister_sysctl_table+0x38/0x110 LR [c00000000006b604] .unregister_sysctl_table+0x34/0x110 Call Trace: [c000000018d97670] [c000000007017270] 0xc000000007017270 (unreliable) [c000000018d97720] [c000000000058710] .detach_destroy_domains+0x30/0xb0 [c000000018d977b0] [c00000000005cf1c] .partition_sched_domains+0x1bc/0x230 [c000000018d97870] [c00000000009fdc4] .rebuild_sched_domains+0xb4/0x4c0 [c000000018d97970] [c0000000000a02e8] .update_flag+0x118/0x170 [c000000018d97a80] [c0000000000a1768] .cpuset_common_file_write+0x568/0x820 [c000000018d97c00] [c00000000009d95c] .cgroup_file_write+0x7c/0x180 [c000000018d97cf0] [c0000000000e76b8] .vfs_write+0xe8/0x1b0 [c000000018d97d90] [c0000000000e810c] .sys_write+0x4c/0x90 [c000000018d97e30] [c00000000000852c] syscall_exit+0x0/0x40 Signed-off-by: Milton Miller <miltonm@bga.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-24 16:23:48 +00:00
register_sched_domain_sysctl();
sched: introduce a mutex and corresponding API to serialize access to doms_curarray doms_cur[] array represents various scheduling domains which are mutually exclusive. Currently cpusets code can modify this array (by calling partition_sched_domains()) as a result of user modifying sched_load_balance flag for various cpusets. This patch introduces a mutex and corresponding API (only when CONFIG_FAIR_GROUP_SCHED is defined) which allows a reader to safely read the doms_cur[] array w/o worrying abt concurrent modifications to the array. The fair group scheduler code (introduced in next patch of this series) makes use of this mutex to walk thr' doms_cur[] array while rebalancing shares of task groups across cpus. Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:00 +00:00
sched: fix missing locking in sched_domains code Concurrent calls to detach_destroy_domains and arch_init_sched_domains were prevented by the old scheduler subsystem cpu hotplug mutex. When this got converted to get_online_cpus() the locking got broken. Unlike before now several processes can concurrently enter the critical sections that were protected by the old lock. So use the already present doms_cur_mutex to protect these sections again. Cc: Gautham R Shenoy <ego@in.ibm.com> Cc: Paul Jackson <pj@sgi.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-28 09:33:07 +00:00
mutex_unlock(&sched_domains_mutex);
cpuset sched_load_balance flag Add a new per-cpuset flag called 'sched_load_balance'. When enabled in a cpuset (the default value) it tells the kernel scheduler that the scheduler should provide the normal load balancing on the CPUs in that cpuset, sometimes moving tasks from one CPU to a second CPU if the second CPU is less loaded and if that task is allowed to run there. When disabled (write "0" to the file) then it tells the kernel scheduler that load balancing is not required for the CPUs in that cpuset. Now even if this flag is disabled for some cpuset, the kernel may still have to load balance some or all the CPUs in that cpuset, if some overlapping cpuset has its sched_load_balance flag enabled. If there are some CPUs that are not in any cpuset whose sched_load_balance flag is enabled, the kernel scheduler will not load balance tasks to those CPUs. Moreover the kernel will partition the 'sched domains' (non-overlapping sets of CPUs over which load balancing is attempted) into the finest granularity partition that it can find, while still keeping any two CPUs that are in the same shed_load_balance enabled cpuset in the same element of the partition. This serves two purposes: 1) It provides a mechanism for real time isolation of some CPUs, and 2) it can be used to improve performance on systems with many CPUs by supporting configurations in which load balancing is not done across all CPUs at once, but rather only done in several smaller disjoint sets of CPUs. This mechanism replaces the earlier overloading of the per-cpuset flag 'cpu_exclusive', which overloading was removed in an earlier patch: cpuset-remove-sched-domain-hooks-from-cpusets See further the Documentation and comments in the code itself. [akpm@linux-foundation.org: don't be weird] Signed-off-by: Paul Jackson <pj@sgi.com> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-19 06:40:20 +00:00
}
[PATCH] sched: mc/smt power savings sched policy sysfs entries 'sched_mc_power_savings' and 'sched_smt_power_savings' in /sys/devices/system/cpu/ control the MC/SMT power savings policy for the scheduler. Based on the values (1-enable, 0-disable) for these controls, sched groups cpu power will be determined for different domains. When power savings policy is enabled and under light load conditions, scheduler will minimize the physical packages/cpu cores carrying the load and thus conserving power(with a perf impact based on the workload characteristics... see OLS 2005 CMP kernel scheduler paper for more details..) Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Con Kolivas <kernel@kolivas.org> Cc: "Chen, Kenneth W" <kenneth.w.chen@intel.com> Cc: "David S. Miller" <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 09:54:42 +00:00
#if defined(CONFIG_SCHED_MC) || defined(CONFIG_SCHED_SMT)
sched: Remove obsolete arch_ prefixes Non weak static functions clearly are not arch specific, so remove the arch_ prefix. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122941.820460566@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:09:42 +00:00
static void reinit_sched_domains(void)
[PATCH] sched: mc/smt power savings sched policy sysfs entries 'sched_mc_power_savings' and 'sched_smt_power_savings' in /sys/devices/system/cpu/ control the MC/SMT power savings policy for the scheduler. Based on the values (1-enable, 0-disable) for these controls, sched groups cpu power will be determined for different domains. When power savings policy is enabled and under light load conditions, scheduler will minimize the physical packages/cpu cores carrying the load and thus conserving power(with a perf impact based on the workload characteristics... see OLS 2005 CMP kernel scheduler paper for more details..) Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Con Kolivas <kernel@kolivas.org> Cc: "Chen, Kenneth W" <kenneth.w.chen@intel.com> Cc: "David S. Miller" <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 09:54:42 +00:00
{
cpu-hotplug: replace per-subsystem mutexes with get_online_cpus() This patch converts the known per-subsystem mutexes to get_online_cpus put_online_cpus. It also eliminates the CPU_LOCK_ACQUIRE and CPU_LOCK_RELEASE hotplug notification events. Signed-off-by: Gautham R Shenoy <ego@in.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:02 +00:00
get_online_cpus();
sched: arch_reinit_sched_domains() must destroy domains to force rebuild What I realized recently is that calling rebuild_sched_domains() in arch_reinit_sched_domains() by itself is not enough when cpusets are enabled. partition_sched_domains() code is trying to avoid unnecessary domain rebuilds and will not actually rebuild anything if new domain masks match the old ones. What this means is that doing echo 1 > /sys/devices/system/cpu/sched_mc_power_savings on a system with cpusets enabled will not take affect untill something changes in the cpuset setup (ie new sets created or deleted). This patch fixes restore correct behaviour where domains must be rebuilt in order to enable MC powersaving flags. Test on quad-core Core2 box with both CONFIG_CPUSETS and !CONFIG_CPUSETS. Also tested on dual-core Core2 laptop. Lockdep is happy and things are working as expected. Signed-off-by: Max Krasnyansky <maxk@qualcomm.com> Tested-by: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-29 20:11:41 +00:00
/* Destroy domains first to force the rebuild */
partition_sched_domains(0, NULL, NULL);
cpu hotplug, sched: Introduce cpu_active_map and redo sched domain managment (take 2) This is based on Linus' idea of creating cpu_active_map that prevents scheduler load balancer from migrating tasks to the cpu that is going down. It allows us to simplify domain management code and avoid unecessary domain rebuilds during cpu hotplug event handling. Please ignore the cpusets part for now. It needs some more work in order to avoid crazy lock nesting. Although I did simplfy and unify domain reinitialization logic. We now simply call partition_sched_domains() in all the cases. This means that we're using exact same code paths as in cpusets case and hence the test below cover cpusets too. Cpuset changes to make rebuild_sched_domains() callable from various contexts are in the separate patch (right next after this one). This not only boots but also easily handles while true; do make clean; make -j 8; done and while true; do on-off-cpu 1; done at the same time. (on-off-cpu 1 simple does echo 0/1 > /sys/.../cpu1/online thing). Suprisingly the box (dual-core Core2) is quite usable. In fact I'm typing this on right now in gnome-terminal and things are moving just fine. Also this is running with most of the debug features enabled (lockdep, mutex, etc) no BUG_ONs or lockdep complaints so far. I believe I addressed all of the Dmitry's comments for original Linus' version. I changed both fair and rt balancer to mask out non-active cpus. And replaced cpu_is_offline() with !cpu_active() in the main scheduler code where it made sense (to me). Signed-off-by: Max Krasnyanskiy <maxk@qualcomm.com> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Gregory Haskins <ghaskins@novell.com> Cc: dmitry.adamushko@gmail.com Cc: pj@sgi.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-15 11:43:49 +00:00
rebuild_sched_domains();
cpu-hotplug: replace per-subsystem mutexes with get_online_cpus() This patch converts the known per-subsystem mutexes to get_online_cpus put_online_cpus. It also eliminates the CPU_LOCK_ACQUIRE and CPU_LOCK_RELEASE hotplug notification events. Signed-off-by: Gautham R Shenoy <ego@in.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:02 +00:00
put_online_cpus();
[PATCH] sched: mc/smt power savings sched policy sysfs entries 'sched_mc_power_savings' and 'sched_smt_power_savings' in /sys/devices/system/cpu/ control the MC/SMT power savings policy for the scheduler. Based on the values (1-enable, 0-disable) for these controls, sched groups cpu power will be determined for different domains. When power savings policy is enabled and under light load conditions, scheduler will minimize the physical packages/cpu cores carrying the load and thus conserving power(with a perf impact based on the workload characteristics... see OLS 2005 CMP kernel scheduler paper for more details..) Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Con Kolivas <kernel@kolivas.org> Cc: "Chen, Kenneth W" <kenneth.w.chen@intel.com> Cc: "David S. Miller" <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 09:54:42 +00:00
}
static ssize_t sched_power_savings_store(const char *buf, size_t count, int smt)
{
sched: framework for sched_mc/smt_power_savings=N Impact: extend range of /sys/devices/system/cpu/sched_mc_power_savings Currently the sched_mc/smt_power_savings variable is a boolean, which either enables or disables topology based power savings. This patch extends the behaviour of the variable from boolean to multivalued, such that based on the value, we decide how aggressively do we want to perform powersavings balance at appropriate sched domain based on topology. Variable levels of power saving tunable would benefit end user to match the required level of power savings vs performance trade-off depending on the system configuration and workloads. This version makes the sched_mc_power_savings global variable to take more values (0,1,2). Later versions can have a single tunable called sched_power_savings instead of sched_{mc,smt}_power_savings. Signed-off-by: Gautham R Shenoy <ego@in.ibm.com> Signed-off-by: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com> Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-18 17:56:09 +00:00
unsigned int level = 0;
[PATCH] sched: mc/smt power savings sched policy sysfs entries 'sched_mc_power_savings' and 'sched_smt_power_savings' in /sys/devices/system/cpu/ control the MC/SMT power savings policy for the scheduler. Based on the values (1-enable, 0-disable) for these controls, sched groups cpu power will be determined for different domains. When power savings policy is enabled and under light load conditions, scheduler will minimize the physical packages/cpu cores carrying the load and thus conserving power(with a perf impact based on the workload characteristics... see OLS 2005 CMP kernel scheduler paper for more details..) Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Con Kolivas <kernel@kolivas.org> Cc: "Chen, Kenneth W" <kenneth.w.chen@intel.com> Cc: "David S. Miller" <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 09:54:42 +00:00
sched: framework for sched_mc/smt_power_savings=N Impact: extend range of /sys/devices/system/cpu/sched_mc_power_savings Currently the sched_mc/smt_power_savings variable is a boolean, which either enables or disables topology based power savings. This patch extends the behaviour of the variable from boolean to multivalued, such that based on the value, we decide how aggressively do we want to perform powersavings balance at appropriate sched domain based on topology. Variable levels of power saving tunable would benefit end user to match the required level of power savings vs performance trade-off depending on the system configuration and workloads. This version makes the sched_mc_power_savings global variable to take more values (0,1,2). Later versions can have a single tunable called sched_power_savings instead of sched_{mc,smt}_power_savings. Signed-off-by: Gautham R Shenoy <ego@in.ibm.com> Signed-off-by: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com> Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-18 17:56:09 +00:00
if (sscanf(buf, "%u", &level) != 1)
return -EINVAL;
/*
* level is always be positive so don't check for
* level < POWERSAVINGS_BALANCE_NONE which is 0
* What happens on 0 or 1 byte write,
* need to check for count as well?
*/
if (level >= MAX_POWERSAVINGS_BALANCE_LEVELS)
[PATCH] sched: mc/smt power savings sched policy sysfs entries 'sched_mc_power_savings' and 'sched_smt_power_savings' in /sys/devices/system/cpu/ control the MC/SMT power savings policy for the scheduler. Based on the values (1-enable, 0-disable) for these controls, sched groups cpu power will be determined for different domains. When power savings policy is enabled and under light load conditions, scheduler will minimize the physical packages/cpu cores carrying the load and thus conserving power(with a perf impact based on the workload characteristics... see OLS 2005 CMP kernel scheduler paper for more details..) Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Con Kolivas <kernel@kolivas.org> Cc: "Chen, Kenneth W" <kenneth.w.chen@intel.com> Cc: "David S. Miller" <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 09:54:42 +00:00
return -EINVAL;
if (smt)
sched: framework for sched_mc/smt_power_savings=N Impact: extend range of /sys/devices/system/cpu/sched_mc_power_savings Currently the sched_mc/smt_power_savings variable is a boolean, which either enables or disables topology based power savings. This patch extends the behaviour of the variable from boolean to multivalued, such that based on the value, we decide how aggressively do we want to perform powersavings balance at appropriate sched domain based on topology. Variable levels of power saving tunable would benefit end user to match the required level of power savings vs performance trade-off depending on the system configuration and workloads. This version makes the sched_mc_power_savings global variable to take more values (0,1,2). Later versions can have a single tunable called sched_power_savings instead of sched_{mc,smt}_power_savings. Signed-off-by: Gautham R Shenoy <ego@in.ibm.com> Signed-off-by: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com> Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-18 17:56:09 +00:00
sched_smt_power_savings = level;
[PATCH] sched: mc/smt power savings sched policy sysfs entries 'sched_mc_power_savings' and 'sched_smt_power_savings' in /sys/devices/system/cpu/ control the MC/SMT power savings policy for the scheduler. Based on the values (1-enable, 0-disable) for these controls, sched groups cpu power will be determined for different domains. When power savings policy is enabled and under light load conditions, scheduler will minimize the physical packages/cpu cores carrying the load and thus conserving power(with a perf impact based on the workload characteristics... see OLS 2005 CMP kernel scheduler paper for more details..) Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Con Kolivas <kernel@kolivas.org> Cc: "Chen, Kenneth W" <kenneth.w.chen@intel.com> Cc: "David S. Miller" <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 09:54:42 +00:00
else
sched: framework for sched_mc/smt_power_savings=N Impact: extend range of /sys/devices/system/cpu/sched_mc_power_savings Currently the sched_mc/smt_power_savings variable is a boolean, which either enables or disables topology based power savings. This patch extends the behaviour of the variable from boolean to multivalued, such that based on the value, we decide how aggressively do we want to perform powersavings balance at appropriate sched domain based on topology. Variable levels of power saving tunable would benefit end user to match the required level of power savings vs performance trade-off depending on the system configuration and workloads. This version makes the sched_mc_power_savings global variable to take more values (0,1,2). Later versions can have a single tunable called sched_power_savings instead of sched_{mc,smt}_power_savings. Signed-off-by: Gautham R Shenoy <ego@in.ibm.com> Signed-off-by: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com> Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-18 17:56:09 +00:00
sched_mc_power_savings = level;
[PATCH] sched: mc/smt power savings sched policy sysfs entries 'sched_mc_power_savings' and 'sched_smt_power_savings' in /sys/devices/system/cpu/ control the MC/SMT power savings policy for the scheduler. Based on the values (1-enable, 0-disable) for these controls, sched groups cpu power will be determined for different domains. When power savings policy is enabled and under light load conditions, scheduler will minimize the physical packages/cpu cores carrying the load and thus conserving power(with a perf impact based on the workload characteristics... see OLS 2005 CMP kernel scheduler paper for more details..) Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Con Kolivas <kernel@kolivas.org> Cc: "Chen, Kenneth W" <kenneth.w.chen@intel.com> Cc: "David S. Miller" <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 09:54:42 +00:00
sched: Remove obsolete arch_ prefixes Non weak static functions clearly are not arch specific, so remove the arch_ prefix. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122941.820460566@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:09:42 +00:00
reinit_sched_domains();
[PATCH] sched: mc/smt power savings sched policy sysfs entries 'sched_mc_power_savings' and 'sched_smt_power_savings' in /sys/devices/system/cpu/ control the MC/SMT power savings policy for the scheduler. Based on the values (1-enable, 0-disable) for these controls, sched groups cpu power will be determined for different domains. When power savings policy is enabled and under light load conditions, scheduler will minimize the physical packages/cpu cores carrying the load and thus conserving power(with a perf impact based on the workload characteristics... see OLS 2005 CMP kernel scheduler paper for more details..) Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Con Kolivas <kernel@kolivas.org> Cc: "Chen, Kenneth W" <kenneth.w.chen@intel.com> Cc: "David S. Miller" <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 09:54:42 +00:00
sched: clean up arch_reinit_sched_domains() - Make arch_reinit_sched_domains() static. It was exported to be used in s390, but now rebuild_sched_domains() is used instead. - Make it return void. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-05 11:07:50 +00:00
return count;
[PATCH] sched: mc/smt power savings sched policy sysfs entries 'sched_mc_power_savings' and 'sched_smt_power_savings' in /sys/devices/system/cpu/ control the MC/SMT power savings policy for the scheduler. Based on the values (1-enable, 0-disable) for these controls, sched groups cpu power will be determined for different domains. When power savings policy is enabled and under light load conditions, scheduler will minimize the physical packages/cpu cores carrying the load and thus conserving power(with a perf impact based on the workload characteristics... see OLS 2005 CMP kernel scheduler paper for more details..) Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Con Kolivas <kernel@kolivas.org> Cc: "Chen, Kenneth W" <kenneth.w.chen@intel.com> Cc: "David S. Miller" <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 09:54:42 +00:00
}
#ifdef CONFIG_SCHED_MC
sched: make scheduler sysfs attributes sysdev class devices They are really class devices, but were incorrectly declared. This leads to crashes with the recent changes that makes non normal sysdevs use a different prototype. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Andi Kleen <ak@linux.intel.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Pierre Ossman <drzeus-list@drzeus.cx> Cc: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-30 05:33:52 +00:00
static ssize_t sched_mc_power_savings_show(struct sysdev_class *class,
sysdev: Pass attribute in sysdev_class attributes show/store Passing the attribute to the low level IO functions allows all kinds of cleanups, by sharing low level IO code without requiring an own function for every piece of data. Also drivers can extend the attributes with own data fields and use that in the low level function. Similar to sysdev_attributes and normal attributes. This is a tree-wide sweep, converting everything in one go. No functional changes in this patch other than passing the new argument everywhere. Tested on x86, the non x86 parts are uncompiled. Signed-off-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-01-05 11:47:58 +00:00
struct sysdev_class_attribute *attr,
sched: make scheduler sysfs attributes sysdev class devices They are really class devices, but were incorrectly declared. This leads to crashes with the recent changes that makes non normal sysdevs use a different prototype. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Andi Kleen <ak@linux.intel.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Pierre Ossman <drzeus-list@drzeus.cx> Cc: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-30 05:33:52 +00:00
char *page)
[PATCH] sched: mc/smt power savings sched policy sysfs entries 'sched_mc_power_savings' and 'sched_smt_power_savings' in /sys/devices/system/cpu/ control the MC/SMT power savings policy for the scheduler. Based on the values (1-enable, 0-disable) for these controls, sched groups cpu power will be determined for different domains. When power savings policy is enabled and under light load conditions, scheduler will minimize the physical packages/cpu cores carrying the load and thus conserving power(with a perf impact based on the workload characteristics... see OLS 2005 CMP kernel scheduler paper for more details..) Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Con Kolivas <kernel@kolivas.org> Cc: "Chen, Kenneth W" <kenneth.w.chen@intel.com> Cc: "David S. Miller" <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 09:54:42 +00:00
{
return sprintf(page, "%u\n", sched_mc_power_savings);
}
sched: make scheduler sysfs attributes sysdev class devices They are really class devices, but were incorrectly declared. This leads to crashes with the recent changes that makes non normal sysdevs use a different prototype. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Andi Kleen <ak@linux.intel.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Pierre Ossman <drzeus-list@drzeus.cx> Cc: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-30 05:33:52 +00:00
static ssize_t sched_mc_power_savings_store(struct sysdev_class *class,
sysdev: Pass attribute in sysdev_class attributes show/store Passing the attribute to the low level IO functions allows all kinds of cleanups, by sharing low level IO code without requiring an own function for every piece of data. Also drivers can extend the attributes with own data fields and use that in the low level function. Similar to sysdev_attributes and normal attributes. This is a tree-wide sweep, converting everything in one go. No functional changes in this patch other than passing the new argument everywhere. Tested on x86, the non x86 parts are uncompiled. Signed-off-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-01-05 11:47:58 +00:00
struct sysdev_class_attribute *attr,
[PATCH] sched: clean up fallout of recent changes Clean up some of the impact of recent (and not so recent) scheduler changes: - turning macros into nice inline functions - sanitizing and unifying variable definitions - whitespace, style consistency, 80-lines, comment correctness, spelling and curly braces police Due to the macro hell and variable placement simplifications there's even 26 bytes of .text saved: text data bss dec hex filename 25510 4153 192 29855 749f sched.o.before 25484 4153 192 29829 7485 sched.o.after [akpm@osdl.org: build fix] Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-03 07:25:40 +00:00
const char *buf, size_t count)
[PATCH] sched: mc/smt power savings sched policy sysfs entries 'sched_mc_power_savings' and 'sched_smt_power_savings' in /sys/devices/system/cpu/ control the MC/SMT power savings policy for the scheduler. Based on the values (1-enable, 0-disable) for these controls, sched groups cpu power will be determined for different domains. When power savings policy is enabled and under light load conditions, scheduler will minimize the physical packages/cpu cores carrying the load and thus conserving power(with a perf impact based on the workload characteristics... see OLS 2005 CMP kernel scheduler paper for more details..) Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Con Kolivas <kernel@kolivas.org> Cc: "Chen, Kenneth W" <kenneth.w.chen@intel.com> Cc: "David S. Miller" <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 09:54:42 +00:00
{
return sched_power_savings_store(buf, count, 0);
}
sched: make scheduler sysfs attributes sysdev class devices They are really class devices, but were incorrectly declared. This leads to crashes with the recent changes that makes non normal sysdevs use a different prototype. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Andi Kleen <ak@linux.intel.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Pierre Ossman <drzeus-list@drzeus.cx> Cc: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-30 05:33:52 +00:00
static SYSDEV_CLASS_ATTR(sched_mc_power_savings, 0644,
sched_mc_power_savings_show,
sched_mc_power_savings_store);
[PATCH] sched: mc/smt power savings sched policy sysfs entries 'sched_mc_power_savings' and 'sched_smt_power_savings' in /sys/devices/system/cpu/ control the MC/SMT power savings policy for the scheduler. Based on the values (1-enable, 0-disable) for these controls, sched groups cpu power will be determined for different domains. When power savings policy is enabled and under light load conditions, scheduler will minimize the physical packages/cpu cores carrying the load and thus conserving power(with a perf impact based on the workload characteristics... see OLS 2005 CMP kernel scheduler paper for more details..) Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Con Kolivas <kernel@kolivas.org> Cc: "Chen, Kenneth W" <kenneth.w.chen@intel.com> Cc: "David S. Miller" <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 09:54:42 +00:00
#endif
#ifdef CONFIG_SCHED_SMT
sched: make scheduler sysfs attributes sysdev class devices They are really class devices, but were incorrectly declared. This leads to crashes with the recent changes that makes non normal sysdevs use a different prototype. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Andi Kleen <ak@linux.intel.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Pierre Ossman <drzeus-list@drzeus.cx> Cc: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-30 05:33:52 +00:00
static ssize_t sched_smt_power_savings_show(struct sysdev_class *dev,
sysdev: Pass attribute in sysdev_class attributes show/store Passing the attribute to the low level IO functions allows all kinds of cleanups, by sharing low level IO code without requiring an own function for every piece of data. Also drivers can extend the attributes with own data fields and use that in the low level function. Similar to sysdev_attributes and normal attributes. This is a tree-wide sweep, converting everything in one go. No functional changes in this patch other than passing the new argument everywhere. Tested on x86, the non x86 parts are uncompiled. Signed-off-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-01-05 11:47:58 +00:00
struct sysdev_class_attribute *attr,
sched: make scheduler sysfs attributes sysdev class devices They are really class devices, but were incorrectly declared. This leads to crashes with the recent changes that makes non normal sysdevs use a different prototype. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Andi Kleen <ak@linux.intel.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Pierre Ossman <drzeus-list@drzeus.cx> Cc: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-30 05:33:52 +00:00
char *page)
[PATCH] sched: mc/smt power savings sched policy sysfs entries 'sched_mc_power_savings' and 'sched_smt_power_savings' in /sys/devices/system/cpu/ control the MC/SMT power savings policy for the scheduler. Based on the values (1-enable, 0-disable) for these controls, sched groups cpu power will be determined for different domains. When power savings policy is enabled and under light load conditions, scheduler will minimize the physical packages/cpu cores carrying the load and thus conserving power(with a perf impact based on the workload characteristics... see OLS 2005 CMP kernel scheduler paper for more details..) Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Con Kolivas <kernel@kolivas.org> Cc: "Chen, Kenneth W" <kenneth.w.chen@intel.com> Cc: "David S. Miller" <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 09:54:42 +00:00
{
return sprintf(page, "%u\n", sched_smt_power_savings);
}
sched: make scheduler sysfs attributes sysdev class devices They are really class devices, but were incorrectly declared. This leads to crashes with the recent changes that makes non normal sysdevs use a different prototype. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Andi Kleen <ak@linux.intel.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Pierre Ossman <drzeus-list@drzeus.cx> Cc: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-30 05:33:52 +00:00
static ssize_t sched_smt_power_savings_store(struct sysdev_class *dev,
sysdev: Pass attribute in sysdev_class attributes show/store Passing the attribute to the low level IO functions allows all kinds of cleanups, by sharing low level IO code without requiring an own function for every piece of data. Also drivers can extend the attributes with own data fields and use that in the low level function. Similar to sysdev_attributes and normal attributes. This is a tree-wide sweep, converting everything in one go. No functional changes in this patch other than passing the new argument everywhere. Tested on x86, the non x86 parts are uncompiled. Signed-off-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-01-05 11:47:58 +00:00
struct sysdev_class_attribute *attr,
[PATCH] sched: clean up fallout of recent changes Clean up some of the impact of recent (and not so recent) scheduler changes: - turning macros into nice inline functions - sanitizing and unifying variable definitions - whitespace, style consistency, 80-lines, comment correctness, spelling and curly braces police Due to the macro hell and variable placement simplifications there's even 26 bytes of .text saved: text data bss dec hex filename 25510 4153 192 29855 749f sched.o.before 25484 4153 192 29829 7485 sched.o.after [akpm@osdl.org: build fix] Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-03 07:25:40 +00:00
const char *buf, size_t count)
[PATCH] sched: mc/smt power savings sched policy sysfs entries 'sched_mc_power_savings' and 'sched_smt_power_savings' in /sys/devices/system/cpu/ control the MC/SMT power savings policy for the scheduler. Based on the values (1-enable, 0-disable) for these controls, sched groups cpu power will be determined for different domains. When power savings policy is enabled and under light load conditions, scheduler will minimize the physical packages/cpu cores carrying the load and thus conserving power(with a perf impact based on the workload characteristics... see OLS 2005 CMP kernel scheduler paper for more details..) Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Con Kolivas <kernel@kolivas.org> Cc: "Chen, Kenneth W" <kenneth.w.chen@intel.com> Cc: "David S. Miller" <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 09:54:42 +00:00
{
return sched_power_savings_store(buf, count, 1);
}
sched: make scheduler sysfs attributes sysdev class devices They are really class devices, but were incorrectly declared. This leads to crashes with the recent changes that makes non normal sysdevs use a different prototype. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Andi Kleen <ak@linux.intel.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Pierre Ossman <drzeus-list@drzeus.cx> Cc: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-30 05:33:52 +00:00
static SYSDEV_CLASS_ATTR(sched_smt_power_savings, 0644,
sched_smt_power_savings_show,
sched: make global code static This patch makes the following needlessly global code static: - arch_reinit_sched_domains() - struct attr_sched_mc_power_savings - struct attr_sched_smt_power_savings Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-08-12 16:08:19 +00:00
sched_smt_power_savings_store);
#endif
sched: mark sched_create_sysfs_power_savings_entries() as __init Impact: cleanup The only caller is cpu_dev_init() which is marked as __init. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-05 11:18:02 +00:00
int __init sched_create_sysfs_power_savings_entries(struct sysdev_class *cls)
sched: make global code static This patch makes the following needlessly global code static: - arch_reinit_sched_domains() - struct attr_sched_mc_power_savings - struct attr_sched_smt_power_savings Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-08-12 16:08:19 +00:00
{
int err = 0;
#ifdef CONFIG_SCHED_SMT
if (smt_capable())
err = sysfs_create_file(&cls->kset.kobj,
&attr_sched_smt_power_savings.attr);
#endif
#ifdef CONFIG_SCHED_MC
if (!err && mc_capable())
err = sysfs_create_file(&cls->kset.kobj,
&attr_sched_mc_power_savings.attr);
#endif
return err;
}
sched: add comments for ifdefs in sched.c make sched.c easier to read. Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-30 12:23:45 +00:00
#endif /* CONFIG_SCHED_MC || CONFIG_SCHED_SMT */
[PATCH] sched: mc/smt power savings sched policy sysfs entries 'sched_mc_power_savings' and 'sched_smt_power_savings' in /sys/devices/system/cpu/ control the MC/SMT power savings policy for the scheduler. Based on the values (1-enable, 0-disable) for these controls, sched groups cpu power will be determined for different domains. When power savings policy is enabled and under light load conditions, scheduler will minimize the physical packages/cpu cores carrying the load and thus conserving power(with a perf impact based on the workload characteristics... see OLS 2005 CMP kernel scheduler paper for more details..) Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Con Kolivas <kernel@kolivas.org> Cc: "Chen, Kenneth W" <kenneth.w.chen@intel.com> Cc: "David S. Miller" <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 09:54:42 +00:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
/*
sched: adjust when cpu_active and cpuset configurations are updated during cpu on/offlining Currently, when a cpu goes down, cpu_active is cleared before CPU_DOWN_PREPARE starts and cpuset configuration is updated from a default priority cpu notifier. When a cpu is coming up, it's set before CPU_ONLINE but cpuset configuration again is updated from the same cpu notifier. For cpu notifiers, this presents an inconsistent state. Threads which a CPU_DOWN_PREPARE notifier expects to be bound to the CPU can be migrated to other cpus because the cpu is no more inactive. Fix it by updating cpu_active in the highest priority cpu notifier and cpuset configuration in the second highest when a cpu is coming up. Down path is updated similarly. This guarantees that all other cpu notifiers see consistent cpu_active and cpuset configuration. cpuset_track_online_cpus() notifier is converted to cpuset_update_active_cpus() which just updates the configuration and now called from cpuset_cpu_[in]active() notifiers registered from sched_init_smp(). If cpuset is disabled, cpuset_update_active_cpus() degenerates into partition_sched_domains() making separate notifier for !CONFIG_CPUSETS unnecessary. This problem is triggered by cmwq. During CPU_DOWN_PREPARE, hotplug callback creates a kthread and kthread_bind()s it to the target cpu, and the thread is expected to run on that cpu. * Ingo's test discovered __cpuinit/exit markups were incorrect. Fixed. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Ingo Molnar <mingo@elte.hu> Cc: Paul Menage <menage@google.com>
2010-06-08 19:40:36 +00:00
* Update cpusets according to cpu_active mask. If cpusets are
* disabled, cpuset_update_active_cpus() becomes a simple wrapper
* around partition_sched_domains().
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
*/
sched, cpuset: Drop __cpuexit from cpu hotplug callbacks Commit 3a101d05 (sched: adjust when cpu_active and cpuset configurations are updated during cpu on/offlining) added hotplug notifiers marked with __cpuexit; however, ia64 drops text in __cpuexit during link unlike x86. This means that functions which are referenced during init but used only for cpu hot unplugging afterwards shouldn't be marked with __cpuexit. Drop __cpuexit from those functions. Reported-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Tony Luck <tony.luck@intel.com> Cc: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <4C1FDF5B.1040301@kernel.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-06-21 21:53:31 +00:00
static int cpuset_cpu_active(struct notifier_block *nfb, unsigned long action,
void *hcpu)
cpu hotplug, sched: Introduce cpu_active_map and redo sched domain managment (take 2) This is based on Linus' idea of creating cpu_active_map that prevents scheduler load balancer from migrating tasks to the cpu that is going down. It allows us to simplify domain management code and avoid unecessary domain rebuilds during cpu hotplug event handling. Please ignore the cpusets part for now. It needs some more work in order to avoid crazy lock nesting. Although I did simplfy and unify domain reinitialization logic. We now simply call partition_sched_domains() in all the cases. This means that we're using exact same code paths as in cpusets case and hence the test below cover cpusets too. Cpuset changes to make rebuild_sched_domains() callable from various contexts are in the separate patch (right next after this one). This not only boots but also easily handles while true; do make clean; make -j 8; done and while true; do on-off-cpu 1; done at the same time. (on-off-cpu 1 simple does echo 0/1 > /sys/.../cpu1/online thing). Suprisingly the box (dual-core Core2) is quite usable. In fact I'm typing this on right now in gnome-terminal and things are moving just fine. Also this is running with most of the debug features enabled (lockdep, mutex, etc) no BUG_ONs or lockdep complaints so far. I believe I addressed all of the Dmitry's comments for original Linus' version. I changed both fair and rt balancer to mask out non-active cpus. And replaced cpu_is_offline() with !cpu_active() in the main scheduler code where it made sense (to me). Signed-off-by: Max Krasnyanskiy <maxk@qualcomm.com> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Gregory Haskins <ghaskins@novell.com> Cc: dmitry.adamushko@gmail.com Cc: pj@sgi.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-15 11:43:49 +00:00
{
sched: adjust when cpu_active and cpuset configurations are updated during cpu on/offlining Currently, when a cpu goes down, cpu_active is cleared before CPU_DOWN_PREPARE starts and cpuset configuration is updated from a default priority cpu notifier. When a cpu is coming up, it's set before CPU_ONLINE but cpuset configuration again is updated from the same cpu notifier. For cpu notifiers, this presents an inconsistent state. Threads which a CPU_DOWN_PREPARE notifier expects to be bound to the CPU can be migrated to other cpus because the cpu is no more inactive. Fix it by updating cpu_active in the highest priority cpu notifier and cpuset configuration in the second highest when a cpu is coming up. Down path is updated similarly. This guarantees that all other cpu notifiers see consistent cpu_active and cpuset configuration. cpuset_track_online_cpus() notifier is converted to cpuset_update_active_cpus() which just updates the configuration and now called from cpuset_cpu_[in]active() notifiers registered from sched_init_smp(). If cpuset is disabled, cpuset_update_active_cpus() degenerates into partition_sched_domains() making separate notifier for !CONFIG_CPUSETS unnecessary. This problem is triggered by cmwq. During CPU_DOWN_PREPARE, hotplug callback creates a kthread and kthread_bind()s it to the target cpu, and the thread is expected to run on that cpu. * Ingo's test discovered __cpuinit/exit markups were incorrect. Fixed. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Ingo Molnar <mingo@elte.hu> Cc: Paul Menage <menage@google.com>
2010-06-08 19:40:36 +00:00
switch (action & ~CPU_TASKS_FROZEN) {
cpu hotplug, sched: Introduce cpu_active_map and redo sched domain managment (take 2) This is based on Linus' idea of creating cpu_active_map that prevents scheduler load balancer from migrating tasks to the cpu that is going down. It allows us to simplify domain management code and avoid unecessary domain rebuilds during cpu hotplug event handling. Please ignore the cpusets part for now. It needs some more work in order to avoid crazy lock nesting. Although I did simplfy and unify domain reinitialization logic. We now simply call partition_sched_domains() in all the cases. This means that we're using exact same code paths as in cpusets case and hence the test below cover cpusets too. Cpuset changes to make rebuild_sched_domains() callable from various contexts are in the separate patch (right next after this one). This not only boots but also easily handles while true; do make clean; make -j 8; done and while true; do on-off-cpu 1; done at the same time. (on-off-cpu 1 simple does echo 0/1 > /sys/.../cpu1/online thing). Suprisingly the box (dual-core Core2) is quite usable. In fact I'm typing this on right now in gnome-terminal and things are moving just fine. Also this is running with most of the debug features enabled (lockdep, mutex, etc) no BUG_ONs or lockdep complaints so far. I believe I addressed all of the Dmitry's comments for original Linus' version. I changed both fair and rt balancer to mask out non-active cpus. And replaced cpu_is_offline() with !cpu_active() in the main scheduler code where it made sense (to me). Signed-off-by: Max Krasnyanskiy <maxk@qualcomm.com> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Gregory Haskins <ghaskins@novell.com> Cc: dmitry.adamushko@gmail.com Cc: pj@sgi.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-15 11:43:49 +00:00
case CPU_ONLINE:
sched: Fix balance vs hotplug race Since (e761b77: cpu hotplug, sched: Introduce cpu_active_map and redo sched domain managment) we have cpu_active_mask which is suppose to rule scheduler migration and load-balancing, except it never (fully) did. The particular problem being solved here is a crash in try_to_wake_up() where select_task_rq() ends up selecting an offline cpu because select_task_rq_fair() trusts the sched_domain tree to reflect the current state of affairs, similarly select_task_rq_rt() trusts the root_domain. However, the sched_domains are updated from CPU_DEAD, which is after the cpu is taken offline and after stop_machine is done. Therefore it can race perfectly well with code assuming the domains are right. Cure this by building the domains from cpu_active_mask on CPU_DOWN_PREPARE. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-11-25 12:31:39 +00:00
case CPU_DOWN_FAILED:
sched: adjust when cpu_active and cpuset configurations are updated during cpu on/offlining Currently, when a cpu goes down, cpu_active is cleared before CPU_DOWN_PREPARE starts and cpuset configuration is updated from a default priority cpu notifier. When a cpu is coming up, it's set before CPU_ONLINE but cpuset configuration again is updated from the same cpu notifier. For cpu notifiers, this presents an inconsistent state. Threads which a CPU_DOWN_PREPARE notifier expects to be bound to the CPU can be migrated to other cpus because the cpu is no more inactive. Fix it by updating cpu_active in the highest priority cpu notifier and cpuset configuration in the second highest when a cpu is coming up. Down path is updated similarly. This guarantees that all other cpu notifiers see consistent cpu_active and cpuset configuration. cpuset_track_online_cpus() notifier is converted to cpuset_update_active_cpus() which just updates the configuration and now called from cpuset_cpu_[in]active() notifiers registered from sched_init_smp(). If cpuset is disabled, cpuset_update_active_cpus() degenerates into partition_sched_domains() making separate notifier for !CONFIG_CPUSETS unnecessary. This problem is triggered by cmwq. During CPU_DOWN_PREPARE, hotplug callback creates a kthread and kthread_bind()s it to the target cpu, and the thread is expected to run on that cpu. * Ingo's test discovered __cpuinit/exit markups were incorrect. Fixed. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Ingo Molnar <mingo@elte.hu> Cc: Paul Menage <menage@google.com>
2010-06-08 19:40:36 +00:00
cpuset_update_active_cpus();
cpu hotplug, sched: Introduce cpu_active_map and redo sched domain managment (take 2) This is based on Linus' idea of creating cpu_active_map that prevents scheduler load balancer from migrating tasks to the cpu that is going down. It allows us to simplify domain management code and avoid unecessary domain rebuilds during cpu hotplug event handling. Please ignore the cpusets part for now. It needs some more work in order to avoid crazy lock nesting. Although I did simplfy and unify domain reinitialization logic. We now simply call partition_sched_domains() in all the cases. This means that we're using exact same code paths as in cpusets case and hence the test below cover cpusets too. Cpuset changes to make rebuild_sched_domains() callable from various contexts are in the separate patch (right next after this one). This not only boots but also easily handles while true; do make clean; make -j 8; done and while true; do on-off-cpu 1; done at the same time. (on-off-cpu 1 simple does echo 0/1 > /sys/.../cpu1/online thing). Suprisingly the box (dual-core Core2) is quite usable. In fact I'm typing this on right now in gnome-terminal and things are moving just fine. Also this is running with most of the debug features enabled (lockdep, mutex, etc) no BUG_ONs or lockdep complaints so far. I believe I addressed all of the Dmitry's comments for original Linus' version. I changed both fair and rt balancer to mask out non-active cpus. And replaced cpu_is_offline() with !cpu_active() in the main scheduler code where it made sense (to me). Signed-off-by: Max Krasnyanskiy <maxk@qualcomm.com> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Gregory Haskins <ghaskins@novell.com> Cc: dmitry.adamushko@gmail.com Cc: pj@sgi.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-15 11:43:49 +00:00
return NOTIFY_OK;
sched: adjust when cpu_active and cpuset configurations are updated during cpu on/offlining Currently, when a cpu goes down, cpu_active is cleared before CPU_DOWN_PREPARE starts and cpuset configuration is updated from a default priority cpu notifier. When a cpu is coming up, it's set before CPU_ONLINE but cpuset configuration again is updated from the same cpu notifier. For cpu notifiers, this presents an inconsistent state. Threads which a CPU_DOWN_PREPARE notifier expects to be bound to the CPU can be migrated to other cpus because the cpu is no more inactive. Fix it by updating cpu_active in the highest priority cpu notifier and cpuset configuration in the second highest when a cpu is coming up. Down path is updated similarly. This guarantees that all other cpu notifiers see consistent cpu_active and cpuset configuration. cpuset_track_online_cpus() notifier is converted to cpuset_update_active_cpus() which just updates the configuration and now called from cpuset_cpu_[in]active() notifiers registered from sched_init_smp(). If cpuset is disabled, cpuset_update_active_cpus() degenerates into partition_sched_domains() making separate notifier for !CONFIG_CPUSETS unnecessary. This problem is triggered by cmwq. During CPU_DOWN_PREPARE, hotplug callback creates a kthread and kthread_bind()s it to the target cpu, and the thread is expected to run on that cpu. * Ingo's test discovered __cpuinit/exit markups were incorrect. Fixed. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Ingo Molnar <mingo@elte.hu> Cc: Paul Menage <menage@google.com>
2010-06-08 19:40:36 +00:00
default:
return NOTIFY_DONE;
}
}
cpu hotplug, sched: Introduce cpu_active_map and redo sched domain managment (take 2) This is based on Linus' idea of creating cpu_active_map that prevents scheduler load balancer from migrating tasks to the cpu that is going down. It allows us to simplify domain management code and avoid unecessary domain rebuilds during cpu hotplug event handling. Please ignore the cpusets part for now. It needs some more work in order to avoid crazy lock nesting. Although I did simplfy and unify domain reinitialization logic. We now simply call partition_sched_domains() in all the cases. This means that we're using exact same code paths as in cpusets case and hence the test below cover cpusets too. Cpuset changes to make rebuild_sched_domains() callable from various contexts are in the separate patch (right next after this one). This not only boots but also easily handles while true; do make clean; make -j 8; done and while true; do on-off-cpu 1; done at the same time. (on-off-cpu 1 simple does echo 0/1 > /sys/.../cpu1/online thing). Suprisingly the box (dual-core Core2) is quite usable. In fact I'm typing this on right now in gnome-terminal and things are moving just fine. Also this is running with most of the debug features enabled (lockdep, mutex, etc) no BUG_ONs or lockdep complaints so far. I believe I addressed all of the Dmitry's comments for original Linus' version. I changed both fair and rt balancer to mask out non-active cpus. And replaced cpu_is_offline() with !cpu_active() in the main scheduler code where it made sense (to me). Signed-off-by: Max Krasnyanskiy <maxk@qualcomm.com> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Gregory Haskins <ghaskins@novell.com> Cc: dmitry.adamushko@gmail.com Cc: pj@sgi.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-15 11:43:49 +00:00
sched, cpuset: Drop __cpuexit from cpu hotplug callbacks Commit 3a101d05 (sched: adjust when cpu_active and cpuset configurations are updated during cpu on/offlining) added hotplug notifiers marked with __cpuexit; however, ia64 drops text in __cpuexit during link unlike x86. This means that functions which are referenced during init but used only for cpu hot unplugging afterwards shouldn't be marked with __cpuexit. Drop __cpuexit from those functions. Reported-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Tony Luck <tony.luck@intel.com> Cc: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <4C1FDF5B.1040301@kernel.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-06-21 21:53:31 +00:00
static int cpuset_cpu_inactive(struct notifier_block *nfb, unsigned long action,
void *hcpu)
sched: adjust when cpu_active and cpuset configurations are updated during cpu on/offlining Currently, when a cpu goes down, cpu_active is cleared before CPU_DOWN_PREPARE starts and cpuset configuration is updated from a default priority cpu notifier. When a cpu is coming up, it's set before CPU_ONLINE but cpuset configuration again is updated from the same cpu notifier. For cpu notifiers, this presents an inconsistent state. Threads which a CPU_DOWN_PREPARE notifier expects to be bound to the CPU can be migrated to other cpus because the cpu is no more inactive. Fix it by updating cpu_active in the highest priority cpu notifier and cpuset configuration in the second highest when a cpu is coming up. Down path is updated similarly. This guarantees that all other cpu notifiers see consistent cpu_active and cpuset configuration. cpuset_track_online_cpus() notifier is converted to cpuset_update_active_cpus() which just updates the configuration and now called from cpuset_cpu_[in]active() notifiers registered from sched_init_smp(). If cpuset is disabled, cpuset_update_active_cpus() degenerates into partition_sched_domains() making separate notifier for !CONFIG_CPUSETS unnecessary. This problem is triggered by cmwq. During CPU_DOWN_PREPARE, hotplug callback creates a kthread and kthread_bind()s it to the target cpu, and the thread is expected to run on that cpu. * Ingo's test discovered __cpuinit/exit markups were incorrect. Fixed. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Ingo Molnar <mingo@elte.hu> Cc: Paul Menage <menage@google.com>
2010-06-08 19:40:36 +00:00
{
switch (action & ~CPU_TASKS_FROZEN) {
case CPU_DOWN_PREPARE:
cpuset_update_active_cpus();
return NOTIFY_OK;
cpu hotplug, sched: Introduce cpu_active_map and redo sched domain managment (take 2) This is based on Linus' idea of creating cpu_active_map that prevents scheduler load balancer from migrating tasks to the cpu that is going down. It allows us to simplify domain management code and avoid unecessary domain rebuilds during cpu hotplug event handling. Please ignore the cpusets part for now. It needs some more work in order to avoid crazy lock nesting. Although I did simplfy and unify domain reinitialization logic. We now simply call partition_sched_domains() in all the cases. This means that we're using exact same code paths as in cpusets case and hence the test below cover cpusets too. Cpuset changes to make rebuild_sched_domains() callable from various contexts are in the separate patch (right next after this one). This not only boots but also easily handles while true; do make clean; make -j 8; done and while true; do on-off-cpu 1; done at the same time. (on-off-cpu 1 simple does echo 0/1 > /sys/.../cpu1/online thing). Suprisingly the box (dual-core Core2) is quite usable. In fact I'm typing this on right now in gnome-terminal and things are moving just fine. Also this is running with most of the debug features enabled (lockdep, mutex, etc) no BUG_ONs or lockdep complaints so far. I believe I addressed all of the Dmitry's comments for original Linus' version. I changed both fair and rt balancer to mask out non-active cpus. And replaced cpu_is_offline() with !cpu_active() in the main scheduler code where it made sense (to me). Signed-off-by: Max Krasnyanskiy <maxk@qualcomm.com> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Gregory Haskins <ghaskins@novell.com> Cc: dmitry.adamushko@gmail.com Cc: pj@sgi.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-15 11:43:49 +00:00
default:
return NOTIFY_DONE;
}
}
static int update_runtime(struct notifier_block *nfb,
unsigned long action, void *hcpu)
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
{
sched: fix hotplug cpus on ia64 Cliff Wickman wrote: > I built an ia64 kernel from Andrew's tree (2.6.26-rc2-mm1) > and get a very predictable hotplug cpu problem. > billberry1:/tmp/cpw # ./dis > disabled cpu 17 > enabled cpu 17 > billberry1:/tmp/cpw # ./dis > disabled cpu 17 > enabled cpu 17 > billberry1:/tmp/cpw # ./dis > > The script that disables the cpu always hangs (unkillable) > on the 3rd attempt. > > And a bit further: > The kstopmachine thread always sits on the run queue (real time) for about > 30 minutes before running. this fix solves some (but not all) issues between CPU hotplug and RT bandwidth throttling. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-05 12:49:58 +00:00
int cpu = (int)(long)hcpu;
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
switch (action) {
case CPU_DOWN_PREPARE:
Add suspend-related notifications for CPU hotplug Since nonboot CPUs are now disabled after tasks and devices have been frozen and the CPU hotplug infrastructure is used for this purpose, we need special CPU hotplug notifications that will help the CPU-hotplug-aware subsystems distinguish normal CPU hotplug events from CPU hotplug events related to a system-wide suspend or resume operation in progress. This patch introduces such notifications and causes them to be used during suspend and resume transitions. It also changes all of the CPU-hotplug-aware subsystems to take these notifications into consideration (for now they are handled in the same way as the corresponding "normal" ones). [oleg@tv-sign.ru: cleanups] Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Cc: Gautham R Shenoy <ego@in.ibm.com> Cc: Pavel Machek <pavel@ucw.cz> Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-09 09:35:10 +00:00
case CPU_DOWN_PREPARE_FROZEN:
sched: fix hotplug cpus on ia64 Cliff Wickman wrote: > I built an ia64 kernel from Andrew's tree (2.6.26-rc2-mm1) > and get a very predictable hotplug cpu problem. > billberry1:/tmp/cpw # ./dis > disabled cpu 17 > enabled cpu 17 > billberry1:/tmp/cpw # ./dis > disabled cpu 17 > enabled cpu 17 > billberry1:/tmp/cpw # ./dis > > The script that disables the cpu always hangs (unkillable) > on the 3rd attempt. > > And a bit further: > The kstopmachine thread always sits on the run queue (real time) for about > 30 minutes before running. this fix solves some (but not all) issues between CPU hotplug and RT bandwidth throttling. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-05 12:49:58 +00:00
disable_runtime(cpu_rq(cpu));
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
return NOTIFY_OK;
case CPU_DOWN_FAILED:
Add suspend-related notifications for CPU hotplug Since nonboot CPUs are now disabled after tasks and devices have been frozen and the CPU hotplug infrastructure is used for this purpose, we need special CPU hotplug notifications that will help the CPU-hotplug-aware subsystems distinguish normal CPU hotplug events from CPU hotplug events related to a system-wide suspend or resume operation in progress. This patch introduces such notifications and causes them to be used during suspend and resume transitions. It also changes all of the CPU-hotplug-aware subsystems to take these notifications into consideration (for now they are handled in the same way as the corresponding "normal" ones). [oleg@tv-sign.ru: cleanups] Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Cc: Gautham R Shenoy <ego@in.ibm.com> Cc: Pavel Machek <pavel@ucw.cz> Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-09 09:35:10 +00:00
case CPU_DOWN_FAILED_FROZEN:
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
case CPU_ONLINE:
Add suspend-related notifications for CPU hotplug Since nonboot CPUs are now disabled after tasks and devices have been frozen and the CPU hotplug infrastructure is used for this purpose, we need special CPU hotplug notifications that will help the CPU-hotplug-aware subsystems distinguish normal CPU hotplug events from CPU hotplug events related to a system-wide suspend or resume operation in progress. This patch introduces such notifications and causes them to be used during suspend and resume transitions. It also changes all of the CPU-hotplug-aware subsystems to take these notifications into consideration (for now they are handled in the same way as the corresponding "normal" ones). [oleg@tv-sign.ru: cleanups] Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Cc: Gautham R Shenoy <ego@in.ibm.com> Cc: Pavel Machek <pavel@ucw.cz> Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-09 09:35:10 +00:00
case CPU_ONLINE_FROZEN:
sched: fix hotplug cpus on ia64 Cliff Wickman wrote: > I built an ia64 kernel from Andrew's tree (2.6.26-rc2-mm1) > and get a very predictable hotplug cpu problem. > billberry1:/tmp/cpw # ./dis > disabled cpu 17 > enabled cpu 17 > billberry1:/tmp/cpw # ./dis > disabled cpu 17 > enabled cpu 17 > billberry1:/tmp/cpw # ./dis > > The script that disables the cpu always hangs (unkillable) > on the 3rd attempt. > > And a bit further: > The kstopmachine thread always sits on the run queue (real time) for about > 30 minutes before running. this fix solves some (but not all) issues between CPU hotplug and RT bandwidth throttling. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-05 12:49:58 +00:00
enable_runtime(cpu_rq(cpu));
cpu hotplug, sched: Introduce cpu_active_map and redo sched domain managment (take 2) This is based on Linus' idea of creating cpu_active_map that prevents scheduler load balancer from migrating tasks to the cpu that is going down. It allows us to simplify domain management code and avoid unecessary domain rebuilds during cpu hotplug event handling. Please ignore the cpusets part for now. It needs some more work in order to avoid crazy lock nesting. Although I did simplfy and unify domain reinitialization logic. We now simply call partition_sched_domains() in all the cases. This means that we're using exact same code paths as in cpusets case and hence the test below cover cpusets too. Cpuset changes to make rebuild_sched_domains() callable from various contexts are in the separate patch (right next after this one). This not only boots but also easily handles while true; do make clean; make -j 8; done and while true; do on-off-cpu 1; done at the same time. (on-off-cpu 1 simple does echo 0/1 > /sys/.../cpu1/online thing). Suprisingly the box (dual-core Core2) is quite usable. In fact I'm typing this on right now in gnome-terminal and things are moving just fine. Also this is running with most of the debug features enabled (lockdep, mutex, etc) no BUG_ONs or lockdep complaints so far. I believe I addressed all of the Dmitry's comments for original Linus' version. I changed both fair and rt balancer to mask out non-active cpus. And replaced cpu_is_offline() with !cpu_active() in the main scheduler code where it made sense (to me). Signed-off-by: Max Krasnyanskiy <maxk@qualcomm.com> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Gregory Haskins <ghaskins@novell.com> Cc: dmitry.adamushko@gmail.com Cc: pj@sgi.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-15 11:43:49 +00:00
return NOTIFY_OK;
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
default:
return NOTIFY_DONE;
}
}
void __init sched_init_smp(void)
{
sched: convert cpu_isolated_map to cpumask_var_t. Impact: stack usage reduction, (future) size reduction, cleanup Dynamically allocating cpumasks (when CONFIG_CPUMASK_OFFSTACK) saves space for small nr_cpu_ids but big CONFIG_NR_CPUS. cpumask_var_t is just a struct cpumask for !CONFIG_CPUMASK_OFFSTACK. We can also use cpulist_parse() instead of doing it manually in isolated_cpu_setup. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-24 16:05:12 +00:00
cpumask_var_t non_isolated_cpus;
alloc_cpumask_var(&non_isolated_cpus, GFP_KERNEL);
sched: Fix potential NULL derference of doms_cur If CONFIG_CPUMASK_OFFSTACK is enabled but doms_cur alloc failed in arch_init_sched_domains(), doms_cur will move back to fallback_doms. But this time, fallback_doms has not been initialized yet. Signed-off-by: Yong Zhang <yong.zhang0@gmail.com> Cc: a.p.zijlstra@chello.nl LKML-Reference: <1252930816-7672-1-git-send-email-yong.zhang0@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-09-14 12:20:16 +00:00
alloc_cpumask_var(&fallback_doms, GFP_KERNEL);
[PATCH] sched: force /sbin/init off isolated cpus Force /sbin/init off isolated cpus (unless every CPU is specified as an isolcpu). Users seem to think that the isolated CPUs shouldn't have much running on them to begin with. That's fair enough: intuitive, I guess. It also means that the cpu affinity masks of tasks will not include isolcpus by default, which is also more intuitive, perhaps. /sbin/init is spawned from the boot CPU's idle thread, and /sbin/init starts the rest of userspace. So if the boot CPU is specified to be an isolcpu, then prior to this patch, all of userspace will be run there. (throw in a couple of plausible devinit -> cpuinit conversions I spotted while we're here). Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: Dimitri Sivanich <sivanich@sgi.com> Acked-by: Paul Jackson <pj@sgi.com> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-03 08:14:04 +00:00
cpu-hotplug: replace per-subsystem mutexes with get_online_cpus() This patch converts the known per-subsystem mutexes to get_online_cpus put_online_cpus. It also eliminates the CPU_LOCK_ACQUIRE and CPU_LOCK_RELEASE hotplug notification events. Signed-off-by: Gautham R Shenoy <ego@in.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:02 +00:00
get_online_cpus();
sched: fix missing locking in sched_domains code Concurrent calls to detach_destroy_domains and arch_init_sched_domains were prevented by the old scheduler subsystem cpu hotplug mutex. When this got converted to get_online_cpus() the locking got broken. Unlike before now several processes can concurrently enter the critical sections that were protected by the old lock. So use the already present doms_cur_mutex to protect these sections again. Cc: Gautham R Shenoy <ego@in.ibm.com> Cc: Paul Jackson <pj@sgi.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-28 09:33:07 +00:00
mutex_lock(&sched_domains_mutex);
sched: Remove obsolete arch_ prefixes Non weak static functions clearly are not arch specific, so remove the arch_ prefix. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122941.820460566@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:09:42 +00:00
init_sched_domains(cpu_active_mask);
sched: convert cpu_isolated_map to cpumask_var_t. Impact: stack usage reduction, (future) size reduction, cleanup Dynamically allocating cpumasks (when CONFIG_CPUMASK_OFFSTACK) saves space for small nr_cpu_ids but big CONFIG_NR_CPUS. cpumask_var_t is just a struct cpumask for !CONFIG_CPUMASK_OFFSTACK. We can also use cpulist_parse() instead of doing it manually in isolated_cpu_setup. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-24 16:05:12 +00:00
cpumask_andnot(non_isolated_cpus, cpu_possible_mask, cpu_isolated_map);
if (cpumask_empty(non_isolated_cpus))
cpumask_set_cpu(smp_processor_id(), non_isolated_cpus);
sched: fix missing locking in sched_domains code Concurrent calls to detach_destroy_domains and arch_init_sched_domains were prevented by the old scheduler subsystem cpu hotplug mutex. When this got converted to get_online_cpus() the locking got broken. Unlike before now several processes can concurrently enter the critical sections that were protected by the old lock. So use the already present doms_cur_mutex to protect these sections again. Cc: Gautham R Shenoy <ego@in.ibm.com> Cc: Paul Jackson <pj@sgi.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-28 09:33:07 +00:00
mutex_unlock(&sched_domains_mutex);
cpu-hotplug: replace per-subsystem mutexes with get_online_cpus() This patch converts the known per-subsystem mutexes to get_online_cpus put_online_cpus. It also eliminates the CPU_LOCK_ACQUIRE and CPU_LOCK_RELEASE hotplug notification events. Signed-off-by: Gautham R Shenoy <ego@in.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:02 +00:00
put_online_cpus();
cpu hotplug, sched: Introduce cpu_active_map and redo sched domain managment (take 2) This is based on Linus' idea of creating cpu_active_map that prevents scheduler load balancer from migrating tasks to the cpu that is going down. It allows us to simplify domain management code and avoid unecessary domain rebuilds during cpu hotplug event handling. Please ignore the cpusets part for now. It needs some more work in order to avoid crazy lock nesting. Although I did simplfy and unify domain reinitialization logic. We now simply call partition_sched_domains() in all the cases. This means that we're using exact same code paths as in cpusets case and hence the test below cover cpusets too. Cpuset changes to make rebuild_sched_domains() callable from various contexts are in the separate patch (right next after this one). This not only boots but also easily handles while true; do make clean; make -j 8; done and while true; do on-off-cpu 1; done at the same time. (on-off-cpu 1 simple does echo 0/1 > /sys/.../cpu1/online thing). Suprisingly the box (dual-core Core2) is quite usable. In fact I'm typing this on right now in gnome-terminal and things are moving just fine. Also this is running with most of the debug features enabled (lockdep, mutex, etc) no BUG_ONs or lockdep complaints so far. I believe I addressed all of the Dmitry's comments for original Linus' version. I changed both fair and rt balancer to mask out non-active cpus. And replaced cpu_is_offline() with !cpu_active() in the main scheduler code where it made sense (to me). Signed-off-by: Max Krasnyanskiy <maxk@qualcomm.com> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Gregory Haskins <ghaskins@novell.com> Cc: dmitry.adamushko@gmail.com Cc: pj@sgi.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-15 11:43:49 +00:00
sched: adjust when cpu_active and cpuset configurations are updated during cpu on/offlining Currently, when a cpu goes down, cpu_active is cleared before CPU_DOWN_PREPARE starts and cpuset configuration is updated from a default priority cpu notifier. When a cpu is coming up, it's set before CPU_ONLINE but cpuset configuration again is updated from the same cpu notifier. For cpu notifiers, this presents an inconsistent state. Threads which a CPU_DOWN_PREPARE notifier expects to be bound to the CPU can be migrated to other cpus because the cpu is no more inactive. Fix it by updating cpu_active in the highest priority cpu notifier and cpuset configuration in the second highest when a cpu is coming up. Down path is updated similarly. This guarantees that all other cpu notifiers see consistent cpu_active and cpuset configuration. cpuset_track_online_cpus() notifier is converted to cpuset_update_active_cpus() which just updates the configuration and now called from cpuset_cpu_[in]active() notifiers registered from sched_init_smp(). If cpuset is disabled, cpuset_update_active_cpus() degenerates into partition_sched_domains() making separate notifier for !CONFIG_CPUSETS unnecessary. This problem is triggered by cmwq. During CPU_DOWN_PREPARE, hotplug callback creates a kthread and kthread_bind()s it to the target cpu, and the thread is expected to run on that cpu. * Ingo's test discovered __cpuinit/exit markups were incorrect. Fixed. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Ingo Molnar <mingo@elte.hu> Cc: Paul Menage <menage@google.com>
2010-06-08 19:40:36 +00:00
hotcpu_notifier(cpuset_cpu_active, CPU_PRI_CPUSET_ACTIVE);
hotcpu_notifier(cpuset_cpu_inactive, CPU_PRI_CPUSET_INACTIVE);
cpu hotplug, sched: Introduce cpu_active_map and redo sched domain managment (take 2) This is based on Linus' idea of creating cpu_active_map that prevents scheduler load balancer from migrating tasks to the cpu that is going down. It allows us to simplify domain management code and avoid unecessary domain rebuilds during cpu hotplug event handling. Please ignore the cpusets part for now. It needs some more work in order to avoid crazy lock nesting. Although I did simplfy and unify domain reinitialization logic. We now simply call partition_sched_domains() in all the cases. This means that we're using exact same code paths as in cpusets case and hence the test below cover cpusets too. Cpuset changes to make rebuild_sched_domains() callable from various contexts are in the separate patch (right next after this one). This not only boots but also easily handles while true; do make clean; make -j 8; done and while true; do on-off-cpu 1; done at the same time. (on-off-cpu 1 simple does echo 0/1 > /sys/.../cpu1/online thing). Suprisingly the box (dual-core Core2) is quite usable. In fact I'm typing this on right now in gnome-terminal and things are moving just fine. Also this is running with most of the debug features enabled (lockdep, mutex, etc) no BUG_ONs or lockdep complaints so far. I believe I addressed all of the Dmitry's comments for original Linus' version. I changed both fair and rt balancer to mask out non-active cpus. And replaced cpu_is_offline() with !cpu_active() in the main scheduler code where it made sense (to me). Signed-off-by: Max Krasnyanskiy <maxk@qualcomm.com> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Gregory Haskins <ghaskins@novell.com> Cc: dmitry.adamushko@gmail.com Cc: pj@sgi.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-15 11:43:49 +00:00
/* RT runtime code needs to handle some hotplug events */
hotcpu_notifier(update_runtime, 0);
sched: fix hrtick_start_fair and CPU-Hotplug Gautham R Shenoy reported: > While running the usual CPU-Hotplug stress tests on linux-2.6.25, > I noticed the following in the console logs. > > This is a wee bit difficult to reproduce. In the past 10 runs I hit this > only once. > > ------------[ cut here ]------------ > > WARNING: at kernel/sched.c:962 hrtick+0x2e/0x65() > > Just wondering if we are doing a good job at handling the cancellation > of any per-cpu scheduler timers during CPU-Hotplug. This looks like its indeed not cancelled at all and migrates the it to another cpu. Fix it via a proper hotplug notifier mechanism. Reported-by: Gautham R Shenoy <ego@in.ibm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: stable@kernel.org Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-29 08:02:46 +00:00
init_hrtick();
[PATCH] sched: force /sbin/init off isolated cpus Force /sbin/init off isolated cpus (unless every CPU is specified as an isolcpu). Users seem to think that the isolated CPUs shouldn't have much running on them to begin with. That's fair enough: intuitive, I guess. It also means that the cpu affinity masks of tasks will not include isolcpus by default, which is also more intuitive, perhaps. /sbin/init is spawned from the boot CPU's idle thread, and /sbin/init starts the rest of userspace. So if the boot CPU is specified to be an isolcpu, then prior to this patch, all of userspace will be run there. (throw in a couple of plausible devinit -> cpuinit conversions I spotted while we're here). Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: Dimitri Sivanich <sivanich@sgi.com> Acked-by: Paul Jackson <pj@sgi.com> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-03 08:14:04 +00:00
/* Move init over to a non-isolated CPU */
sched: convert cpu_isolated_map to cpumask_var_t. Impact: stack usage reduction, (future) size reduction, cleanup Dynamically allocating cpumasks (when CONFIG_CPUMASK_OFFSTACK) saves space for small nr_cpu_ids but big CONFIG_NR_CPUS. cpumask_var_t is just a struct cpumask for !CONFIG_CPUMASK_OFFSTACK. We can also use cpulist_parse() instead of doing it manually in isolated_cpu_setup. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-24 16:05:12 +00:00
if (set_cpus_allowed_ptr(current, non_isolated_cpus) < 0)
[PATCH] sched: force /sbin/init off isolated cpus Force /sbin/init off isolated cpus (unless every CPU is specified as an isolcpu). Users seem to think that the isolated CPUs shouldn't have much running on them to begin with. That's fair enough: intuitive, I guess. It also means that the cpu affinity masks of tasks will not include isolcpus by default, which is also more intuitive, perhaps. /sbin/init is spawned from the boot CPU's idle thread, and /sbin/init starts the rest of userspace. So if the boot CPU is specified to be an isolcpu, then prior to this patch, all of userspace will be run there. (throw in a couple of plausible devinit -> cpuinit conversions I spotted while we're here). Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: Dimitri Sivanich <sivanich@sgi.com> Acked-by: Paul Jackson <pj@sgi.com> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-03 08:14:04 +00:00
BUG();
sched: reintroduce SMP tunings again Yanmin Zhang reported an aim7 regression and bisected it down to: | commit 38ad464d410dadceda1563f36bdb0be7fe4c8938 | Author: Ingo Molnar <mingo@elte.hu> | Date: Mon Oct 15 17:00:02 2007 +0200 | | sched: uniform tunings | | use the same defaults on both UP and SMP. fix this by reintroducing similar SMP tunings again. This resolves the regression. (also update the comments to match the ilog2(nr_cpus) tuning effect) Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-11-09 21:39:38 +00:00
sched_init_granularity();
sched: convert cpu_isolated_map to cpumask_var_t. Impact: stack usage reduction, (future) size reduction, cleanup Dynamically allocating cpumasks (when CONFIG_CPUMASK_OFFSTACK) saves space for small nr_cpu_ids but big CONFIG_NR_CPUS. cpumask_var_t is just a struct cpumask for !CONFIG_CPUMASK_OFFSTACK. We can also use cpulist_parse() instead of doing it manually in isolated_cpu_setup. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-24 16:05:12 +00:00
free_cpumask_var(non_isolated_cpus);
sched: convert falback_doms to cpumask_var_t. Impact: (future) size reduction for large NR_CPUS. Dynamically allocating cpumasks (when CONFIG_CPUMASK_OFFSTACK) saves space for small nr_cpu_ids but big CONFIG_NR_CPUS. cpumask_var_t is just a struct cpumask for !CONFIG_CPUMASK_OFFSTACK. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-24 16:05:12 +00:00
sched: convert local_cpu_mask to cpumask_var_t. Impact: (future) size reduction for large NR_CPUS. Dynamically allocating cpumasks (when CONFIG_CPUMASK_OFFSTACK) saves space for small nr_cpu_ids but big CONFIG_NR_CPUS. cpumask_var_t is just a struct cpumask for !CONFIG_CPUMASK_OFFSTACK. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-24 16:05:13 +00:00
init_sched_rt_class();
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
}
#else
void __init sched_init_smp(void)
{
sched: reintroduce SMP tunings again Yanmin Zhang reported an aim7 regression and bisected it down to: | commit 38ad464d410dadceda1563f36bdb0be7fe4c8938 | Author: Ingo Molnar <mingo@elte.hu> | Date: Mon Oct 15 17:00:02 2007 +0200 | | sched: uniform tunings | | use the same defaults on both UP and SMP. fix this by reintroducing similar SMP tunings again. This resolves the regression. (also update the comments to match the ilog2(nr_cpus) tuning effect) Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-11-09 21:39:38 +00:00
sched_init_granularity();
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
}
#endif /* CONFIG_SMP */
timers: /proc/sys sysctl hook to enable timer migration * Arun R Bharadwaj <arun@linux.vnet.ibm.com> [2009-04-16 12:11:36]: This patch creates the /proc/sys sysctl interface at /proc/sys/kernel/timer_migration Timer migration is enabled by default. To disable timer migration, when CONFIG_SCHED_DEBUG = y, echo 0 > /proc/sys/kernel/timer_migration Signed-off-by: Arun R Bharadwaj <arun@linux.vnet.ibm.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2009-04-16 06:45:34 +00:00
const_debug unsigned int sysctl_timer_migration = 1;
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
int in_sched_functions(unsigned long addr)
{
return in_lock_functions(addr) ||
(addr >= (unsigned long)__sched_text_start
&& addr < (unsigned long)__sched_text_end);
}
sched: Separate group-scheduling code more clearly Clean up cfs/rt runqueue initialization by moving group scheduling related code into the corresponding functions. Also, keep group scheduling as an add-on, so that things are only done additionally, i. e. remove the init_*_rq() calls from init_tg_*_entry(). (This removes a redundant initalization during sched_init()). In case of group scheduling rt_rq->highest_prio.curr is now initialized twice, but adding another #ifdef seems not worth it. Signed-off-by: Jan H. Schönherr <schnhrr@cs.tu-berlin.de> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1310661163-16606-1-git-send-email-schnhrr@cs.tu-berlin.de Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-14 16:32:43 +00:00
static void init_cfs_rq(struct cfs_rq *cfs_rq)
sched: cfs core code apply the CFS core code. this change switches over the scheduler core to CFS's modular design and makes use of kernel/sched_fair/rt/idletask.c to implement Linux's scheduling policies. thanks to Andrew Morton and Thomas Gleixner for lots of detailed review feedback and for fixlets. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
2007-07-09 16:51:59 +00:00
{
cfs_rq->tasks_timeline = RB_ROOT;
sched: fair-group: de-couple load-balancing from the rb-trees De-couple load-balancing from the rb-trees, so that I can change their organization. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 17:45:00 +00:00
INIT_LIST_HEAD(&cfs_rq->tasks);
sched: add vslice add vslice: the load-dependent "virtual slice" a task should run ideally, so that the observed latency stays within the sched_latency window. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-15 15:00:10 +00:00
cfs_rq->min_vruntime = (u64)(-(1LL << 20));
sched: Fix 32bit race Commit 3fe1698b7fe0 ("sched: Deal with non-atomic min_vruntime reads on 32bit") forgot to initialize min_vruntime_copy which could lead to an infinite while loop in task_waking_fair() under some circumstances (early boot, lucky timing). [ This bug was also reported by others that blamed it on the RCU initialization problems ] Reported-and-tested-by: Bruno Wolff III <bruno@wolff.to> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-07-11 14:28:50 +00:00
#ifndef CONFIG_64BIT
cfs_rq->min_vruntime_copy = cfs_rq->min_vruntime;
#endif
sched: cfs core code apply the CFS core code. this change switches over the scheduler core to CFS's modular design and makes use of kernel/sched_fair/rt/idletask.c to implement Linux's scheduling policies. thanks to Andrew Morton and Thomas Gleixner for lots of detailed review feedback and for fixlets. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
2007-07-09 16:51:59 +00:00
}
sched: rt time limit Very simple time limit on the realtime scheduling classes. Allow the rq's realtime class to consume sched_rt_ratio of every sched_rt_period slice. If the class exceeds this quota the fair class will preempt the realtime class. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:29 +00:00
static void init_rt_rq(struct rt_rq *rt_rq, struct rq *rq)
{
struct rt_prio_array *array;
int i;
array = &rt_rq->active;
for (i = 0; i < MAX_RT_PRIO; i++) {
INIT_LIST_HEAD(array->queue + i);
__clear_bit(i, array->bitmap);
}
/* delimiter for bitsearch: */
__set_bit(MAX_RT_PRIO, array->bitmap);
sched: Separate group-scheduling code more clearly Clean up cfs/rt runqueue initialization by moving group scheduling related code into the corresponding functions. Also, keep group scheduling as an add-on, so that things are only done additionally, i. e. remove the init_*_rq() calls from init_tg_*_entry(). (This removes a redundant initalization during sched_init()). In case of group scheduling rt_rq->highest_prio.curr is now initialized twice, but adding another #ifdef seems not worth it. Signed-off-by: Jan H. Schönherr <schnhrr@cs.tu-berlin.de> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1310661163-16606-1-git-send-email-schnhrr@cs.tu-berlin.de Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-14 16:32:43 +00:00
#if defined CONFIG_SMP
sched: track the next-highest priority on each runqueue We will use this later in the series to reduce the amount of rq-lock contention during a pull operation Signed-off-by: Gregory Haskins <ghaskins@novell.com>
2008-12-29 14:39:49 +00:00
rt_rq->highest_prio.curr = MAX_RT_PRIO;
rt_rq->highest_prio.next = MAX_RT_PRIO;
sched: rt time limit Very simple time limit on the realtime scheduling classes. Allow the rq's realtime class to consume sched_rt_ratio of every sched_rt_period slice. If the class exceeds this quota the fair class will preempt the realtime class. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:29 +00:00
rt_rq->rt_nr_migratory = 0;
rt_rq->overloaded = 0;
plist: Remove the need to supply locks to plist heads This was legacy code brought over from the RT tree and is no longer necessary. Signed-off-by: Dima Zavin <dima@android.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Cc: Daniel Walker <dwalker@codeaurora.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Andi Kleen <andi@firstfloor.org> Cc: Lai Jiangshan <laijs@cn.fujitsu.com> Link: http://lkml.kernel.org/r/1310084879-10351-2-git-send-email-dima@android.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-08 00:27:59 +00:00
plist_head_init(&rt_rq->pushable_tasks);
sched: rt time limit Very simple time limit on the realtime scheduling classes. Allow the rq's realtime class to consume sched_rt_ratio of every sched_rt_period slice. If the class exceeds this quota the fair class will preempt the realtime class. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:29 +00:00
#endif
rt_rq->rt_time = 0;
rt_rq->rt_throttled = 0;
sched: rt-group: smp balancing Currently the rt group scheduling does a per cpu runtime limit, however the rt load balancer makes no guarantees about an equal spread of real- time tasks, just that at any one time, the highest priority tasks run. Solve this by making the runtime limit a global property by borrowing excessive runtime from the other cpus once the local limit runs out. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 17:44:58 +00:00
rt_rq->rt_runtime = 0;
sched: Convert rt_runtime_lock to raw_spinlock Convert locks which cannot be sleeping locks in preempt-rt to raw_spinlocks. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Ingo Molnar <mingo@elte.hu>
2009-11-17 14:32:06 +00:00
raw_spin_lock_init(&rt_rq->rt_runtime_lock);
sched: rt time limit Very simple time limit on the realtime scheduling classes. Allow the rq's realtime class to consume sched_rt_ratio of every sched_rt_period slice. If the class exceeds this quota the fair class will preempt the realtime class. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:29 +00:00
}
sched: rt group scheduling Extend group scheduling to also cover the realtime classes. It uses the time limiting introduced by the previous patch to allow multiple realtime groups. The hard time limit is required to keep behaviour deterministic. The algorithms used make the realtime scheduler O(tg), linear scaling wrt the number of task groups. This is the worst case behaviour I can't seem to get out of, the avg. case of the algorithms can be improved, I focused on correctness and worst case. [ akpm@linux-foundation.org: move side-effects out of BUG_ON(). ] Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:30 +00:00
#ifdef CONFIG_FAIR_GROUP_SCHED
sched: allow the group scheduler to have multiple levels This patch makes the group scheduler multi hierarchy aware. [a.p.zijlstra@chello.nl: rt-parts and assorted fixes] Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 17:44:59 +00:00
static void init_tg_cfs_entry(struct task_group *tg, struct cfs_rq *cfs_rq,
sched: Implement on-demand (active) cfs_rq list Make certain load-balance actions scale per number of active cgroups instead of the number of existing cgroups. This makes wakeup/sleep paths more expensive, but is a win for systems where the vast majority of existing cgroups are idle. Signed-off-by: Paul Turner <pjt@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20101115234937.666535048@google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-15 23:47:01 +00:00
struct sched_entity *se, int cpu,
sched: allow the group scheduler to have multiple levels This patch makes the group scheduler multi hierarchy aware. [a.p.zijlstra@chello.nl: rt-parts and assorted fixes] Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 17:44:59 +00:00
struct sched_entity *parent)
sched: rt group scheduling Extend group scheduling to also cover the realtime classes. It uses the time limiting introduced by the previous patch to allow multiple realtime groups. The hard time limit is required to keep behaviour deterministic. The algorithms used make the realtime scheduler O(tg), linear scaling wrt the number of task groups. This is the worst case behaviour I can't seem to get out of, the avg. case of the algorithms can be improved, I focused on correctness and worst case. [ akpm@linux-foundation.org: move side-effects out of BUG_ON(). ] Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:30 +00:00
{
sched: allow the group scheduler to have multiple levels This patch makes the group scheduler multi hierarchy aware. [a.p.zijlstra@chello.nl: rt-parts and assorted fixes] Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 17:44:59 +00:00
struct rq *rq = cpu_rq(cpu);
sched: Separate group-scheduling code more clearly Clean up cfs/rt runqueue initialization by moving group scheduling related code into the corresponding functions. Also, keep group scheduling as an add-on, so that things are only done additionally, i. e. remove the init_*_rq() calls from init_tg_*_entry(). (This removes a redundant initalization during sched_init()). In case of group scheduling rt_rq->highest_prio.curr is now initialized twice, but adding another #ifdef seems not worth it. Signed-off-by: Jan H. Schönherr <schnhrr@cs.tu-berlin.de> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1310661163-16606-1-git-send-email-schnhrr@cs.tu-berlin.de Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-14 16:32:43 +00:00
sched: rt group scheduling Extend group scheduling to also cover the realtime classes. It uses the time limiting introduced by the previous patch to allow multiple realtime groups. The hard time limit is required to keep behaviour deterministic. The algorithms used make the realtime scheduler O(tg), linear scaling wrt the number of task groups. This is the worst case behaviour I can't seem to get out of, the avg. case of the algorithms can be improved, I focused on correctness and worst case. [ akpm@linux-foundation.org: move side-effects out of BUG_ON(). ] Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:30 +00:00
cfs_rq->tg = tg;
sched: Separate group-scheduling code more clearly Clean up cfs/rt runqueue initialization by moving group scheduling related code into the corresponding functions. Also, keep group scheduling as an add-on, so that things are only done additionally, i. e. remove the init_*_rq() calls from init_tg_*_entry(). (This removes a redundant initalization during sched_init()). In case of group scheduling rt_rq->highest_prio.curr is now initialized twice, but adding another #ifdef seems not worth it. Signed-off-by: Jan H. Schönherr <schnhrr@cs.tu-berlin.de> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1310661163-16606-1-git-send-email-schnhrr@cs.tu-berlin.de Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-14 16:32:43 +00:00
cfs_rq->rq = rq;
#ifdef CONFIG_SMP
/* allow initial update_cfs_load() to truncate */
cfs_rq->load_stamp = 1;
#endif
sched: Introduce primitives to account for CFS bandwidth tracking In this patch we introduce the notion of CFS bandwidth, partitioned into globally unassigned bandwidth, and locally claimed bandwidth. - The global bandwidth is per task_group, it represents a pool of unclaimed bandwidth that cfs_rqs can allocate from. - The local bandwidth is tracked per-cfs_rq, this represents allotments from the global pool bandwidth assigned to a specific cpu. Bandwidth is managed via cgroupfs, adding two new interfaces to the cpu subsystem: - cpu.cfs_period_us : the bandwidth period in usecs - cpu.cfs_quota_us : the cpu bandwidth (in usecs) that this tg will be allowed to consume over period above. Signed-off-by: Paul Turner <pjt@google.com> Signed-off-by: Nikhil Rao <ncrao@google.com> Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com> Reviewed-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110721184756.972636699@google.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-21 16:43:28 +00:00
init_cfs_rq_runtime(cfs_rq);
sched: rt group scheduling Extend group scheduling to also cover the realtime classes. It uses the time limiting introduced by the previous patch to allow multiple realtime groups. The hard time limit is required to keep behaviour deterministic. The algorithms used make the realtime scheduler O(tg), linear scaling wrt the number of task groups. This is the worst case behaviour I can't seem to get out of, the avg. case of the algorithms can be improved, I focused on correctness and worst case. [ akpm@linux-foundation.org: move side-effects out of BUG_ON(). ] Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:30 +00:00
sched: Separate group-scheduling code more clearly Clean up cfs/rt runqueue initialization by moving group scheduling related code into the corresponding functions. Also, keep group scheduling as an add-on, so that things are only done additionally, i. e. remove the init_*_rq() calls from init_tg_*_entry(). (This removes a redundant initalization during sched_init()). In case of group scheduling rt_rq->highest_prio.curr is now initialized twice, but adding another #ifdef seems not worth it. Signed-off-by: Jan H. Schönherr <schnhrr@cs.tu-berlin.de> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1310661163-16606-1-git-send-email-schnhrr@cs.tu-berlin.de Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-14 16:32:43 +00:00
tg->cfs_rq[cpu] = cfs_rq;
sched: rt group scheduling Extend group scheduling to also cover the realtime classes. It uses the time limiting introduced by the previous patch to allow multiple realtime groups. The hard time limit is required to keep behaviour deterministic. The algorithms used make the realtime scheduler O(tg), linear scaling wrt the number of task groups. This is the worst case behaviour I can't seem to get out of, the avg. case of the algorithms can be improved, I focused on correctness and worst case. [ akpm@linux-foundation.org: move side-effects out of BUG_ON(). ] Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:30 +00:00
tg->se[cpu] = se;
sched: Separate group-scheduling code more clearly Clean up cfs/rt runqueue initialization by moving group scheduling related code into the corresponding functions. Also, keep group scheduling as an add-on, so that things are only done additionally, i. e. remove the init_*_rq() calls from init_tg_*_entry(). (This removes a redundant initalization during sched_init()). In case of group scheduling rt_rq->highest_prio.curr is now initialized twice, but adding another #ifdef seems not worth it. Signed-off-by: Jan H. Schönherr <schnhrr@cs.tu-berlin.de> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1310661163-16606-1-git-send-email-schnhrr@cs.tu-berlin.de Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-14 16:32:43 +00:00
sched: Consolidate the name of root_task_group and init_task_group root_task_group is the leftover of USER_SCHED, now it's always same to init_task_group. But as Mike suggested, root_task_group is maybe the suitable name to keep for a tree. So in this patch: init_task_group --> root_task_group init_task_group_load --> root_task_group_load INIT_TASK_GROUP_LOAD --> ROOT_TASK_GROUP_LOAD Suggested-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Yong Zhang <yong.zhang0@gmail.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20110107071736.GA32635@windriver.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-01-07 07:17:36 +00:00
/* se could be NULL for root_task_group */
sched: mix tasks and groups This patch allows tasks and groups to exist in the same cfs_rq. With this change the CFS group scheduling follows a 1/(M+N) model from a 1/(1+N) fairness model where M tasks and N groups exist at the cfs_rq level. [a.p.zijlstra@chello.nl: rt bits and assorted fixes] Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 17:44:59 +00:00
if (!se)
return;
sched: allow the group scheduler to have multiple levels This patch makes the group scheduler multi hierarchy aware. [a.p.zijlstra@chello.nl: rt-parts and assorted fixes] Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 17:44:59 +00:00
if (!parent)
se->cfs_rq = &rq->cfs;
else
se->cfs_rq = parent->my_q;
sched: rt group scheduling Extend group scheduling to also cover the realtime classes. It uses the time limiting introduced by the previous patch to allow multiple realtime groups. The hard time limit is required to keep behaviour deterministic. The algorithms used make the realtime scheduler O(tg), linear scaling wrt the number of task groups. This is the worst case behaviour I can't seem to get out of, the avg. case of the algorithms can be improved, I focused on correctness and worst case. [ akpm@linux-foundation.org: move side-effects out of BUG_ON(). ] Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:30 +00:00
se->my_q = cfs_rq;
sched: Update tg->shares after cpu.shares write Formerly sched_group_set_shares would force a rebalance by overflowing domain share sums. Now that per-cpu averages are maintained we can set the true value by issuing an update_cfs_shares() following a tg->shares update. Also initialize tg se->load to 0 for consistency since we'll now set correct weights on enqueue. Signed-off-by: Paul Turner <pjt@google.com?> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20101115234938.465521344@google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-15 23:47:10 +00:00
update_load_set(&se->load, 0);
sched: allow the group scheduler to have multiple levels This patch makes the group scheduler multi hierarchy aware. [a.p.zijlstra@chello.nl: rt-parts and assorted fixes] Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 17:44:59 +00:00
se->parent = parent;
sched: rt group scheduling Extend group scheduling to also cover the realtime classes. It uses the time limiting introduced by the previous patch to allow multiple realtime groups. The hard time limit is required to keep behaviour deterministic. The algorithms used make the realtime scheduler O(tg), linear scaling wrt the number of task groups. This is the worst case behaviour I can't seem to get out of, the avg. case of the algorithms can be improved, I focused on correctness and worst case. [ akpm@linux-foundation.org: move side-effects out of BUG_ON(). ] Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:30 +00:00
}
sched: rt-group: make rt groups scheduling configurable Make the rt group scheduler compile time configurable. Keep it experimental for now. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-13 14:45:40 +00:00
#endif
sched: rt group scheduling Extend group scheduling to also cover the realtime classes. It uses the time limiting introduced by the previous patch to allow multiple realtime groups. The hard time limit is required to keep behaviour deterministic. The algorithms used make the realtime scheduler O(tg), linear scaling wrt the number of task groups. This is the worst case behaviour I can't seem to get out of, the avg. case of the algorithms can be improved, I focused on correctness and worst case. [ akpm@linux-foundation.org: move side-effects out of BUG_ON(). ] Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:30 +00:00
sched: rt-group: make rt groups scheduling configurable Make the rt group scheduler compile time configurable. Keep it experimental for now. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-13 14:45:40 +00:00
#ifdef CONFIG_RT_GROUP_SCHED
sched: allow the group scheduler to have multiple levels This patch makes the group scheduler multi hierarchy aware. [a.p.zijlstra@chello.nl: rt-parts and assorted fixes] Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 17:44:59 +00:00
static void init_tg_rt_entry(struct task_group *tg, struct rt_rq *rt_rq,
sched: Implement on-demand (active) cfs_rq list Make certain load-balance actions scale per number of active cgroups instead of the number of existing cgroups. This makes wakeup/sleep paths more expensive, but is a win for systems where the vast majority of existing cgroups are idle. Signed-off-by: Paul Turner <pjt@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20101115234937.666535048@google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-15 23:47:01 +00:00
struct sched_rt_entity *rt_se, int cpu,
sched: allow the group scheduler to have multiple levels This patch makes the group scheduler multi hierarchy aware. [a.p.zijlstra@chello.nl: rt-parts and assorted fixes] Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 17:44:59 +00:00
struct sched_rt_entity *parent)
sched: rt group scheduling Extend group scheduling to also cover the realtime classes. It uses the time limiting introduced by the previous patch to allow multiple realtime groups. The hard time limit is required to keep behaviour deterministic. The algorithms used make the realtime scheduler O(tg), linear scaling wrt the number of task groups. This is the worst case behaviour I can't seem to get out of, the avg. case of the algorithms can be improved, I focused on correctness and worst case. [ akpm@linux-foundation.org: move side-effects out of BUG_ON(). ] Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:30 +00:00
{
sched: allow the group scheduler to have multiple levels This patch makes the group scheduler multi hierarchy aware. [a.p.zijlstra@chello.nl: rt-parts and assorted fixes] Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 17:44:59 +00:00
struct rq *rq = cpu_rq(cpu);
sched: Separate group-scheduling code more clearly Clean up cfs/rt runqueue initialization by moving group scheduling related code into the corresponding functions. Also, keep group scheduling as an add-on, so that things are only done additionally, i. e. remove the init_*_rq() calls from init_tg_*_entry(). (This removes a redundant initalization during sched_init()). In case of group scheduling rt_rq->highest_prio.curr is now initialized twice, but adding another #ifdef seems not worth it. Signed-off-by: Jan H. Schönherr <schnhrr@cs.tu-berlin.de> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1310661163-16606-1-git-send-email-schnhrr@cs.tu-berlin.de Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-14 16:32:43 +00:00
rt_rq->highest_prio.curr = MAX_RT_PRIO;
rt_rq->rt_nr_boosted = 0;
rt_rq->rq = rq;
sched: rt group scheduling Extend group scheduling to also cover the realtime classes. It uses the time limiting introduced by the previous patch to allow multiple realtime groups. The hard time limit is required to keep behaviour deterministic. The algorithms used make the realtime scheduler O(tg), linear scaling wrt the number of task groups. This is the worst case behaviour I can't seem to get out of, the avg. case of the algorithms can be improved, I focused on correctness and worst case. [ akpm@linux-foundation.org: move side-effects out of BUG_ON(). ] Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:30 +00:00
rt_rq->tg = tg;
sched: Separate group-scheduling code more clearly Clean up cfs/rt runqueue initialization by moving group scheduling related code into the corresponding functions. Also, keep group scheduling as an add-on, so that things are only done additionally, i. e. remove the init_*_rq() calls from init_tg_*_entry(). (This removes a redundant initalization during sched_init()). In case of group scheduling rt_rq->highest_prio.curr is now initialized twice, but adding another #ifdef seems not worth it. Signed-off-by: Jan H. Schönherr <schnhrr@cs.tu-berlin.de> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1310661163-16606-1-git-send-email-schnhrr@cs.tu-berlin.de Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-14 16:32:43 +00:00
tg->rt_rq[cpu] = rt_rq;
sched: rt group scheduling Extend group scheduling to also cover the realtime classes. It uses the time limiting introduced by the previous patch to allow multiple realtime groups. The hard time limit is required to keep behaviour deterministic. The algorithms used make the realtime scheduler O(tg), linear scaling wrt the number of task groups. This is the worst case behaviour I can't seem to get out of, the avg. case of the algorithms can be improved, I focused on correctness and worst case. [ akpm@linux-foundation.org: move side-effects out of BUG_ON(). ] Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:30 +00:00
tg->rt_se[cpu] = rt_se;
sched: Separate group-scheduling code more clearly Clean up cfs/rt runqueue initialization by moving group scheduling related code into the corresponding functions. Also, keep group scheduling as an add-on, so that things are only done additionally, i. e. remove the init_*_rq() calls from init_tg_*_entry(). (This removes a redundant initalization during sched_init()). In case of group scheduling rt_rq->highest_prio.curr is now initialized twice, but adding another #ifdef seems not worth it. Signed-off-by: Jan H. Schönherr <schnhrr@cs.tu-berlin.de> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1310661163-16606-1-git-send-email-schnhrr@cs.tu-berlin.de Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-14 16:32:43 +00:00
sched: mix tasks and groups This patch allows tasks and groups to exist in the same cfs_rq. With this change the CFS group scheduling follows a 1/(M+N) model from a 1/(1+N) fairness model where M tasks and N groups exist at the cfs_rq level. [a.p.zijlstra@chello.nl: rt bits and assorted fixes] Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 17:44:59 +00:00
if (!rt_se)
return;
sched: allow the group scheduler to have multiple levels This patch makes the group scheduler multi hierarchy aware. [a.p.zijlstra@chello.nl: rt-parts and assorted fixes] Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 17:44:59 +00:00
if (!parent)
rt_se->rt_rq = &rq->rt;
else
rt_se->rt_rq = parent->my_q;
sched: rt group scheduling Extend group scheduling to also cover the realtime classes. It uses the time limiting introduced by the previous patch to allow multiple realtime groups. The hard time limit is required to keep behaviour deterministic. The algorithms used make the realtime scheduler O(tg), linear scaling wrt the number of task groups. This is the worst case behaviour I can't seem to get out of, the avg. case of the algorithms can be improved, I focused on correctness and worst case. [ akpm@linux-foundation.org: move side-effects out of BUG_ON(). ] Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:30 +00:00
rt_se->my_q = rt_rq;
sched: allow the group scheduler to have multiple levels This patch makes the group scheduler multi hierarchy aware. [a.p.zijlstra@chello.nl: rt-parts and assorted fixes] Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 17:44:59 +00:00
rt_se->parent = parent;
sched: rt group scheduling Extend group scheduling to also cover the realtime classes. It uses the time limiting introduced by the previous patch to allow multiple realtime groups. The hard time limit is required to keep behaviour deterministic. The algorithms used make the realtime scheduler O(tg), linear scaling wrt the number of task groups. This is the worst case behaviour I can't seem to get out of, the avg. case of the algorithms can be improved, I focused on correctness and worst case. [ akpm@linux-foundation.org: move side-effects out of BUG_ON(). ] Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:30 +00:00
INIT_LIST_HEAD(&rt_se->run_list);
}
#endif
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
void __init sched_init(void)
{
sched: cfs core code apply the CFS core code. this change switches over the scheduler core to CFS's modular design and makes use of kernel/sched_fair/rt/idletask.c to implement Linux's scheduling policies. thanks to Andrew Morton and Thomas Gleixner for lots of detailed review feedback and for fixlets. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
2007-07-09 16:51:59 +00:00
int i, j;
sched: remove fixed NR_CPUS sized arrays in kernel_sched_c * Change fixed size arrays to per_cpu variables or dynamically allocated arrays in sched_init() and sched_init_smp(). (1) static struct sched_entity *init_sched_entity_p[NR_CPUS]; (1) static struct cfs_rq *init_cfs_rq_p[NR_CPUS]; (1) static struct sched_rt_entity *init_sched_rt_entity_p[NR_CPUS]; (1) static struct rt_rq *init_rt_rq_p[NR_CPUS]; static struct sched_group **sched_group_nodes_bycpu[NR_CPUS]; (1) - these arrays are allocated via alloc_bootmem_low() * Change sched_domain_debug_one() to use cpulist_scnprintf instead of cpumask_scnprintf. This reduces the output buffer required and improves readability when large NR_CPU count machines arrive. * In sched_create_group() we allocate new arrays based on nr_cpu_ids. Signed-off-by: Mike Travis <travis@sgi.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-05 01:11:04 +00:00
unsigned long alloc_size = 0, ptr;
#ifdef CONFIG_FAIR_GROUP_SCHED
alloc_size += 2 * nr_cpu_ids * sizeof(void **);
#endif
#ifdef CONFIG_RT_GROUP_SCHED
alloc_size += 2 * nr_cpu_ids * sizeof(void **);
sched: fix the task_group hierarchy for UID grouping UID grouping doesn't actually have a task_group representing the root of the task_group tree. Add one. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 17:45:00 +00:00
#endif
cpumask: remove cpumask allocation from idle_balance Impact: fix circular locking Steven reports a circular locking from alloc_cpumask_var doing a wakeup. We get rid of this using the tried-and-true technique of using a per-cpu cpumask_var_t rather than doing an alloc every time. Simpler and more robust than a rare, implicit allocation within an atomic codepath. Reported-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> LKML-Reference: <alpine.DEB.2.00.0903181729360.31583@gandalf.stny.rr.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-19 04:52:20 +00:00
#ifdef CONFIG_CPUMASK_OFFSTACK
cpumask: remove cpumask allocation from idle_balance, fix Impact: fix boot crash Fix typo in the size calculation. Reported-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> LKML-Reference: <alpine.DEB.2.00.0903181729360.31583@gandalf.stny.rr.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-19 04:52:20 +00:00
alloc_size += num_possible_cpus() * cpumask_size();
sched: remove fixed NR_CPUS sized arrays in kernel_sched_c * Change fixed size arrays to per_cpu variables or dynamically allocated arrays in sched_init() and sched_init_smp(). (1) static struct sched_entity *init_sched_entity_p[NR_CPUS]; (1) static struct cfs_rq *init_cfs_rq_p[NR_CPUS]; (1) static struct sched_rt_entity *init_sched_rt_entity_p[NR_CPUS]; (1) static struct rt_rq *init_rt_rq_p[NR_CPUS]; static struct sched_group **sched_group_nodes_bycpu[NR_CPUS]; (1) - these arrays are allocated via alloc_bootmem_low() * Change sched_domain_debug_one() to use cpulist_scnprintf instead of cpumask_scnprintf. This reduces the output buffer required and improves readability when large NR_CPU count machines arrive. * In sched_create_group() we allocate new arrays based on nr_cpu_ids. Signed-off-by: Mike Travis <travis@sgi.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-05 01:11:04 +00:00
#endif
if (alloc_size) {
sched: use kzalloc() instead of the bootmem allocator Now that kmem_cache_init() happens before sched_init(), we should use kzalloc() and not the bootmem allocator. Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
2009-06-10 20:42:36 +00:00
ptr = (unsigned long)kzalloc(alloc_size, GFP_NOWAIT);
sched: remove fixed NR_CPUS sized arrays in kernel_sched_c * Change fixed size arrays to per_cpu variables or dynamically allocated arrays in sched_init() and sched_init_smp(). (1) static struct sched_entity *init_sched_entity_p[NR_CPUS]; (1) static struct cfs_rq *init_cfs_rq_p[NR_CPUS]; (1) static struct sched_rt_entity *init_sched_rt_entity_p[NR_CPUS]; (1) static struct rt_rq *init_rt_rq_p[NR_CPUS]; static struct sched_group **sched_group_nodes_bycpu[NR_CPUS]; (1) - these arrays are allocated via alloc_bootmem_low() * Change sched_domain_debug_one() to use cpulist_scnprintf instead of cpumask_scnprintf. This reduces the output buffer required and improves readability when large NR_CPU count machines arrive. * In sched_create_group() we allocate new arrays based on nr_cpu_ids. Signed-off-by: Mike Travis <travis@sgi.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-05 01:11:04 +00:00
#ifdef CONFIG_FAIR_GROUP_SCHED
sched: Consolidate the name of root_task_group and init_task_group root_task_group is the leftover of USER_SCHED, now it's always same to init_task_group. But as Mike suggested, root_task_group is maybe the suitable name to keep for a tree. So in this patch: init_task_group --> root_task_group init_task_group_load --> root_task_group_load INIT_TASK_GROUP_LOAD --> ROOT_TASK_GROUP_LOAD Suggested-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Yong Zhang <yong.zhang0@gmail.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20110107071736.GA32635@windriver.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-01-07 07:17:36 +00:00
root_task_group.se = (struct sched_entity **)ptr;
sched: remove fixed NR_CPUS sized arrays in kernel_sched_c * Change fixed size arrays to per_cpu variables or dynamically allocated arrays in sched_init() and sched_init_smp(). (1) static struct sched_entity *init_sched_entity_p[NR_CPUS]; (1) static struct cfs_rq *init_cfs_rq_p[NR_CPUS]; (1) static struct sched_rt_entity *init_sched_rt_entity_p[NR_CPUS]; (1) static struct rt_rq *init_rt_rq_p[NR_CPUS]; static struct sched_group **sched_group_nodes_bycpu[NR_CPUS]; (1) - these arrays are allocated via alloc_bootmem_low() * Change sched_domain_debug_one() to use cpulist_scnprintf instead of cpumask_scnprintf. This reduces the output buffer required and improves readability when large NR_CPU count machines arrive. * In sched_create_group() we allocate new arrays based on nr_cpu_ids. Signed-off-by: Mike Travis <travis@sgi.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-05 01:11:04 +00:00
ptr += nr_cpu_ids * sizeof(void **);
sched: Consolidate the name of root_task_group and init_task_group root_task_group is the leftover of USER_SCHED, now it's always same to init_task_group. But as Mike suggested, root_task_group is maybe the suitable name to keep for a tree. So in this patch: init_task_group --> root_task_group init_task_group_load --> root_task_group_load INIT_TASK_GROUP_LOAD --> ROOT_TASK_GROUP_LOAD Suggested-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Yong Zhang <yong.zhang0@gmail.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20110107071736.GA32635@windriver.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-01-07 07:17:36 +00:00
root_task_group.cfs_rq = (struct cfs_rq **)ptr;
sched: remove fixed NR_CPUS sized arrays in kernel_sched_c * Change fixed size arrays to per_cpu variables or dynamically allocated arrays in sched_init() and sched_init_smp(). (1) static struct sched_entity *init_sched_entity_p[NR_CPUS]; (1) static struct cfs_rq *init_cfs_rq_p[NR_CPUS]; (1) static struct sched_rt_entity *init_sched_rt_entity_p[NR_CPUS]; (1) static struct rt_rq *init_rt_rq_p[NR_CPUS]; static struct sched_group **sched_group_nodes_bycpu[NR_CPUS]; (1) - these arrays are allocated via alloc_bootmem_low() * Change sched_domain_debug_one() to use cpulist_scnprintf instead of cpumask_scnprintf. This reduces the output buffer required and improves readability when large NR_CPU count machines arrive. * In sched_create_group() we allocate new arrays based on nr_cpu_ids. Signed-off-by: Mike Travis <travis@sgi.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-05 01:11:04 +00:00
ptr += nr_cpu_ids * sizeof(void **);
sched: fix the task_group hierarchy for UID grouping UID grouping doesn't actually have a task_group representing the root of the task_group tree. Add one. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 17:45:00 +00:00
sched: add comments for ifdefs in sched.c make sched.c easier to read. Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-30 12:23:45 +00:00
#endif /* CONFIG_FAIR_GROUP_SCHED */
sched: remove fixed NR_CPUS sized arrays in kernel_sched_c * Change fixed size arrays to per_cpu variables or dynamically allocated arrays in sched_init() and sched_init_smp(). (1) static struct sched_entity *init_sched_entity_p[NR_CPUS]; (1) static struct cfs_rq *init_cfs_rq_p[NR_CPUS]; (1) static struct sched_rt_entity *init_sched_rt_entity_p[NR_CPUS]; (1) static struct rt_rq *init_rt_rq_p[NR_CPUS]; static struct sched_group **sched_group_nodes_bycpu[NR_CPUS]; (1) - these arrays are allocated via alloc_bootmem_low() * Change sched_domain_debug_one() to use cpulist_scnprintf instead of cpumask_scnprintf. This reduces the output buffer required and improves readability when large NR_CPU count machines arrive. * In sched_create_group() we allocate new arrays based on nr_cpu_ids. Signed-off-by: Mike Travis <travis@sgi.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-05 01:11:04 +00:00
#ifdef CONFIG_RT_GROUP_SCHED
sched: Consolidate the name of root_task_group and init_task_group root_task_group is the leftover of USER_SCHED, now it's always same to init_task_group. But as Mike suggested, root_task_group is maybe the suitable name to keep for a tree. So in this patch: init_task_group --> root_task_group init_task_group_load --> root_task_group_load INIT_TASK_GROUP_LOAD --> ROOT_TASK_GROUP_LOAD Suggested-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Yong Zhang <yong.zhang0@gmail.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20110107071736.GA32635@windriver.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-01-07 07:17:36 +00:00
root_task_group.rt_se = (struct sched_rt_entity **)ptr;
sched: remove fixed NR_CPUS sized arrays in kernel_sched_c * Change fixed size arrays to per_cpu variables or dynamically allocated arrays in sched_init() and sched_init_smp(). (1) static struct sched_entity *init_sched_entity_p[NR_CPUS]; (1) static struct cfs_rq *init_cfs_rq_p[NR_CPUS]; (1) static struct sched_rt_entity *init_sched_rt_entity_p[NR_CPUS]; (1) static struct rt_rq *init_rt_rq_p[NR_CPUS]; static struct sched_group **sched_group_nodes_bycpu[NR_CPUS]; (1) - these arrays are allocated via alloc_bootmem_low() * Change sched_domain_debug_one() to use cpulist_scnprintf instead of cpumask_scnprintf. This reduces the output buffer required and improves readability when large NR_CPU count machines arrive. * In sched_create_group() we allocate new arrays based on nr_cpu_ids. Signed-off-by: Mike Travis <travis@sgi.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-05 01:11:04 +00:00
ptr += nr_cpu_ids * sizeof(void **);
sched: Consolidate the name of root_task_group and init_task_group root_task_group is the leftover of USER_SCHED, now it's always same to init_task_group. But as Mike suggested, root_task_group is maybe the suitable name to keep for a tree. So in this patch: init_task_group --> root_task_group init_task_group_load --> root_task_group_load INIT_TASK_GROUP_LOAD --> ROOT_TASK_GROUP_LOAD Suggested-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Yong Zhang <yong.zhang0@gmail.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20110107071736.GA32635@windriver.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-01-07 07:17:36 +00:00
root_task_group.rt_rq = (struct rt_rq **)ptr;
sched: fix the task_group hierarchy for UID grouping UID grouping doesn't actually have a task_group representing the root of the task_group tree. Add one. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 17:45:00 +00:00
ptr += nr_cpu_ids * sizeof(void **);
sched: add comments for ifdefs in sched.c make sched.c easier to read. Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-30 12:23:45 +00:00
#endif /* CONFIG_RT_GROUP_SCHED */
cpumask: remove cpumask allocation from idle_balance Impact: fix circular locking Steven reports a circular locking from alloc_cpumask_var doing a wakeup. We get rid of this using the tried-and-true technique of using a per-cpu cpumask_var_t rather than doing an alloc every time. Simpler and more robust than a rare, implicit allocation within an atomic codepath. Reported-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> LKML-Reference: <alpine.DEB.2.00.0903181729360.31583@gandalf.stny.rr.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-19 04:52:20 +00:00
#ifdef CONFIG_CPUMASK_OFFSTACK
for_each_possible_cpu(i) {
per_cpu(load_balance_tmpmask, i) = (void *)ptr;
ptr += cpumask_size();
}
#endif /* CONFIG_CPUMASK_OFFSTACK */
sched: remove fixed NR_CPUS sized arrays in kernel_sched_c * Change fixed size arrays to per_cpu variables or dynamically allocated arrays in sched_init() and sched_init_smp(). (1) static struct sched_entity *init_sched_entity_p[NR_CPUS]; (1) static struct cfs_rq *init_cfs_rq_p[NR_CPUS]; (1) static struct sched_rt_entity *init_sched_rt_entity_p[NR_CPUS]; (1) static struct rt_rq *init_rt_rq_p[NR_CPUS]; static struct sched_group **sched_group_nodes_bycpu[NR_CPUS]; (1) - these arrays are allocated via alloc_bootmem_low() * Change sched_domain_debug_one() to use cpulist_scnprintf instead of cpumask_scnprintf. This reduces the output buffer required and improves readability when large NR_CPU count machines arrive. * In sched_create_group() we allocate new arrays based on nr_cpu_ids. Signed-off-by: Mike Travis <travis@sgi.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-05 01:11:04 +00:00
}
sched: cfs core code apply the CFS core code. this change switches over the scheduler core to CFS's modular design and makes use of kernel/sched_fair/rt/idletask.c to implement Linux's scheduling policies. thanks to Andrew Morton and Thomas Gleixner for lots of detailed review feedback and for fixlets. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
2007-07-09 16:51:59 +00:00
sched: add sched-domain roots We add the notion of a root-domain which will be used later to rescope global variables to per-domain variables. Each exclusive cpuset essentially defines an island domain by fully partitioning the member cpus from any other cpuset. However, we currently still maintain some policy/state as global variables which transcend all cpusets. Consider, for instance, rt-overload state. Whenever a new exclusive cpuset is created, we also create a new root-domain object and move each cpu member to the root-domain's span. By default the system creates a single root-domain with all cpus as members (mimicking the global state we have today). We add some plumbing for storing class specific data in our root-domain. Whenever a RQ is switching root-domains (because of repartitioning) we give each sched_class the opportunity to remove any state from its old domain and add state to the new one. This logic doesn't have any clients yet but it will later in the series. Signed-off-by: Gregory Haskins <ghaskins@novell.com> CC: Christoph Lameter <clameter@sgi.com> CC: Paul Jackson <pj@sgi.com> CC: Simon Derr <simon.derr@bull.net> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:18 +00:00
#ifdef CONFIG_SMP
init_defrootdomain();
#endif
sched: rt-group: synchonised bandwidth period Various SMP balancing algorithms require that the bandwidth period run in sync. Possible improvements are moving the rt_bandwidth thing into root_domain and keeping a span per rt_bandwidth which marks throttled cpus. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 17:44:57 +00:00
init_rt_bandwidth(&def_rt_bandwidth,
global_rt_period(), global_rt_runtime());
#ifdef CONFIG_RT_GROUP_SCHED
sched: Consolidate the name of root_task_group and init_task_group root_task_group is the leftover of USER_SCHED, now it's always same to init_task_group. But as Mike suggested, root_task_group is maybe the suitable name to keep for a tree. So in this patch: init_task_group --> root_task_group init_task_group_load --> root_task_group_load INIT_TASK_GROUP_LOAD --> ROOT_TASK_GROUP_LOAD Suggested-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Yong Zhang <yong.zhang0@gmail.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20110107071736.GA32635@windriver.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-01-07 07:17:36 +00:00
init_rt_bandwidth(&root_task_group.rt_bandwidth,
sched: rt-group: synchonised bandwidth period Various SMP balancing algorithms require that the bandwidth period run in sync. Possible improvements are moving the rt_bandwidth thing into root_domain and keeping a span per rt_bandwidth which marks throttled cpus. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 17:44:57 +00:00
global_rt_period(), global_rt_runtime());
sched: add comments for ifdefs in sched.c make sched.c easier to read. Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-30 12:23:45 +00:00
#endif /* CONFIG_RT_GROUP_SCHED */
sched: rt-group: synchonised bandwidth period Various SMP balancing algorithms require that the bandwidth period run in sync. Possible improvements are moving the rt_bandwidth thing into root_domain and keeping a span per rt_bandwidth which marks throttled cpus. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 17:44:57 +00:00
sched: Remove USER_SCHED Remove the USER_SCHED feature. It has been scheduled to be removed in 2.6.34 as per http://marc.info/?l=linux-kernel&m=125728479022976&w=2 Signed-off-by: Dhaval Giani <dhaval.giani@gmail.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1263990378.24844.3.camel@localhost> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-01-20 12:26:18 +00:00
#ifdef CONFIG_CGROUP_SCHED
sched: Consolidate the name of root_task_group and init_task_group root_task_group is the leftover of USER_SCHED, now it's always same to init_task_group. But as Mike suggested, root_task_group is maybe the suitable name to keep for a tree. So in this patch: init_task_group --> root_task_group init_task_group_load --> root_task_group_load INIT_TASK_GROUP_LOAD --> ROOT_TASK_GROUP_LOAD Suggested-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Yong Zhang <yong.zhang0@gmail.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20110107071736.GA32635@windriver.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-01-07 07:17:36 +00:00
list_add(&root_task_group.list, &task_groups);
INIT_LIST_HEAD(&root_task_group.children);
sched: Add 'autogroup' scheduling feature: automated per session task groups A recurring complaint from CFS users is that parallel kbuild has a negative impact on desktop interactivity. This patch implements an idea from Linus, to automatically create task groups. Currently, only per session autogroups are implemented, but the patch leaves the way open for enhancement. Implementation: each task's signal struct contains an inherited pointer to a refcounted autogroup struct containing a task group pointer, the default for all tasks pointing to the init_task_group. When a task calls setsid(), a new task group is created, the process is moved into the new task group, and a reference to the preveious task group is dropped. Child processes inherit this task group thereafter, and increase it's refcount. When the last thread of a process exits, the process's reference is dropped, such that when the last process referencing an autogroup exits, the autogroup is destroyed. At runqueue selection time, IFF a task has no cgroup assignment, its current autogroup is used. Autogroup bandwidth is controllable via setting it's nice level through the proc filesystem: cat /proc/<pid>/autogroup Displays the task's group and the group's nice level. echo <nice level> > /proc/<pid>/autogroup Sets the task group's shares to the weight of nice <level> task. Setting nice level is rate limited for !admin users due to the abuse risk of task group locking. The feature is enabled from boot by default if CONFIG_SCHED_AUTOGROUP=y is selected, but can be disabled via the boot option noautogroup, and can also be turned on/off on the fly via: echo [01] > /proc/sys/kernel/sched_autogroup_enabled ... which will automatically move tasks to/from the root task group. Signed-off-by: Mike Galbraith <efault@gmx.de> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Markus Trippelsdorf <markus@trippelsdorf.de> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Paul Turner <pjt@google.com> Cc: Oleg Nesterov <oleg@redhat.com> [ Removed the task_group_path() debug code, and fixed !EVENTFD build failure. ] Signed-off-by: Ingo Molnar <mingo@elte.hu> LKML-Reference: <1290281700.28711.9.camel@maggy.simson.net> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-30 13:18:03 +00:00
autogroup_init(&init_task);
sched: Remove USER_SCHED Remove the USER_SCHED feature. It has been scheduled to be removed in 2.6.34 as per http://marc.info/?l=linux-kernel&m=125728479022976&w=2 Signed-off-by: Dhaval Giani <dhaval.giani@gmail.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1263990378.24844.3.camel@localhost> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-01-20 12:26:18 +00:00
#endif /* CONFIG_CGROUP_SCHED */
sched: rt group scheduling Extend group scheduling to also cover the realtime classes. It uses the time limiting introduced by the previous patch to allow multiple realtime groups. The hard time limit is required to keep behaviour deterministic. The algorithms used make the realtime scheduler O(tg), linear scaling wrt the number of task groups. This is the worst case behaviour I can't seem to get out of, the avg. case of the algorithms can be improved, I focused on correctness and worst case. [ akpm@linux-foundation.org: move side-effects out of BUG_ON(). ] Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:30 +00:00
[PATCH] for_each_possible_cpu: fixes for generic part replaces for_each_cpu with for_each_possible_cpu(). Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-28 09:56:37 +00:00
for_each_possible_cpu(i) {
[PATCH] sched: cleanup, convert sched.c-internal typedefs to struct convert: - runqueue_t to 'struct rq' - prio_array_t to 'struct prio_array' - migration_req_t to 'struct migration_req' I was the one who added these but they are both against the kernel coding style and also were used inconsistently at places. So just get rid of them at once, now that we are flushing the scheduler patch-queue anyway. Conversion was mostly scripted, the result was reviewed and all secondary whitespace and style impact (if any) was fixed up by hand. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-03 07:25:42 +00:00
struct rq *rq;
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
rq = cpu_rq(i);
sched: Convert rq->lock to raw_spinlock Convert locks which cannot be sleeping locks in preempt-rt to raw_spinlocks. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Ingo Molnar <mingo@elte.hu>
2009-11-17 13:28:38 +00:00
raw_spin_lock_init(&rq->lock);
[PATCH] sched: balance timers Do CPU load averaging over a number of different intervals. Allow each interval to be chosen by sending a parameter to source_load and target_load. 0 is instantaneous, idx > 0 returns a decaying average with the most recent sample weighted at 2^(idx-1). To a maximum of 3 (could be easily increased). So generally a higher number will result in more conservative balancing. Signed-off-by: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-25 21:57:13 +00:00
rq->nr_running = 0;
sched, timers: move calc_load() to scheduler Dimitri Sivanich noticed that xtime_lock is held write locked across calc_load() which iterates over all online CPUs. That can cause long latencies for xtime_lock readers on large SMP systems. The load average calculation is an rough estimate anyway so there is no real need to protect the readers vs. the update. It's not a problem when the avenrun array is updated while a reader copies the values. Instead of iterating over all online CPUs let the scheduler_tick code update the number of active tasks shortly before the avenrun update happens. The avenrun update itself is handled by the CPU which calls do_timer(). [ Impact: reduce xtime_lock write locked section ] Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org>
2009-04-11 08:43:41 +00:00
rq->calc_load_active = 0;
rq->calc_load_update = jiffies + LOAD_FREQ;
sched: Separate group-scheduling code more clearly Clean up cfs/rt runqueue initialization by moving group scheduling related code into the corresponding functions. Also, keep group scheduling as an add-on, so that things are only done additionally, i. e. remove the init_*_rq() calls from init_tg_*_entry(). (This removes a redundant initalization during sched_init()). In case of group scheduling rt_rq->highest_prio.curr is now initialized twice, but adding another #ifdef seems not worth it. Signed-off-by: Jan H. Schönherr <schnhrr@cs.tu-berlin.de> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1310661163-16606-1-git-send-email-schnhrr@cs.tu-berlin.de Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-14 16:32:43 +00:00
init_cfs_rq(&rq->cfs);
sched: rt group scheduling Extend group scheduling to also cover the realtime classes. It uses the time limiting introduced by the previous patch to allow multiple realtime groups. The hard time limit is required to keep behaviour deterministic. The algorithms used make the realtime scheduler O(tg), linear scaling wrt the number of task groups. This is the worst case behaviour I can't seem to get out of, the avg. case of the algorithms can be improved, I focused on correctness and worst case. [ akpm@linux-foundation.org: move side-effects out of BUG_ON(). ] Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:30 +00:00
init_rt_rq(&rq->rt, rq);
sched: cfs core code apply the CFS core code. this change switches over the scheduler core to CFS's modular design and makes use of kernel/sched_fair/rt/idletask.c to implement Linux's scheduling policies. thanks to Andrew Morton and Thomas Gleixner for lots of detailed review feedback and for fixlets. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
2007-07-09 16:51:59 +00:00
#ifdef CONFIG_FAIR_GROUP_SCHED
sched: Consolidate the name of root_task_group and init_task_group root_task_group is the leftover of USER_SCHED, now it's always same to init_task_group. But as Mike suggested, root_task_group is maybe the suitable name to keep for a tree. So in this patch: init_task_group --> root_task_group init_task_group_load --> root_task_group_load INIT_TASK_GROUP_LOAD --> ROOT_TASK_GROUP_LOAD Suggested-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Yong Zhang <yong.zhang0@gmail.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20110107071736.GA32635@windriver.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-01-07 07:17:36 +00:00
root_task_group.shares = root_task_group_load;
sched: rt group scheduling Extend group scheduling to also cover the realtime classes. It uses the time limiting introduced by the previous patch to allow multiple realtime groups. The hard time limit is required to keep behaviour deterministic. The algorithms used make the realtime scheduler O(tg), linear scaling wrt the number of task groups. This is the worst case behaviour I can't seem to get out of, the avg. case of the algorithms can be improved, I focused on correctness and worst case. [ akpm@linux-foundation.org: move side-effects out of BUG_ON(). ] Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:30 +00:00
INIT_LIST_HEAD(&rq->leaf_cfs_rq_list);
sched: mix tasks and groups This patch allows tasks and groups to exist in the same cfs_rq. With this change the CFS group scheduling follows a 1/(M+N) model from a 1/(1+N) fairness model where M tasks and N groups exist at the cfs_rq level. [a.p.zijlstra@chello.nl: rt bits and assorted fixes] Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 17:44:59 +00:00
/*
sched: Consolidate the name of root_task_group and init_task_group root_task_group is the leftover of USER_SCHED, now it's always same to init_task_group. But as Mike suggested, root_task_group is maybe the suitable name to keep for a tree. So in this patch: init_task_group --> root_task_group init_task_group_load --> root_task_group_load INIT_TASK_GROUP_LOAD --> ROOT_TASK_GROUP_LOAD Suggested-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Yong Zhang <yong.zhang0@gmail.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20110107071736.GA32635@windriver.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-01-07 07:17:36 +00:00
* How much cpu bandwidth does root_task_group get?
sched: mix tasks and groups This patch allows tasks and groups to exist in the same cfs_rq. With this change the CFS group scheduling follows a 1/(M+N) model from a 1/(1+N) fairness model where M tasks and N groups exist at the cfs_rq level. [a.p.zijlstra@chello.nl: rt bits and assorted fixes] Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 17:44:59 +00:00
*
* In case of task-groups formed thr' the cgroup filesystem, it
* gets 100% of the cpu resources in the system. This overall
* system cpu resource is divided among the tasks of
sched: Consolidate the name of root_task_group and init_task_group root_task_group is the leftover of USER_SCHED, now it's always same to init_task_group. But as Mike suggested, root_task_group is maybe the suitable name to keep for a tree. So in this patch: init_task_group --> root_task_group init_task_group_load --> root_task_group_load INIT_TASK_GROUP_LOAD --> ROOT_TASK_GROUP_LOAD Suggested-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Yong Zhang <yong.zhang0@gmail.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20110107071736.GA32635@windriver.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-01-07 07:17:36 +00:00
* root_task_group and its child task-groups in a fair manner,
sched: mix tasks and groups This patch allows tasks and groups to exist in the same cfs_rq. With this change the CFS group scheduling follows a 1/(M+N) model from a 1/(1+N) fairness model where M tasks and N groups exist at the cfs_rq level. [a.p.zijlstra@chello.nl: rt bits and assorted fixes] Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 17:44:59 +00:00
* based on each entity's (task or task-group's) weight
* (se->load.weight).
*
sched: Consolidate the name of root_task_group and init_task_group root_task_group is the leftover of USER_SCHED, now it's always same to init_task_group. But as Mike suggested, root_task_group is maybe the suitable name to keep for a tree. So in this patch: init_task_group --> root_task_group init_task_group_load --> root_task_group_load INIT_TASK_GROUP_LOAD --> ROOT_TASK_GROUP_LOAD Suggested-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Yong Zhang <yong.zhang0@gmail.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20110107071736.GA32635@windriver.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-01-07 07:17:36 +00:00
* In other words, if root_task_group has 10 tasks of weight
sched: mix tasks and groups This patch allows tasks and groups to exist in the same cfs_rq. With this change the CFS group scheduling follows a 1/(M+N) model from a 1/(1+N) fairness model where M tasks and N groups exist at the cfs_rq level. [a.p.zijlstra@chello.nl: rt bits and assorted fixes] Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 17:44:59 +00:00
* 1024) and two child groups A0 and A1 (of weight 1024 each),
* then A0's share of the cpu resource is:
*
perf_counter: initialize the per-cpu context earlier percpu scheduling for perfcounters wants to take the context lock, but that lock first needs to be initialized. Currently it is an early_initcall() - but that is too late, the task tick runs much sooner than that. Call it explicitly from the scheduler init sequence instead. [ Impact: fix access-before-init crash ] LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-05-04 17:13:30 +00:00
* A0's bandwidth = 1024 / (10*1024 + 1024 + 1024) = 8.33%
sched: mix tasks and groups This patch allows tasks and groups to exist in the same cfs_rq. With this change the CFS group scheduling follows a 1/(M+N) model from a 1/(1+N) fairness model where M tasks and N groups exist at the cfs_rq level. [a.p.zijlstra@chello.nl: rt bits and assorted fixes] Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 17:44:59 +00:00
*
sched: Consolidate the name of root_task_group and init_task_group root_task_group is the leftover of USER_SCHED, now it's always same to init_task_group. But as Mike suggested, root_task_group is maybe the suitable name to keep for a tree. So in this patch: init_task_group --> root_task_group init_task_group_load --> root_task_group_load INIT_TASK_GROUP_LOAD --> ROOT_TASK_GROUP_LOAD Suggested-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Yong Zhang <yong.zhang0@gmail.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20110107071736.GA32635@windriver.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-01-07 07:17:36 +00:00
* We achieve this by letting root_task_group's tasks sit
* directly in rq->cfs (i.e root_task_group->se[] = NULL).
sched: mix tasks and groups This patch allows tasks and groups to exist in the same cfs_rq. With this change the CFS group scheduling follows a 1/(M+N) model from a 1/(1+N) fairness model where M tasks and N groups exist at the cfs_rq level. [a.p.zijlstra@chello.nl: rt bits and assorted fixes] Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 17:44:59 +00:00
*/
sched: Introduce primitives to account for CFS bandwidth tracking In this patch we introduce the notion of CFS bandwidth, partitioned into globally unassigned bandwidth, and locally claimed bandwidth. - The global bandwidth is per task_group, it represents a pool of unclaimed bandwidth that cfs_rqs can allocate from. - The local bandwidth is tracked per-cfs_rq, this represents allotments from the global pool bandwidth assigned to a specific cpu. Bandwidth is managed via cgroupfs, adding two new interfaces to the cpu subsystem: - cpu.cfs_period_us : the bandwidth period in usecs - cpu.cfs_quota_us : the cpu bandwidth (in usecs) that this tg will be allowed to consume over period above. Signed-off-by: Paul Turner <pjt@google.com> Signed-off-by: Nikhil Rao <ncrao@google.com> Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com> Reviewed-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110721184756.972636699@google.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-21 16:43:28 +00:00
init_cfs_bandwidth(&root_task_group.cfs_bandwidth);
sched: Consolidate the name of root_task_group and init_task_group root_task_group is the leftover of USER_SCHED, now it's always same to init_task_group. But as Mike suggested, root_task_group is maybe the suitable name to keep for a tree. So in this patch: init_task_group --> root_task_group init_task_group_load --> root_task_group_load INIT_TASK_GROUP_LOAD --> ROOT_TASK_GROUP_LOAD Suggested-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Yong Zhang <yong.zhang0@gmail.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20110107071736.GA32635@windriver.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-01-07 07:17:36 +00:00
init_tg_cfs_entry(&root_task_group, &rq->cfs, NULL, i, NULL);
sched: mix tasks and groups This patch allows tasks and groups to exist in the same cfs_rq. With this change the CFS group scheduling follows a 1/(M+N) model from a 1/(1+N) fairness model where M tasks and N groups exist at the cfs_rq level. [a.p.zijlstra@chello.nl: rt bits and assorted fixes] Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 17:44:59 +00:00
#endif /* CONFIG_FAIR_GROUP_SCHED */
rq->rt.rt_runtime = def_rt_bandwidth.rt_runtime;
sched: rt-group: make rt groups scheduling configurable Make the rt group scheduler compile time configurable. Keep it experimental for now. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-13 14:45:40 +00:00
#ifdef CONFIG_RT_GROUP_SCHED
sched: rt group scheduling Extend group scheduling to also cover the realtime classes. It uses the time limiting introduced by the previous patch to allow multiple realtime groups. The hard time limit is required to keep behaviour deterministic. The algorithms used make the realtime scheduler O(tg), linear scaling wrt the number of task groups. This is the worst case behaviour I can't seem to get out of, the avg. case of the algorithms can be improved, I focused on correctness and worst case. [ akpm@linux-foundation.org: move side-effects out of BUG_ON(). ] Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:30 +00:00
INIT_LIST_HEAD(&rq->leaf_rt_rq_list);
sched: Consolidate the name of root_task_group and init_task_group root_task_group is the leftover of USER_SCHED, now it's always same to init_task_group. But as Mike suggested, root_task_group is maybe the suitable name to keep for a tree. So in this patch: init_task_group --> root_task_group init_task_group_load --> root_task_group_load INIT_TASK_GROUP_LOAD --> ROOT_TASK_GROUP_LOAD Suggested-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Yong Zhang <yong.zhang0@gmail.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20110107071736.GA32635@windriver.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-01-07 07:17:36 +00:00
init_tg_rt_entry(&root_task_group, &rq->rt, NULL, i, NULL);
sched: cfs core code apply the CFS core code. this change switches over the scheduler core to CFS's modular design and makes use of kernel/sched_fair/rt/idletask.c to implement Linux's scheduling policies. thanks to Andrew Morton and Thomas Gleixner for lots of detailed review feedback and for fixlets. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
2007-07-09 16:51:59 +00:00
#endif
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
sched: cfs core code apply the CFS core code. this change switches over the scheduler core to CFS's modular design and makes use of kernel/sched_fair/rt/idletask.c to implement Linux's scheduling policies. thanks to Andrew Morton and Thomas Gleixner for lots of detailed review feedback and for fixlets. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
2007-07-09 16:51:59 +00:00
for (j = 0; j < CPU_LOAD_IDX_MAX; j++)
rq->cpu_load[j] = 0;
sched: Avoid side-effect of tickless idle on update_cpu_load tickless idle has a negative side effect on update_cpu_load(), which in turn can affect load balancing behavior. update_cpu_load() is supposed to be called every tick, to keep track of various load indicies. With tickless idle, there are no scheduler ticks called on the idle CPUs. Idle CPUs may still do load balancing (with idle_load_balance CPU) using the stale cpu_load. It will also cause problems when all CPUs go idle for a while and become active again. In this case loads would not degrade as expected. This is how rq->nr_load_updates change looks like under different conditions: <cpu_num> <nr_load_updates change> All CPUS idle for 10 seconds (HZ=1000) 0 1621 10 496 11 139 12 875 13 1672 14 12 15 21 1 1472 2 2426 3 1161 4 2108 5 1525 6 701 7 249 8 766 9 1967 One CPU busy rest idle for 10 seconds 0 10003 10 601 11 95 12 966 13 1597 14 114 15 98 1 3457 2 93 3 6679 4 1425 5 1479 6 595 7 193 8 633 9 1687 All CPUs busy for 10 seconds 0 10026 10 10026 11 10026 12 10026 13 10025 14 10025 15 10025 1 10026 2 10026 3 10026 4 10026 5 10026 6 10026 7 10026 8 10026 9 10026 That is update_cpu_load works properly only when all CPUs are busy. If all are idle, all the CPUs get way lower updates. And when few CPUs are busy and rest are idle, only busy and ilb CPU does proper updates and rest of the idle CPUs will do lower updates. The patch keeps track of when a last update was done and fixes up the load avg based on current time. On one of my test system SPECjbb with warehouse 1..numcpus, patch improves throughput numbers by ~1% (average of 6 runs). On another test system (with different domain hierarchy) there is no noticable change in perf. Signed-off-by: Venkatesh Pallipadi <venki@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Thomas Gleixner <tglx@linutronix.de> LKML-Reference: <AANLkTilLtDWQsAUrIxJ6s04WTgmw9GuOODc5AOrYsaR5@mail.gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-05-18 01:14:43 +00:00
rq->last_load_update_tick = jiffies;
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
#ifdef CONFIG_SMP
[PATCH] sched: null domains Fix the last 2 places that directly access a runqueue's sched-domain and assume it cannot be NULL. That allows the use of NULL for domain, instead of a dummy domain, to signify no balancing is to happen. No functional changes. Signed-off-by: Nick Piggin <nickpiggin@yahoo.com.au> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-25 21:57:24 +00:00
rq->sd = NULL;
sched: add sched-domain roots We add the notion of a root-domain which will be used later to rescope global variables to per-domain variables. Each exclusive cpuset essentially defines an island domain by fully partitioning the member cpus from any other cpuset. However, we currently still maintain some policy/state as global variables which transcend all cpusets. Consider, for instance, rt-overload state. Whenever a new exclusive cpuset is created, we also create a new root-domain object and move each cpu member to the root-domain's span. By default the system creates a single root-domain with all cpus as members (mimicking the global state we have today). We add some plumbing for storing class specific data in our root-domain. Whenever a RQ is switching root-domains (because of repartitioning) we give each sched_class the opportunity to remove any state from its old domain and add state to the new one. This logic doesn't have any clients yet but it will later in the series. Signed-off-by: Gregory Haskins <ghaskins@novell.com> CC: Christoph Lameter <clameter@sgi.com> CC: Paul Jackson <pj@sgi.com> CC: Simon Derr <simon.derr@bull.net> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:18 +00:00
rq->rd = NULL;
sched: Introduce SCHED_POWER_SCALE to scale cpu_power calculations SCHED_LOAD_SCALE is used to increase nice resolution and to scale cpu_power calculations in the scheduler. This patch introduces SCHED_POWER_SCALE and converts all uses of SCHED_LOAD_SCALE for scaling cpu_power to use SCHED_POWER_SCALE instead. This is a preparatory patch for increasing the resolution of SCHED_LOAD_SCALE, and there is no need to increase resolution for cpu_power calculations. Signed-off-by: Nikhil Rao <ncrao@google.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Nikunj A. Dadhania <nikunj@linux.vnet.ibm.com> Cc: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Cc: Stephan Barwolf <stephan.baerwolf@tu-ilmenau.de> Cc: Mike Galbraith <efault@gmx.de> Link: http://lkml.kernel.org/r/1305738580-9924-3-git-send-email-ncrao@google.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-05-18 17:09:39 +00:00
rq->cpu_power = SCHED_POWER_SCALE;
sched: Enhance the pre/post scheduling logic We currently have an explicit "needs_post" vtable method which returns a stack variable for whether we should later run post-schedule. This leads to an awkward exchange of the variable as it bubbles back up out of the context switch. Peter Zijlstra observed that this information could be stored in the run-queue itself instead of handled on the stack. Therefore, we revert to the method of having context_switch return void, and update an internal rq->post_schedule variable when we require further processing. In addition, we fix a race condition where we try to access current->sched_class without holding the rq->lock. This is technically racy, as the sched-class could change out from under us. Instead, we reference the per-rq post_schedule variable with the runqueue unlocked, but with preemption disabled to see if we need to reacquire the rq->lock. Finally, we clean the code up slightly by removing the #ifdef CONFIG_SMP conditionals from the schedule() call, and implement some inline helper functions instead. This patch passes checkpatch, and rt-migrate. Signed-off-by: Gregory Haskins <ghaskins@novell.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20090729150422.17691.55590.stgit@dev.haskins.net> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-07-29 15:08:47 +00:00
rq->post_schedule = 0;
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
rq->active_balance = 0;
sched: cfs core code apply the CFS core code. this change switches over the scheduler core to CFS's modular design and makes use of kernel/sched_fair/rt/idletask.c to implement Linux's scheduling policies. thanks to Andrew Morton and Thomas Gleixner for lots of detailed review feedback and for fixlets. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
2007-07-09 16:51:59 +00:00
rq->next_balance = jiffies;
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
rq->push_cpu = 0;
[PATCH] Fix longstanding load balancing bug in the scheduler The scheduler will stop load balancing if the most busy processor contains processes pinned via processor affinity. The scheduler currently only does one search for busiest cpu. If it cannot pull any tasks away from the busiest cpu because they were pinned then the scheduler goes into a corner and sulks leaving the idle processors idle. F.e. If you have processor 0 busy running four tasks pinned via taskset, there are none on processor 1 and one just started two processes on processor 2 then the scheduler will not move one of the two processes away from processor 2. This patch fixes that issue by forcing the scheduler to come out of its corner and retrying the load balancing by considering other processors for load balancing. This patch was originally developed by John Hawkes and discussed at http://marc.theaimsgroup.com/?l=linux-kernel&m=113901368523205&w=2. I have removed extraneous material and gone back to equipping struct rq with the cpu the queue is associated with since this makes the patch much easier and it is likely that others in the future will have the same difficulty of figuring out which processor owns which runqueue. The overhead added through these patches is a single word on the stack if the kernel is configured to support 32 cpus or less (32 bit). For 32 bit environments the maximum number of cpus that can be configued is 255 which would result in the use of 32 bytes additional on the stack. On IA64 up to 1k cpus can be configured which will result in the use of 128 additional bytes on the stack. The maximum additional cache footprint is one cacheline. Typically memory use will be much less than a cacheline and the additional cpumask will be placed on the stack in a cacheline that already contains other local variable. Signed-off-by: Christoph Lameter <clameter@sgi.com> Cc: John Hawkes <hawkes@sgi.com> Cc: "Siddha, Suresh B" <suresh.b.siddha@intel.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Peter Williams <pwil3058@bigpond.net.au> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-26 06:30:51 +00:00
rq->cpu = i;
sched: fix cpupri hotplug support The RT folks over at RedHat found an issue w.r.t. hotplug support which was traced to problems with the cpupri infrastructure in the scheduler: https://bugzilla.redhat.com/show_bug.cgi?id=449676 This bug affects 23-rt12+, 24-rtX, 25-rtX, and sched-devel. This patch applies to 25.4-rt4, though it should trivially apply to most cpupri enabled kernels mentioned above. It turned out that the issue was that offline cpus could get inadvertently registered with cpupri so that they were erroneously selected during migration decisions. The end result would be an OOPS as the offline cpu had tasks routed to it. This patch generalizes the old join/leave domain interface into an online/offline interface, and adjusts the root-domain/hotplug code to utilize it. I was able to easily reproduce the issue prior to this patch, and am no longer able to reproduce it after this patch. I can offline cpus indefinately and everything seems to be in working order. Thanks to Arnaldo (acme), Thomas, and Peter for doing the legwork to point me in the right direction. Also thank you to Peter for reviewing the early iterations of this patch. Signed-off-by: Gregory Haskins <ghaskins@novell.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-06-04 19:04:05 +00:00
rq->online = 0;
sched: Fix and clean up rate-limit newidle code Commit 1b9508f, "Rate-limit newidle" has been confirmed to fix the netperf UDP loopback regression reported by Alex Shi. This is a cleanup and a fix: - moved to a more out of the way spot - fix to ensure that balancing doesn't try to balance runqueues which haven't gone online yet, which can mess up CPU enumeration during boot. Reported-by: Alex Shi <alex.shi@intel.com> Reported-by: Zhang, Yanmin <yanmin_zhang@linux.intel.com> Signed-off-by: Mike Galbraith <efault@gmx.de> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: <stable@kernel.org> # .32.x: a1f84a3: sched: Check for an idle shared cache Cc: <stable@kernel.org> # .32.x: 1b9508f: sched: Rate-limit newidle Cc: <stable@kernel.org> # .32.x: fd21073: sched: Fix affinity logic Cc: <stable@kernel.org> # .32.x LKML-Reference: <1257821402.5648.17.camel@marge.simson.net> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-11-10 02:50:02 +00:00
rq->idle_stamp = 0;
rq->avg_idle = 2*sysctl_sched_migration_cost;
sched: dynamically update the root-domain span/online maps The baseline code statically builds the span maps when the domain is formed. Previous attempts at dynamically updating the maps caused a suspend-to-ram regression, which should now be fixed. Signed-off-by: Gregory Haskins <ghaskins@novell.com> CC: Gautham R Shenoy <ego@in.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:26 +00:00
rq_attach_root(rq, &def_root_domain);
sched: Change nohz idle load balancing logic to push model In the new push model, all idle CPUs indeed go into nohz mode. There is still the concept of idle load balancer (performing the load balancing on behalf of all the idle cpu's in the system). Busy CPU kicks the nohz balancer when any of the nohz CPUs need idle load balancing. The kickee CPU does the idle load balancing on behalf of all idle CPUs instead of the normal idle balance. This addresses the below two problems with the current nohz ilb logic: * the idle load balancer continued to have periodic ticks during idle and wokeup frequently, even though it did not have any rebalancing to do on behalf of any of the idle CPUs. * On x86 and CPUs that have APIC timer stoppage on idle CPUs, this periodic wakeup can result in a periodic additional interrupt on a CPU doing the timer broadcast. Also currently we are migrating the unpinned timers from an idle to the cpu doing idle load balancing (when all the cpus in the system are idle, there is no idle load balancing cpu and timers get added to the same idle cpu where the request was made. So the existing optimization works only on semi idle system). And In semi idle system, we no longer have periodic ticks on the idle load balancer CPU. Using that cpu will add more delays to the timers than intended (as that cpu's timer base may not be uptodate wrt jiffies etc). This was causing mysterious slowdowns during boot etc. For now, in the semi idle case, use the nearest busy cpu for migrating timers from an idle cpu. This is good for power-savings anyway. Signed-off-by: Venkatesh Pallipadi <venki@google.com> Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Thomas Gleixner <tglx@linutronix.de> LKML-Reference: <1274486981.2840.46.camel@sbs-t61.sc.intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-05-22 00:09:41 +00:00
#ifdef CONFIG_NO_HZ
rq->nohz_balance_kick = 0;
init_sched_softirq_csd(&per_cpu(remote_sched_softirq_cb, i));
#endif
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
#endif
sched: high-res preemption tick Use HR-timers (when available) to deliver an accurate preemption tick. The regular scheduler tick that runs at 1/HZ can be too coarse when nice level are used. The fairness system will still keep the cpu utilisation 'fair' by then delaying the task that got an excessive amount of CPU time but try to minimize this by delivering preemption points spot-on. The average frequency of this extra interrupt is sched_latency / nr_latency. Which need not be higher than 1/HZ, its just that the distribution within the sched_latency period is important. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:29 +00:00
init_rq_hrtick(rq);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
atomic_set(&rq->nr_iowait, 0);
}
[PATCH] sched: implement smpnice Problem: The introduction of separate run queues per CPU has brought with it "nice" enforcement problems that are best described by a simple example. For the sake of argument suppose that on a single CPU machine with a nice==19 hard spinner and a nice==0 hard spinner running that the nice==0 task gets 95% of the CPU and the nice==19 task gets 5% of the CPU. Now suppose that there is a system with 2 CPUs and 2 nice==19 hard spinners and 2 nice==0 hard spinners running. The user of this system would be entitled to expect that the nice==0 tasks each get 95% of a CPU and the nice==19 tasks only get 5% each. However, whether this expectation is met is pretty much down to luck as there are four equally likely distributions of the tasks to the CPUs that the load balancing code will consider to be balanced with loads of 2.0 for each CPU. Two of these distributions involve one nice==0 and one nice==19 task per CPU and in these circumstances the users expectations will be met. The other two distributions both involve both nice==0 tasks being on one CPU and both nice==19 being on the other CPU and each task will get 50% of a CPU and the user's expectations will not be met. Solution: The solution to this problem that is implemented in the attached patch is to use weighted loads when determining if the system is balanced and, when an imbalance is detected, to move an amount of weighted load between run queues (as opposed to a number of tasks) to restore the balance. Once again, the easiest way to explain why both of these measures are necessary is to use a simple example. Suppose that (in a slight variation of the above example) that we have a two CPU system with 4 nice==0 and 4 nice=19 hard spinning tasks running and that the 4 nice==0 tasks are on one CPU and the 4 nice==19 tasks are on the other CPU. The weighted loads for the two CPUs would be 4.0 and 0.2 respectively and the load balancing code would move 2 tasks resulting in one CPU with a load of 2.0 and the other with load of 2.2. If this was considered to be a big enough imbalance to justify moving a task and that task was moved using the current move_tasks() then it would move the highest priority task that it found and this would result in one CPU with a load of 3.0 and the other with a load of 1.2 which would result in the movement of a task in the opposite direction and so on -- infinite loop. If, on the other hand, an amount of load to be moved is calculated from the imbalance (in this case 0.1) and move_tasks() skips tasks until it find ones whose contributions to the weighted load are less than this amount it would move two of the nice==19 tasks resulting in a system with 2 nice==0 and 2 nice=19 on each CPU with loads of 2.1 for each CPU. One of the advantages of this mechanism is that on a system where all tasks have nice==0 the load balancing calculations would be mathematically identical to the current load balancing code. Notes: struct task_struct: has a new field load_weight which (in a trade off of space for speed) stores the contribution that this task makes to a CPU's weighted load when it is runnable. struct runqueue: has a new field raw_weighted_load which is the sum of the load_weight values for the currently runnable tasks on this run queue. This field always needs to be updated when nr_running is updated so two new inline functions inc_nr_running() and dec_nr_running() have been created to make sure that this happens. This also offers a convenient way to optimize away this part of the smpnice mechanism when CONFIG_SMP is not defined. int try_to_wake_up(): in this function the value SCHED_LOAD_BALANCE is used to represent the load contribution of a single task in various calculations in the code that decides which CPU to put the waking task on. While this would be a valid on a system where the nice values for the runnable tasks were distributed evenly around zero it will lead to anomalous load balancing if the distribution is skewed in either direction. To overcome this problem SCHED_LOAD_SCALE has been replaced by the load_weight for the relevant task or by the average load_weight per task for the queue in question (as appropriate). int move_tasks(): The modifications to this function were complicated by the fact that active_load_balance() uses it to move exactly one task without checking whether an imbalance actually exists. This precluded the simple overloading of max_nr_move with max_load_move and necessitated the addition of the latter as an extra argument to the function. The internal implementation is then modified to move up to max_nr_move tasks and max_load_move of weighted load. This slightly complicates the code where move_tasks() is called and if ever active_load_balance() is changed to not use move_tasks() the implementation of move_tasks() should be simplified accordingly. struct sched_group *find_busiest_group(): Similar to try_to_wake_up(), there are places in this function where SCHED_LOAD_SCALE is used to represent the load contribution of a single task and the same issues are created. A similar solution is adopted except that it is now the average per task contribution to a group's load (as opposed to a run queue) that is required. As this value is not directly available from the group it is calculated on the fly as the queues in the groups are visited when determining the busiest group. A key change to this function is that it is no longer to scale down *imbalance on exit as move_tasks() uses the load in its scaled form. void set_user_nice(): has been modified to update the task's load_weight field when it's nice value and also to ensure that its run queue's raw_weighted_load field is updated if it was runnable. From: "Siddha, Suresh B" <suresh.b.siddha@intel.com> With smpnice, sched groups with highest priority tasks can mask the imbalance between the other sched groups with in the same domain. This patch fixes some of the listed down scenarios by not considering the sched groups which are lightly loaded. a) on a simple 4-way MP system, if we have one high priority and 4 normal priority tasks, with smpnice we would like to see the high priority task scheduled on one cpu, two other cpus getting one normal task each and the fourth cpu getting the remaining two normal tasks. but with current smpnice extra normal priority task keeps jumping from one cpu to another cpu having the normal priority task. This is because of the busiest_has_loaded_cpus, nr_loaded_cpus logic.. We are not including the cpu with high priority task in max_load calculations but including that in total and avg_load calcuations.. leading to max_load < avg_load and load balance between cpus running normal priority tasks(2 Vs 1) will always show imbalanace as one normal priority and the extra normal priority task will keep moving from one cpu to another cpu having normal priority task.. b) 4-way system with HT (8 logical processors). Package-P0 T0 has a highest priority task, T1 is idle. Package-P1 Both T0 and T1 have 1 normal priority task each.. P2 and P3 are idle. With this patch, one of the normal priority tasks on P1 will be moved to P2 or P3.. c) With the current weighted smp nice calculations, it doesn't always make sense to look at the highest weighted runqueue in the busy group.. Consider a load balance scenario on a DP with HT system, with Package-0 containing one high priority and one low priority, Package-1 containing one low priority(with other thread being idle).. Package-1 thinks that it need to take the low priority thread from Package-0. And find_busiest_queue() returns the cpu thread with highest priority task.. And ultimately(with help of active load balance) we move high priority task to Package-1. And same continues with Package-0 now, moving high priority task from package-1 to package-0.. Even without the presence of active load balance, load balance will fail to balance the above scenario.. Fix find_busiest_queue to use "imbalance" when it is lightly loaded. [kernel@kolivas.org: sched: store weighted load on up] [kernel@kolivas.org: sched: add discrete weighted cpu load function] [suresh.b.siddha@intel.com: sched: remove dead code] Signed-off-by: Peter Williams <pwil3058@bigpond.com.au> Cc: "Siddha, Suresh B" <suresh.b.siddha@intel.com> Cc: "Chen, Kenneth W" <kenneth.w.chen@intel.com> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Con Kolivas <kernel@kolivas.org> Cc: John Hawkes <hawkes@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 09:54:34 +00:00
set_load_weight(&init_task);
[PATCH] pi-futex: missing pi_waiters plist initialization Initialize init task's pi_waiters plist. Otherwise cpu hotplug of cpu 0 might crash, since rt_mutex_getprio() accesses an uninitialized list head. call chain which led to crash: take_cpu_down sched_idle_next __setscheduler rt_mutex_getprio Using PLIST_HEAD_INIT in the INIT_TASK macro doesn't work unfortunately, since the pi_waiters member is only conditionally present. Cc: Arjan van de Ven <arjan@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-30 10:03:52 +00:00
[PATCH] sched: arch preempt notifier mechanism This adds a general mechanism whereby a task can request the scheduler to notify it whenever it is preempted or scheduled back in. This allows the task to swap any special-purpose registers like the fpu or Intel's VT registers. Signed-off-by: Avi Kivity <avi@qumranet.com> [ mingo@elte.hu: fixes, cleanups ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-26 11:40:43 +00:00
#ifdef CONFIG_PREEMPT_NOTIFIERS
INIT_HLIST_HEAD(&init_task.preempt_notifiers);
#endif
[PATCH] sched: use softirq for load balancing Call rebalance_tick (renamed to run_rebalance_domains) from a newly introduced softirq. We calculate the earliest time for each layer of sched domains to be rescanned (this is the rescan time for idle) and use the earliest of those to schedule the softirq via a new field "next_balance" added to struct rq. Signed-off-by: Christoph Lameter <clameter@sgi.com> Cc: Peter Williams <pwil3058@bigpond.net.au> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Christoph Lameter <clameter@sgi.com> Cc: "Siddha, Suresh B" <suresh.b.siddha@intel.com> Cc: "Chen, Kenneth W" <kenneth.w.chen@intel.com> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 10:20:25 +00:00
#ifdef CONFIG_SMP
Remove argument from open_softirq which is always NULL As git-grep shows, open_softirq() is always called with the last argument being NULL block/blk-core.c: open_softirq(BLOCK_SOFTIRQ, blk_done_softirq, NULL); kernel/hrtimer.c: open_softirq(HRTIMER_SOFTIRQ, run_hrtimer_softirq, NULL); kernel/rcuclassic.c: open_softirq(RCU_SOFTIRQ, rcu_process_callbacks, NULL); kernel/rcupreempt.c: open_softirq(RCU_SOFTIRQ, rcu_process_callbacks, NULL); kernel/sched.c: open_softirq(SCHED_SOFTIRQ, run_rebalance_domains, NULL); kernel/softirq.c: open_softirq(TASKLET_SOFTIRQ, tasklet_action, NULL); kernel/softirq.c: open_softirq(HI_SOFTIRQ, tasklet_hi_action, NULL); kernel/timer.c: open_softirq(TIMER_SOFTIRQ, run_timer_softirq, NULL); net/core/dev.c: open_softirq(NET_TX_SOFTIRQ, net_tx_action, NULL); net/core/dev.c: open_softirq(NET_RX_SOFTIRQ, net_rx_action, NULL); This observation has already been made by Matthew Wilcox in June 2002 (http://www.cs.helsinki.fi/linux/linux-kernel/2002-25/0687.html) "I notice that none of the current softirq routines use the data element passed to them." and the situation hasn't changed since them. So it appears we can safely remove that extra argument to save 128 (54) bytes of kernel data (text). Signed-off-by: Carlos R. Mafra <crmafra@ift.unesp.br> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-15 14:15:37 +00:00
open_softirq(SCHED_SOFTIRQ, run_rebalance_domains);
[PATCH] sched: use softirq for load balancing Call rebalance_tick (renamed to run_rebalance_domains) from a newly introduced softirq. We calculate the earliest time for each layer of sched domains to be rescanned (this is the rescan time for idle) and use the earliest of those to schedule the softirq via a new field "next_balance" added to struct rq. Signed-off-by: Christoph Lameter <clameter@sgi.com> Cc: Peter Williams <pwil3058@bigpond.net.au> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Christoph Lameter <clameter@sgi.com> Cc: "Siddha, Suresh B" <suresh.b.siddha@intel.com> Cc: "Chen, Kenneth W" <kenneth.w.chen@intel.com> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 10:20:25 +00:00
#endif
[PATCH] pi-futex: missing pi_waiters plist initialization Initialize init task's pi_waiters plist. Otherwise cpu hotplug of cpu 0 might crash, since rt_mutex_getprio() accesses an uninitialized list head. call chain which led to crash: take_cpu_down sched_idle_next __setscheduler rt_mutex_getprio Using PLIST_HEAD_INIT in the INIT_TASK macro doesn't work unfortunately, since the pi_waiters member is only conditionally present. Cc: Arjan van de Ven <arjan@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-30 10:03:52 +00:00
#ifdef CONFIG_RT_MUTEXES
plist: Remove the need to supply locks to plist heads This was legacy code brought over from the RT tree and is no longer necessary. Signed-off-by: Dima Zavin <dima@android.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Cc: Daniel Walker <dwalker@codeaurora.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Andi Kleen <andi@firstfloor.org> Cc: Lai Jiangshan <laijs@cn.fujitsu.com> Link: http://lkml.kernel.org/r/1310084879-10351-2-git-send-email-dima@android.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-08 00:27:59 +00:00
plist_head_init(&init_task.pi_waiters);
[PATCH] pi-futex: missing pi_waiters plist initialization Initialize init task's pi_waiters plist. Otherwise cpu hotplug of cpu 0 might crash, since rt_mutex_getprio() accesses an uninitialized list head. call chain which led to crash: take_cpu_down sched_idle_next __setscheduler rt_mutex_getprio Using PLIST_HEAD_INIT in the INIT_TASK macro doesn't work unfortunately, since the pi_waiters member is only conditionally present. Cc: Arjan van de Ven <arjan@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-30 10:03:52 +00:00
#endif
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
/*
* The boot idle thread does lazy MMU switching as well:
*/
atomic_inc(&init_mm.mm_count);
enter_lazy_tlb(&init_mm, current);
/*
* Make us the idle thread. Technically, schedule() should not be
* called from this thread, however somewhere below it might be,
* but because we are the idle thread, we just pick up running again
* when this runqueue becomes "idle".
*/
init_idle(current, smp_processor_id());
sched, timers: move calc_load() to scheduler Dimitri Sivanich noticed that xtime_lock is held write locked across calc_load() which iterates over all online CPUs. That can cause long latencies for xtime_lock readers on large SMP systems. The load average calculation is an rough estimate anyway so there is no real need to protect the readers vs. the update. It's not a problem when the avenrun array is updated while a reader copies the values. Instead of iterating over all online CPUs let the scheduler_tick code update the number of active tasks shortly before the avenrun update happens. The avenrun update itself is handled by the CPU which calls do_timer(). [ Impact: reduce xtime_lock write locked section ] Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org>
2009-04-11 08:43:41 +00:00
calc_load_update = jiffies + LOAD_FREQ;
sched: cfs core code apply the CFS core code. this change switches over the scheduler core to CFS's modular design and makes use of kernel/sched_fair/rt/idletask.c to implement Linux's scheduling policies. thanks to Andrew Morton and Thomas Gleixner for lots of detailed review feedback and for fixlets. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
2007-07-09 16:51:59 +00:00
/*
* During early bootup we pretend to be a normal task:
*/
current->sched_class = &fair_sched_class;
sched: make early bootup sched_clock() use safer do not call sched_clock() too early. Not only might rq->idle not be set up - but pure per-cpu data might not be accessible either. this solves an ia64 early bootup hang with CONFIG_PRINTK_TIME=y. Tested-by: Tony Luck <tony.luck@gmail.com> Acked-by: Tony Luck <tony.luck@gmail.com> Acked-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-13 13:02:36 +00:00
sched: convert nohz_cpu_mask to cpumask_var_t. Impact: (future) size reduction for large NR_CPUS. Dynamically allocating cpumasks (when CONFIG_CPUMASK_OFFSTACK) saves space for small nr_cpu_ids but big CONFIG_NR_CPUS. cpumask_var_t is just a struct cpumask for !CONFIG_CPUMASK_OFFSTACK. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-24 16:05:04 +00:00
/* Allocate the nohz_cpu_mask if CONFIG_CPUMASK_OFFSTACK */
sched: Fix boot crash by zalloc()ing most of the cpu masks I got a boot crash when forcing cpumasks offstack on 32 bit, because find_new_ilb() returned 3 on my UP system (nohz.cpu_mask wasn't zeroed). AFAICT the others need to be zeroed too: only nohz.ilb_grp_nohz_mask is initialized before use. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <200911022037.21282.rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-11-02 10:07:20 +00:00
zalloc_cpumask_var(&nohz_cpu_mask, GFP_NOWAIT);
sched: convert nohz struct to cpumask_var_t, fix Impact: build fix Fix the !CONFIG_SMP case. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Acked-by: Mike Travis <travis@sgi.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-24 23:27:51 +00:00
#ifdef CONFIG_SMP
sched: Avoid allocations in sched_domain_debug() Since we're all serialized by sched_domains_mutex we can use sched_domains_tmpmask and avoid having to do allocations. This means we can use sched_domains_debug() for cpu_attach_domain() again. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110407122942.664347467@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-07 12:09:58 +00:00
zalloc_cpumask_var(&sched_domains_tmpmask, GFP_NOWAIT);
sched: convert nohz struct to cpumask_var_t. Impact: (future) size reduction for large NR_CPUS. Dynamically allocating cpumasks (when CONFIG_CPUMASK_OFFSTACK) saves space for small nr_cpu_ids but big CONFIG_NR_CPUS. cpumask_var_t is just a struct cpumask for !CONFIG_CPUMASK_OFFSTACK. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-24 16:05:09 +00:00
#ifdef CONFIG_NO_HZ
sched: Change nohz idle load balancing logic to push model In the new push model, all idle CPUs indeed go into nohz mode. There is still the concept of idle load balancer (performing the load balancing on behalf of all the idle cpu's in the system). Busy CPU kicks the nohz balancer when any of the nohz CPUs need idle load balancing. The kickee CPU does the idle load balancing on behalf of all idle CPUs instead of the normal idle balance. This addresses the below two problems with the current nohz ilb logic: * the idle load balancer continued to have periodic ticks during idle and wokeup frequently, even though it did not have any rebalancing to do on behalf of any of the idle CPUs. * On x86 and CPUs that have APIC timer stoppage on idle CPUs, this periodic wakeup can result in a periodic additional interrupt on a CPU doing the timer broadcast. Also currently we are migrating the unpinned timers from an idle to the cpu doing idle load balancing (when all the cpus in the system are idle, there is no idle load balancing cpu and timers get added to the same idle cpu where the request was made. So the existing optimization works only on semi idle system). And In semi idle system, we no longer have periodic ticks on the idle load balancer CPU. Using that cpu will add more delays to the timers than intended (as that cpu's timer base may not be uptodate wrt jiffies etc). This was causing mysterious slowdowns during boot etc. For now, in the semi idle case, use the nearest busy cpu for migrating timers from an idle cpu. This is good for power-savings anyway. Signed-off-by: Venkatesh Pallipadi <venki@google.com> Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Thomas Gleixner <tglx@linutronix.de> LKML-Reference: <1274486981.2840.46.camel@sbs-t61.sc.intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-05-22 00:09:41 +00:00
zalloc_cpumask_var(&nohz.idle_cpus_mask, GFP_NOWAIT);
alloc_cpumask_var(&nohz.grp_idle_mask, GFP_NOWAIT);
atomic_set(&nohz.load_balancer, nr_cpu_ids);
atomic_set(&nohz.first_pick_cpu, nr_cpu_ids);
atomic_set(&nohz.second_pick_cpu, nr_cpu_ids);
sched: convert nohz struct to cpumask_var_t. Impact: (future) size reduction for large NR_CPUS. Dynamically allocating cpumasks (when CONFIG_CPUMASK_OFFSTACK) saves space for small nr_cpu_ids but big CONFIG_NR_CPUS. cpumask_var_t is just a struct cpumask for !CONFIG_CPUMASK_OFFSTACK. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-24 16:05:09 +00:00
#endif
sched: Fix isolcpus boot option Anton Blanchard wrote: > We allocate and zero cpu_isolated_map after the isolcpus > __setup option has run. This means cpu_isolated_map always > ends up empty and if CPUMASK_OFFSTACK is enabled we write to a > cpumask that hasn't been allocated. I introduced this regression in 49557e620339cb13 (sched: Fix boot crash by zalloc()ing most of the cpu masks). Use the bootmem allocator if they set isolcpus=, otherwise allocate and zero like normal. Reported-by: Anton Blanchard <anton@samba.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: peterz@infradead.org Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: <stable@kernel.org> LKML-Reference: <200912021409.17013.rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu> Tested-by: Anton Blanchard <anton@samba.org>
2009-12-02 03:39:16 +00:00
/* May be allocated at isolcpus cmdline parse time */
if (cpu_isolated_map == NULL)
zalloc_cpumask_var(&cpu_isolated_map, GFP_NOWAIT);
sched: convert nohz struct to cpumask_var_t, fix Impact: build fix Fix the !CONFIG_SMP case. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Acked-by: Mike Travis <travis@sgi.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-24 23:27:51 +00:00
#endif /* SMP */
sched: convert nohz_cpu_mask to cpumask_var_t. Impact: (future) size reduction for large NR_CPUS. Dynamically allocating cpumasks (when CONFIG_CPUMASK_OFFSTACK) saves space for small nr_cpu_ids but big CONFIG_NR_CPUS. cpumask_var_t is just a struct cpumask for !CONFIG_CPUMASK_OFFSTACK. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-24 16:05:04 +00:00
sched: make early bootup sched_clock() use safer do not call sched_clock() too early. Not only might rq->idle not be set up - but pure per-cpu data might not be accessible either. this solves an ia64 early bootup hang with CONFIG_PRINTK_TIME=y. Tested-by: Tony Luck <tony.luck@gmail.com> Acked-by: Tony Luck <tony.luck@gmail.com> Acked-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-13 13:02:36 +00:00
scheduler_running = 1;
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
}
sched: Generalize sleep inside spinlock detection The sleeping inside spinlock detection is actually used for more general sleeping inside atomic sections debugging: preemption disabled, rcu read side critical sections, interrupts, interrupt disabled, etc... Change the name of the config and its help section to reflect its more general role. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Acked-by: Randy Dunlap <randy.dunlap@oracle.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Ingo Molnar <mingo@elte.hu>
2011-06-08 17:31:56 +00:00
#ifdef CONFIG_DEBUG_ATOMIC_SLEEP
sched: Add a preempt count base offset to __might_sleep() Add a preempt count base offset to compare against the current preempt level count. It prepares to pull up the might_sleep check from cond_resched() to cond_resched_lock() and cond_resched_bh(). For these two helpers, we need to respectively ensure that once we'll unlock the given spinlock / reenable local softirqs, we will reach a sleepable state. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> [ Move and rename preempt_count_equals() ] Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1247725694-6082-4-git-send-email-fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-07-16 13:44:29 +00:00
static inline int preempt_count_equals(int preempt_offset)
{
sched: Teach might_sleep() about preemptible RCU In practice, it is harmless to voluntarily sleep in a rcu_read_lock() section if we are running under preempt rcu, but it is illegal if we build a kernel running non-preemptable rcu. Currently, might_sleep() doesn't notice sleepable operations under rcu_read_lock() sections if we are running under preemptable rcu because preempt_count() is left untouched after rcu_read_lock() in this case. But we want developers who test their changes under such config to notice the "sleeping while atomic" issues. So we add rcu_read_lock_nesting to prempt_count() in might_sleep() checks. [ v2: Handle rcu-tiny ] Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <1260991265-8451-1-git-send-regression-fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-16 19:21:05 +00:00
int nested = (preempt_count() & ~PREEMPT_ACTIVE) + rcu_preempt_depth();
sched: Add a preempt count base offset to __might_sleep() Add a preempt count base offset to compare against the current preempt level count. It prepares to pull up the might_sleep check from cond_resched() to cond_resched_lock() and cond_resched_bh(). For these two helpers, we need to respectively ensure that once we'll unlock the given spinlock / reenable local softirqs, we will reach a sleepable state. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> [ Move and rename preempt_count_equals() ] Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1247725694-6082-4-git-send-email-fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-07-16 13:44:29 +00:00
BKL: That's all, folks This removes the implementation of the big kernel lock, at last. A lot of people have worked on this in the past, I so the credit for this patch should be with everyone who participated in the hunt. The names on the Cc list are the people that were the most active in this, according to the recorded git history, in alphabetical order. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Alan Cox <alan@linux.intel.com> Cc: Alessio Igor Bogani <abogani@texware.it> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andrew Hendry <andrew.hendry@gmail.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Christoph Hellwig <hch@infradead.org> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Hans Verkuil <hverkuil@xs4all.nl> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: Jan Blunck <jblunck@infradead.org> Cc: John Kacur <jkacur@redhat.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Matthew Wilcox <matthew@wil.cx> Cc: Oliver Neukum <oliver@neukum.org> Cc: Paul Menage <menage@google.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-01-25 21:52:22 +00:00
return (nested == preempt_offset);
sched: Add a preempt count base offset to __might_sleep() Add a preempt count base offset to compare against the current preempt level count. It prepares to pull up the might_sleep check from cond_resched() to cond_resched_lock() and cond_resched_bh(). For these two helpers, we need to respectively ensure that once we'll unlock the given spinlock / reenable local softirqs, we will reach a sleepable state. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> [ Move and rename preempt_count_equals() ] Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1247725694-6082-4-git-send-email-fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-07-16 13:44:29 +00:00
}
sched: might_sleep(): Make file parameter const char * Fixes a warning when building with g++: warning: deprecated conversion from string constant to 'char*' And the file parameter use is constant, so mark it as such. Signed-off-by: Simon Kagstrom <simon.kagstrom@netinsight.net> Cc: peterz@infradead.org LKML-Reference: <20091223110818.442d848e@marrow.netinsight.se> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-23 10:08:18 +00:00
void __might_sleep(const char *file, int line, int preempt_offset)
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
{
static unsigned long prev_jiffy; /* ratelimiting */
sched: Add a preempt count base offset to __might_sleep() Add a preempt count base offset to compare against the current preempt level count. It prepares to pull up the might_sleep check from cond_resched() to cond_resched_lock() and cond_resched_bh(). For these two helpers, we need to respectively ensure that once we'll unlock the given spinlock / reenable local softirqs, we will reach a sleepable state. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> [ Move and rename preempt_count_equals() ] Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1247725694-6082-4-git-send-email-fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-07-16 13:44:29 +00:00
if ((preempt_count_equals(preempt_offset) && !irqs_disabled()) ||
system_state != SYSTEM_RUNNING || oops_in_progress)
sched: clean up __might_sleep() add KERN_ to the printout and clean up the flow a bit. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-28 09:34:43 +00:00
return;
if (time_before(jiffies, prev_jiffy + HZ) && prev_jiffy)
return;
prev_jiffy = jiffies;
sched: Restore printk sanity Revert the braindead pr_* crap. (Commit 663997d "sched: Use pr_fmt() and pr_<level>()") It's dumb and causes stupid "sched: " strings all over the place. Signed-off-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Mike Galbraith <efault@gmx.de> Cc: Joe Perches <joe@perches.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> LKML-Reference: <1261315437.4314.6.camel@laptop> [ i dont mind the pr_*() patterns that much - but Peter dislikes them with a vengence. ] [ - v2: remove spurious diffstat from changelog :-/ ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-20 13:23:57 +00:00
printk(KERN_ERR
"BUG: sleeping function called from invalid context at %s:%d\n",
file, line);
printk(KERN_ERR
"in_atomic(): %d, irqs_disabled(): %d, pid: %d, name: %s\n",
in_atomic(), irqs_disabled(),
current->pid, current->comm);
sched: clean up __might_sleep() add KERN_ to the printout and clean up the flow a bit. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-28 09:34:43 +00:00
debug_show_held_locks(current);
if (irqs_disabled())
print_irqtrace_events(current);
dump_stack();
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
}
EXPORT_SYMBOL(__might_sleep);
#endif
#ifdef CONFIG_MAGIC_SYSRQ
sched: cleanup: refactor normalize_rt_tasks Replace a particularly ugly ifdef with an inline and a new macro. Also split up the function to be easier to read. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 15:00:15 +00:00
static void normalize_task(struct rq *rq, struct task_struct *p)
{
sched: Fix switch_from_fair() When a task is taken out of the fair class we must ensure the vruntime is properly normalized because when we put it back in it will assume to be normalized. The case that goes wrong is when changing away from the fair class while sleeping. Sleeping tasks have non-normalized vruntime in order to make sleeper-fairness work. So treat the switch away from fair as a wakeup and preserve the relative vruntime. Also update sysrq-n to call the ->switch_{to,from} methods. Reported-by: Onkalo Samu <samu.p.onkalo@nokia.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-01-17 16:03:27 +00:00
const struct sched_class *prev_class = p->sched_class;
int old_prio = p->prio;
sched: cleanup: refactor normalize_rt_tasks Replace a particularly ugly ifdef with an inline and a new macro. Also split up the function to be easier to read. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 15:00:15 +00:00
int on_rq;
sched: add optional support for CONFIG_HAVE_UNSTABLE_SCHED_CLOCK this replaces the rq->clock stuff (and possibly cpu_clock()). - architectures that have an 'imperfect' hardware clock can set CONFIG_HAVE_UNSTABLE_SCHED_CLOCK - the 'jiffie' window might be superfulous when we update tick_gtod before the __update_sched_clock() call in sched_clock_tick() - cpu_clock() might be implemented as: sched_clock_cpu(smp_processor_id()) if the accuracy proves good enough - how far can TSC drift in a single jiffie when considering the filtering and idle hooks? [ mingo@elte.hu: various fixes and cleanups ] Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-05-03 16:29:28 +00:00
sched: Provide p->on_rq Provide a generic p->on_rq because the p->se.on_rq semantics are unfavourable for lockless wakeups but needed for sched_fair. In particular, p->on_rq is only cleared when we actually dequeue the task in schedule() and not on any random dequeue as done by things like __migrate_task() and __sched_setscheduler(). This also allows us to remove p->se usage from !sched_fair code. Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110405152728.949545047@chello.nl
2011-04-05 15:23:44 +00:00
on_rq = p->on_rq;
sched: cleanup: refactor normalize_rt_tasks Replace a particularly ugly ifdef with an inline and a new macro. Also split up the function to be easier to read. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 15:00:15 +00:00
if (on_rq)
deactivate_task(rq, p, 0);
__setscheduler(rq, p, SCHED_NORMAL, 0);
if (on_rq) {
activate_task(rq, p, 0);
resched_task(rq->curr);
}
sched: Fix switch_from_fair() When a task is taken out of the fair class we must ensure the vruntime is properly normalized because when we put it back in it will assume to be normalized. The case that goes wrong is when changing away from the fair class while sleeping. Sleeping tasks have non-normalized vruntime in order to make sleeper-fairness work. So treat the switch away from fair as a wakeup and preserve the relative vruntime. Also update sysrq-n to call the ->switch_{to,from} methods. Reported-by: Onkalo Samu <samu.p.onkalo@nokia.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-01-17 16:03:27 +00:00
check_class_changed(rq, p, prev_class, old_prio);
sched: cleanup: refactor normalize_rt_tasks Replace a particularly ugly ifdef with an inline and a new macro. Also split up the function to be easier to read. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 15:00:15 +00:00
}
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
void normalize_rt_tasks(void)
{
sched: fix SysRq-N (normalize RT tasks) Gene Heskett reported the following problem while testing CFS: SysRq-N is not always effective in normalizing tasks back to SCHED_OTHER. The reason for that turns out to be the following bug: - normalize_rt_tasks() uses for_each_process() to iterate through all tasks in the system. The problem is, this method does not iterate through all tasks, it iterates through all thread groups. The proper mechanism to enumerate over all threads is to use a do_each_thread() + while_each_thread() loop. Reported-by: Gene Heskett <gene.heskett@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-06-17 16:37:45 +00:00
struct task_struct *g, *p;
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
unsigned long flags;
[PATCH] sched: cleanup, convert sched.c-internal typedefs to struct convert: - runqueue_t to 'struct rq' - prio_array_t to 'struct prio_array' - migration_req_t to 'struct migration_req' I was the one who added these but they are both against the kernel coding style and also were used inconsistently at places. So just get rid of them at once, now that we are flushing the scheduler patch-queue anyway. Conversion was mostly scripted, the result was reviewed and all secondary whitespace and style impact (if any) was fixed up by hand. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-03 07:25:42 +00:00
struct rq *rq;
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
sched: fix incorrect irq lock usage in normalize_rt_tasks() lockdep spotted this bogus irq locking. normalize_rt_tasks() can be called from hardirq context through sysrq-n Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-13 14:45:39 +00:00
read_lock_irqsave(&tasklist_lock, flags);
sched: fix SysRq-N (normalize RT tasks) Gene Heskett reported the following problem while testing CFS: SysRq-N is not always effective in normalizing tasks back to SCHED_OTHER. The reason for that turns out to be the following bug: - normalize_rt_tasks() uses for_each_process() to iterate through all tasks in the system. The problem is, this method does not iterate through all tasks, it iterates through all thread groups. The proper mechanism to enumerate over all threads is to use a do_each_thread() + while_each_thread() loop. Reported-by: Gene Heskett <gene.heskett@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-06-17 16:37:45 +00:00
do_each_thread(g, p) {
sched: do not normalize kernel threads via SysRq-N do not normalize kernel threads via SysRq-N: the migration threads, softlockup threads, etc. might be essential for the system to function properly. So only zap user tasks. pointed out by Andi Kleen. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 15:00:18 +00:00
/*
* Only normalize user tasks:
*/
if (!p->mm)
continue;
[PATCH] sched: reduce debug code move the rest of the debugging/instrumentation code to under CONFIG_SCHEDSTATS too. This reduces code size and speeds code up: text data bss dec hex filename 33044 4122 28 37194 914a sched.o.before 32708 4122 28 36858 8ffa sched.o.after Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-08-02 15:41:40 +00:00
p->se.exec_start = 0;
#ifdef CONFIG_SCHEDSTATS
sched: Implement group scheduler statistics in one struct Put all statistic fields of sched_entity in one struct, sched_statistics, and embed it into sched_entity. This change allows to memset the sched_statistics to 0 when needed (for instance when forking), avoiding bugs of non initialized fields. Signed-off-by: Lucas De Marchi <lucas.de.marchi@gmail.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1268275065-18542-1-git-send-email-lucas.de.marchi@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-03-11 02:37:45 +00:00
p->se.statistics.wait_start = 0;
p->se.statistics.sleep_start = 0;
p->se.statistics.block_start = 0;
[PATCH] sched: reduce debug code move the rest of the debugging/instrumentation code to under CONFIG_SCHEDSTATS too. This reduces code size and speeds code up: text data bss dec hex filename 33044 4122 28 37194 914a sched.o.before 32708 4122 28 36858 8ffa sched.o.after Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-08-02 15:41:40 +00:00
#endif
sched: cfs core code apply the CFS core code. this change switches over the scheduler core to CFS's modular design and makes use of kernel/sched_fair/rt/idletask.c to implement Linux's scheduling policies. thanks to Andrew Morton and Thomas Gleixner for lots of detailed review feedback and for fixlets. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
2007-07-09 16:51:59 +00:00
if (!rt_task(p)) {
/*
* Renice negative nice level userspace
* tasks back to 0:
*/
if (TASK_NICE(p) < 0 && p->mm)
set_user_nice(p, 0);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
continue;
sched: cfs core code apply the CFS core code. this change switches over the scheduler core to CFS's modular design and makes use of kernel/sched_fair/rt/idletask.c to implement Linux's scheduling policies. thanks to Andrew Morton and Thomas Gleixner for lots of detailed review feedback and for fixlets. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
2007-07-09 16:51:59 +00:00
}
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
sched: Convert pi_lock to raw_spinlock Convert locks which cannot be sleeping locks in preempt-rt to raw_spinlocks. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Ingo Molnar <mingo@elte.hu>
2009-11-17 13:54:03 +00:00
raw_spin_lock(&p->pi_lock);
[PATCH] pi-futex: scheduler support for pi Add framework to boost/unboost the priority of RT tasks. This consists of: - caching the 'normal' priority in ->normal_prio - providing a functions to set/get the priority of the task - make sched_setscheduler() aware of boosting The effective_prio() cleanups also fix a priority-calculation bug pointed out by Andrey Gelman, in set_user_nice(). has_rt_policy() fix: Peter Williams <pwil3058@bigpond.net.au> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Cc: Andrey Gelman <agelman@012.net.il> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 09:54:51 +00:00
rq = __task_rq_lock(p);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
sched: do not normalize kernel threads via SysRq-N do not normalize kernel threads via SysRq-N: the migration threads, softlockup threads, etc. might be essential for the system to function properly. So only zap user tasks. pointed out by Andi Kleen. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 15:00:18 +00:00
normalize_task(rq, p);
sched: cleanup: refactor normalize_rt_tasks Replace a particularly ugly ifdef with an inline and a new macro. Also split up the function to be easier to read. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 15:00:15 +00:00
[PATCH] pi-futex: scheduler support for pi Add framework to boost/unboost the priority of RT tasks. This consists of: - caching the 'normal' priority in ->normal_prio - providing a functions to set/get the priority of the task - make sched_setscheduler() aware of boosting The effective_prio() cleanups also fix a priority-calculation bug pointed out by Andrey Gelman, in set_user_nice(). has_rt_policy() fix: Peter Williams <pwil3058@bigpond.net.au> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Cc: Andrey Gelman <agelman@012.net.il> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 09:54:51 +00:00
__task_rq_unlock(rq);
sched: Convert pi_lock to raw_spinlock Convert locks which cannot be sleeping locks in preempt-rt to raw_spinlocks. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Ingo Molnar <mingo@elte.hu>
2009-11-17 13:54:03 +00:00
raw_spin_unlock(&p->pi_lock);
sched: fix SysRq-N (normalize RT tasks) Gene Heskett reported the following problem while testing CFS: SysRq-N is not always effective in normalizing tasks back to SCHED_OTHER. The reason for that turns out to be the following bug: - normalize_rt_tasks() uses for_each_process() to iterate through all tasks in the system. The problem is, this method does not iterate through all tasks, it iterates through all thread groups. The proper mechanism to enumerate over all threads is to use a do_each_thread() + while_each_thread() loop. Reported-by: Gene Heskett <gene.heskett@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-06-17 16:37:45 +00:00
} while_each_thread(g, p);
sched: fix incorrect irq lock usage in normalize_rt_tasks() lockdep spotted this bogus irq locking. normalize_rt_tasks() can be called from hardirq context through sysrq-n Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-13 14:45:39 +00:00
read_unlock_irqrestore(&tasklist_lock, flags);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
}
#endif /* CONFIG_MAGIC_SYSRQ */
Mark ia64-specific MCA/INIT scheduler hooks as dangerous ..and only enable them for ia64. The functions are only valid when the whole system has been totally stopped and no scheduler activity is ongoing on any CPU, and interrupts are globally disabled. In other words, they aren't useful for anything else. So make sure that nobody can use them by mistake. Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-12 14:59:21 +00:00
kdb: core for kgdb back end (2 of 2) This patch contains the hooks and instrumentation into kernel which live outside the kernel/debug directory, which the kdb core will call to run commands like lsmod, dmesg, bt etc... CC: linux-arch@vger.kernel.org Signed-off-by: Jason Wessel <jason.wessel@windriver.com> Signed-off-by: Martin Hicks <mort@sgi.com>
2010-05-21 02:04:21 +00:00
#if defined(CONFIG_IA64) || defined(CONFIG_KGDB_KDB)
Mark ia64-specific MCA/INIT scheduler hooks as dangerous ..and only enable them for ia64. The functions are only valid when the whole system has been totally stopped and no scheduler activity is ongoing on any CPU, and interrupts are globally disabled. In other words, they aren't useful for anything else. So make sure that nobody can use them by mistake. Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-12 14:59:21 +00:00
/*
kdb: core for kgdb back end (2 of 2) This patch contains the hooks and instrumentation into kernel which live outside the kernel/debug directory, which the kdb core will call to run commands like lsmod, dmesg, bt etc... CC: linux-arch@vger.kernel.org Signed-off-by: Jason Wessel <jason.wessel@windriver.com> Signed-off-by: Martin Hicks <mort@sgi.com>
2010-05-21 02:04:21 +00:00
* These functions are only useful for the IA64 MCA handling, or kdb.
Mark ia64-specific MCA/INIT scheduler hooks as dangerous ..and only enable them for ia64. The functions are only valid when the whole system has been totally stopped and no scheduler activity is ongoing on any CPU, and interrupts are globally disabled. In other words, they aren't useful for anything else. So make sure that nobody can use them by mistake. Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-12 14:59:21 +00:00
*
* They can only be called when the whole system has been
* stopped - every CPU needs to be quiescent, and no scheduling
* activity can take place. Using them for anything else would
* be a serious bug, and as a result, they aren't even visible
* under any other configuration.
*/
/**
* curr_task - return the current task for a given cpu.
* @cpu: the processor in question.
*
* ONLY VALID WHEN THE WHOLE SYSTEM IS STOPPED!
*/
[PATCH] sched: cleanup, remove task_t, convert to struct task_struct cleanup: remove task_t and convert all the uses to struct task_struct. I introduced it for the scheduler anno and it was a mistake. Conversion was mostly scripted, the result was reviewed and all secondary whitespace and style impact (if any) was fixed up by hand. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-03 07:25:41 +00:00
struct task_struct *curr_task(int cpu)
Mark ia64-specific MCA/INIT scheduler hooks as dangerous ..and only enable them for ia64. The functions are only valid when the whole system has been totally stopped and no scheduler activity is ongoing on any CPU, and interrupts are globally disabled. In other words, they aren't useful for anything else. So make sure that nobody can use them by mistake. Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-12 14:59:21 +00:00
{
return cpu_curr(cpu);
}
kdb: core for kgdb back end (2 of 2) This patch contains the hooks and instrumentation into kernel which live outside the kernel/debug directory, which the kdb core will call to run commands like lsmod, dmesg, bt etc... CC: linux-arch@vger.kernel.org Signed-off-by: Jason Wessel <jason.wessel@windriver.com> Signed-off-by: Martin Hicks <mort@sgi.com>
2010-05-21 02:04:21 +00:00
#endif /* defined(CONFIG_IA64) || defined(CONFIG_KGDB_KDB) */
#ifdef CONFIG_IA64
Mark ia64-specific MCA/INIT scheduler hooks as dangerous ..and only enable them for ia64. The functions are only valid when the whole system has been totally stopped and no scheduler activity is ongoing on any CPU, and interrupts are globally disabled. In other words, they aren't useful for anything else. So make sure that nobody can use them by mistake. Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-12 14:59:21 +00:00
/**
* set_curr_task - set the current task for a given cpu.
* @cpu: the processor in question.
* @p: the task pointer to set.
*
* Description: This function must only be used when non-maskable interrupts
sched: style cleanups style cleanup of various changes that were done recently. no code changed: text data bss dec hex filename 23680 2542 28 26250 668a sched.o.before 23680 2542 28 26250 668a sched.o.after Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-12-05 14:46:09 +00:00
* are serviced on a separate stack. It allows the architecture to switch the
* notion of the current task on a cpu in a non-blocking manner. This function
Mark ia64-specific MCA/INIT scheduler hooks as dangerous ..and only enable them for ia64. The functions are only valid when the whole system has been totally stopped and no scheduler activity is ongoing on any CPU, and interrupts are globally disabled. In other words, they aren't useful for anything else. So make sure that nobody can use them by mistake. Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-12 14:59:21 +00:00
* must be called with all CPU's synchronized, and interrupts disabled, the
* and caller must save the original value of the current task (see
* curr_task() above) and restore that value before reenabling interrupts and
* re-starting the system.
*
* ONLY VALID WHEN THE WHOLE SYSTEM IS STOPPED!
*/
[PATCH] sched: cleanup, remove task_t, convert to struct task_struct cleanup: remove task_t and convert all the uses to struct task_struct. I introduced it for the scheduler anno and it was a mistake. Conversion was mostly scripted, the result was reviewed and all secondary whitespace and style impact (if any) was fixed up by hand. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-03 07:25:41 +00:00
void set_curr_task(int cpu, struct task_struct *p)
Mark ia64-specific MCA/INIT scheduler hooks as dangerous ..and only enable them for ia64. The functions are only valid when the whole system has been totally stopped and no scheduler activity is ongoing on any CPU, and interrupts are globally disabled. In other words, they aren't useful for anything else. So make sure that nobody can use them by mistake. Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-12 14:59:21 +00:00
{
cpu_curr(cpu) = p;
}
#endif
sched: group-scheduler core Add interface to control cpu bandwidth allocation to task-groups. (not yet configurable, due to missing CONFIG_CONTAINERS) Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
2007-10-15 15:00:07 +00:00
sched: rt-group: clean up the ifdeffery Clean up some of the excessive ifdeffery introduces in the last patch. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-13 14:45:40 +00:00
#ifdef CONFIG_FAIR_GROUP_SCHED
static void free_fair_sched_group(struct task_group *tg)
sched: rt group scheduling Extend group scheduling to also cover the realtime classes. It uses the time limiting introduced by the previous patch to allow multiple realtime groups. The hard time limit is required to keep behaviour deterministic. The algorithms used make the realtime scheduler O(tg), linear scaling wrt the number of task groups. This is the worst case behaviour I can't seem to get out of, the avg. case of the algorithms can be improved, I focused on correctness and worst case. [ akpm@linux-foundation.org: move side-effects out of BUG_ON(). ] Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:30 +00:00
{
int i;
sched: Introduce primitives to account for CFS bandwidth tracking In this patch we introduce the notion of CFS bandwidth, partitioned into globally unassigned bandwidth, and locally claimed bandwidth. - The global bandwidth is per task_group, it represents a pool of unclaimed bandwidth that cfs_rqs can allocate from. - The local bandwidth is tracked per-cfs_rq, this represents allotments from the global pool bandwidth assigned to a specific cpu. Bandwidth is managed via cgroupfs, adding two new interfaces to the cpu subsystem: - cpu.cfs_period_us : the bandwidth period in usecs - cpu.cfs_quota_us : the cpu bandwidth (in usecs) that this tg will be allowed to consume over period above. Signed-off-by: Paul Turner <pjt@google.com> Signed-off-by: Nikhil Rao <ncrao@google.com> Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com> Reviewed-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110721184756.972636699@google.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-21 16:43:28 +00:00
destroy_cfs_bandwidth(tg_cfs_bandwidth(tg));
sched: rt group scheduling Extend group scheduling to also cover the realtime classes. It uses the time limiting introduced by the previous patch to allow multiple realtime groups. The hard time limit is required to keep behaviour deterministic. The algorithms used make the realtime scheduler O(tg), linear scaling wrt the number of task groups. This is the worst case behaviour I can't seem to get out of, the avg. case of the algorithms can be improved, I focused on correctness and worst case. [ akpm@linux-foundation.org: move side-effects out of BUG_ON(). ] Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:30 +00:00
for_each_possible_cpu(i) {
if (tg->cfs_rq)
kfree(tg->cfs_rq[i]);
if (tg->se)
kfree(tg->se[i]);
}
kfree(tg->cfs_rq);
kfree(tg->se);
}
sched: allow the group scheduler to have multiple levels This patch makes the group scheduler multi hierarchy aware. [a.p.zijlstra@chello.nl: rt-parts and assorted fixes] Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 17:44:59 +00:00
static
int alloc_fair_sched_group(struct task_group *tg, struct task_group *parent)
sched: group-scheduler core Add interface to control cpu bandwidth allocation to task-groups. (not yet configurable, due to missing CONFIG_CONTAINERS) Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
2007-10-15 15:00:07 +00:00
{
struct cfs_rq *cfs_rq;
sched: cleanup for alloc_rt/fair_sched_group() Impact: cleanup Remove checking parent == NULL. It won't be NULLL, because we dynamically create sub task_group only, and sub task_group always has its parent. (root task_group is statically defined) Also replace kmalloc_node(GFP_ZERO) with kzalloc_node(). Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-29 09:03:22 +00:00
struct sched_entity *se;
sched: group-scheduler core Add interface to control cpu bandwidth allocation to task-groups. (not yet configurable, due to missing CONFIG_CONTAINERS) Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
2007-10-15 15:00:07 +00:00
int i;
sched: remove fixed NR_CPUS sized arrays in kernel_sched_c * Change fixed size arrays to per_cpu variables or dynamically allocated arrays in sched_init() and sched_init_smp(). (1) static struct sched_entity *init_sched_entity_p[NR_CPUS]; (1) static struct cfs_rq *init_cfs_rq_p[NR_CPUS]; (1) static struct sched_rt_entity *init_sched_rt_entity_p[NR_CPUS]; (1) static struct rt_rq *init_rt_rq_p[NR_CPUS]; static struct sched_group **sched_group_nodes_bycpu[NR_CPUS]; (1) - these arrays are allocated via alloc_bootmem_low() * Change sched_domain_debug_one() to use cpulist_scnprintf instead of cpumask_scnprintf. This reduces the output buffer required and improves readability when large NR_CPU count machines arrive. * In sched_create_group() we allocate new arrays based on nr_cpu_ids. Signed-off-by: Mike Travis <travis@sgi.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-05 01:11:04 +00:00
tg->cfs_rq = kzalloc(sizeof(cfs_rq) * nr_cpu_ids, GFP_KERNEL);
sched: group-scheduler core Add interface to control cpu bandwidth allocation to task-groups. (not yet configurable, due to missing CONFIG_CONTAINERS) Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
2007-10-15 15:00:07 +00:00
if (!tg->cfs_rq)
goto err;
sched: remove fixed NR_CPUS sized arrays in kernel_sched_c * Change fixed size arrays to per_cpu variables or dynamically allocated arrays in sched_init() and sched_init_smp(). (1) static struct sched_entity *init_sched_entity_p[NR_CPUS]; (1) static struct cfs_rq *init_cfs_rq_p[NR_CPUS]; (1) static struct sched_rt_entity *init_sched_rt_entity_p[NR_CPUS]; (1) static struct rt_rq *init_rt_rq_p[NR_CPUS]; static struct sched_group **sched_group_nodes_bycpu[NR_CPUS]; (1) - these arrays are allocated via alloc_bootmem_low() * Change sched_domain_debug_one() to use cpulist_scnprintf instead of cpumask_scnprintf. This reduces the output buffer required and improves readability when large NR_CPU count machines arrive. * In sched_create_group() we allocate new arrays based on nr_cpu_ids. Signed-off-by: Mike Travis <travis@sgi.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-05 01:11:04 +00:00
tg->se = kzalloc(sizeof(se) * nr_cpu_ids, GFP_KERNEL);
sched: group-scheduler core Add interface to control cpu bandwidth allocation to task-groups. (not yet configurable, due to missing CONFIG_CONTAINERS) Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
2007-10-15 15:00:07 +00:00
if (!tg->se)
goto err;
sched: rt-group: make rt groups scheduling configurable Make the rt group scheduler compile time configurable. Keep it experimental for now. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-13 14:45:40 +00:00
tg->shares = NICE_0_LOAD;
sched: group-scheduler core Add interface to control cpu bandwidth allocation to task-groups. (not yet configurable, due to missing CONFIG_CONTAINERS) Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
2007-10-15 15:00:07 +00:00
sched: Introduce primitives to account for CFS bandwidth tracking In this patch we introduce the notion of CFS bandwidth, partitioned into globally unassigned bandwidth, and locally claimed bandwidth. - The global bandwidth is per task_group, it represents a pool of unclaimed bandwidth that cfs_rqs can allocate from. - The local bandwidth is tracked per-cfs_rq, this represents allotments from the global pool bandwidth assigned to a specific cpu. Bandwidth is managed via cgroupfs, adding two new interfaces to the cpu subsystem: - cpu.cfs_period_us : the bandwidth period in usecs - cpu.cfs_quota_us : the cpu bandwidth (in usecs) that this tg will be allowed to consume over period above. Signed-off-by: Paul Turner <pjt@google.com> Signed-off-by: Nikhil Rao <ncrao@google.com> Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com> Reviewed-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110721184756.972636699@google.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-21 16:43:28 +00:00
init_cfs_bandwidth(tg_cfs_bandwidth(tg));
sched: group-scheduler core Add interface to control cpu bandwidth allocation to task-groups. (not yet configurable, due to missing CONFIG_CONTAINERS) Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
2007-10-15 15:00:07 +00:00
for_each_possible_cpu(i) {
sched: cleanup for alloc_rt/fair_sched_group() Impact: cleanup Remove checking parent == NULL. It won't be NULLL, because we dynamically create sub task_group only, and sub task_group always has its parent. (root task_group is statically defined) Also replace kmalloc_node(GFP_ZERO) with kzalloc_node(). Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-29 09:03:22 +00:00
cfs_rq = kzalloc_node(sizeof(struct cfs_rq),
GFP_KERNEL, cpu_to_node(i));
sched: group-scheduler core Add interface to control cpu bandwidth allocation to task-groups. (not yet configurable, due to missing CONFIG_CONTAINERS) Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
2007-10-15 15:00:07 +00:00
if (!cfs_rq)
goto err;
sched: cleanup for alloc_rt/fair_sched_group() Impact: cleanup Remove checking parent == NULL. It won't be NULLL, because we dynamically create sub task_group only, and sub task_group always has its parent. (root task_group is statically defined) Also replace kmalloc_node(GFP_ZERO) with kzalloc_node(). Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-29 09:03:22 +00:00
se = kzalloc_node(sizeof(struct sched_entity),
GFP_KERNEL, cpu_to_node(i));
sched: group-scheduler core Add interface to control cpu bandwidth allocation to task-groups. (not yet configurable, due to missing CONFIG_CONTAINERS) Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
2007-10-15 15:00:07 +00:00
if (!se)
sched: Fix memory leak in two error corner cases If the second in each of these pairs of allocations fails, then the first one will not be freed in the error route out. Found by a static code analysis tool. Signed-off-by: Phil Carmody <ext-phil.2.carmody@nokia.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1260448177-28448-1-git-send-email-ext-phil.2.carmody@nokia.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-10 12:29:37 +00:00
goto err_free_rq;
sched: group-scheduler core Add interface to control cpu bandwidth allocation to task-groups. (not yet configurable, due to missing CONFIG_CONTAINERS) Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
2007-10-15 15:00:07 +00:00
sched: Separate group-scheduling code more clearly Clean up cfs/rt runqueue initialization by moving group scheduling related code into the corresponding functions. Also, keep group scheduling as an add-on, so that things are only done additionally, i. e. remove the init_*_rq() calls from init_tg_*_entry(). (This removes a redundant initalization during sched_init()). In case of group scheduling rt_rq->highest_prio.curr is now initialized twice, but adding another #ifdef seems not worth it. Signed-off-by: Jan H. Schönherr <schnhrr@cs.tu-berlin.de> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1310661163-16606-1-git-send-email-schnhrr@cs.tu-berlin.de Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-14 16:32:43 +00:00
init_cfs_rq(cfs_rq);
sched: Implement on-demand (active) cfs_rq list Make certain load-balance actions scale per number of active cgroups instead of the number of existing cgroups. This makes wakeup/sleep paths more expensive, but is a win for systems where the vast majority of existing cgroups are idle. Signed-off-by: Paul Turner <pjt@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20101115234937.666535048@google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-15 23:47:01 +00:00
init_tg_cfs_entry(tg, cfs_rq, se, i, parent->se[i]);
sched: rt-group: clean up the ifdeffery Clean up some of the excessive ifdeffery introduces in the last patch. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-13 14:45:40 +00:00
}
return 1;
sched: Unindent labels Labels should be on column 0. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-17 19:46:10 +00:00
err_free_rq:
sched: Fix memory leak in two error corner cases If the second in each of these pairs of allocations fails, then the first one will not be freed in the error route out. Found by a static code analysis tool. Signed-off-by: Phil Carmody <ext-phil.2.carmody@nokia.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1260448177-28448-1-git-send-email-ext-phil.2.carmody@nokia.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-10 12:29:37 +00:00
kfree(cfs_rq);
sched: Unindent labels Labels should be on column 0. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-17 19:46:10 +00:00
err:
sched: rt-group: clean up the ifdeffery Clean up some of the excessive ifdeffery introduces in the last patch. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-13 14:45:40 +00:00
return 0;
}
static inline void unregister_fair_sched_group(struct task_group *tg, int cpu)
{
sched: Implement on-demand (active) cfs_rq list Make certain load-balance actions scale per number of active cgroups instead of the number of existing cgroups. This makes wakeup/sleep paths more expensive, but is a win for systems where the vast majority of existing cgroups are idle. Signed-off-by: Paul Turner <pjt@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20101115234937.666535048@google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-15 23:47:01 +00:00
struct rq *rq = cpu_rq(cpu);
unsigned long flags;
/*
* Only empty task groups can be destroyed; so we can speculatively
* check on_list without danger of it being re-added.
*/
if (!tg->cfs_rq[cpu]->on_list)
return;
raw_spin_lock_irqsave(&rq->lock, flags);
sched: Fix unregister_fair_sched_group() In the flipping and flopping between calling unregister_fair_sched_group() on a per-cpu versus per-group basis we ended up in a bad state. Remove from the list for the passed cpu as opposed to some arbitrary index. ( This fixes explosions w/ autogroup as well as a group creation/destruction stress test. ) Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Paul Turner <pjt@google.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> LKML-Reference: <20101130005740.080828123@google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-30 00:55:40 +00:00
list_del_leaf_cfs_rq(tg->cfs_rq[cpu]);
sched: Implement on-demand (active) cfs_rq list Make certain load-balance actions scale per number of active cgroups instead of the number of existing cgroups. This makes wakeup/sleep paths more expensive, but is a win for systems where the vast majority of existing cgroups are idle. Signed-off-by: Paul Turner <pjt@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20101115234937.666535048@google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-15 23:47:01 +00:00
raw_spin_unlock_irqrestore(&rq->lock, flags);
sched: rt-group: clean up the ifdeffery Clean up some of the excessive ifdeffery introduces in the last patch. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-13 14:45:40 +00:00
}
sched: Fix (harmless) typo 'CONFG_FAIR_GROUP_SCHED' This patch fixes a typo located in a comment. Signed-off-by: Jan Schoenherr <schnhrr@cs.tu-berlin.de> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1310580816-10861-2-git-send-email-schnhrr@cs.tu-berlin.de Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-13 18:13:31 +00:00
#else /* !CONFIG_FAIR_GROUP_SCHED */
sched: rt-group: clean up the ifdeffery Clean up some of the excessive ifdeffery introduces in the last patch. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-13 14:45:40 +00:00
static inline void free_fair_sched_group(struct task_group *tg)
{
}
sched: allow the group scheduler to have multiple levels This patch makes the group scheduler multi hierarchy aware. [a.p.zijlstra@chello.nl: rt-parts and assorted fixes] Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 17:44:59 +00:00
static inline
int alloc_fair_sched_group(struct task_group *tg, struct task_group *parent)
sched: rt-group: clean up the ifdeffery Clean up some of the excessive ifdeffery introduces in the last patch. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-13 14:45:40 +00:00
{
return 1;
}
static inline void unregister_fair_sched_group(struct task_group *tg, int cpu)
{
}
sched: add comments for ifdefs in sched.c make sched.c easier to read. Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-30 12:23:45 +00:00
#endif /* CONFIG_FAIR_GROUP_SCHED */
sched: rt-group: make rt groups scheduling configurable Make the rt group scheduler compile time configurable. Keep it experimental for now. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-13 14:45:40 +00:00
#ifdef CONFIG_RT_GROUP_SCHED
sched: rt-group: clean up the ifdeffery Clean up some of the excessive ifdeffery introduces in the last patch. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-13 14:45:40 +00:00
static void free_rt_sched_group(struct task_group *tg)
{
int i;
sched: Do not attempt to destroy uninitialized rt_bandwidth If a task group is to be created and alloc_fair_sched_group() fails, then the rt_bandwidth of the corresponding task group is not yet initialized. The caller, sched_create_group(), starts a clean up procedure which calls free_rt_sched_group() which unconditionally destroys the not yet initialized rt_bandwidth. This crashes or hangs the system in lock_hrtimer_base(): UP systems dereference a NULL pointer, while SMP systems loop endlessly on a condition that cannot become true. This patch simply avoids the destruction of rt_bandwidth when the initialization code path was not reached. (This was discovered by accident with a custom kernel modification.) Signed-off-by: Bianca Lutz <sowilo@cs.tu-berlin.de> Signed-off-by: Jan Schoenherr <schnhrr@cs.tu-berlin.de> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1310580816-10861-7-git-send-email-schnhrr@cs.tu-berlin.de Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-13 18:13:36 +00:00
if (tg->rt_se)
destroy_rt_bandwidth(&tg->rt_bandwidth);
sched: rt-group: synchonised bandwidth period Various SMP balancing algorithms require that the bandwidth period run in sync. Possible improvements are moving the rt_bandwidth thing into root_domain and keeping a span per rt_bandwidth which marks throttled cpus. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 17:44:57 +00:00
sched: rt-group: clean up the ifdeffery Clean up some of the excessive ifdeffery introduces in the last patch. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-13 14:45:40 +00:00
for_each_possible_cpu(i) {
if (tg->rt_rq)
kfree(tg->rt_rq[i]);
if (tg->rt_se)
kfree(tg->rt_se[i]);
}
kfree(tg->rt_rq);
kfree(tg->rt_se);
}
sched: allow the group scheduler to have multiple levels This patch makes the group scheduler multi hierarchy aware. [a.p.zijlstra@chello.nl: rt-parts and assorted fixes] Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 17:44:59 +00:00
static
int alloc_rt_sched_group(struct task_group *tg, struct task_group *parent)
sched: rt-group: clean up the ifdeffery Clean up some of the excessive ifdeffery introduces in the last patch. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-13 14:45:40 +00:00
{
struct rt_rq *rt_rq;
sched: cleanup for alloc_rt/fair_sched_group() Impact: cleanup Remove checking parent == NULL. It won't be NULLL, because we dynamically create sub task_group only, and sub task_group always has its parent. (root task_group is statically defined) Also replace kmalloc_node(GFP_ZERO) with kzalloc_node(). Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-29 09:03:22 +00:00
struct sched_rt_entity *rt_se;
sched: rt-group: clean up the ifdeffery Clean up some of the excessive ifdeffery introduces in the last patch. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-13 14:45:40 +00:00
int i;
sched: remove fixed NR_CPUS sized arrays in kernel_sched_c * Change fixed size arrays to per_cpu variables or dynamically allocated arrays in sched_init() and sched_init_smp(). (1) static struct sched_entity *init_sched_entity_p[NR_CPUS]; (1) static struct cfs_rq *init_cfs_rq_p[NR_CPUS]; (1) static struct sched_rt_entity *init_sched_rt_entity_p[NR_CPUS]; (1) static struct rt_rq *init_rt_rq_p[NR_CPUS]; static struct sched_group **sched_group_nodes_bycpu[NR_CPUS]; (1) - these arrays are allocated via alloc_bootmem_low() * Change sched_domain_debug_one() to use cpulist_scnprintf instead of cpumask_scnprintf. This reduces the output buffer required and improves readability when large NR_CPU count machines arrive. * In sched_create_group() we allocate new arrays based on nr_cpu_ids. Signed-off-by: Mike Travis <travis@sgi.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-05 01:11:04 +00:00
tg->rt_rq = kzalloc(sizeof(rt_rq) * nr_cpu_ids, GFP_KERNEL);
sched: rt-group: clean up the ifdeffery Clean up some of the excessive ifdeffery introduces in the last patch. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-13 14:45:40 +00:00
if (!tg->rt_rq)
goto err;
sched: remove fixed NR_CPUS sized arrays in kernel_sched_c * Change fixed size arrays to per_cpu variables or dynamically allocated arrays in sched_init() and sched_init_smp(). (1) static struct sched_entity *init_sched_entity_p[NR_CPUS]; (1) static struct cfs_rq *init_cfs_rq_p[NR_CPUS]; (1) static struct sched_rt_entity *init_sched_rt_entity_p[NR_CPUS]; (1) static struct rt_rq *init_rt_rq_p[NR_CPUS]; static struct sched_group **sched_group_nodes_bycpu[NR_CPUS]; (1) - these arrays are allocated via alloc_bootmem_low() * Change sched_domain_debug_one() to use cpulist_scnprintf instead of cpumask_scnprintf. This reduces the output buffer required and improves readability when large NR_CPU count machines arrive. * In sched_create_group() we allocate new arrays based on nr_cpu_ids. Signed-off-by: Mike Travis <travis@sgi.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-05 01:11:04 +00:00
tg->rt_se = kzalloc(sizeof(rt_se) * nr_cpu_ids, GFP_KERNEL);
sched: rt-group: clean up the ifdeffery Clean up some of the excessive ifdeffery introduces in the last patch. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-13 14:45:40 +00:00
if (!tg->rt_se)
goto err;
sched: rt-group: synchonised bandwidth period Various SMP balancing algorithms require that the bandwidth period run in sync. Possible improvements are moving the rt_bandwidth thing into root_domain and keeping a span per rt_bandwidth which marks throttled cpus. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 17:44:57 +00:00
init_rt_bandwidth(&tg->rt_bandwidth,
ktime_to_ns(def_rt_bandwidth.rt_period), 0);
sched: rt-group: clean up the ifdeffery Clean up some of the excessive ifdeffery introduces in the last patch. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-13 14:45:40 +00:00
for_each_possible_cpu(i) {
sched: cleanup for alloc_rt/fair_sched_group() Impact: cleanup Remove checking parent == NULL. It won't be NULLL, because we dynamically create sub task_group only, and sub task_group always has its parent. (root task_group is statically defined) Also replace kmalloc_node(GFP_ZERO) with kzalloc_node(). Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-29 09:03:22 +00:00
rt_rq = kzalloc_node(sizeof(struct rt_rq),
GFP_KERNEL, cpu_to_node(i));
sched: rt group scheduling Extend group scheduling to also cover the realtime classes. It uses the time limiting introduced by the previous patch to allow multiple realtime groups. The hard time limit is required to keep behaviour deterministic. The algorithms used make the realtime scheduler O(tg), linear scaling wrt the number of task groups. This is the worst case behaviour I can't seem to get out of, the avg. case of the algorithms can be improved, I focused on correctness and worst case. [ akpm@linux-foundation.org: move side-effects out of BUG_ON(). ] Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:30 +00:00
if (!rt_rq)
goto err;
sched: group-scheduler core Add interface to control cpu bandwidth allocation to task-groups. (not yet configurable, due to missing CONFIG_CONTAINERS) Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
2007-10-15 15:00:07 +00:00
sched: cleanup for alloc_rt/fair_sched_group() Impact: cleanup Remove checking parent == NULL. It won't be NULLL, because we dynamically create sub task_group only, and sub task_group always has its parent. (root task_group is statically defined) Also replace kmalloc_node(GFP_ZERO) with kzalloc_node(). Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-29 09:03:22 +00:00
rt_se = kzalloc_node(sizeof(struct sched_rt_entity),
GFP_KERNEL, cpu_to_node(i));
sched: rt group scheduling Extend group scheduling to also cover the realtime classes. It uses the time limiting introduced by the previous patch to allow multiple realtime groups. The hard time limit is required to keep behaviour deterministic. The algorithms used make the realtime scheduler O(tg), linear scaling wrt the number of task groups. This is the worst case behaviour I can't seem to get out of, the avg. case of the algorithms can be improved, I focused on correctness and worst case. [ akpm@linux-foundation.org: move side-effects out of BUG_ON(). ] Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:30 +00:00
if (!rt_se)
sched: Fix memory leak in two error corner cases If the second in each of these pairs of allocations fails, then the first one will not be freed in the error route out. Found by a static code analysis tool. Signed-off-by: Phil Carmody <ext-phil.2.carmody@nokia.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1260448177-28448-1-git-send-email-ext-phil.2.carmody@nokia.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-10 12:29:37 +00:00
goto err_free_rq;
sched: group-scheduler core Add interface to control cpu bandwidth allocation to task-groups. (not yet configurable, due to missing CONFIG_CONTAINERS) Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
2007-10-15 15:00:07 +00:00
sched: Separate group-scheduling code more clearly Clean up cfs/rt runqueue initialization by moving group scheduling related code into the corresponding functions. Also, keep group scheduling as an add-on, so that things are only done additionally, i. e. remove the init_*_rq() calls from init_tg_*_entry(). (This removes a redundant initalization during sched_init()). In case of group scheduling rt_rq->highest_prio.curr is now initialized twice, but adding another #ifdef seems not worth it. Signed-off-by: Jan H. Schönherr <schnhrr@cs.tu-berlin.de> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1310661163-16606-1-git-send-email-schnhrr@cs.tu-berlin.de Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-14 16:32:43 +00:00
init_rt_rq(rt_rq, cpu_rq(i));
rt_rq->rt_runtime = tg->rt_bandwidth.rt_runtime;
sched: Implement on-demand (active) cfs_rq list Make certain load-balance actions scale per number of active cgroups instead of the number of existing cgroups. This makes wakeup/sleep paths more expensive, but is a win for systems where the vast majority of existing cgroups are idle. Signed-off-by: Paul Turner <pjt@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20101115234937.666535048@google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-15 23:47:01 +00:00
init_tg_rt_entry(tg, rt_rq, rt_se, i, parent->rt_se[i]);
sched: group-scheduler core Add interface to control cpu bandwidth allocation to task-groups. (not yet configurable, due to missing CONFIG_CONTAINERS) Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
2007-10-15 15:00:07 +00:00
}
sched: rt-group: clean up the ifdeffery Clean up some of the excessive ifdeffery introduces in the last patch. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-13 14:45:40 +00:00
return 1;
sched: Unindent labels Labels should be on column 0. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-17 19:46:10 +00:00
err_free_rq:
sched: Fix memory leak in two error corner cases If the second in each of these pairs of allocations fails, then the first one will not be freed in the error route out. Found by a static code analysis tool. Signed-off-by: Phil Carmody <ext-phil.2.carmody@nokia.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1260448177-28448-1-git-send-email-ext-phil.2.carmody@nokia.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-10 12:29:37 +00:00
kfree(rt_rq);
sched: Unindent labels Labels should be on column 0. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-17 19:46:10 +00:00
err:
sched: rt-group: clean up the ifdeffery Clean up some of the excessive ifdeffery introduces in the last patch. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-13 14:45:40 +00:00
return 0;
}
sched: add comments for ifdefs in sched.c make sched.c easier to read. Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-30 12:23:45 +00:00
#else /* !CONFIG_RT_GROUP_SCHED */
sched: rt-group: clean up the ifdeffery Clean up some of the excessive ifdeffery introduces in the last patch. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-13 14:45:40 +00:00
static inline void free_rt_sched_group(struct task_group *tg)
{
}
sched: allow the group scheduler to have multiple levels This patch makes the group scheduler multi hierarchy aware. [a.p.zijlstra@chello.nl: rt-parts and assorted fixes] Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 17:44:59 +00:00
static inline
int alloc_rt_sched_group(struct task_group *tg, struct task_group *parent)
sched: rt-group: clean up the ifdeffery Clean up some of the excessive ifdeffery introduces in the last patch. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-13 14:45:40 +00:00
{
return 1;
}
sched: add comments for ifdefs in sched.c make sched.c easier to read. Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-30 12:23:45 +00:00
#endif /* CONFIG_RT_GROUP_SCHED */
sched: rt-group: clean up the ifdeffery Clean up some of the excessive ifdeffery introduces in the last patch. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-13 14:45:40 +00:00
sched: Remove USER_SCHED Remove the USER_SCHED feature. It has been scheduled to be removed in 2.6.34 as per http://marc.info/?l=linux-kernel&m=125728479022976&w=2 Signed-off-by: Dhaval Giani <dhaval.giani@gmail.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1263990378.24844.3.camel@localhost> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-01-20 12:26:18 +00:00
#ifdef CONFIG_CGROUP_SCHED
sched: rt-group: clean up the ifdeffery Clean up some of the excessive ifdeffery introduces in the last patch. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-13 14:45:40 +00:00
static void free_sched_group(struct task_group *tg)
{
free_fair_sched_group(tg);
free_rt_sched_group(tg);
sched: Fix struct autogroup memory leak Seems I lost a change somewhere, leaking memory. sched: fix struct autogroup memory leak Add missing change to actually use autogroup_free(). Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1294222285.8369.2.camel@marge.simson.net> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-01-05 10:11:25 +00:00
autogroup_free(tg);
sched: rt-group: clean up the ifdeffery Clean up some of the excessive ifdeffery introduces in the last patch. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-13 14:45:40 +00:00
kfree(tg);
}
/* allocate runqueue etc for a new task group */
sched: allow the group scheduler to have multiple levels This patch makes the group scheduler multi hierarchy aware. [a.p.zijlstra@chello.nl: rt-parts and assorted fixes] Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 17:44:59 +00:00
struct task_group *sched_create_group(struct task_group *parent)
sched: rt-group: clean up the ifdeffery Clean up some of the excessive ifdeffery introduces in the last patch. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-13 14:45:40 +00:00
{
struct task_group *tg;
unsigned long flags;
tg = kzalloc(sizeof(*tg), GFP_KERNEL);
if (!tg)
return ERR_PTR(-ENOMEM);
sched: allow the group scheduler to have multiple levels This patch makes the group scheduler multi hierarchy aware. [a.p.zijlstra@chello.nl: rt-parts and assorted fixes] Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 17:44:59 +00:00
if (!alloc_fair_sched_group(tg, parent))
sched: rt-group: clean up the ifdeffery Clean up some of the excessive ifdeffery introduces in the last patch. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-13 14:45:40 +00:00
goto err;
sched: allow the group scheduler to have multiple levels This patch makes the group scheduler multi hierarchy aware. [a.p.zijlstra@chello.nl: rt-parts and assorted fixes] Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 17:44:59 +00:00
if (!alloc_rt_sched_group(tg, parent))
sched: rt-group: clean up the ifdeffery Clean up some of the excessive ifdeffery introduces in the last patch. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-13 14:45:40 +00:00
goto err;
sched: fair-group: separate tg->shares from task_group_lock On Mon, 2008-02-11 at 15:09 +0300, Denis V. Lunev wrote: > BUG: sleeping function called from invalid context > at /home/den/src/linux-netns26/kernel/mutex.c:209 > in_atomic():1, irqs_disabled():0 > no locks held by swapper/0. > Pid: 0, comm: swapper Not tainted 2.6.24 #304 > > Call Trace: > <IRQ> [<ffffffff80252d1e>] ? __debug_show_held_locks+0x15/0x27 > [<ffffffff8022c2a8>] __might_sleep+0xc0/0xdf > [<ffffffff8049f1df>] mutex_lock_nested+0x28/0x2a9 > [<ffffffff80231294>] sched_destroy_group+0x18/0xea > [<ffffffff8023e835>] sched_destroy_user+0xd/0xf > [<ffffffff8023e8c1>] free_uid+0x8a/0xab > [<ffffffff80233e24>] __put_task_struct+0x3f/0xd3 > [<ffffffff80236708>] delayed_put_task_struct+0x23/0x25 > [<ffffffff8026fda7>] __rcu_process_callbacks+0x8d/0x215 > [<ffffffff8026ff52>] rcu_process_callbacks+0x23/0x44 > [<ffffffff8023a2ae>] __do_softirq+0x79/0xf8 > [<ffffffff8020f8c3>] ? profile_pc+0x2a/0x67 > [<ffffffff8020d38c>] call_softirq+0x1c/0x30 > [<ffffffff8020f689>] do_softirq+0x61/0x9c > [<ffffffff8023a233>] irq_exit+0x51/0x53 > [<ffffffff8021bd1a>] smp_apic_timer_interrupt+0x77/0xad > [<ffffffff8020ce3b>] apic_timer_interrupt+0x6b/0x70 > <EOI> [<ffffffff8020b0dd>] ? default_idle+0x43/0x76 > [<ffffffff8020b0db>] ? default_idle+0x41/0x76 > [<ffffffff8020b09a>] ? default_idle+0x0/0x76 > [<ffffffff8020b186>] ? cpu_idle+0x76/0x98 separate the tg->shares protection from the task_group lock. Reported-by: Denis V. Lunev <den@openvz.org> Tested-by: Denis V. Lunev <den@openvz.org> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-13 14:45:39 +00:00
spin_lock_irqsave(&task_group_lock, flags);
sched: rt group scheduling Extend group scheduling to also cover the realtime classes. It uses the time limiting introduced by the previous patch to allow multiple realtime groups. The hard time limit is required to keep behaviour deterministic. The algorithms used make the realtime scheduler O(tg), linear scaling wrt the number of task groups. This is the worst case behaviour I can't seem to get out of, the avg. case of the algorithms can be improved, I focused on correctness and worst case. [ akpm@linux-foundation.org: move side-effects out of BUG_ON(). ] Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:30 +00:00
list_add_rcu(&tg->list, &task_groups);
sched: task_group hierarchy Add the full parent<->child relation thing into task_groups as well. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 17:45:00 +00:00
WARN_ON(!parent); /* root should already exist */
tg->parent = parent;
INIT_LIST_HEAD(&tg->children);
sched: fix the race between walk_tg_tree and sched_create_group With 2.6.27-rc3, I hit a kernel panic when running volanoMark on my new x86_64 machine. I also hit it with other 2.6.27-rc kernels. See below log. Basically, function walk_tg_tree and sched_create_group have a race between accessing and initiating tg->children. Below patch fixes it by moving tg->children initiation to the front of linking tg->siblings to parent->children. {----------------panic log------------} BUG: unable to handle kernel NULL pointer dereference at 0000000000000000 IP: [<ffffffff802292ab>] walk_tg_tree+0x45/0x7f PGD 1be1c4067 PUD 1bdd8d067 PMD 0 Oops: 0000 [1] SMP CPU 11 Modules linked in: igb Pid: 22979, comm: java Not tainted 2.6.27-rc3 #1 RIP: 0010:[<ffffffff802292ab>] [<ffffffff802292ab>] walk_tg_tree+0x45/0x7f RSP: 0018:ffff8801bfbbbd18 EFLAGS: 00010083 RAX: 0000000000000000 RBX: ffff8800be0dce40 RCX: ffffffffffffffc0 RDX: ffff880102c43740 RSI: 0000000000000000 RDI: ffff8800be0dce40 RBP: ffff8801bfbbbd48 R08: ffff8800ba437bc8 R09: 0000000000001f40 R10: ffff8801be812100 R11: ffffffff805fdf44 R12: ffff880102c43740 R13: 0000000000000000 R14: ffffffff8022cf0f R15: ffffffff8022749f FS: 00000000568ac950(0063) GS:ffff8801bfa26d00(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b CR2: 0000000000000000 CR3: 00000001bd848000 CR4: 00000000000006e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Process java (pid: 22979, threadinfo ffff8801b145a000, task ffff8801bf18e450) Stack: 0000000000000001 ffff8800ba5c8d60 0000000000000001 0000000000000001 ffff8800bad1ccb8 0000000000000000 ffff8801bfbbbd98 ffffffff8022ed37 0000000000000001 0000000000000286 ffff8801bd5ee180 ffff8800ba437bc8 Call Trace: <IRQ> [<ffffffff8022ed37>] try_to_wake_up+0x71/0x24c [<ffffffff80247177>] autoremove_wake_function+0x9/0x2e [<ffffffff80228039>] ? __wake_up_common+0x46/0x76 [<ffffffff802296d5>] __wake_up+0x38/0x4f [<ffffffff806169cc>] tcp_v4_rcv+0x380/0x62e Signed-off-by: Zhang Yanmin <yanmin_zhang@linux.intel.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2030-08-14 07:56:40 +00:00
list_add_rcu(&tg->siblings, &parent->children);
sched: fair-group: separate tg->shares from task_group_lock On Mon, 2008-02-11 at 15:09 +0300, Denis V. Lunev wrote: > BUG: sleeping function called from invalid context > at /home/den/src/linux-netns26/kernel/mutex.c:209 > in_atomic():1, irqs_disabled():0 > no locks held by swapper/0. > Pid: 0, comm: swapper Not tainted 2.6.24 #304 > > Call Trace: > <IRQ> [<ffffffff80252d1e>] ? __debug_show_held_locks+0x15/0x27 > [<ffffffff8022c2a8>] __might_sleep+0xc0/0xdf > [<ffffffff8049f1df>] mutex_lock_nested+0x28/0x2a9 > [<ffffffff80231294>] sched_destroy_group+0x18/0xea > [<ffffffff8023e835>] sched_destroy_user+0xd/0xf > [<ffffffff8023e8c1>] free_uid+0x8a/0xab > [<ffffffff80233e24>] __put_task_struct+0x3f/0xd3 > [<ffffffff80236708>] delayed_put_task_struct+0x23/0x25 > [<ffffffff8026fda7>] __rcu_process_callbacks+0x8d/0x215 > [<ffffffff8026ff52>] rcu_process_callbacks+0x23/0x44 > [<ffffffff8023a2ae>] __do_softirq+0x79/0xf8 > [<ffffffff8020f8c3>] ? profile_pc+0x2a/0x67 > [<ffffffff8020d38c>] call_softirq+0x1c/0x30 > [<ffffffff8020f689>] do_softirq+0x61/0x9c > [<ffffffff8023a233>] irq_exit+0x51/0x53 > [<ffffffff8021bd1a>] smp_apic_timer_interrupt+0x77/0xad > [<ffffffff8020ce3b>] apic_timer_interrupt+0x6b/0x70 > <EOI> [<ffffffff8020b0dd>] ? default_idle+0x43/0x76 > [<ffffffff8020b0db>] ? default_idle+0x41/0x76 > [<ffffffff8020b09a>] ? default_idle+0x0/0x76 > [<ffffffff8020b186>] ? cpu_idle+0x76/0x98 separate the tg->shares protection from the task_group lock. Reported-by: Denis V. Lunev <den@openvz.org> Tested-by: Denis V. Lunev <den@openvz.org> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-13 14:45:39 +00:00
spin_unlock_irqrestore(&task_group_lock, flags);
sched: group-scheduler core Add interface to control cpu bandwidth allocation to task-groups. (not yet configurable, due to missing CONFIG_CONTAINERS) Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
2007-10-15 15:00:07 +00:00
sched: clean up code under CONFIG_FAIR_GROUP_SCHED With the view of supporting user-id based fair scheduling (and not just container-based fair scheduling), this patch renames several functions and makes them independent of whether they are being used for container or user-id based fair scheduling. Also fix a problem reported by KAMEZAWA Hiroyuki (wrt allocating less-sized array for tg->cfs_rq[] and tf->se[]). Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-15 15:00:09 +00:00
return tg;
sched: group-scheduler core Add interface to control cpu bandwidth allocation to task-groups. (not yet configurable, due to missing CONFIG_CONTAINERS) Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
2007-10-15 15:00:07 +00:00
err:
sched: rt group scheduling Extend group scheduling to also cover the realtime classes. It uses the time limiting introduced by the previous patch to allow multiple realtime groups. The hard time limit is required to keep behaviour deterministic. The algorithms used make the realtime scheduler O(tg), linear scaling wrt the number of task groups. This is the worst case behaviour I can't seem to get out of, the avg. case of the algorithms can be improved, I focused on correctness and worst case. [ akpm@linux-foundation.org: move side-effects out of BUG_ON(). ] Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:30 +00:00
free_sched_group(tg);
sched: group-scheduler core Add interface to control cpu bandwidth allocation to task-groups. (not yet configurable, due to missing CONFIG_CONTAINERS) Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
2007-10-15 15:00:07 +00:00
return ERR_PTR(-ENOMEM);
}
sched: clean up code under CONFIG_FAIR_GROUP_SCHED With the view of supporting user-id based fair scheduling (and not just container-based fair scheduling), this patch renames several functions and makes them independent of whether they are being used for container or user-id based fair scheduling. Also fix a problem reported by KAMEZAWA Hiroyuki (wrt allocating less-sized array for tg->cfs_rq[] and tf->se[]). Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-15 15:00:09 +00:00
/* rcu callback to free various structures associated with a task group */
sched: rt group scheduling Extend group scheduling to also cover the realtime classes. It uses the time limiting introduced by the previous patch to allow multiple realtime groups. The hard time limit is required to keep behaviour deterministic. The algorithms used make the realtime scheduler O(tg), linear scaling wrt the number of task groups. This is the worst case behaviour I can't seem to get out of, the avg. case of the algorithms can be improved, I focused on correctness and worst case. [ akpm@linux-foundation.org: move side-effects out of BUG_ON(). ] Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:30 +00:00
static void free_sched_group_rcu(struct rcu_head *rhp)
sched: group-scheduler core Add interface to control cpu bandwidth allocation to task-groups. (not yet configurable, due to missing CONFIG_CONTAINERS) Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
2007-10-15 15:00:07 +00:00
{
/* now it should be safe to free those cfs_rqs */
sched: rt group scheduling Extend group scheduling to also cover the realtime classes. It uses the time limiting introduced by the previous patch to allow multiple realtime groups. The hard time limit is required to keep behaviour deterministic. The algorithms used make the realtime scheduler O(tg), linear scaling wrt the number of task groups. This is the worst case behaviour I can't seem to get out of, the avg. case of the algorithms can be improved, I focused on correctness and worst case. [ akpm@linux-foundation.org: move side-effects out of BUG_ON(). ] Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:30 +00:00
free_sched_group(container_of(rhp, struct task_group, rcu));
sched: group-scheduler core Add interface to control cpu bandwidth allocation to task-groups. (not yet configurable, due to missing CONFIG_CONTAINERS) Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
2007-10-15 15:00:07 +00:00
}
sched: clean up code under CONFIG_FAIR_GROUP_SCHED With the view of supporting user-id based fair scheduling (and not just container-based fair scheduling), this patch renames several functions and makes them independent of whether they are being used for container or user-id based fair scheduling. Also fix a problem reported by KAMEZAWA Hiroyuki (wrt allocating less-sized array for tg->cfs_rq[] and tf->se[]). Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-15 15:00:09 +00:00
/* Destroy runqueue etc associated with a task group */
sched: cleanup: rename task_grp to task_group cleanup: rename task_grp to task_group. No need to save two characters and 'grp' is annoying to read. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 15:00:14 +00:00
void sched_destroy_group(struct task_group *tg)
sched: group-scheduler core Add interface to control cpu bandwidth allocation to task-groups. (not yet configurable, due to missing CONFIG_CONTAINERS) Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
2007-10-15 15:00:07 +00:00
{
sched: fair-group: separate tg->shares from task_group_lock On Mon, 2008-02-11 at 15:09 +0300, Denis V. Lunev wrote: > BUG: sleeping function called from invalid context > at /home/den/src/linux-netns26/kernel/mutex.c:209 > in_atomic():1, irqs_disabled():0 > no locks held by swapper/0. > Pid: 0, comm: swapper Not tainted 2.6.24 #304 > > Call Trace: > <IRQ> [<ffffffff80252d1e>] ? __debug_show_held_locks+0x15/0x27 > [<ffffffff8022c2a8>] __might_sleep+0xc0/0xdf > [<ffffffff8049f1df>] mutex_lock_nested+0x28/0x2a9 > [<ffffffff80231294>] sched_destroy_group+0x18/0xea > [<ffffffff8023e835>] sched_destroy_user+0xd/0xf > [<ffffffff8023e8c1>] free_uid+0x8a/0xab > [<ffffffff80233e24>] __put_task_struct+0x3f/0xd3 > [<ffffffff80236708>] delayed_put_task_struct+0x23/0x25 > [<ffffffff8026fda7>] __rcu_process_callbacks+0x8d/0x215 > [<ffffffff8026ff52>] rcu_process_callbacks+0x23/0x44 > [<ffffffff8023a2ae>] __do_softirq+0x79/0xf8 > [<ffffffff8020f8c3>] ? profile_pc+0x2a/0x67 > [<ffffffff8020d38c>] call_softirq+0x1c/0x30 > [<ffffffff8020f689>] do_softirq+0x61/0x9c > [<ffffffff8023a233>] irq_exit+0x51/0x53 > [<ffffffff8021bd1a>] smp_apic_timer_interrupt+0x77/0xad > [<ffffffff8020ce3b>] apic_timer_interrupt+0x6b/0x70 > <EOI> [<ffffffff8020b0dd>] ? default_idle+0x43/0x76 > [<ffffffff8020b0db>] ? default_idle+0x41/0x76 > [<ffffffff8020b09a>] ? default_idle+0x0/0x76 > [<ffffffff8020b186>] ? cpu_idle+0x76/0x98 separate the tg->shares protection from the task_group lock. Reported-by: Denis V. Lunev <den@openvz.org> Tested-by: Denis V. Lunev <den@openvz.org> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-13 14:45:39 +00:00
unsigned long flags;
sched: clean up code under CONFIG_FAIR_GROUP_SCHED With the view of supporting user-id based fair scheduling (and not just container-based fair scheduling), this patch renames several functions and makes them independent of whether they are being used for container or user-id based fair scheduling. Also fix a problem reported by KAMEZAWA Hiroyuki (wrt allocating less-sized array for tg->cfs_rq[] and tf->se[]). Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-15 15:00:09 +00:00
int i;
sched: group-scheduler core Add interface to control cpu bandwidth allocation to task-groups. (not yet configurable, due to missing CONFIG_CONTAINERS) Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
2007-10-15 15:00:07 +00:00
sched: Implement on-demand (active) cfs_rq list Make certain load-balance actions scale per number of active cgroups instead of the number of existing cgroups. This makes wakeup/sleep paths more expensive, but is a win for systems where the vast majority of existing cgroups are idle. Signed-off-by: Paul Turner <pjt@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20101115234937.666535048@google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-15 23:47:01 +00:00
/* end participation in shares distribution */
for_each_possible_cpu(i)
sched: rt-group: clean up the ifdeffery Clean up some of the excessive ifdeffery introduces in the last patch. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-13 14:45:40 +00:00
unregister_fair_sched_group(tg, i);
sched: Implement on-demand (active) cfs_rq list Make certain load-balance actions scale per number of active cgroups instead of the number of existing cgroups. This makes wakeup/sleep paths more expensive, but is a win for systems where the vast majority of existing cgroups are idle. Signed-off-by: Paul Turner <pjt@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20101115234937.666535048@google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-15 23:47:01 +00:00
spin_lock_irqsave(&task_group_lock, flags);
sched: rt group scheduling Extend group scheduling to also cover the realtime classes. It uses the time limiting introduced by the previous patch to allow multiple realtime groups. The hard time limit is required to keep behaviour deterministic. The algorithms used make the realtime scheduler O(tg), linear scaling wrt the number of task groups. This is the worst case behaviour I can't seem to get out of, the avg. case of the algorithms can be improved, I focused on correctness and worst case. [ akpm@linux-foundation.org: move side-effects out of BUG_ON(). ] Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:30 +00:00
list_del_rcu(&tg->list);
sched: task_group hierarchy Add the full parent<->child relation thing into task_groups as well. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 17:45:00 +00:00
list_del_rcu(&tg->siblings);
sched: fair-group: separate tg->shares from task_group_lock On Mon, 2008-02-11 at 15:09 +0300, Denis V. Lunev wrote: > BUG: sleeping function called from invalid context > at /home/den/src/linux-netns26/kernel/mutex.c:209 > in_atomic():1, irqs_disabled():0 > no locks held by swapper/0. > Pid: 0, comm: swapper Not tainted 2.6.24 #304 > > Call Trace: > <IRQ> [<ffffffff80252d1e>] ? __debug_show_held_locks+0x15/0x27 > [<ffffffff8022c2a8>] __might_sleep+0xc0/0xdf > [<ffffffff8049f1df>] mutex_lock_nested+0x28/0x2a9 > [<ffffffff80231294>] sched_destroy_group+0x18/0xea > [<ffffffff8023e835>] sched_destroy_user+0xd/0xf > [<ffffffff8023e8c1>] free_uid+0x8a/0xab > [<ffffffff80233e24>] __put_task_struct+0x3f/0xd3 > [<ffffffff80236708>] delayed_put_task_struct+0x23/0x25 > [<ffffffff8026fda7>] __rcu_process_callbacks+0x8d/0x215 > [<ffffffff8026ff52>] rcu_process_callbacks+0x23/0x44 > [<ffffffff8023a2ae>] __do_softirq+0x79/0xf8 > [<ffffffff8020f8c3>] ? profile_pc+0x2a/0x67 > [<ffffffff8020d38c>] call_softirq+0x1c/0x30 > [<ffffffff8020f689>] do_softirq+0x61/0x9c > [<ffffffff8023a233>] irq_exit+0x51/0x53 > [<ffffffff8021bd1a>] smp_apic_timer_interrupt+0x77/0xad > [<ffffffff8020ce3b>] apic_timer_interrupt+0x6b/0x70 > <EOI> [<ffffffff8020b0dd>] ? default_idle+0x43/0x76 > [<ffffffff8020b0db>] ? default_idle+0x41/0x76 > [<ffffffff8020b09a>] ? default_idle+0x0/0x76 > [<ffffffff8020b186>] ? cpu_idle+0x76/0x98 separate the tg->shares protection from the task_group lock. Reported-by: Denis V. Lunev <den@openvz.org> Tested-by: Denis V. Lunev <den@openvz.org> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-13 14:45:39 +00:00
spin_unlock_irqrestore(&task_group_lock, flags);
sched: clean up code under CONFIG_FAIR_GROUP_SCHED With the view of supporting user-id based fair scheduling (and not just container-based fair scheduling), this patch renames several functions and makes them independent of whether they are being used for container or user-id based fair scheduling. Also fix a problem reported by KAMEZAWA Hiroyuki (wrt allocating less-sized array for tg->cfs_rq[] and tf->se[]). Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-15 15:00:09 +00:00
/* wait for possible concurrent references to cfs_rqs complete */
sched: rt group scheduling Extend group scheduling to also cover the realtime classes. It uses the time limiting introduced by the previous patch to allow multiple realtime groups. The hard time limit is required to keep behaviour deterministic. The algorithms used make the realtime scheduler O(tg), linear scaling wrt the number of task groups. This is the worst case behaviour I can't seem to get out of, the avg. case of the algorithms can be improved, I focused on correctness and worst case. [ akpm@linux-foundation.org: move side-effects out of BUG_ON(). ] Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:30 +00:00
call_rcu(&tg->rcu, free_sched_group_rcu);
sched: group-scheduler core Add interface to control cpu bandwidth allocation to task-groups. (not yet configurable, due to missing CONFIG_CONTAINERS) Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
2007-10-15 15:00:07 +00:00
}
sched: clean up code under CONFIG_FAIR_GROUP_SCHED With the view of supporting user-id based fair scheduling (and not just container-based fair scheduling), this patch renames several functions and makes them independent of whether they are being used for container or user-id based fair scheduling. Also fix a problem reported by KAMEZAWA Hiroyuki (wrt allocating less-sized array for tg->cfs_rq[] and tf->se[]). Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-15 15:00:09 +00:00
/* change task's runqueue when it moves between groups.
sched: whitespace cleanups more whitespace cleanups. No code changed: text data bss dec hex filename 26553 2790 288 29631 73bf sched.o.before 26553 2790 288 29631 73bf sched.o.after Signed-off-by: Ingo Molnar <mingo@elte.hu> Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-15 15:00:12 +00:00
* The caller of this function should have put the task in its new group
* by now. This function just updates tsk->se.cfs_rq and tsk->se.parent to
* reflect its new group.
sched: clean up code under CONFIG_FAIR_GROUP_SCHED With the view of supporting user-id based fair scheduling (and not just container-based fair scheduling), this patch renames several functions and makes them independent of whether they are being used for container or user-id based fair scheduling. Also fix a problem reported by KAMEZAWA Hiroyuki (wrt allocating less-sized array for tg->cfs_rq[] and tf->se[]). Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-15 15:00:09 +00:00
*/
void sched_move_task(struct task_struct *tsk)
sched: group-scheduler core Add interface to control cpu bandwidth allocation to task-groups. (not yet configurable, due to missing CONFIG_CONTAINERS) Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
2007-10-15 15:00:07 +00:00
{
int on_rq, running;
unsigned long flags;
struct rq *rq;
rq = task_rq_lock(tsk, &flags);
sched: fix crash on ia64, introduce task_current() Some services (e.g. sched_setscheduler(), rt_mutex_setprio() and sched_move_task()) must handle a given task differently in case it's the 'rq->curr' task on its run-queue. The task_running() interface is not suitable for determining such tasks for platforms with one of the following options: #define __ARCH_WANT_UNLOCKED_CTXSW #define __ARCH_WANT_INTERRUPTS_ON_CTXSW Due to the fact that it makes use of 'p->oncpu == 1' as a criterion but such a task is not necessarily 'rq->curr'. The detailed explanation is available here: https://lists.linux-foundation.org/pipermail/containers/2007-December/009262.html Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Tested-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Tested-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
2007-12-18 14:21:13 +00:00
running = task_current(rq, tsk);
sched: Provide p->on_rq Provide a generic p->on_rq because the p->se.on_rq semantics are unfavourable for lockless wakeups but needed for sched_fair. In particular, p->on_rq is only cleared when we actually dequeue the task in schedule() and not on any random dequeue as done by things like __migrate_task() and __sched_setscheduler(). This also allows us to remove p->se usage from !sched_fair code. Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110405152728.949545047@chello.nl
2011-04-05 15:23:44 +00:00
on_rq = tsk->on_rq;
sched: group-scheduler core Add interface to control cpu bandwidth allocation to task-groups. (not yet configurable, due to missing CONFIG_CONTAINERS) Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
2007-10-15 15:00:07 +00:00
sched: fix race in schedule() Fix a hard to trigger crash seen in the -rt kernel that also affects the vanilla scheduler. There is a race condition between schedule() and some dequeue/enqueue functions; rt_mutex_setprio(), __setscheduler() and sched_move_task(). When scheduling to idle, idle_balance() is called to pull tasks from other busy processor. It might drop the rq lock. It means that those 3 functions encounter on_rq=0 and running=1. The current task should be put when running. Here is a possible scenario: CPU0 CPU1 | schedule() | ->deactivate_task() | ->idle_balance() | -->load_balance_newidle() rt_mutex_setprio() | | --->double_lock_balance() *get lock *rel lock * on_rq=0, ruuning=1 | * sched_class is changed | *rel lock *get lock : | : ->put_prev_task_rt() ->pick_next_task_fair() => panic The current process of CPU1(P1) is scheduling. Deactivated P1, and the scheduler looks for another process on other CPU's runqueue because CPU1 will be idle. idle_balance(), load_balance_newidle() and double_lock_balance() are called and double_lock_balance() could drop the rq lock. On the other hand, CPU0 is trying to boost the priority of P1. The result of boosting only P1's prio and sched_class are changed to RT. The sched entities of P1 and P1's group are never put. It makes cfs_rq invalid, because the cfs_rq has curr and no leaf, but pick_next_task_fair() is called, then the kernel panics. Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-03-10 18:01:20 +00:00
if (on_rq)
sched: group-scheduler core Add interface to control cpu bandwidth allocation to task-groups. (not yet configurable, due to missing CONFIG_CONTAINERS) Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
2007-10-15 15:00:07 +00:00
dequeue_task(rq, tsk, 0);
sched: fix race in schedule() Fix a hard to trigger crash seen in the -rt kernel that also affects the vanilla scheduler. There is a race condition between schedule() and some dequeue/enqueue functions; rt_mutex_setprio(), __setscheduler() and sched_move_task(). When scheduling to idle, idle_balance() is called to pull tasks from other busy processor. It might drop the rq lock. It means that those 3 functions encounter on_rq=0 and running=1. The current task should be put when running. Here is a possible scenario: CPU0 CPU1 | schedule() | ->deactivate_task() | ->idle_balance() | -->load_balance_newidle() rt_mutex_setprio() | | --->double_lock_balance() *get lock *rel lock * on_rq=0, ruuning=1 | * sched_class is changed | *rel lock *get lock : | : ->put_prev_task_rt() ->pick_next_task_fair() => panic The current process of CPU1(P1) is scheduling. Deactivated P1, and the scheduler looks for another process on other CPU's runqueue because CPU1 will be idle. idle_balance(), load_balance_newidle() and double_lock_balance() are called and double_lock_balance() could drop the rq lock. On the other hand, CPU0 is trying to boost the priority of P1. The result of boosting only P1's prio and sched_class are changed to RT. The sched entities of P1 and P1's group are never put. It makes cfs_rq invalid, because the cfs_rq has curr and no leaf, but pick_next_task_fair() is called, then the kernel panics. Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-03-10 18:01:20 +00:00
if (unlikely(running))
tsk->sched_class->put_prev_task(rq, tsk);
sched: group-scheduler core Add interface to control cpu bandwidth allocation to task-groups. (not yet configurable, due to missing CONFIG_CONTAINERS) Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
2007-10-15 15:00:07 +00:00
sched: retain vruntime Kei Tokunaga reported an interactivity problem when moving tasks between control groups. Tasks would retain their old vruntime when moved between groups, this can cause funny lags. Re-set the vruntime on group move to fit within the new tree. Reported-by: Kei Tokunaga <tokunaga.keiich@jp.fujitsu.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-29 20:21:01 +00:00
#ifdef CONFIG_FAIR_GROUP_SCHED
sched, cgroup: Fixup broken cgroup movement Dima noticed that we fail to correct the ->vruntime of sleeping tasks when we move them between cgroups. Reported-by: Dima Zavin <dima@android.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Tested-by: Mike Galbraith <efault@gmx.de> LKML-Reference: <1287150604.29097.1513.camel@twins> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-15 13:24:15 +00:00
if (tsk->sched_class->task_move_group)
tsk->sched_class->task_move_group(tsk, on_rq);
else
sched: retain vruntime Kei Tokunaga reported an interactivity problem when moving tasks between control groups. Tasks would retain their old vruntime when moved between groups, this can cause funny lags. Re-set the vruntime on group move to fit within the new tree. Reported-by: Kei Tokunaga <tokunaga.keiich@jp.fujitsu.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-29 20:21:01 +00:00
#endif
sched, cgroup: Fixup broken cgroup movement Dima noticed that we fail to correct the ->vruntime of sleeping tasks when we move them between cgroups. Reported-by: Dima Zavin <dima@android.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Tested-by: Mike Galbraith <efault@gmx.de> LKML-Reference: <1287150604.29097.1513.camel@twins> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-15 13:24:15 +00:00
set_task_rq(tsk, task_cpu(tsk));
sched: retain vruntime Kei Tokunaga reported an interactivity problem when moving tasks between control groups. Tasks would retain their old vruntime when moved between groups, this can cause funny lags. Re-set the vruntime on group move to fit within the new tree. Reported-by: Kei Tokunaga <tokunaga.keiich@jp.fujitsu.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-29 20:21:01 +00:00
sched: fix race in schedule() Fix a hard to trigger crash seen in the -rt kernel that also affects the vanilla scheduler. There is a race condition between schedule() and some dequeue/enqueue functions; rt_mutex_setprio(), __setscheduler() and sched_move_task(). When scheduling to idle, idle_balance() is called to pull tasks from other busy processor. It might drop the rq lock. It means that those 3 functions encounter on_rq=0 and running=1. The current task should be put when running. Here is a possible scenario: CPU0 CPU1 | schedule() | ->deactivate_task() | ->idle_balance() | -->load_balance_newidle() rt_mutex_setprio() | | --->double_lock_balance() *get lock *rel lock * on_rq=0, ruuning=1 | * sched_class is changed | *rel lock *get lock : | : ->put_prev_task_rt() ->pick_next_task_fair() => panic The current process of CPU1(P1) is scheduling. Deactivated P1, and the scheduler looks for another process on other CPU's runqueue because CPU1 will be idle. idle_balance(), load_balance_newidle() and double_lock_balance() are called and double_lock_balance() could drop the rq lock. On the other hand, CPU0 is trying to boost the priority of P1. The result of boosting only P1's prio and sched_class are changed to RT. The sched entities of P1 and P1's group are never put. It makes cfs_rq invalid, because the cfs_rq has curr and no leaf, but pick_next_task_fair() is called, then the kernel panics. Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-03-10 18:01:20 +00:00
if (unlikely(running))
tsk->sched_class->set_curr_task(rq);
if (on_rq)
sched: Add enqueue/dequeue flags In order to reduce the dependency on TASK_WAKING rework the enqueue interface to support a proper flags field. Replace the int wakeup, bool head arguments with an int flags argument and create the following flags: ENQUEUE_WAKEUP - the enqueue is a wakeup of a sleeping task, ENQUEUE_WAKING - the enqueue has relative vruntime due to having sched_class::task_waking() called, ENQUEUE_HEAD - the waking task should be places on the head of the priority queue (where appropriate). For symmetry also convert sched_class::dequeue() to a flags scheme. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-03-24 15:38:48 +00:00
enqueue_task(rq, tsk, 0);
sched: group-scheduler core Add interface to control cpu bandwidth allocation to task-groups. (not yet configurable, due to missing CONFIG_CONTAINERS) Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
2007-10-15 15:00:07 +00:00
sched: Add p->pi_lock to task_rq_lock() In order to be able to call set_task_cpu() while either holding p->pi_lock or task_rq(p)->lock we need to hold both locks in order to stabilize task_rq(). This makes task_rq_lock() acquire both locks, and have __task_rq_lock() validate that p->pi_lock is held. This increases the locking overhead for most scheduler syscalls but allows reduction of rq->lock contention for some scheduler hot paths (ttwu). Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110405152729.232781355@chello.nl Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-05 15:23:51 +00:00
task_rq_unlock(rq, tsk, &flags);
sched: group-scheduler core Add interface to control cpu bandwidth allocation to task-groups. (not yet configurable, due to missing CONFIG_CONTAINERS) Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
2007-10-15 15:00:07 +00:00
}
sched: Remove USER_SCHED Remove the USER_SCHED feature. It has been scheduled to be removed in 2.6.34 as per http://marc.info/?l=linux-kernel&m=125728479022976&w=2 Signed-off-by: Dhaval Giani <dhaval.giani@gmail.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1263990378.24844.3.camel@localhost> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-01-20 12:26:18 +00:00
#endif /* CONFIG_CGROUP_SCHED */
sched: group-scheduler core Add interface to control cpu bandwidth allocation to task-groups. (not yet configurable, due to missing CONFIG_CONTAINERS) Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
2007-10-15 15:00:07 +00:00
sched: rt-group: make rt groups scheduling configurable Make the rt group scheduler compile time configurable. Keep it experimental for now. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-13 14:45:40 +00:00
#ifdef CONFIG_FAIR_GROUP_SCHED
sched: fair-group: separate tg->shares from task_group_lock On Mon, 2008-02-11 at 15:09 +0300, Denis V. Lunev wrote: > BUG: sleeping function called from invalid context > at /home/den/src/linux-netns26/kernel/mutex.c:209 > in_atomic():1, irqs_disabled():0 > no locks held by swapper/0. > Pid: 0, comm: swapper Not tainted 2.6.24 #304 > > Call Trace: > <IRQ> [<ffffffff80252d1e>] ? __debug_show_held_locks+0x15/0x27 > [<ffffffff8022c2a8>] __might_sleep+0xc0/0xdf > [<ffffffff8049f1df>] mutex_lock_nested+0x28/0x2a9 > [<ffffffff80231294>] sched_destroy_group+0x18/0xea > [<ffffffff8023e835>] sched_destroy_user+0xd/0xf > [<ffffffff8023e8c1>] free_uid+0x8a/0xab > [<ffffffff80233e24>] __put_task_struct+0x3f/0xd3 > [<ffffffff80236708>] delayed_put_task_struct+0x23/0x25 > [<ffffffff8026fda7>] __rcu_process_callbacks+0x8d/0x215 > [<ffffffff8026ff52>] rcu_process_callbacks+0x23/0x44 > [<ffffffff8023a2ae>] __do_softirq+0x79/0xf8 > [<ffffffff8020f8c3>] ? profile_pc+0x2a/0x67 > [<ffffffff8020d38c>] call_softirq+0x1c/0x30 > [<ffffffff8020f689>] do_softirq+0x61/0x9c > [<ffffffff8023a233>] irq_exit+0x51/0x53 > [<ffffffff8021bd1a>] smp_apic_timer_interrupt+0x77/0xad > [<ffffffff8020ce3b>] apic_timer_interrupt+0x6b/0x70 > <EOI> [<ffffffff8020b0dd>] ? default_idle+0x43/0x76 > [<ffffffff8020b0db>] ? default_idle+0x41/0x76 > [<ffffffff8020b09a>] ? default_idle+0x0/0x76 > [<ffffffff8020b186>] ? cpu_idle+0x76/0x98 separate the tg->shares protection from the task_group lock. Reported-by: Denis V. Lunev <den@openvz.org> Tested-by: Denis V. Lunev <den@openvz.org> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-13 14:45:39 +00:00
static DEFINE_MUTEX(shares_mutex);
sched: cleanup: rename task_grp to task_group cleanup: rename task_grp to task_group. No need to save two characters and 'grp' is annoying to read. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 15:00:14 +00:00
int sched_group_set_shares(struct task_group *tg, unsigned long shares)
sched: group-scheduler core Add interface to control cpu bandwidth allocation to task-groups. (not yet configurable, due to missing CONFIG_CONTAINERS) Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
2007-10-15 15:00:07 +00:00
{
int i;
sched: fair-group: separate tg->shares from task_group_lock On Mon, 2008-02-11 at 15:09 +0300, Denis V. Lunev wrote: > BUG: sleeping function called from invalid context > at /home/den/src/linux-netns26/kernel/mutex.c:209 > in_atomic():1, irqs_disabled():0 > no locks held by swapper/0. > Pid: 0, comm: swapper Not tainted 2.6.24 #304 > > Call Trace: > <IRQ> [<ffffffff80252d1e>] ? __debug_show_held_locks+0x15/0x27 > [<ffffffff8022c2a8>] __might_sleep+0xc0/0xdf > [<ffffffff8049f1df>] mutex_lock_nested+0x28/0x2a9 > [<ffffffff80231294>] sched_destroy_group+0x18/0xea > [<ffffffff8023e835>] sched_destroy_user+0xd/0xf > [<ffffffff8023e8c1>] free_uid+0x8a/0xab > [<ffffffff80233e24>] __put_task_struct+0x3f/0xd3 > [<ffffffff80236708>] delayed_put_task_struct+0x23/0x25 > [<ffffffff8026fda7>] __rcu_process_callbacks+0x8d/0x215 > [<ffffffff8026ff52>] rcu_process_callbacks+0x23/0x44 > [<ffffffff8023a2ae>] __do_softirq+0x79/0xf8 > [<ffffffff8020f8c3>] ? profile_pc+0x2a/0x67 > [<ffffffff8020d38c>] call_softirq+0x1c/0x30 > [<ffffffff8020f689>] do_softirq+0x61/0x9c > [<ffffffff8023a233>] irq_exit+0x51/0x53 > [<ffffffff8021bd1a>] smp_apic_timer_interrupt+0x77/0xad > [<ffffffff8020ce3b>] apic_timer_interrupt+0x6b/0x70 > <EOI> [<ffffffff8020b0dd>] ? default_idle+0x43/0x76 > [<ffffffff8020b0db>] ? default_idle+0x41/0x76 > [<ffffffff8020b09a>] ? default_idle+0x0/0x76 > [<ffffffff8020b186>] ? cpu_idle+0x76/0x98 separate the tg->shares protection from the task_group lock. Reported-by: Denis V. Lunev <den@openvz.org> Tested-by: Denis V. Lunev <den@openvz.org> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-13 14:45:39 +00:00
unsigned long flags;
sched: group scheduler, set uid share fix setting cpu share to 1 causes hangs, as reported in: http://bugzilla.kernel.org/show_bug.cgi?id=9779 as the default share is 1024, the values of 0 and 1 can indeed cause problems. Limit it to 2 or higher values. These values can only be set by the root user - but still it makes sense to protect against nonsensical values. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-22 10:24:58 +00:00
sched: allow the group scheduler to have multiple levels This patch makes the group scheduler multi hierarchy aware. [a.p.zijlstra@chello.nl: rt-parts and assorted fixes] Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 17:44:59 +00:00
/*
* We can't change the weight of the root cgroup.
*/
if (!tg->se[0])
return -EINVAL;
sched, cgroups: Fix MIN_SHARES on 64-bit boxen Commit c8b28116 ("sched: Increase SCHED_LOAD_SCALE resolution") intended to have no user-visible effect, but allows setting cpu.shares to < MIN_SHARES, which the user then sees. Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Nikhil Rao <ncrao@google.com> Link: http://lkml.kernel.org/r/1307192600.8618.3.camel@marge.simson.net Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-06-04 13:03:20 +00:00
shares = clamp(shares, scale_load(MIN_SHARES), scale_load(MAX_SHARES));
sched: revert load_balance_monitor() changes The following commits cause a number of regressions: commit 58e2d4ca581167c2a079f4ee02be2f0bc52e8729 Author: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Date: Fri Jan 25 21:08:00 2008 +0100 sched: group scheduling, change how cpu load is calculated commit 6b2d7700266b9402e12824e11e0099ae6a4a6a79 Author: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Date: Fri Jan 25 21:08:00 2008 +0100 sched: group scheduler, fix fairness of cpu bandwidth allocation for task groups Namely: - very frequent wakeups on SMP, reported by PowerTop users. - cacheline trashing on (large) SMP - some latencies larger than 500ms While there is a mergeable patch to fix the latter, the former issues are not fixable in a manner suitable for .25 (we're at -rc3 now). Hence we revert them and try again in v2.6.26. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> CC: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Tested-by: Alexey Zaytsev <alexey.zaytsev@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-25 16:34:02 +00:00
sched: fair-group: separate tg->shares from task_group_lock On Mon, 2008-02-11 at 15:09 +0300, Denis V. Lunev wrote: > BUG: sleeping function called from invalid context > at /home/den/src/linux-netns26/kernel/mutex.c:209 > in_atomic():1, irqs_disabled():0 > no locks held by swapper/0. > Pid: 0, comm: swapper Not tainted 2.6.24 #304 > > Call Trace: > <IRQ> [<ffffffff80252d1e>] ? __debug_show_held_locks+0x15/0x27 > [<ffffffff8022c2a8>] __might_sleep+0xc0/0xdf > [<ffffffff8049f1df>] mutex_lock_nested+0x28/0x2a9 > [<ffffffff80231294>] sched_destroy_group+0x18/0xea > [<ffffffff8023e835>] sched_destroy_user+0xd/0xf > [<ffffffff8023e8c1>] free_uid+0x8a/0xab > [<ffffffff80233e24>] __put_task_struct+0x3f/0xd3 > [<ffffffff80236708>] delayed_put_task_struct+0x23/0x25 > [<ffffffff8026fda7>] __rcu_process_callbacks+0x8d/0x215 > [<ffffffff8026ff52>] rcu_process_callbacks+0x23/0x44 > [<ffffffff8023a2ae>] __do_softirq+0x79/0xf8 > [<ffffffff8020f8c3>] ? profile_pc+0x2a/0x67 > [<ffffffff8020d38c>] call_softirq+0x1c/0x30 > [<ffffffff8020f689>] do_softirq+0x61/0x9c > [<ffffffff8023a233>] irq_exit+0x51/0x53 > [<ffffffff8021bd1a>] smp_apic_timer_interrupt+0x77/0xad > [<ffffffff8020ce3b>] apic_timer_interrupt+0x6b/0x70 > <EOI> [<ffffffff8020b0dd>] ? default_idle+0x43/0x76 > [<ffffffff8020b0db>] ? default_idle+0x41/0x76 > [<ffffffff8020b09a>] ? default_idle+0x0/0x76 > [<ffffffff8020b186>] ? cpu_idle+0x76/0x98 separate the tg->shares protection from the task_group lock. Reported-by: Denis V. Lunev <den@openvz.org> Tested-by: Denis V. Lunev <den@openvz.org> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-13 14:45:39 +00:00
mutex_lock(&shares_mutex);
sched: clean up code under CONFIG_FAIR_GROUP_SCHED With the view of supporting user-id based fair scheduling (and not just container-based fair scheduling), this patch renames several functions and makes them independent of whether they are being used for container or user-id based fair scheduling. Also fix a problem reported by KAMEZAWA Hiroyuki (wrt allocating less-sized array for tg->cfs_rq[] and tf->se[]). Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-15 15:00:09 +00:00
if (tg->shares == shares)
sched: group scheduling, sysfs tunables Add tunables in sysfs to modify a user's cpu share. A directory is created in sysfs for each new user in the system. /sys/kernel/uids/<uid>/cpu_share Reading this file returns the cpu shares granted for the user. Writing into this file modifies the cpu share for the user. Only an administrator is allowed to modify a user's cpu share. Ex: # cd /sys/kernel/uids/ # cat 512/cpu_share 1024 # echo 2048 > 512/cpu_share # cat 512/cpu_share 2048 # Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 15:00:14 +00:00
goto done;
sched: group-scheduler core Add interface to control cpu bandwidth allocation to task-groups. (not yet configurable, due to missing CONFIG_CONTAINERS) Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
2007-10-15 15:00:07 +00:00
sched: clean up code under CONFIG_FAIR_GROUP_SCHED With the view of supporting user-id based fair scheduling (and not just container-based fair scheduling), this patch renames several functions and makes them independent of whether they are being used for container or user-id based fair scheduling. Also fix a problem reported by KAMEZAWA Hiroyuki (wrt allocating less-sized array for tg->cfs_rq[] and tf->se[]). Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-15 15:00:09 +00:00
tg->shares = shares;
sched: revert revert of: fair-group: SMP-nice for group scheduling Try again.. Initial commit: 18d95a2832c1392a2d63227a7a6d433cb9f2037e Revert: 6363ca57c76b7b83639ca8c83fc285fa26a7880e Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Cc: Mike Galbraith <efault@gmx.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-27 11:41:14 +00:00
for_each_possible_cpu(i) {
sched: Update tg->shares after cpu.shares write Formerly sched_group_set_shares would force a rebalance by overflowing domain share sums. Now that per-cpu averages are maintained we can set the true value by issuing an update_cfs_shares() following a tg->shares update. Also initialize tg se->load to 0 for consistency since we'll now set correct weights on enqueue. Signed-off-by: Paul Turner <pjt@google.com?> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20101115234938.465521344@google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-15 23:47:10 +00:00
struct rq *rq = cpu_rq(i);
struct sched_entity *se;
se = tg->se[i];
/* Propagate contribution to hierarchy */
raw_spin_lock_irqsave(&rq->lock, flags);
for_each_sched_entity(se)
sched: Simplify update_cfs_shares parameters Re-visiting this: Since update_cfs_shares will now only ever re-weight an entity that is a relative parent of the current entity in enqueue_entity; we can safely issue the account_entity_enqueue relative to that cfs_rq and avoid the requirement for special handling of the enqueue case in update_cfs_shares. Signed-off-by: Paul Turner <pjt@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20110122044851.915214637@google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-01-22 04:45:01 +00:00
update_cfs_shares(group_cfs_rq(se));
sched: Update tg->shares after cpu.shares write Formerly sched_group_set_shares would force a rebalance by overflowing domain share sums. Now that per-cpu averages are maintained we can set the true value by issuing an update_cfs_shares() following a tg->shares update. Also initialize tg se->load to 0 for consistency since we'll now set correct weights on enqueue. Signed-off-by: Paul Turner <pjt@google.com?> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20101115234938.465521344@google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-15 23:47:10 +00:00
raw_spin_unlock_irqrestore(&rq->lock, flags);
sched: revert revert of: fair-group: SMP-nice for group scheduling Try again.. Initial commit: 18d95a2832c1392a2d63227a7a6d433cb9f2037e Revert: 6363ca57c76b7b83639ca8c83fc285fa26a7880e Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Cc: Mike Galbraith <efault@gmx.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-27 11:41:14 +00:00
}
sched: group-scheduler core Add interface to control cpu bandwidth allocation to task-groups. (not yet configurable, due to missing CONFIG_CONTAINERS) Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
2007-10-15 15:00:07 +00:00
sched: group scheduling, sysfs tunables Add tunables in sysfs to modify a user's cpu share. A directory is created in sysfs for each new user in the system. /sys/kernel/uids/<uid>/cpu_share Reading this file returns the cpu shares granted for the user. Writing into this file modifies the cpu share for the user. Only an administrator is allowed to modify a user's cpu share. Ex: # cd /sys/kernel/uids/ # cat 512/cpu_share 1024 # echo 2048 > 512/cpu_share # cat 512/cpu_share 2048 # Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 15:00:14 +00:00
done:
sched: fair-group: separate tg->shares from task_group_lock On Mon, 2008-02-11 at 15:09 +0300, Denis V. Lunev wrote: > BUG: sleeping function called from invalid context > at /home/den/src/linux-netns26/kernel/mutex.c:209 > in_atomic():1, irqs_disabled():0 > no locks held by swapper/0. > Pid: 0, comm: swapper Not tainted 2.6.24 #304 > > Call Trace: > <IRQ> [<ffffffff80252d1e>] ? __debug_show_held_locks+0x15/0x27 > [<ffffffff8022c2a8>] __might_sleep+0xc0/0xdf > [<ffffffff8049f1df>] mutex_lock_nested+0x28/0x2a9 > [<ffffffff80231294>] sched_destroy_group+0x18/0xea > [<ffffffff8023e835>] sched_destroy_user+0xd/0xf > [<ffffffff8023e8c1>] free_uid+0x8a/0xab > [<ffffffff80233e24>] __put_task_struct+0x3f/0xd3 > [<ffffffff80236708>] delayed_put_task_struct+0x23/0x25 > [<ffffffff8026fda7>] __rcu_process_callbacks+0x8d/0x215 > [<ffffffff8026ff52>] rcu_process_callbacks+0x23/0x44 > [<ffffffff8023a2ae>] __do_softirq+0x79/0xf8 > [<ffffffff8020f8c3>] ? profile_pc+0x2a/0x67 > [<ffffffff8020d38c>] call_softirq+0x1c/0x30 > [<ffffffff8020f689>] do_softirq+0x61/0x9c > [<ffffffff8023a233>] irq_exit+0x51/0x53 > [<ffffffff8021bd1a>] smp_apic_timer_interrupt+0x77/0xad > [<ffffffff8020ce3b>] apic_timer_interrupt+0x6b/0x70 > <EOI> [<ffffffff8020b0dd>] ? default_idle+0x43/0x76 > [<ffffffff8020b0db>] ? default_idle+0x41/0x76 > [<ffffffff8020b09a>] ? default_idle+0x0/0x76 > [<ffffffff8020b186>] ? cpu_idle+0x76/0x98 separate the tg->shares protection from the task_group lock. Reported-by: Denis V. Lunev <den@openvz.org> Tested-by: Denis V. Lunev <den@openvz.org> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-13 14:45:39 +00:00
mutex_unlock(&shares_mutex);
sched: clean up code under CONFIG_FAIR_GROUP_SCHED With the view of supporting user-id based fair scheduling (and not just container-based fair scheduling), this patch renames several functions and makes them independent of whether they are being used for container or user-id based fair scheduling. Also fix a problem reported by KAMEZAWA Hiroyuki (wrt allocating less-sized array for tg->cfs_rq[] and tf->se[]). Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-15 15:00:09 +00:00
return 0;
sched: group-scheduler core Add interface to control cpu bandwidth allocation to task-groups. (not yet configurable, due to missing CONFIG_CONTAINERS) Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
2007-10-15 15:00:07 +00:00
}
sched: group scheduling, sysfs tunables Add tunables in sysfs to modify a user's cpu share. A directory is created in sysfs for each new user in the system. /sys/kernel/uids/<uid>/cpu_share Reading this file returns the cpu shares granted for the user. Writing into this file modifies the cpu share for the user. Only an administrator is allowed to modify a user's cpu share. Ex: # cd /sys/kernel/uids/ # cat 512/cpu_share 1024 # echo 2048 > 512/cpu_share # cat 512/cpu_share 2048 # Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 15:00:14 +00:00
unsigned long sched_group_shares(struct task_group *tg)
{
return tg->shares;
}
sched: rt-group: make rt groups scheduling configurable Make the rt group scheduler compile time configurable. Keep it experimental for now. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-13 14:45:40 +00:00
#endif
sched: group scheduling, sysfs tunables Add tunables in sysfs to modify a user's cpu share. A directory is created in sysfs for each new user in the system. /sys/kernel/uids/<uid>/cpu_share Reading this file returns the cpu shares granted for the user. Writing into this file modifies the cpu share for the user. Only an administrator is allowed to modify a user's cpu share. Ex: # cd /sys/kernel/uids/ # cat 512/cpu_share 1024 # echo 2048 > 512/cpu_share # cat 512/cpu_share 2048 # Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-15 15:00:14 +00:00
sched: Validate CFS quota hierarchies Add constraints validation for CFS bandwidth hierarchies. Validate that: max(child bandwidth) <= parent_bandwidth In a quota limited hierarchy, an unconstrained entity (e.g. bandwidth==RUNTIME_INF) inherits the bandwidth of its parent. This constraint is chosen over sum(child_bandwidth) as notion of over-commit is valuable within SCHED_OTHER. Some basic code from the RT case is re-factored for reuse. Signed-off-by: Paul Turner <pjt@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110721184757.083774572@google.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-21 16:43:29 +00:00
#if defined(CONFIG_RT_GROUP_SCHED) || defined(CONFIG_CFS_BANDWIDTH)
sched: rt-group: interface Change the rt_ratio interface to rt_runtime_us, to match rt_period_us. This avoids picking a granularity for the ratio. Extend the /sys/kernel/uids/<uid>/ interface to allow setting the group's rt_runtime. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-13 14:45:39 +00:00
static unsigned long to_ratio(u64 period, u64 runtime)
{
if (runtime == RUNTIME_INF)
sched: rt-bandwidth fixes The last patch allows sysctl_sched_rt_runtime to disable bandwidth accounting for the group scheduler - however it doesn't deal with sched_setscheduler(), which will keep tasks out of groups that have no assigned runtime. If we relax this, we get into the situation where RT tasks can get into a group when we disable bandwidth control, and then starve them by enabling it again. Rework the schedulability code to check for this condition and fail to turn on bandwidth control with -EBUSY when this situation is found. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-19 10:33:06 +00:00
return 1ULL << 20;
sched: rt-group: interface Change the rt_ratio interface to rt_runtime_us, to match rt_period_us. This avoids picking a granularity for the ratio. Extend the /sys/kernel/uids/<uid>/ interface to allow setting the group's rt_runtime. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-13 14:45:39 +00:00
sched: rt-bandwidth fixes The last patch allows sysctl_sched_rt_runtime to disable bandwidth accounting for the group scheduler - however it doesn't deal with sched_setscheduler(), which will keep tasks out of groups that have no assigned runtime. If we relax this, we get into the situation where RT tasks can get into a group when we disable bandwidth control, and then starve them by enabling it again. Rework the schedulability code to check for this condition and fail to turn on bandwidth control with -EBUSY when this situation is found. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-19 10:33:06 +00:00
return div64_u64(runtime << 20, period);
sched: rt-group: interface Change the rt_ratio interface to rt_runtime_us, to match rt_period_us. This avoids picking a granularity for the ratio. Extend the /sys/kernel/uids/<uid>/ interface to allow setting the group's rt_runtime. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-13 14:45:39 +00:00
}
sched: Validate CFS quota hierarchies Add constraints validation for CFS bandwidth hierarchies. Validate that: max(child bandwidth) <= parent_bandwidth In a quota limited hierarchy, an unconstrained entity (e.g. bandwidth==RUNTIME_INF) inherits the bandwidth of its parent. This constraint is chosen over sum(child_bandwidth) as notion of over-commit is valuable within SCHED_OTHER. Some basic code from the RT case is re-factored for reuse. Signed-off-by: Paul Turner <pjt@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110721184757.083774572@google.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-21 16:43:29 +00:00
#endif
#ifdef CONFIG_RT_GROUP_SCHED
/*
* Ensure that the real time constraints are schedulable.
*/
static DEFINE_MUTEX(rt_constraints_mutex);
sched: rt-group: interface Change the rt_ratio interface to rt_runtime_us, to match rt_period_us. This avoids picking a granularity for the ratio. Extend the /sys/kernel/uids/<uid>/ interface to allow setting the group's rt_runtime. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-13 14:45:39 +00:00
sched: rt-bandwidth fixes The last patch allows sysctl_sched_rt_runtime to disable bandwidth accounting for the group scheduler - however it doesn't deal with sched_setscheduler(), which will keep tasks out of groups that have no assigned runtime. If we relax this, we get into the situation where RT tasks can get into a group when we disable bandwidth control, and then starve them by enabling it again. Rework the schedulability code to check for this condition and fail to turn on bandwidth control with -EBUSY when this situation is found. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-19 10:33:06 +00:00
/* Must be called with tasklist_lock held */
static inline int tg_has_rt_tasks(struct task_group *tg)
sched: rt: multi level group constraints multi level rt constraints Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 17:45:00 +00:00
{
sched: rt-bandwidth fixes The last patch allows sysctl_sched_rt_runtime to disable bandwidth accounting for the group scheduler - however it doesn't deal with sched_setscheduler(), which will keep tasks out of groups that have no assigned runtime. If we relax this, we get into the situation where RT tasks can get into a group when we disable bandwidth control, and then starve them by enabling it again. Rework the schedulability code to check for this condition and fail to turn on bandwidth control with -EBUSY when this situation is found. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-19 10:33:06 +00:00
struct task_struct *g, *p;
sched: rt: multi level group constraints multi level rt constraints Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 17:45:00 +00:00
sched: rt-bandwidth fixes The last patch allows sysctl_sched_rt_runtime to disable bandwidth accounting for the group scheduler - however it doesn't deal with sched_setscheduler(), which will keep tasks out of groups that have no assigned runtime. If we relax this, we get into the situation where RT tasks can get into a group when we disable bandwidth control, and then starve them by enabling it again. Rework the schedulability code to check for this condition and fail to turn on bandwidth control with -EBUSY when this situation is found. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-19 10:33:06 +00:00
do_each_thread(g, p) {
if (rt_task(p) && rt_rq_of_se(&p->rt)->tg == tg)
return 1;
} while_each_thread(g, p);
sched: rt: multi level group constraints multi level rt constraints Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 17:45:00 +00:00
sched: rt-bandwidth fixes The last patch allows sysctl_sched_rt_runtime to disable bandwidth accounting for the group scheduler - however it doesn't deal with sched_setscheduler(), which will keep tasks out of groups that have no assigned runtime. If we relax this, we get into the situation where RT tasks can get into a group when we disable bandwidth control, and then starve them by enabling it again. Rework the schedulability code to check for this condition and fail to turn on bandwidth control with -EBUSY when this situation is found. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-19 10:33:06 +00:00
return 0;
}
sched: rt: multi level group constraints multi level rt constraints Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 17:45:00 +00:00
sched: rt-bandwidth fixes The last patch allows sysctl_sched_rt_runtime to disable bandwidth accounting for the group scheduler - however it doesn't deal with sched_setscheduler(), which will keep tasks out of groups that have no assigned runtime. If we relax this, we get into the situation where RT tasks can get into a group when we disable bandwidth control, and then starve them by enabling it again. Rework the schedulability code to check for this condition and fail to turn on bandwidth control with -EBUSY when this situation is found. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-19 10:33:06 +00:00
struct rt_schedulable_data {
struct task_group *tg;
u64 rt_period;
u64 rt_runtime;
};
sched: rt: multi level group constraints multi level rt constraints Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 17:45:00 +00:00
sched: Validate CFS quota hierarchies Add constraints validation for CFS bandwidth hierarchies. Validate that: max(child bandwidth) <= parent_bandwidth In a quota limited hierarchy, an unconstrained entity (e.g. bandwidth==RUNTIME_INF) inherits the bandwidth of its parent. This constraint is chosen over sum(child_bandwidth) as notion of over-commit is valuable within SCHED_OTHER. Some basic code from the RT case is re-factored for reuse. Signed-off-by: Paul Turner <pjt@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110721184757.083774572@google.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-21 16:43:29 +00:00
static int tg_rt_schedulable(struct task_group *tg, void *data)
sched: rt-bandwidth fixes The last patch allows sysctl_sched_rt_runtime to disable bandwidth accounting for the group scheduler - however it doesn't deal with sched_setscheduler(), which will keep tasks out of groups that have no assigned runtime. If we relax this, we get into the situation where RT tasks can get into a group when we disable bandwidth control, and then starve them by enabling it again. Rework the schedulability code to check for this condition and fail to turn on bandwidth control with -EBUSY when this situation is found. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-19 10:33:06 +00:00
{
struct rt_schedulable_data *d = data;
struct task_group *child;
unsigned long total, sum = 0;
u64 period, runtime;
sched: rt: multi level group constraints multi level rt constraints Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 17:45:00 +00:00
sched: rt-bandwidth fixes The last patch allows sysctl_sched_rt_runtime to disable bandwidth accounting for the group scheduler - however it doesn't deal with sched_setscheduler(), which will keep tasks out of groups that have no assigned runtime. If we relax this, we get into the situation where RT tasks can get into a group when we disable bandwidth control, and then starve them by enabling it again. Rework the schedulability code to check for this condition and fail to turn on bandwidth control with -EBUSY when this situation is found. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-19 10:33:06 +00:00
period = ktime_to_ns(tg->rt_bandwidth.rt_period);
runtime = tg->rt_bandwidth.rt_runtime;
sched: rt: multi level group constraints multi level rt constraints Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 17:45:00 +00:00
sched: rt-bandwidth fixes The last patch allows sysctl_sched_rt_runtime to disable bandwidth accounting for the group scheduler - however it doesn't deal with sched_setscheduler(), which will keep tasks out of groups that have no assigned runtime. If we relax this, we get into the situation where RT tasks can get into a group when we disable bandwidth control, and then starve them by enabling it again. Rework the schedulability code to check for this condition and fail to turn on bandwidth control with -EBUSY when this situation is found. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-19 10:33:06 +00:00
if (tg == d->tg) {
period = d->rt_period;
runtime = d->rt_runtime;
sched: rt: multi level group constraints multi level rt constraints Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 17:45:00 +00:00
}
sched: more sanity checks on the bandwidth settings While playing around with it, I noticed we missed some sanity checks. Also add some comments while we're there. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-23 13:33:44 +00:00
/*
* Cannot have more runtime than the period.
*/
if (runtime > period && runtime != RUNTIME_INF)
return -EINVAL;
sched: rt group scheduling Extend group scheduling to also cover the realtime classes. It uses the time limiting introduced by the previous patch to allow multiple realtime groups. The hard time limit is required to keep behaviour deterministic. The algorithms used make the realtime scheduler O(tg), linear scaling wrt the number of task groups. This is the worst case behaviour I can't seem to get out of, the avg. case of the algorithms can be improved, I focused on correctness and worst case. [ akpm@linux-foundation.org: move side-effects out of BUG_ON(). ] Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:30 +00:00
sched: more sanity checks on the bandwidth settings While playing around with it, I noticed we missed some sanity checks. Also add some comments while we're there. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-23 13:33:44 +00:00
/*
* Ensure we don't starve existing RT tasks.
*/
sched: rt-bandwidth fixes The last patch allows sysctl_sched_rt_runtime to disable bandwidth accounting for the group scheduler - however it doesn't deal with sched_setscheduler(), which will keep tasks out of groups that have no assigned runtime. If we relax this, we get into the situation where RT tasks can get into a group when we disable bandwidth control, and then starve them by enabling it again. Rework the schedulability code to check for this condition and fail to turn on bandwidth control with -EBUSY when this situation is found. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-19 10:33:06 +00:00
if (rt_bandwidth_enabled() && !runtime && tg_has_rt_tasks(tg))
return -EBUSY;
sched: rt group scheduling Extend group scheduling to also cover the realtime classes. It uses the time limiting introduced by the previous patch to allow multiple realtime groups. The hard time limit is required to keep behaviour deterministic. The algorithms used make the realtime scheduler O(tg), linear scaling wrt the number of task groups. This is the worst case behaviour I can't seem to get out of, the avg. case of the algorithms can be improved, I focused on correctness and worst case. [ akpm@linux-foundation.org: move side-effects out of BUG_ON(). ] Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:30 +00:00
sched: rt-bandwidth fixes The last patch allows sysctl_sched_rt_runtime to disable bandwidth accounting for the group scheduler - however it doesn't deal with sched_setscheduler(), which will keep tasks out of groups that have no assigned runtime. If we relax this, we get into the situation where RT tasks can get into a group when we disable bandwidth control, and then starve them by enabling it again. Rework the schedulability code to check for this condition and fail to turn on bandwidth control with -EBUSY when this situation is found. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-19 10:33:06 +00:00
total = to_ratio(period, runtime);
sched: rt group scheduling Extend group scheduling to also cover the realtime classes. It uses the time limiting introduced by the previous patch to allow multiple realtime groups. The hard time limit is required to keep behaviour deterministic. The algorithms used make the realtime scheduler O(tg), linear scaling wrt the number of task groups. This is the worst case behaviour I can't seem to get out of, the avg. case of the algorithms can be improved, I focused on correctness and worst case. [ akpm@linux-foundation.org: move side-effects out of BUG_ON(). ] Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:30 +00:00
sched: more sanity checks on the bandwidth settings While playing around with it, I noticed we missed some sanity checks. Also add some comments while we're there. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-23 13:33:44 +00:00
/*
* Nobody can have more than the global setting allows.
*/
if (total > to_ratio(global_rt_period(), global_rt_runtime()))
return -EINVAL;
sched: rt group scheduling Extend group scheduling to also cover the realtime classes. It uses the time limiting introduced by the previous patch to allow multiple realtime groups. The hard time limit is required to keep behaviour deterministic. The algorithms used make the realtime scheduler O(tg), linear scaling wrt the number of task groups. This is the worst case behaviour I can't seem to get out of, the avg. case of the algorithms can be improved, I focused on correctness and worst case. [ akpm@linux-foundation.org: move side-effects out of BUG_ON(). ] Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:30 +00:00
sched: more sanity checks on the bandwidth settings While playing around with it, I noticed we missed some sanity checks. Also add some comments while we're there. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-23 13:33:44 +00:00
/*
* The sum of our children's runtime should not exceed our own.
*/
sched: rt-bandwidth fixes The last patch allows sysctl_sched_rt_runtime to disable bandwidth accounting for the group scheduler - however it doesn't deal with sched_setscheduler(), which will keep tasks out of groups that have no assigned runtime. If we relax this, we get into the situation where RT tasks can get into a group when we disable bandwidth control, and then starve them by enabling it again. Rework the schedulability code to check for this condition and fail to turn on bandwidth control with -EBUSY when this situation is found. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-19 10:33:06 +00:00
list_for_each_entry_rcu(child, &tg->children, siblings) {
period = ktime_to_ns(child->rt_bandwidth.rt_period);
runtime = child->rt_bandwidth.rt_runtime;
sched: rt group scheduling Extend group scheduling to also cover the realtime classes. It uses the time limiting introduced by the previous patch to allow multiple realtime groups. The hard time limit is required to keep behaviour deterministic. The algorithms used make the realtime scheduler O(tg), linear scaling wrt the number of task groups. This is the worst case behaviour I can't seem to get out of, the avg. case of the algorithms can be improved, I focused on correctness and worst case. [ akpm@linux-foundation.org: move side-effects out of BUG_ON(). ] Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:30 +00:00
sched: rt-bandwidth fixes The last patch allows sysctl_sched_rt_runtime to disable bandwidth accounting for the group scheduler - however it doesn't deal with sched_setscheduler(), which will keep tasks out of groups that have no assigned runtime. If we relax this, we get into the situation where RT tasks can get into a group when we disable bandwidth control, and then starve them by enabling it again. Rework the schedulability code to check for this condition and fail to turn on bandwidth control with -EBUSY when this situation is found. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-19 10:33:06 +00:00
if (child == d->tg) {
period = d->rt_period;
runtime = d->rt_runtime;
}
sched: rt group scheduling Extend group scheduling to also cover the realtime classes. It uses the time limiting introduced by the previous patch to allow multiple realtime groups. The hard time limit is required to keep behaviour deterministic. The algorithms used make the realtime scheduler O(tg), linear scaling wrt the number of task groups. This is the worst case behaviour I can't seem to get out of, the avg. case of the algorithms can be improved, I focused on correctness and worst case. [ akpm@linux-foundation.org: move side-effects out of BUG_ON(). ] Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:30 +00:00
sched: rt-bandwidth fixes The last patch allows sysctl_sched_rt_runtime to disable bandwidth accounting for the group scheduler - however it doesn't deal with sched_setscheduler(), which will keep tasks out of groups that have no assigned runtime. If we relax this, we get into the situation where RT tasks can get into a group when we disable bandwidth control, and then starve them by enabling it again. Rework the schedulability code to check for this condition and fail to turn on bandwidth control with -EBUSY when this situation is found. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-19 10:33:06 +00:00
sum += to_ratio(period, runtime);
sched: rt-group: interface Change the rt_ratio interface to rt_runtime_us, to match rt_period_us. This avoids picking a granularity for the ratio. Extend the /sys/kernel/uids/<uid>/ interface to allow setting the group's rt_runtime. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-13 14:45:39 +00:00
}
sched: rt group scheduling Extend group scheduling to also cover the realtime classes. It uses the time limiting introduced by the previous patch to allow multiple realtime groups. The hard time limit is required to keep behaviour deterministic. The algorithms used make the realtime scheduler O(tg), linear scaling wrt the number of task groups. This is the worst case behaviour I can't seem to get out of, the avg. case of the algorithms can be improved, I focused on correctness and worst case. [ akpm@linux-foundation.org: move side-effects out of BUG_ON(). ] Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:30 +00:00
sched: rt-bandwidth fixes The last patch allows sysctl_sched_rt_runtime to disable bandwidth accounting for the group scheduler - however it doesn't deal with sched_setscheduler(), which will keep tasks out of groups that have no assigned runtime. If we relax this, we get into the situation where RT tasks can get into a group when we disable bandwidth control, and then starve them by enabling it again. Rework the schedulability code to check for this condition and fail to turn on bandwidth control with -EBUSY when this situation is found. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-19 10:33:06 +00:00
if (sum > total)
return -EINVAL;
return 0;
sched: rt group scheduling Extend group scheduling to also cover the realtime classes. It uses the time limiting introduced by the previous patch to allow multiple realtime groups. The hard time limit is required to keep behaviour deterministic. The algorithms used make the realtime scheduler O(tg), linear scaling wrt the number of task groups. This is the worst case behaviour I can't seem to get out of, the avg. case of the algorithms can be improved, I focused on correctness and worst case. [ akpm@linux-foundation.org: move side-effects out of BUG_ON(). ] Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:30 +00:00
}
sched: rt-bandwidth fixes The last patch allows sysctl_sched_rt_runtime to disable bandwidth accounting for the group scheduler - however it doesn't deal with sched_setscheduler(), which will keep tasks out of groups that have no assigned runtime. If we relax this, we get into the situation where RT tasks can get into a group when we disable bandwidth control, and then starve them by enabling it again. Rework the schedulability code to check for this condition and fail to turn on bandwidth control with -EBUSY when this situation is found. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-19 10:33:06 +00:00
static int __rt_schedulable(struct task_group *tg, u64 period, u64 runtime)
sched: don't allow rt_runtime_us to be zero for groups having rt tasks This patch checks if we can set the rt_runtime_us to 0. If there is a realtime task in the group, we don't want to set the rt_runtime_us as 0 or bad things will happen. (that task wont get any CPU time despite being TASK_RUNNNG) Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-28 09:51:56 +00:00
{
sched: rt-bandwidth fixes The last patch allows sysctl_sched_rt_runtime to disable bandwidth accounting for the group scheduler - however it doesn't deal with sched_setscheduler(), which will keep tasks out of groups that have no assigned runtime. If we relax this, we get into the situation where RT tasks can get into a group when we disable bandwidth control, and then starve them by enabling it again. Rework the schedulability code to check for this condition and fail to turn on bandwidth control with -EBUSY when this situation is found. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-19 10:33:06 +00:00
struct rt_schedulable_data data = {
.tg = tg,
.rt_period = period,
.rt_runtime = runtime,
};
sched: Validate CFS quota hierarchies Add constraints validation for CFS bandwidth hierarchies. Validate that: max(child bandwidth) <= parent_bandwidth In a quota limited hierarchy, an unconstrained entity (e.g. bandwidth==RUNTIME_INF) inherits the bandwidth of its parent. This constraint is chosen over sum(child_bandwidth) as notion of over-commit is valuable within SCHED_OTHER. Some basic code from the RT case is re-factored for reuse. Signed-off-by: Paul Turner <pjt@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110721184757.083774572@google.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-21 16:43:29 +00:00
return walk_tg_tree(tg_rt_schedulable, tg_nop, &data);
sched: don't allow rt_runtime_us to be zero for groups having rt tasks This patch checks if we can set the rt_runtime_us to 0. If there is a realtime task in the group, we don't want to set the rt_runtime_us as 0 or bad things will happen. (that task wont get any CPU time despite being TASK_RUNNNG) Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-28 09:51:56 +00:00
}
sched: Introduce primitives to account for CFS bandwidth tracking In this patch we introduce the notion of CFS bandwidth, partitioned into globally unassigned bandwidth, and locally claimed bandwidth. - The global bandwidth is per task_group, it represents a pool of unclaimed bandwidth that cfs_rqs can allocate from. - The local bandwidth is tracked per-cfs_rq, this represents allotments from the global pool bandwidth assigned to a specific cpu. Bandwidth is managed via cgroupfs, adding two new interfaces to the cpu subsystem: - cpu.cfs_period_us : the bandwidth period in usecs - cpu.cfs_quota_us : the cpu bandwidth (in usecs) that this tg will be allowed to consume over period above. Signed-off-by: Paul Turner <pjt@google.com> Signed-off-by: Nikhil Rao <ncrao@google.com> Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com> Reviewed-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110721184756.972636699@google.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-21 16:43:28 +00:00
static int tg_set_rt_bandwidth(struct task_group *tg,
sched: rt-group: synchonised bandwidth period Various SMP balancing algorithms require that the bandwidth period run in sync. Possible improvements are moving the rt_bandwidth thing into root_domain and keeping a span per rt_bandwidth which marks throttled cpus. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 17:44:57 +00:00
u64 rt_period, u64 rt_runtime)
sched: rt group scheduling Extend group scheduling to also cover the realtime classes. It uses the time limiting introduced by the previous patch to allow multiple realtime groups. The hard time limit is required to keep behaviour deterministic. The algorithms used make the realtime scheduler O(tg), linear scaling wrt the number of task groups. This is the worst case behaviour I can't seem to get out of, the avg. case of the algorithms can be improved, I focused on correctness and worst case. [ akpm@linux-foundation.org: move side-effects out of BUG_ON(). ] Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:30 +00:00
{
sched: rt-group: smp balancing Currently the rt group scheduling does a per cpu runtime limit, however the rt load balancer makes no guarantees about an equal spread of real- time tasks, just that at any one time, the highest priority tasks run. Solve this by making the runtime limit a global property by borrowing excessive runtime from the other cpus once the local limit runs out. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 17:44:58 +00:00
int i, err = 0;
sched: rt-group: interface Change the rt_ratio interface to rt_runtime_us, to match rt_period_us. This avoids picking a granularity for the ratio. Extend the /sys/kernel/uids/<uid>/ interface to allow setting the group's rt_runtime. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-13 14:45:39 +00:00
mutex_lock(&rt_constraints_mutex);
sched: don't allow rt_runtime_us to be zero for groups having rt tasks This patch checks if we can set the rt_runtime_us to 0. If there is a realtime task in the group, we don't want to set the rt_runtime_us as 0 or bad things will happen. (that task wont get any CPU time despite being TASK_RUNNNG) Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-28 09:51:56 +00:00
read_lock(&tasklist_lock);
sched: rt-bandwidth fixes The last patch allows sysctl_sched_rt_runtime to disable bandwidth accounting for the group scheduler - however it doesn't deal with sched_setscheduler(), which will keep tasks out of groups that have no assigned runtime. If we relax this, we get into the situation where RT tasks can get into a group when we disable bandwidth control, and then starve them by enabling it again. Rework the schedulability code to check for this condition and fail to turn on bandwidth control with -EBUSY when this situation is found. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-19 10:33:06 +00:00
err = __rt_schedulable(tg, rt_period, rt_runtime);
if (err)
sched: rt-group: interface Change the rt_ratio interface to rt_runtime_us, to match rt_period_us. This avoids picking a granularity for the ratio. Extend the /sys/kernel/uids/<uid>/ interface to allow setting the group's rt_runtime. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-13 14:45:39 +00:00
goto unlock;
sched: rt-group: smp balancing Currently the rt group scheduling does a per cpu runtime limit, however the rt load balancer makes no guarantees about an equal spread of real- time tasks, just that at any one time, the highest priority tasks run. Solve this by making the runtime limit a global property by borrowing excessive runtime from the other cpus once the local limit runs out. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 17:44:58 +00:00
sched: Convert rt_runtime_lock to raw_spinlock Convert locks which cannot be sleeping locks in preempt-rt to raw_spinlocks. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Ingo Molnar <mingo@elte.hu>
2009-11-17 14:32:06 +00:00
raw_spin_lock_irq(&tg->rt_bandwidth.rt_runtime_lock);
sched: rt-group: synchonised bandwidth period Various SMP balancing algorithms require that the bandwidth period run in sync. Possible improvements are moving the rt_bandwidth thing into root_domain and keeping a span per rt_bandwidth which marks throttled cpus. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 17:44:57 +00:00
tg->rt_bandwidth.rt_period = ns_to_ktime(rt_period);
tg->rt_bandwidth.rt_runtime = rt_runtime;
sched: rt-group: smp balancing Currently the rt group scheduling does a per cpu runtime limit, however the rt load balancer makes no guarantees about an equal spread of real- time tasks, just that at any one time, the highest priority tasks run. Solve this by making the runtime limit a global property by borrowing excessive runtime from the other cpus once the local limit runs out. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 17:44:58 +00:00
for_each_possible_cpu(i) {
struct rt_rq *rt_rq = tg->rt_rq[i];
sched: Convert rt_runtime_lock to raw_spinlock Convert locks which cannot be sleeping locks in preempt-rt to raw_spinlocks. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Ingo Molnar <mingo@elte.hu>
2009-11-17 14:32:06 +00:00
raw_spin_lock(&rt_rq->rt_runtime_lock);
sched: rt-group: smp balancing Currently the rt group scheduling does a per cpu runtime limit, however the rt load balancer makes no guarantees about an equal spread of real- time tasks, just that at any one time, the highest priority tasks run. Solve this by making the runtime limit a global property by borrowing excessive runtime from the other cpus once the local limit runs out. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 17:44:58 +00:00
rt_rq->rt_runtime = rt_runtime;
sched: Convert rt_runtime_lock to raw_spinlock Convert locks which cannot be sleeping locks in preempt-rt to raw_spinlocks. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Ingo Molnar <mingo@elte.hu>
2009-11-17 14:32:06 +00:00
raw_spin_unlock(&rt_rq->rt_runtime_lock);
sched: rt-group: smp balancing Currently the rt group scheduling does a per cpu runtime limit, however the rt load balancer makes no guarantees about an equal spread of real- time tasks, just that at any one time, the highest priority tasks run. Solve this by making the runtime limit a global property by borrowing excessive runtime from the other cpus once the local limit runs out. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 17:44:58 +00:00
}
sched: Convert rt_runtime_lock to raw_spinlock Convert locks which cannot be sleeping locks in preempt-rt to raw_spinlocks. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Ingo Molnar <mingo@elte.hu>
2009-11-17 14:32:06 +00:00
raw_spin_unlock_irq(&tg->rt_bandwidth.rt_runtime_lock);
sched: Unindent labels Labels should be on column 0. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-17 19:46:10 +00:00
unlock:
sched: don't allow rt_runtime_us to be zero for groups having rt tasks This patch checks if we can set the rt_runtime_us to 0. If there is a realtime task in the group, we don't want to set the rt_runtime_us as 0 or bad things will happen. (that task wont get any CPU time despite being TASK_RUNNNG) Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-28 09:51:56 +00:00
read_unlock(&tasklist_lock);
sched: rt-group: interface Change the rt_ratio interface to rt_runtime_us, to match rt_period_us. This avoids picking a granularity for the ratio. Extend the /sys/kernel/uids/<uid>/ interface to allow setting the group's rt_runtime. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-13 14:45:39 +00:00
mutex_unlock(&rt_constraints_mutex);
return err;
sched: rt group scheduling Extend group scheduling to also cover the realtime classes. It uses the time limiting introduced by the previous patch to allow multiple realtime groups. The hard time limit is required to keep behaviour deterministic. The algorithms used make the realtime scheduler O(tg), linear scaling wrt the number of task groups. This is the worst case behaviour I can't seem to get out of, the avg. case of the algorithms can be improved, I focused on correctness and worst case. [ akpm@linux-foundation.org: move side-effects out of BUG_ON(). ] Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:30 +00:00
}
sched: rt-group: synchonised bandwidth period Various SMP balancing algorithms require that the bandwidth period run in sync. Possible improvements are moving the rt_bandwidth thing into root_domain and keeping a span per rt_bandwidth which marks throttled cpus. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 17:44:57 +00:00
int sched_group_set_rt_runtime(struct task_group *tg, long rt_runtime_us)
{
u64 rt_runtime, rt_period;
rt_period = ktime_to_ns(tg->rt_bandwidth.rt_period);
rt_runtime = (u64)rt_runtime_us * NSEC_PER_USEC;
if (rt_runtime_us < 0)
rt_runtime = RUNTIME_INF;
sched: Introduce primitives to account for CFS bandwidth tracking In this patch we introduce the notion of CFS bandwidth, partitioned into globally unassigned bandwidth, and locally claimed bandwidth. - The global bandwidth is per task_group, it represents a pool of unclaimed bandwidth that cfs_rqs can allocate from. - The local bandwidth is tracked per-cfs_rq, this represents allotments from the global pool bandwidth assigned to a specific cpu. Bandwidth is managed via cgroupfs, adding two new interfaces to the cpu subsystem: - cpu.cfs_period_us : the bandwidth period in usecs - cpu.cfs_quota_us : the cpu bandwidth (in usecs) that this tg will be allowed to consume over period above. Signed-off-by: Paul Turner <pjt@google.com> Signed-off-by: Nikhil Rao <ncrao@google.com> Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com> Reviewed-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110721184756.972636699@google.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-21 16:43:28 +00:00
return tg_set_rt_bandwidth(tg, rt_period, rt_runtime);
sched: rt-group: synchonised bandwidth period Various SMP balancing algorithms require that the bandwidth period run in sync. Possible improvements are moving the rt_bandwidth thing into root_domain and keeping a span per rt_bandwidth which marks throttled cpus. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 17:44:57 +00:00
}
sched: rt-group: interface Change the rt_ratio interface to rt_runtime_us, to match rt_period_us. This avoids picking a granularity for the ratio. Extend the /sys/kernel/uids/<uid>/ interface to allow setting the group's rt_runtime. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-13 14:45:39 +00:00
long sched_group_rt_runtime(struct task_group *tg)
{
u64 rt_runtime_us;
sched: rt-group: synchonised bandwidth period Various SMP balancing algorithms require that the bandwidth period run in sync. Possible improvements are moving the rt_bandwidth thing into root_domain and keeping a span per rt_bandwidth which marks throttled cpus. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 17:44:57 +00:00
if (tg->rt_bandwidth.rt_runtime == RUNTIME_INF)
sched: rt-group: interface Change the rt_ratio interface to rt_runtime_us, to match rt_period_us. This avoids picking a granularity for the ratio. Extend the /sys/kernel/uids/<uid>/ interface to allow setting the group's rt_runtime. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-13 14:45:39 +00:00
return -1;
sched: rt-group: synchonised bandwidth period Various SMP balancing algorithms require that the bandwidth period run in sync. Possible improvements are moving the rt_bandwidth thing into root_domain and keeping a span per rt_bandwidth which marks throttled cpus. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 17:44:57 +00:00
rt_runtime_us = tg->rt_bandwidth.rt_runtime;
sched: rt-group: interface Change the rt_ratio interface to rt_runtime_us, to match rt_period_us. This avoids picking a granularity for the ratio. Extend the /sys/kernel/uids/<uid>/ interface to allow setting the group's rt_runtime. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-13 14:45:39 +00:00
do_div(rt_runtime_us, NSEC_PER_USEC);
return rt_runtime_us;
}
sched: rt-group: synchonised bandwidth period Various SMP balancing algorithms require that the bandwidth period run in sync. Possible improvements are moving the rt_bandwidth thing into root_domain and keeping a span per rt_bandwidth which marks throttled cpus. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 17:44:57 +00:00
int sched_group_set_rt_period(struct task_group *tg, long rt_period_us)
{
u64 rt_runtime, rt_period;
rt_period = (u64)rt_period_us * NSEC_PER_USEC;
rt_runtime = tg->rt_bandwidth.rt_runtime;
sched: fix divide error when trying to configure rt_period to zero Here it is another little Oops we found while configuring invalid values via cgroups: echo 0 > /dev/cgroups/0/cpu.rt_period_us or echo 4294967296 > /dev/cgroups/0/cpu.rt_period_us [ 205.509825] divide error: 0000 [#1] [ 205.510151] Modules linked in: [ 205.510151] [ 205.510151] Pid: 2339, comm: bash Not tainted (2.6.26-rc8 #33) [ 205.510151] EIP: 0060:[<c030c6ef>] EFLAGS: 00000293 CPU: 0 [ 205.510151] EIP is at div64_u64+0x5f/0x70 [ 205.510151] EAX: 0000389f EBX: 00000000 ECX: 00000000 EDX: 00000000 [ 205.510151] ESI: d9800000 EDI: 00000000 EBP: c6cede60 ESP: c6cede50 [ 205.510151] DS: 007b ES: 007b FS: 0000 GS: 0033 SS: 0068 [ 205.510151] Process bash (pid: 2339, ti=c6cec000 task=c79be370 task.ti=c6cec000) [ 205.510151] Stack: d9800000 0000389f c05971a0 d9800000 c6cedeb4 c0214dbd 00000000 00000000 [ 205.510151] c6cede88 c0242bd8 c05377c0 c7a41b40 00000000 00000000 00000000 c05971a0 [ 205.510151] c780ed20 c7508494 c7a41b40 00000000 00000002 c6cedebc c05971a0 ffffffea [ 205.510151] Call Trace: [ 205.510151] [<c0214dbd>] ? __rt_schedulable+0x1cd/0x240 [ 205.510151] [<c0242bd8>] ? cgroup_file_open+0x18/0xe0 [ 205.510151] [<c0214fe4>] ? tg_set_bandwidth+0xa4/0xf0 [ 205.510151] [<c0215066>] ? sched_group_set_rt_period+0x36/0x50 [ 205.510151] [<c021508e>] ? cpu_rt_period_write_uint+0xe/0x10 [ 205.510151] [<c0242dc5>] ? cgroup_file_write+0x125/0x160 [ 205.510151] [<c0232c15>] ? hrtimer_interrupt+0x155/0x190 [ 205.510151] [<c02f047f>] ? security_file_permission+0xf/0x20 [ 205.510151] [<c0277ad8>] ? rw_verify_area+0x48/0xc0 [ 205.510151] [<c0283744>] ? dupfd+0x104/0x130 [ 205.510151] [<c027838c>] ? vfs_write+0x9c/0x160 [ 205.510151] [<c0242ca0>] ? cgroup_file_write+0x0/0x160 [ 205.510151] [<c027850d>] ? sys_write+0x3d/0x70 [ 205.510151] [<c0203019>] ? sysenter_past_esp+0x6a/0x91 [ 205.510151] ======================= [ 205.510151] Code: 0f 45 de 31 f6 0f ad d0 d3 ea f6 c1 20 0f 45 c2 0f 45 d6 89 45 f0 89 55 f4 8b 55 f4 31 c9 8b 45 f0 39 d3 89 c6 77 08 89 d0 31 d2 <f7> f3 89 c1 83 c4 08 89 f0 f7 f3 89 ca 5b 5e 5d c3 55 89 e5 56 [ 205.510151] EIP: [<c030c6ef>] div64_u64+0x5f/0x70 SS:ESP 0068:c6cede50 The attached patch solves the issue for me. I'm checking as soon as possible for the period not being zero since, if it is, going ahead is useless. This way we also save a mutex_lock() and a read_lock() wrt doing it inside tg_set_bandwidth() or __rt_schedulable(). Signed-off-by: Dario Faggioli <raistlin@linux.it> Signed-off-by: Michael Trimarchi <trimarchimichael@yahoo.it> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-26 16:54:09 +00:00
if (rt_period == 0)
return -EINVAL;
sched: Introduce primitives to account for CFS bandwidth tracking In this patch we introduce the notion of CFS bandwidth, partitioned into globally unassigned bandwidth, and locally claimed bandwidth. - The global bandwidth is per task_group, it represents a pool of unclaimed bandwidth that cfs_rqs can allocate from. - The local bandwidth is tracked per-cfs_rq, this represents allotments from the global pool bandwidth assigned to a specific cpu. Bandwidth is managed via cgroupfs, adding two new interfaces to the cpu subsystem: - cpu.cfs_period_us : the bandwidth period in usecs - cpu.cfs_quota_us : the cpu bandwidth (in usecs) that this tg will be allowed to consume over period above. Signed-off-by: Paul Turner <pjt@google.com> Signed-off-by: Nikhil Rao <ncrao@google.com> Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com> Reviewed-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110721184756.972636699@google.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-21 16:43:28 +00:00
return tg_set_rt_bandwidth(tg, rt_period, rt_runtime);
sched: rt-group: synchonised bandwidth period Various SMP balancing algorithms require that the bandwidth period run in sync. Possible improvements are moving the rt_bandwidth thing into root_domain and keeping a span per rt_bandwidth which marks throttled cpus. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 17:44:57 +00:00
}
long sched_group_rt_period(struct task_group *tg)
{
u64 rt_period_us;
rt_period_us = ktime_to_ns(tg->rt_bandwidth.rt_period);
do_div(rt_period_us, NSEC_PER_USEC);
return rt_period_us;
}
static int sched_rt_global_constraints(void)
{
sched: more sanity checks on the bandwidth settings While playing around with it, I noticed we missed some sanity checks. Also add some comments while we're there. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-23 13:33:44 +00:00
u64 runtime, period;
sched: rt-group: synchonised bandwidth period Various SMP balancing algorithms require that the bandwidth period run in sync. Possible improvements are moving the rt_bandwidth thing into root_domain and keeping a span per rt_bandwidth which marks throttled cpus. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 17:44:57 +00:00
int ret = 0;
sched: fix deadlock in setting scheduler parameter to zero Andrei Gusev wrote: > I played witch scheduler settings. After doing something like: > echo -n 1000000 >sched_rt_period_us > > command is locked. I found in kernel.log: > > Sep 11 00:39:34 zaratustra > Sep 11 00:39:34 zaratustra Pid: 4495, comm: bash Tainted: G W > (2.6.26.3 #12) > Sep 11 00:39:34 zaratustra EIP: 0060:[<c0213fc7>] EFLAGS: 00210246 CPU: 0 > Sep 11 00:39:34 zaratustra EIP is at div64_u64+0x57/0x80 > Sep 11 00:39:34 zaratustra EAX: 0000389f EBX: 00000000 ECX: 00000000 > EDX: 00000000 > Sep 11 00:39:34 zaratustra ESI: d9800000 EDI: d9800000 EBP: 0000389f > ESP: ea7a6edc > Sep 11 00:39:34 zaratustra DS: 007b ES: 007b FS: 0000 GS: 0033 SS: 0068 > Sep 11 00:39:34 zaratustra Process bash (pid: 4495, ti=ea7a6000 > task=ea744000 task.ti=ea7a6000) > Sep 11 00:39:34 zaratustra Stack: 00000000 000003e8 d9800000 0000389f > c0119042 00000000 00000000 00000001 > Sep 11 00:39:34 zaratustra 00000000 00000000 ea7a6f54 00010000 00000000 > c04d2e80 00000001 000e7ef0 > Sep 11 00:39:34 zaratustra c01191a3 00000000 00000000 ea7a6fa0 00000001 > ffffffff c04d2e80 ea5b2480 > Sep 11 00:39:34 zaratustra Call Trace: > Sep 11 00:39:34 zaratustra [<c0119042>] __rt_schedulable+0x52/0x130 > Sep 11 00:39:34 zaratustra [<c01191a3>] sched_rt_handler+0x83/0x120 > Sep 11 00:39:34 zaratustra [<c01a76a6>] proc_sys_call_handler+0xb6/0xd0 > Sep 11 00:39:34 zaratustra [<c01a76c0>] proc_sys_write+0x0/0x20 > Sep 11 00:39:34 zaratustra [<c01a76d9>] proc_sys_write+0x19/0x20 > Sep 11 00:39:34 zaratustra [<c016cc68>] vfs_write+0xa8/0x140 > Sep 11 00:39:34 zaratustra [<c016cdd1>] sys_write+0x41/0x80 > Sep 11 00:39:34 zaratustra [<c0103051>] sysenter_past_esp+0x6a/0x91 > Sep 11 00:39:34 zaratustra ======================= > Sep 11 00:39:34 zaratustra Code: c8 41 0f ad f3 d3 ee f6 c1 20 0f 45 de > 31 f6 0f ad ef d3 ed f6 c1 20 0f 45 fd 0f 45 ee 31 c9 39 eb 89 fe 89 ea > 77 08 89 e8 31 d2 <f7> f3 89 c1 89 f0 8b 7c 24 08 f7 f3 8b 74 24 04 89 > ca 8b 1c 24 > Sep 11 00:39:34 zaratustra EIP: [<c0213fc7>] div64_u64+0x57/0x80 SS:ESP > 0068:ea7a6edc > Sep 11 00:39:34 zaratustra ---[ end trace 4eaa2a86a8e2da22 ]--- fix the boundary condition. sysctl_sched_rt_period=0 makes exception at to_ratio(). Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-11 00:00:19 +00:00
if (sysctl_sched_rt_period <= 0)
return -EINVAL;
sched: more sanity checks on the bandwidth settings While playing around with it, I noticed we missed some sanity checks. Also add some comments while we're there. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-23 13:33:44 +00:00
runtime = global_rt_runtime();
period = global_rt_period();
/*
* Sanity check on the sysctl variables.
*/
if (runtime > period && runtime != RUNTIME_INF)
return -EINVAL;
sched: rt: fix the bandwidth contraint computations Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: "Daniel K." <dk@uw.no> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-19 12:22:27 +00:00
sched: rt-group: synchonised bandwidth period Various SMP balancing algorithms require that the bandwidth period run in sync. Possible improvements are moving the rt_bandwidth thing into root_domain and keeping a span per rt_bandwidth which marks throttled cpus. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 17:44:57 +00:00
mutex_lock(&rt_constraints_mutex);
sched: rt-bandwidth fixes The last patch allows sysctl_sched_rt_runtime to disable bandwidth accounting for the group scheduler - however it doesn't deal with sched_setscheduler(), which will keep tasks out of groups that have no assigned runtime. If we relax this, we get into the situation where RT tasks can get into a group when we disable bandwidth control, and then starve them by enabling it again. Rework the schedulability code to check for this condition and fail to turn on bandwidth control with -EBUSY when this situation is found. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-19 10:33:06 +00:00
read_lock(&tasklist_lock);
sched: more sanity checks on the bandwidth settings While playing around with it, I noticed we missed some sanity checks. Also add some comments while we're there. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-23 13:33:44 +00:00
ret = __rt_schedulable(NULL, 0, 0);
sched: rt-bandwidth fixes The last patch allows sysctl_sched_rt_runtime to disable bandwidth accounting for the group scheduler - however it doesn't deal with sched_setscheduler(), which will keep tasks out of groups that have no assigned runtime. If we relax this, we get into the situation where RT tasks can get into a group when we disable bandwidth control, and then starve them by enabling it again. Rework the schedulability code to check for this condition and fail to turn on bandwidth control with -EBUSY when this situation is found. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-19 10:33:06 +00:00
read_unlock(&tasklist_lock);
sched: rt-group: synchonised bandwidth period Various SMP balancing algorithms require that the bandwidth period run in sync. Possible improvements are moving the rt_bandwidth thing into root_domain and keeping a span per rt_bandwidth which marks throttled cpus. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 17:44:57 +00:00
mutex_unlock(&rt_constraints_mutex);
return ret;
}
sched: don't allow setuid to succeed if the user does not have rt bandwidth Impact: fix hung task with certain (non-default) rt-limit settings Corey Hickey reported that on using setuid to change the uid of a rt process, the process would be unkillable and not be running. This is because there was no rt runtime for that user group. Add in a check to see if a user can attach an rt task to its task group. On failure, return EINVAL, which is also returned in CONFIG_CGROUP_SCHED. Reported-by: Corey Hickey <bugfood-ml@fatooh.org> Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-27 09:43:54 +00:00
int sched_rt_can_attach(struct task_group *tg, struct task_struct *tsk)
{
/* Don't accept realtime tasks when there is no way for them to run */
if (rt_task(tsk) && tg->rt_bandwidth.rt_runtime == 0)
return 0;
return 1;
}
sched: add comments for ifdefs in sched.c make sched.c easier to read. Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-30 12:23:45 +00:00
#else /* !CONFIG_RT_GROUP_SCHED */
sched: rt-group: synchonised bandwidth period Various SMP balancing algorithms require that the bandwidth period run in sync. Possible improvements are moving the rt_bandwidth thing into root_domain and keeping a span per rt_bandwidth which marks throttled cpus. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 17:44:57 +00:00
static int sched_rt_global_constraints(void)
{
sched: rt-group: smp balancing Currently the rt group scheduling does a per cpu runtime limit, however the rt load balancer makes no guarantees about an equal spread of real- time tasks, just that at any one time, the highest priority tasks run. Solve this by making the runtime limit a global property by borrowing excessive runtime from the other cpus once the local limit runs out. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 17:44:58 +00:00
unsigned long flags;
int i;
sched: fix deadlock in setting scheduler parameter to zero Andrei Gusev wrote: > I played witch scheduler settings. After doing something like: > echo -n 1000000 >sched_rt_period_us > > command is locked. I found in kernel.log: > > Sep 11 00:39:34 zaratustra > Sep 11 00:39:34 zaratustra Pid: 4495, comm: bash Tainted: G W > (2.6.26.3 #12) > Sep 11 00:39:34 zaratustra EIP: 0060:[<c0213fc7>] EFLAGS: 00210246 CPU: 0 > Sep 11 00:39:34 zaratustra EIP is at div64_u64+0x57/0x80 > Sep 11 00:39:34 zaratustra EAX: 0000389f EBX: 00000000 ECX: 00000000 > EDX: 00000000 > Sep 11 00:39:34 zaratustra ESI: d9800000 EDI: d9800000 EBP: 0000389f > ESP: ea7a6edc > Sep 11 00:39:34 zaratustra DS: 007b ES: 007b FS: 0000 GS: 0033 SS: 0068 > Sep 11 00:39:34 zaratustra Process bash (pid: 4495, ti=ea7a6000 > task=ea744000 task.ti=ea7a6000) > Sep 11 00:39:34 zaratustra Stack: 00000000 000003e8 d9800000 0000389f > c0119042 00000000 00000000 00000001 > Sep 11 00:39:34 zaratustra 00000000 00000000 ea7a6f54 00010000 00000000 > c04d2e80 00000001 000e7ef0 > Sep 11 00:39:34 zaratustra c01191a3 00000000 00000000 ea7a6fa0 00000001 > ffffffff c04d2e80 ea5b2480 > Sep 11 00:39:34 zaratustra Call Trace: > Sep 11 00:39:34 zaratustra [<c0119042>] __rt_schedulable+0x52/0x130 > Sep 11 00:39:34 zaratustra [<c01191a3>] sched_rt_handler+0x83/0x120 > Sep 11 00:39:34 zaratustra [<c01a76a6>] proc_sys_call_handler+0xb6/0xd0 > Sep 11 00:39:34 zaratustra [<c01a76c0>] proc_sys_write+0x0/0x20 > Sep 11 00:39:34 zaratustra [<c01a76d9>] proc_sys_write+0x19/0x20 > Sep 11 00:39:34 zaratustra [<c016cc68>] vfs_write+0xa8/0x140 > Sep 11 00:39:34 zaratustra [<c016cdd1>] sys_write+0x41/0x80 > Sep 11 00:39:34 zaratustra [<c0103051>] sysenter_past_esp+0x6a/0x91 > Sep 11 00:39:34 zaratustra ======================= > Sep 11 00:39:34 zaratustra Code: c8 41 0f ad f3 d3 ee f6 c1 20 0f 45 de > 31 f6 0f ad ef d3 ed f6 c1 20 0f 45 fd 0f 45 ee 31 c9 39 eb 89 fe 89 ea > 77 08 89 e8 31 d2 <f7> f3 89 c1 89 f0 8b 7c 24 08 f7 f3 8b 74 24 04 89 > ca 8b 1c 24 > Sep 11 00:39:34 zaratustra EIP: [<c0213fc7>] div64_u64+0x57/0x80 SS:ESP > 0068:ea7a6edc > Sep 11 00:39:34 zaratustra ---[ end trace 4eaa2a86a8e2da22 ]--- fix the boundary condition. sysctl_sched_rt_period=0 makes exception at to_ratio(). Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-11 00:00:19 +00:00
if (sysctl_sched_rt_period <= 0)
return -EINVAL;
sched: rt: document the risk of small values in the bandwidth settings Thomas noted that we should disallow sysctl_sched_rt_runtime == 0 for (!RT_GROUP) since the root group always has some RT tasks in it. Further, update the documentation to inspire clue. [ Impact: exclude corner-case sysctl_sched_rt_runtime value ] Reported-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20090505155436.863098054@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-05-05 15:50:21 +00:00
/*
* There's always some RT tasks in the root group
* -- migration, kstopmachine etc..
*/
if (sysctl_sched_rt_runtime == 0)
return -EBUSY;
sched: Convert rt_runtime_lock to raw_spinlock Convert locks which cannot be sleeping locks in preempt-rt to raw_spinlocks. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Ingo Molnar <mingo@elte.hu>
2009-11-17 14:32:06 +00:00
raw_spin_lock_irqsave(&def_rt_bandwidth.rt_runtime_lock, flags);
sched: rt-group: smp balancing Currently the rt group scheduling does a per cpu runtime limit, however the rt load balancer makes no guarantees about an equal spread of real- time tasks, just that at any one time, the highest priority tasks run. Solve this by making the runtime limit a global property by borrowing excessive runtime from the other cpus once the local limit runs out. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 17:44:58 +00:00
for_each_possible_cpu(i) {
struct rt_rq *rt_rq = &cpu_rq(i)->rt;
sched: Convert rt_runtime_lock to raw_spinlock Convert locks which cannot be sleeping locks in preempt-rt to raw_spinlocks. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Ingo Molnar <mingo@elte.hu>
2009-11-17 14:32:06 +00:00
raw_spin_lock(&rt_rq->rt_runtime_lock);
sched: rt-group: smp balancing Currently the rt group scheduling does a per cpu runtime limit, however the rt load balancer makes no guarantees about an equal spread of real- time tasks, just that at any one time, the highest priority tasks run. Solve this by making the runtime limit a global property by borrowing excessive runtime from the other cpus once the local limit runs out. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 17:44:58 +00:00
rt_rq->rt_runtime = global_rt_runtime();
sched: Convert rt_runtime_lock to raw_spinlock Convert locks which cannot be sleeping locks in preempt-rt to raw_spinlocks. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Ingo Molnar <mingo@elte.hu>
2009-11-17 14:32:06 +00:00
raw_spin_unlock(&rt_rq->rt_runtime_lock);
sched: rt-group: smp balancing Currently the rt group scheduling does a per cpu runtime limit, however the rt load balancer makes no guarantees about an equal spread of real- time tasks, just that at any one time, the highest priority tasks run. Solve this by making the runtime limit a global property by borrowing excessive runtime from the other cpus once the local limit runs out. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 17:44:58 +00:00
}
sched: Convert rt_runtime_lock to raw_spinlock Convert locks which cannot be sleeping locks in preempt-rt to raw_spinlocks. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Ingo Molnar <mingo@elte.hu>
2009-11-17 14:32:06 +00:00
raw_spin_unlock_irqrestore(&def_rt_bandwidth.rt_runtime_lock, flags);
sched: rt-group: smp balancing Currently the rt group scheduling does a per cpu runtime limit, however the rt load balancer makes no guarantees about an equal spread of real- time tasks, just that at any one time, the highest priority tasks run. Solve this by making the runtime limit a global property by borrowing excessive runtime from the other cpus once the local limit runs out. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 17:44:58 +00:00
sched: rt-group: synchonised bandwidth period Various SMP balancing algorithms require that the bandwidth period run in sync. Possible improvements are moving the rt_bandwidth thing into root_domain and keeping a span per rt_bandwidth which marks throttled cpus. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 17:44:57 +00:00
return 0;
}
sched: add comments for ifdefs in sched.c make sched.c easier to read. Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-30 12:23:45 +00:00
#endif /* CONFIG_RT_GROUP_SCHED */
sched: rt-group: synchonised bandwidth period Various SMP balancing algorithms require that the bandwidth period run in sync. Possible improvements are moving the rt_bandwidth thing into root_domain and keeping a span per rt_bandwidth which marks throttled cpus. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 17:44:57 +00:00
int sched_rt_handler(struct ctl_table *table, int write,
sysctl: remove "struct file *" argument of ->proc_handler It's unused. It isn't needed -- read or write flag is already passed and sysctl shouldn't care about the rest. It _was_ used in two places at arch/frv for some reason. Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Cc: David Howells <dhowells@redhat.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: "David S. Miller" <davem@davemloft.net> Cc: James Morris <jmorris@namei.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-23 22:57:19 +00:00
void __user *buffer, size_t *lenp,
sched: rt-group: synchonised bandwidth period Various SMP balancing algorithms require that the bandwidth period run in sync. Possible improvements are moving the rt_bandwidth thing into root_domain and keeping a span per rt_bandwidth which marks throttled cpus. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 17:44:57 +00:00
loff_t *ppos)
{
int ret;
int old_period, old_runtime;
static DEFINE_MUTEX(mutex);
mutex_lock(&mutex);
old_period = sysctl_sched_rt_period;
old_runtime = sysctl_sched_rt_runtime;
sysctl: remove "struct file *" argument of ->proc_handler It's unused. It isn't needed -- read or write flag is already passed and sysctl shouldn't care about the rest. It _was_ used in two places at arch/frv for some reason. Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Cc: David Howells <dhowells@redhat.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: "David S. Miller" <davem@davemloft.net> Cc: James Morris <jmorris@namei.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-23 22:57:19 +00:00
ret = proc_dointvec(table, write, buffer, lenp, ppos);
sched: rt-group: synchonised bandwidth period Various SMP balancing algorithms require that the bandwidth period run in sync. Possible improvements are moving the rt_bandwidth thing into root_domain and keeping a span per rt_bandwidth which marks throttled cpus. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 17:44:57 +00:00
if (!ret && write) {
ret = sched_rt_global_constraints();
if (ret) {
sysctl_sched_rt_period = old_period;
sysctl_sched_rt_runtime = old_runtime;
} else {
def_rt_bandwidth.rt_runtime = global_rt_runtime();
def_rt_bandwidth.rt_period =
ns_to_ktime(global_rt_period());
}
}
mutex_unlock(&mutex);
return ret;
}
Hook up group scheduler with control groups Enable "cgroup" (formerly containers) based fair group scheduling. This will let administrator create arbitrary groups of tasks (using "cgroup" pseudo filesystem) and control their cpu bandwidth usage. [akpm@linux-foundation.org: fix cpp condition] Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Cc: Randy Dunlap <randy.dunlap@oracle.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Paul Menage <menage@google.com> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-19 06:41:03 +00:00
sched: rt-group: make rt groups scheduling configurable Make the rt group scheduler compile time configurable. Keep it experimental for now. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-13 14:45:40 +00:00
#ifdef CONFIG_CGROUP_SCHED
Hook up group scheduler with control groups Enable "cgroup" (formerly containers) based fair group scheduling. This will let administrator create arbitrary groups of tasks (using "cgroup" pseudo filesystem) and control their cpu bandwidth usage. [akpm@linux-foundation.org: fix cpp condition] Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Cc: Randy Dunlap <randy.dunlap@oracle.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Paul Menage <menage@google.com> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-19 06:41:03 +00:00
/* return corresponding task_group object of a cgroup */
sched: clean up some control group code - replace "cont" with "cgrp" in a few places in the CFS cgroup code, - use write_uint rather than write for cpu.shares write function Signed-off-by: Paul Menage <menage@google.com> Acked-by : Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-24 16:23:50 +00:00
static inline struct task_group *cgroup_tg(struct cgroup *cgrp)
Hook up group scheduler with control groups Enable "cgroup" (formerly containers) based fair group scheduling. This will let administrator create arbitrary groups of tasks (using "cgroup" pseudo filesystem) and control their cpu bandwidth usage. [akpm@linux-foundation.org: fix cpp condition] Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Cc: Randy Dunlap <randy.dunlap@oracle.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Paul Menage <menage@google.com> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-19 06:41:03 +00:00
{
sched: clean up some control group code - replace "cont" with "cgrp" in a few places in the CFS cgroup code, - use write_uint rather than write for cpu.shares write function Signed-off-by: Paul Menage <menage@google.com> Acked-by : Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-24 16:23:50 +00:00
return container_of(cgroup_subsys_state(cgrp, cpu_cgroup_subsys_id),
struct task_group, css);
Hook up group scheduler with control groups Enable "cgroup" (formerly containers) based fair group scheduling. This will let administrator create arbitrary groups of tasks (using "cgroup" pseudo filesystem) and control their cpu bandwidth usage. [akpm@linux-foundation.org: fix cpp condition] Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Cc: Randy Dunlap <randy.dunlap@oracle.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Paul Menage <menage@google.com> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-19 06:41:03 +00:00
}
static struct cgroup_subsys_state *
sched: clean up some control group code - replace "cont" with "cgrp" in a few places in the CFS cgroup code, - use write_uint rather than write for cpu.shares write function Signed-off-by: Paul Menage <menage@google.com> Acked-by : Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-24 16:23:50 +00:00
cpu_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cgrp)
Hook up group scheduler with control groups Enable "cgroup" (formerly containers) based fair group scheduling. This will let administrator create arbitrary groups of tasks (using "cgroup" pseudo filesystem) and control their cpu bandwidth usage. [akpm@linux-foundation.org: fix cpp condition] Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Cc: Randy Dunlap <randy.dunlap@oracle.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Paul Menage <menage@google.com> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-19 06:41:03 +00:00
{
sched: allow the group scheduler to have multiple levels This patch makes the group scheduler multi hierarchy aware. [a.p.zijlstra@chello.nl: rt-parts and assorted fixes] Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 17:44:59 +00:00
struct task_group *tg, *parent;
Hook up group scheduler with control groups Enable "cgroup" (formerly containers) based fair group scheduling. This will let administrator create arbitrary groups of tasks (using "cgroup" pseudo filesystem) and control their cpu bandwidth usage. [akpm@linux-foundation.org: fix cpp condition] Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Cc: Randy Dunlap <randy.dunlap@oracle.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Paul Menage <menage@google.com> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-19 06:41:03 +00:00
sched: clean up some control group code - replace "cont" with "cgrp" in a few places in the CFS cgroup code, - use write_uint rather than write for cpu.shares write function Signed-off-by: Paul Menage <menage@google.com> Acked-by : Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-24 16:23:50 +00:00
if (!cgrp->parent) {
Hook up group scheduler with control groups Enable "cgroup" (formerly containers) based fair group scheduling. This will let administrator create arbitrary groups of tasks (using "cgroup" pseudo filesystem) and control their cpu bandwidth usage. [akpm@linux-foundation.org: fix cpp condition] Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Cc: Randy Dunlap <randy.dunlap@oracle.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Paul Menage <menage@google.com> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-19 06:41:03 +00:00
/* This is early initialization for the top cgroup */
sched: Consolidate the name of root_task_group and init_task_group root_task_group is the leftover of USER_SCHED, now it's always same to init_task_group. But as Mike suggested, root_task_group is maybe the suitable name to keep for a tree. So in this patch: init_task_group --> root_task_group init_task_group_load --> root_task_group_load INIT_TASK_GROUP_LOAD --> ROOT_TASK_GROUP_LOAD Suggested-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Yong Zhang <yong.zhang0@gmail.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20110107071736.GA32635@windriver.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-01-07 07:17:36 +00:00
return &root_task_group.css;
Hook up group scheduler with control groups Enable "cgroup" (formerly containers) based fair group scheduling. This will let administrator create arbitrary groups of tasks (using "cgroup" pseudo filesystem) and control their cpu bandwidth usage. [akpm@linux-foundation.org: fix cpp condition] Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Cc: Randy Dunlap <randy.dunlap@oracle.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Paul Menage <menage@google.com> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-19 06:41:03 +00:00
}
sched: allow the group scheduler to have multiple levels This patch makes the group scheduler multi hierarchy aware. [a.p.zijlstra@chello.nl: rt-parts and assorted fixes] Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 17:44:59 +00:00
parent = cgroup_tg(cgrp->parent);
tg = sched_create_group(parent);
Hook up group scheduler with control groups Enable "cgroup" (formerly containers) based fair group scheduling. This will let administrator create arbitrary groups of tasks (using "cgroup" pseudo filesystem) and control their cpu bandwidth usage. [akpm@linux-foundation.org: fix cpp condition] Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Cc: Randy Dunlap <randy.dunlap@oracle.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Paul Menage <menage@google.com> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-19 06:41:03 +00:00
if (IS_ERR(tg))
return ERR_PTR(-ENOMEM);
return &tg->css;
}
sched: style cleanups style cleanup of various changes that were done recently. no code changed: text data bss dec hex filename 23680 2542 28 26250 668a sched.o.before 23680 2542 28 26250 668a sched.o.after Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-12-05 14:46:09 +00:00
static void
cpu_cgroup_destroy(struct cgroup_subsys *ss, struct cgroup *cgrp)
Hook up group scheduler with control groups Enable "cgroup" (formerly containers) based fair group scheduling. This will let administrator create arbitrary groups of tasks (using "cgroup" pseudo filesystem) and control their cpu bandwidth usage. [akpm@linux-foundation.org: fix cpp condition] Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Cc: Randy Dunlap <randy.dunlap@oracle.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Paul Menage <menage@google.com> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-19 06:41:03 +00:00
{
sched: clean up some control group code - replace "cont" with "cgrp" in a few places in the CFS cgroup code, - use write_uint rather than write for cpu.shares write function Signed-off-by: Paul Menage <menage@google.com> Acked-by : Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-24 16:23:50 +00:00
struct task_group *tg = cgroup_tg(cgrp);
Hook up group scheduler with control groups Enable "cgroup" (formerly containers) based fair group scheduling. This will let administrator create arbitrary groups of tasks (using "cgroup" pseudo filesystem) and control their cpu bandwidth usage. [akpm@linux-foundation.org: fix cpp condition] Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Cc: Randy Dunlap <randy.dunlap@oracle.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Paul Menage <menage@google.com> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-19 06:41:03 +00:00
sched_destroy_group(tg);
}
sched: style cleanups style cleanup of various changes that were done recently. no code changed: text data bss dec hex filename 23680 2542 28 26250 668a sched.o.before 23680 2542 28 26250 668a sched.o.after Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-12-05 14:46:09 +00:00
static int
cgroups: let ss->can_attach and ss->attach do whole threadgroups at a time Alter the ss->can_attach and ss->attach functions to be able to deal with a whole threadgroup at a time, for use in cgroup_attach_proc. (This is a pre-patch to cgroup-procs-writable.patch.) Currently, new mode of the attach function can only tell the subsystem about the old cgroup of the threadgroup leader. No subsystem currently needs that information for each thread that's being moved, but if one were to be added (for example, one that counts tasks within a group) this bit would need to be reworked a bit to tell the subsystem the right information. [hidave.darkstar@gmail.com: fix build] Signed-off-by: Ben Blum <bblum@google.com> Signed-off-by: Paul Menage <menage@google.com> Acked-by: Li Zefan <lizf@cn.fujitsu.com> Reviewed-by: Matt Helsley <matthltc@us.ibm.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Ingo Molnar <mingo@elte.hu> Cc: Dave Young <hidave.darkstar@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-23 22:56:31 +00:00
cpu_cgroup_can_attach_task(struct cgroup *cgrp, struct task_struct *tsk)
Hook up group scheduler with control groups Enable "cgroup" (formerly containers) based fair group scheduling. This will let administrator create arbitrary groups of tasks (using "cgroup" pseudo filesystem) and control their cpu bandwidth usage. [akpm@linux-foundation.org: fix cpp condition] Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Cc: Randy Dunlap <randy.dunlap@oracle.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Paul Menage <menage@google.com> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-19 06:41:03 +00:00
{
sched: rt-group: refure unrunnable tasks Refuse to accept or create RT tasks in groups that can't run them. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-13 14:45:40 +00:00
#ifdef CONFIG_RT_GROUP_SCHED
sched: don't allow setuid to succeed if the user does not have rt bandwidth Impact: fix hung task with certain (non-default) rt-limit settings Corey Hickey reported that on using setuid to change the uid of a rt process, the process would be unkillable and not be running. This is because there was no rt runtime for that user group. Add in a check to see if a user can attach an rt task to its task group. On failure, return EINVAL, which is also returned in CONFIG_CGROUP_SCHED. Reported-by: Corey Hickey <bugfood-ml@fatooh.org> Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-27 09:43:54 +00:00
if (!sched_rt_can_attach(cgroup_tg(cgrp), tsk))
sched: rt-group: refure unrunnable tasks Refuse to accept or create RT tasks in groups that can't run them. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-13 14:45:40 +00:00
return -EINVAL;
#else
Hook up group scheduler with control groups Enable "cgroup" (formerly containers) based fair group scheduling. This will let administrator create arbitrary groups of tasks (using "cgroup" pseudo filesystem) and control their cpu bandwidth usage. [akpm@linux-foundation.org: fix cpp condition] Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Cc: Randy Dunlap <randy.dunlap@oracle.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Paul Menage <menage@google.com> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-19 06:41:03 +00:00
/* We don't support RT-tasks being in separate groups */
if (tsk->sched_class != &fair_sched_class)
return -EINVAL;
sched: rt-group: refure unrunnable tasks Refuse to accept or create RT tasks in groups that can't run them. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-13 14:45:40 +00:00
#endif
cgroups: let ss->can_attach and ss->attach do whole threadgroups at a time Alter the ss->can_attach and ss->attach functions to be able to deal with a whole threadgroup at a time, for use in cgroup_attach_proc. (This is a pre-patch to cgroup-procs-writable.patch.) Currently, new mode of the attach function can only tell the subsystem about the old cgroup of the threadgroup leader. No subsystem currently needs that information for each thread that's being moved, but if one were to be added (for example, one that counts tasks within a group) this bit would need to be reworked a bit to tell the subsystem the right information. [hidave.darkstar@gmail.com: fix build] Signed-off-by: Ben Blum <bblum@google.com> Signed-off-by: Paul Menage <menage@google.com> Acked-by: Li Zefan <lizf@cn.fujitsu.com> Reviewed-by: Matt Helsley <matthltc@us.ibm.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Ingo Molnar <mingo@elte.hu> Cc: Dave Young <hidave.darkstar@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-23 22:56:31 +00:00
return 0;
}
Hook up group scheduler with control groups Enable "cgroup" (formerly containers) based fair group scheduling. This will let administrator create arbitrary groups of tasks (using "cgroup" pseudo filesystem) and control their cpu bandwidth usage. [akpm@linux-foundation.org: fix cpp condition] Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Cc: Randy Dunlap <randy.dunlap@oracle.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Paul Menage <menage@google.com> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-19 06:41:03 +00:00
static void
cgroups: add per-thread subsystem callbacks Add cgroup subsystem callbacks for per-thread attachment in atomic contexts Add can_attach_task(), pre_attach(), and attach_task() as new callbacks for cgroups's subsystem interface. Unlike can_attach and attach, these are for per-thread operations, to be called potentially many times when attaching an entire threadgroup. Also, the old "bool threadgroup" interface is removed, as replaced by this. All subsystems are modified for the new interface - of note is cpuset, which requires from/to nodemasks for attach to be globally scoped (though per-cpuset would work too) to persist from its pre_attach to attach_task and attach. This is a pre-patch for cgroup-procs-writable.patch. Signed-off-by: Ben Blum <bblum@andrew.cmu.edu> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Matt Helsley <matthltc@us.ibm.com> Reviewed-by: Paul Menage <menage@google.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: Miao Xie <miaox@cn.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-05-26 23:25:19 +00:00
cpu_cgroup_attach_task(struct cgroup *cgrp, struct task_struct *tsk)
Hook up group scheduler with control groups Enable "cgroup" (formerly containers) based fair group scheduling. This will let administrator create arbitrary groups of tasks (using "cgroup" pseudo filesystem) and control their cpu bandwidth usage. [akpm@linux-foundation.org: fix cpp condition] Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Cc: Randy Dunlap <randy.dunlap@oracle.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Paul Menage <menage@google.com> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-19 06:41:03 +00:00
{
sched_move_task(tsk);
}
sched, cgroup: Use exit hook to avoid use-after-free crash By not notifying the controller of the on-exit move back to init_css_set, we fail to move the task out of the previous cgroup's cfs_rq. This leads to an opportunity for a cgroup-destroy to come in and free the cgroup (there are no active tasks left in it after all) to which the not-quite dead task is still enqueued. Reported-by: Miklos Vajna <vmiklos@frugalware.org> Fixed-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: <stable@kernel.org> Cc: Mike Galbraith <efault@gmx.de> Signed-off-by: Ingo Molnar <mingo@elte.hu> LKML-Reference: <1293206353.29444.205.camel@laptop>
2011-01-19 11:26:11 +00:00
static void
cgroup: Fix cgroup_subsys::exit callback Make the ::exit method act like ::attach, it is after all very nearly the same thing. The bug had no effect on correctness - fixing it is an optimization for the scheduler. Also, later perf-cgroups patches rely on it. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Paul Menage <menage@google.com> LKML-Reference: <1297160655.13327.92.camel@laptop> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-02-07 16:02:20 +00:00
cpu_cgroup_exit(struct cgroup_subsys *ss, struct cgroup *cgrp,
struct cgroup *old_cgrp, struct task_struct *task)
sched, cgroup: Use exit hook to avoid use-after-free crash By not notifying the controller of the on-exit move back to init_css_set, we fail to move the task out of the previous cgroup's cfs_rq. This leads to an opportunity for a cgroup-destroy to come in and free the cgroup (there are no active tasks left in it after all) to which the not-quite dead task is still enqueued. Reported-by: Miklos Vajna <vmiklos@frugalware.org> Fixed-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: <stable@kernel.org> Cc: Mike Galbraith <efault@gmx.de> Signed-off-by: Ingo Molnar <mingo@elte.hu> LKML-Reference: <1293206353.29444.205.camel@laptop>
2011-01-19 11:26:11 +00:00
{
/*
* cgroup_exit() is called in the copy_process() failure path.
* Ignore this case since the task hasn't ran yet, this avoids
* trying to poke a half freed task state from generic code.
*/
if (!(task->flags & PF_EXITING))
return;
sched_move_task(task);
}
sched: rt-group: make rt groups scheduling configurable Make the rt group scheduler compile time configurable. Keep it experimental for now. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-13 14:45:40 +00:00
#ifdef CONFIG_FAIR_GROUP_SCHED
CGroup API files: rename read/write_uint methods to read_write_u64 Several people have justifiably complained that the "_uint" suffix is inappropriate for functions that handle u64 values, so this patch just renames all these functions and their users to have the suffic _u64. [peterz@infradead.org: build fix] Signed-off-by: Paul Menage <menage@google.com> Cc: "Li Zefan" <lizf@cn.fujitsu.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Paul Jackson <pj@sgi.com> Cc: Pavel Emelyanov <xemul@openvz.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: "YAMAMOTO Takashi" <yamamoto@valinux.co.jp> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29 07:59:56 +00:00
static int cpu_shares_write_u64(struct cgroup *cgrp, struct cftype *cftype,
sched: clean up some control group code - replace "cont" with "cgrp" in a few places in the CFS cgroup code, - use write_uint rather than write for cpu.shares write function Signed-off-by: Paul Menage <menage@google.com> Acked-by : Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-24 16:23:50 +00:00
u64 shareval)
Hook up group scheduler with control groups Enable "cgroup" (formerly containers) based fair group scheduling. This will let administrator create arbitrary groups of tasks (using "cgroup" pseudo filesystem) and control their cpu bandwidth usage. [akpm@linux-foundation.org: fix cpp condition] Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Cc: Randy Dunlap <randy.dunlap@oracle.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Paul Menage <menage@google.com> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-19 06:41:03 +00:00
{
sched: Increase SCHED_LOAD_SCALE resolution Introduce SCHED_LOAD_RESOLUTION, which scales is added to SCHED_LOAD_SHIFT and increases the resolution of SCHED_LOAD_SCALE. This patch sets the value of SCHED_LOAD_RESOLUTION to 10, scaling up the weights for all sched entities by a factor of 1024. With this extra resolution, we can handle deeper cgroup hiearchies and the scheduler can do better shares distribution and load load balancing on larger systems (especially for low weight task groups). This does not change the existing user interface, the scaled weights are only used internally. We do not modify prio_to_weight values or inverses, but use the original weights when calculating the inverse which is used to scale execution time delta in calc_delta_mine(). This ensures we do not lose accuracy when accounting time to the sched entities. Thanks to Nikunj Dadhania for fixing an bug in c_d_m() that broken fairness. Below is some analysis of the performance costs/improvements of this patch. 1. Micro-arch performance costs: Experiment was to run Ingo's pipe_test_100k 200 times with the task pinned to one cpu. I measured instruction, cycles and stalled-cycles for the runs. See: http://thread.gmane.org/gmane.linux.kernel/1129232/focus=1129389 for more info. -tip (baseline): Performance counter stats for '/root/load-scale/pipe-test-100k' (200 runs): 964,991,769 instructions # 0.82 insns per cycle # 0.33 stalled cycles per insn # ( +- 0.05% ) 1,171,186,635 cycles # 0.000 GHz ( +- 0.08% ) 306,373,664 stalled-cycles-backend # 26.16% backend cycles idle ( +- 0.28% ) 314,933,621 stalled-cycles-frontend # 26.89% frontend cycles idle ( +- 0.34% ) 1.122405684 seconds time elapsed ( +- 0.05% ) -tip+patches: Performance counter stats for './load-scale/pipe-test-100k' (200 runs): 963,624,821 instructions # 0.82 insns per cycle # 0.33 stalled cycles per insn # ( +- 0.04% ) 1,175,215,649 cycles # 0.000 GHz ( +- 0.08% ) 315,321,126 stalled-cycles-backend # 26.83% backend cycles idle ( +- 0.28% ) 316,835,873 stalled-cycles-frontend # 26.96% frontend cycles idle ( +- 0.29% ) 1.122238659 seconds time elapsed ( +- 0.06% ) With this patch, instructions decrease by ~0.10% and cycles increase by 0.27%. This doesn't look statistically significant. The number of stalled cycles in the backend increased from 26.16% to 26.83%. This can be attributed to the shifts we do in c_d_m() and other places. The fraction of stalled cycles in the frontend remains about the same, at 26.96% compared to 26.89% in -tip. 2. Balancing low-weight task groups Test setup: run 50 tasks with random sleep/busy times (biased around 100ms) in a low weight container (with cpu.shares = 2). Measure %idle as reported by mpstat over a 10s window. -tip (baseline): 06:47:48 PM CPU %usr %nice %sys %iowait %irq %soft %steal %guest %idle intr/s 06:47:49 PM all 94.32 0.00 0.06 0.00 0.00 0.00 0.00 0.00 5.62 15888.00 06:47:50 PM all 94.57 0.00 0.62 0.00 0.00 0.00 0.00 0.00 4.81 16180.00 06:47:51 PM all 94.69 0.00 0.06 0.00 0.00 0.00 0.00 0.00 5.25 15966.00 06:47:52 PM all 95.81 0.00 0.00 0.00 0.00 0.00 0.00 0.00 4.19 16053.00 06:47:53 PM all 94.88 0.06 0.00 0.00 0.00 0.00 0.00 0.00 5.06 15984.00 06:47:54 PM all 93.31 0.00 0.00 0.00 0.00 0.00 0.00 0.00 6.69 15806.00 06:47:55 PM all 94.19 0.00 0.06 0.00 0.00 0.00 0.00 0.00 5.75 15896.00 06:47:56 PM all 92.87 0.00 0.00 0.00 0.00 0.00 0.00 0.00 7.13 15716.00 06:47:57 PM all 94.88 0.00 0.00 0.00 0.00 0.00 0.00 0.00 5.12 15982.00 06:47:58 PM all 95.44 0.00 0.00 0.00 0.00 0.00 0.00 0.00 4.56 16075.00 Average: all 94.49 0.01 0.08 0.00 0.00 0.00 0.00 0.00 5.42 15954.60 -tip+patches: 06:47:03 PM CPU %usr %nice %sys %iowait %irq %soft %steal %guest %idle intr/s 06:47:04 PM all 100.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 16630.00 06:47:05 PM all 99.69 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.31 16580.20 06:47:06 PM all 99.69 0.00 0.06 0.00 0.00 0.00 0.00 0.00 0.25 16596.00 06:47:07 PM all 99.20 0.00 0.74 0.00 0.00 0.06 0.00 0.00 0.00 17838.61 06:47:08 PM all 100.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 16540.00 06:47:09 PM all 100.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 16575.00 06:47:10 PM all 100.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 16614.00 06:47:11 PM all 99.94 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.06 16588.00 06:47:12 PM all 99.94 0.00 0.06 0.00 0.00 0.00 0.00 0.00 0.00 16593.00 06:47:13 PM all 99.94 0.00 0.06 0.00 0.00 0.00 0.00 0.00 0.00 16551.00 Average: all 99.84 0.00 0.09 0.00 0.00 0.01 0.00 0.00 0.06 16711.58 We see an improvement in idle% on the system (drops from 5.42% on -tip to 0.06% with the patches). We see an improvement in idle% on the system (drops from 5.42% on -tip to 0.06% with the patches). Signed-off-by: Nikhil Rao <ncrao@google.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Nikunj A. Dadhania <nikunj@linux.vnet.ibm.com> Cc: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Cc: Stephan Barwolf <stephan.baerwolf@tu-ilmenau.de> Cc: Mike Galbraith <efault@gmx.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/1305754668-18792-1-git-send-email-ncrao@google.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-05-18 21:37:48 +00:00
return sched_group_set_shares(cgroup_tg(cgrp), scale_load(shareval));
Hook up group scheduler with control groups Enable "cgroup" (formerly containers) based fair group scheduling. This will let administrator create arbitrary groups of tasks (using "cgroup" pseudo filesystem) and control their cpu bandwidth usage. [akpm@linux-foundation.org: fix cpp condition] Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Cc: Randy Dunlap <randy.dunlap@oracle.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Paul Menage <menage@google.com> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-19 06:41:03 +00:00
}
CGroup API files: rename read/write_uint methods to read_write_u64 Several people have justifiably complained that the "_uint" suffix is inappropriate for functions that handle u64 values, so this patch just renames all these functions and their users to have the suffic _u64. [peterz@infradead.org: build fix] Signed-off-by: Paul Menage <menage@google.com> Cc: "Li Zefan" <lizf@cn.fujitsu.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Paul Jackson <pj@sgi.com> Cc: Pavel Emelyanov <xemul@openvz.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: "YAMAMOTO Takashi" <yamamoto@valinux.co.jp> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29 07:59:56 +00:00
static u64 cpu_shares_read_u64(struct cgroup *cgrp, struct cftype *cft)
Hook up group scheduler with control groups Enable "cgroup" (formerly containers) based fair group scheduling. This will let administrator create arbitrary groups of tasks (using "cgroup" pseudo filesystem) and control their cpu bandwidth usage. [akpm@linux-foundation.org: fix cpp condition] Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Cc: Randy Dunlap <randy.dunlap@oracle.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Paul Menage <menage@google.com> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-19 06:41:03 +00:00
{
sched: clean up some control group code - replace "cont" with "cgrp" in a few places in the CFS cgroup code, - use write_uint rather than write for cpu.shares write function Signed-off-by: Paul Menage <menage@google.com> Acked-by : Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-24 16:23:50 +00:00
struct task_group *tg = cgroup_tg(cgrp);
Hook up group scheduler with control groups Enable "cgroup" (formerly containers) based fair group scheduling. This will let administrator create arbitrary groups of tasks (using "cgroup" pseudo filesystem) and control their cpu bandwidth usage. [akpm@linux-foundation.org: fix cpp condition] Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Cc: Randy Dunlap <randy.dunlap@oracle.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Paul Menage <menage@google.com> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-19 06:41:03 +00:00
sched: Increase SCHED_LOAD_SCALE resolution Introduce SCHED_LOAD_RESOLUTION, which scales is added to SCHED_LOAD_SHIFT and increases the resolution of SCHED_LOAD_SCALE. This patch sets the value of SCHED_LOAD_RESOLUTION to 10, scaling up the weights for all sched entities by a factor of 1024. With this extra resolution, we can handle deeper cgroup hiearchies and the scheduler can do better shares distribution and load load balancing on larger systems (especially for low weight task groups). This does not change the existing user interface, the scaled weights are only used internally. We do not modify prio_to_weight values or inverses, but use the original weights when calculating the inverse which is used to scale execution time delta in calc_delta_mine(). This ensures we do not lose accuracy when accounting time to the sched entities. Thanks to Nikunj Dadhania for fixing an bug in c_d_m() that broken fairness. Below is some analysis of the performance costs/improvements of this patch. 1. Micro-arch performance costs: Experiment was to run Ingo's pipe_test_100k 200 times with the task pinned to one cpu. I measured instruction, cycles and stalled-cycles for the runs. See: http://thread.gmane.org/gmane.linux.kernel/1129232/focus=1129389 for more info. -tip (baseline): Performance counter stats for '/root/load-scale/pipe-test-100k' (200 runs): 964,991,769 instructions # 0.82 insns per cycle # 0.33 stalled cycles per insn # ( +- 0.05% ) 1,171,186,635 cycles # 0.000 GHz ( +- 0.08% ) 306,373,664 stalled-cycles-backend # 26.16% backend cycles idle ( +- 0.28% ) 314,933,621 stalled-cycles-frontend # 26.89% frontend cycles idle ( +- 0.34% ) 1.122405684 seconds time elapsed ( +- 0.05% ) -tip+patches: Performance counter stats for './load-scale/pipe-test-100k' (200 runs): 963,624,821 instructions # 0.82 insns per cycle # 0.33 stalled cycles per insn # ( +- 0.04% ) 1,175,215,649 cycles # 0.000 GHz ( +- 0.08% ) 315,321,126 stalled-cycles-backend # 26.83% backend cycles idle ( +- 0.28% ) 316,835,873 stalled-cycles-frontend # 26.96% frontend cycles idle ( +- 0.29% ) 1.122238659 seconds time elapsed ( +- 0.06% ) With this patch, instructions decrease by ~0.10% and cycles increase by 0.27%. This doesn't look statistically significant. The number of stalled cycles in the backend increased from 26.16% to 26.83%. This can be attributed to the shifts we do in c_d_m() and other places. The fraction of stalled cycles in the frontend remains about the same, at 26.96% compared to 26.89% in -tip. 2. Balancing low-weight task groups Test setup: run 50 tasks with random sleep/busy times (biased around 100ms) in a low weight container (with cpu.shares = 2). Measure %idle as reported by mpstat over a 10s window. -tip (baseline): 06:47:48 PM CPU %usr %nice %sys %iowait %irq %soft %steal %guest %idle intr/s 06:47:49 PM all 94.32 0.00 0.06 0.00 0.00 0.00 0.00 0.00 5.62 15888.00 06:47:50 PM all 94.57 0.00 0.62 0.00 0.00 0.00 0.00 0.00 4.81 16180.00 06:47:51 PM all 94.69 0.00 0.06 0.00 0.00 0.00 0.00 0.00 5.25 15966.00 06:47:52 PM all 95.81 0.00 0.00 0.00 0.00 0.00 0.00 0.00 4.19 16053.00 06:47:53 PM all 94.88 0.06 0.00 0.00 0.00 0.00 0.00 0.00 5.06 15984.00 06:47:54 PM all 93.31 0.00 0.00 0.00 0.00 0.00 0.00 0.00 6.69 15806.00 06:47:55 PM all 94.19 0.00 0.06 0.00 0.00 0.00 0.00 0.00 5.75 15896.00 06:47:56 PM all 92.87 0.00 0.00 0.00 0.00 0.00 0.00 0.00 7.13 15716.00 06:47:57 PM all 94.88 0.00 0.00 0.00 0.00 0.00 0.00 0.00 5.12 15982.00 06:47:58 PM all 95.44 0.00 0.00 0.00 0.00 0.00 0.00 0.00 4.56 16075.00 Average: all 94.49 0.01 0.08 0.00 0.00 0.00 0.00 0.00 5.42 15954.60 -tip+patches: 06:47:03 PM CPU %usr %nice %sys %iowait %irq %soft %steal %guest %idle intr/s 06:47:04 PM all 100.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 16630.00 06:47:05 PM all 99.69 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.31 16580.20 06:47:06 PM all 99.69 0.00 0.06 0.00 0.00 0.00 0.00 0.00 0.25 16596.00 06:47:07 PM all 99.20 0.00 0.74 0.00 0.00 0.06 0.00 0.00 0.00 17838.61 06:47:08 PM all 100.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 16540.00 06:47:09 PM all 100.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 16575.00 06:47:10 PM all 100.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 16614.00 06:47:11 PM all 99.94 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.06 16588.00 06:47:12 PM all 99.94 0.00 0.06 0.00 0.00 0.00 0.00 0.00 0.00 16593.00 06:47:13 PM all 99.94 0.00 0.06 0.00 0.00 0.00 0.00 0.00 0.00 16551.00 Average: all 99.84 0.00 0.09 0.00 0.00 0.01 0.00 0.00 0.06 16711.58 We see an improvement in idle% on the system (drops from 5.42% on -tip to 0.06% with the patches). We see an improvement in idle% on the system (drops from 5.42% on -tip to 0.06% with the patches). Signed-off-by: Nikhil Rao <ncrao@google.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Nikunj A. Dadhania <nikunj@linux.vnet.ibm.com> Cc: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Cc: Stephan Barwolf <stephan.baerwolf@tu-ilmenau.de> Cc: Mike Galbraith <efault@gmx.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/1305754668-18792-1-git-send-email-ncrao@google.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-05-18 21:37:48 +00:00
return (u64) scale_load_down(tg->shares);
Hook up group scheduler with control groups Enable "cgroup" (formerly containers) based fair group scheduling. This will let administrator create arbitrary groups of tasks (using "cgroup" pseudo filesystem) and control their cpu bandwidth usage. [akpm@linux-foundation.org: fix cpp condition] Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Cc: Randy Dunlap <randy.dunlap@oracle.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Paul Menage <menage@google.com> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-19 06:41:03 +00:00
}
sched: Introduce primitives to account for CFS bandwidth tracking In this patch we introduce the notion of CFS bandwidth, partitioned into globally unassigned bandwidth, and locally claimed bandwidth. - The global bandwidth is per task_group, it represents a pool of unclaimed bandwidth that cfs_rqs can allocate from. - The local bandwidth is tracked per-cfs_rq, this represents allotments from the global pool bandwidth assigned to a specific cpu. Bandwidth is managed via cgroupfs, adding two new interfaces to the cpu subsystem: - cpu.cfs_period_us : the bandwidth period in usecs - cpu.cfs_quota_us : the cpu bandwidth (in usecs) that this tg will be allowed to consume over period above. Signed-off-by: Paul Turner <pjt@google.com> Signed-off-by: Nikhil Rao <ncrao@google.com> Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com> Reviewed-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110721184756.972636699@google.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-21 16:43:28 +00:00
#ifdef CONFIG_CFS_BANDWIDTH
sched: Validate CFS quota hierarchies Add constraints validation for CFS bandwidth hierarchies. Validate that: max(child bandwidth) <= parent_bandwidth In a quota limited hierarchy, an unconstrained entity (e.g. bandwidth==RUNTIME_INF) inherits the bandwidth of its parent. This constraint is chosen over sum(child_bandwidth) as notion of over-commit is valuable within SCHED_OTHER. Some basic code from the RT case is re-factored for reuse. Signed-off-by: Paul Turner <pjt@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110721184757.083774572@google.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-21 16:43:29 +00:00
static DEFINE_MUTEX(cfs_constraints_mutex);
sched: Introduce primitives to account for CFS bandwidth tracking In this patch we introduce the notion of CFS bandwidth, partitioned into globally unassigned bandwidth, and locally claimed bandwidth. - The global bandwidth is per task_group, it represents a pool of unclaimed bandwidth that cfs_rqs can allocate from. - The local bandwidth is tracked per-cfs_rq, this represents allotments from the global pool bandwidth assigned to a specific cpu. Bandwidth is managed via cgroupfs, adding two new interfaces to the cpu subsystem: - cpu.cfs_period_us : the bandwidth period in usecs - cpu.cfs_quota_us : the cpu bandwidth (in usecs) that this tg will be allowed to consume over period above. Signed-off-by: Paul Turner <pjt@google.com> Signed-off-by: Nikhil Rao <ncrao@google.com> Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com> Reviewed-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110721184756.972636699@google.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-21 16:43:28 +00:00
const u64 max_cfs_quota_period = 1 * NSEC_PER_SEC; /* 1s */
const u64 min_cfs_quota_period = 1 * NSEC_PER_MSEC; /* 1ms */
sched: Validate CFS quota hierarchies Add constraints validation for CFS bandwidth hierarchies. Validate that: max(child bandwidth) <= parent_bandwidth In a quota limited hierarchy, an unconstrained entity (e.g. bandwidth==RUNTIME_INF) inherits the bandwidth of its parent. This constraint is chosen over sum(child_bandwidth) as notion of over-commit is valuable within SCHED_OTHER. Some basic code from the RT case is re-factored for reuse. Signed-off-by: Paul Turner <pjt@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110721184757.083774572@google.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-21 16:43:29 +00:00
static int __cfs_schedulable(struct task_group *tg, u64 period, u64 runtime);
sched: Introduce primitives to account for CFS bandwidth tracking In this patch we introduce the notion of CFS bandwidth, partitioned into globally unassigned bandwidth, and locally claimed bandwidth. - The global bandwidth is per task_group, it represents a pool of unclaimed bandwidth that cfs_rqs can allocate from. - The local bandwidth is tracked per-cfs_rq, this represents allotments from the global pool bandwidth assigned to a specific cpu. Bandwidth is managed via cgroupfs, adding two new interfaces to the cpu subsystem: - cpu.cfs_period_us : the bandwidth period in usecs - cpu.cfs_quota_us : the cpu bandwidth (in usecs) that this tg will be allowed to consume over period above. Signed-off-by: Paul Turner <pjt@google.com> Signed-off-by: Nikhil Rao <ncrao@google.com> Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com> Reviewed-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110721184756.972636699@google.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-21 16:43:28 +00:00
static int tg_set_cfs_bandwidth(struct task_group *tg, u64 period, u64 quota)
{
sched: Validate CFS quota hierarchies Add constraints validation for CFS bandwidth hierarchies. Validate that: max(child bandwidth) <= parent_bandwidth In a quota limited hierarchy, an unconstrained entity (e.g. bandwidth==RUNTIME_INF) inherits the bandwidth of its parent. This constraint is chosen over sum(child_bandwidth) as notion of over-commit is valuable within SCHED_OTHER. Some basic code from the RT case is re-factored for reuse. Signed-off-by: Paul Turner <pjt@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110721184757.083774572@google.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-21 16:43:29 +00:00
int i, ret = 0;
sched: Introduce primitives to account for CFS bandwidth tracking In this patch we introduce the notion of CFS bandwidth, partitioned into globally unassigned bandwidth, and locally claimed bandwidth. - The global bandwidth is per task_group, it represents a pool of unclaimed bandwidth that cfs_rqs can allocate from. - The local bandwidth is tracked per-cfs_rq, this represents allotments from the global pool bandwidth assigned to a specific cpu. Bandwidth is managed via cgroupfs, adding two new interfaces to the cpu subsystem: - cpu.cfs_period_us : the bandwidth period in usecs - cpu.cfs_quota_us : the cpu bandwidth (in usecs) that this tg will be allowed to consume over period above. Signed-off-by: Paul Turner <pjt@google.com> Signed-off-by: Nikhil Rao <ncrao@google.com> Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com> Reviewed-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110721184756.972636699@google.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-21 16:43:28 +00:00
struct cfs_bandwidth *cfs_b = tg_cfs_bandwidth(tg);
if (tg == &root_task_group)
return -EINVAL;
/*
* Ensure we have at some amount of bandwidth every period. This is
* to prevent reaching a state of large arrears when throttled via
* entity_tick() resulting in prolonged exit starvation.
*/
if (quota < min_cfs_quota_period || period < min_cfs_quota_period)
return -EINVAL;
/*
* Likewise, bound things on the otherside by preventing insane quota
* periods. This also allows us to normalize in computing quota
* feasibility.
*/
if (period > max_cfs_quota_period)
return -EINVAL;
sched: Validate CFS quota hierarchies Add constraints validation for CFS bandwidth hierarchies. Validate that: max(child bandwidth) <= parent_bandwidth In a quota limited hierarchy, an unconstrained entity (e.g. bandwidth==RUNTIME_INF) inherits the bandwidth of its parent. This constraint is chosen over sum(child_bandwidth) as notion of over-commit is valuable within SCHED_OTHER. Some basic code from the RT case is re-factored for reuse. Signed-off-by: Paul Turner <pjt@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110721184757.083774572@google.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-21 16:43:29 +00:00
mutex_lock(&cfs_constraints_mutex);
ret = __cfs_schedulable(tg, period, quota);
if (ret)
goto out_unlock;
sched: Introduce primitives to account for CFS bandwidth tracking In this patch we introduce the notion of CFS bandwidth, partitioned into globally unassigned bandwidth, and locally claimed bandwidth. - The global bandwidth is per task_group, it represents a pool of unclaimed bandwidth that cfs_rqs can allocate from. - The local bandwidth is tracked per-cfs_rq, this represents allotments from the global pool bandwidth assigned to a specific cpu. Bandwidth is managed via cgroupfs, adding two new interfaces to the cpu subsystem: - cpu.cfs_period_us : the bandwidth period in usecs - cpu.cfs_quota_us : the cpu bandwidth (in usecs) that this tg will be allowed to consume over period above. Signed-off-by: Paul Turner <pjt@google.com> Signed-off-by: Nikhil Rao <ncrao@google.com> Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com> Reviewed-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110721184756.972636699@google.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-21 16:43:28 +00:00
raw_spin_lock_irq(&cfs_b->lock);
cfs_b->period = ns_to_ktime(period);
cfs_b->quota = quota;
sched: Accumulate per-cfs_rq cpu usage and charge against bandwidth Account bandwidth usage on the cfs_rq level versus the task_groups to which they belong. Whether we are tracking bandwidth on a given cfs_rq is maintained under cfs_rq->runtime_enabled. cfs_rq's which belong to a bandwidth constrained task_group have their runtime accounted via the update_curr() path, which withdraws bandwidth from the global pool as desired. Updates involving the global pool are currently protected under cfs_bandwidth->lock, local runtime is protected by rq->lock. This patch only assigns and tracks quota, no action is taken in the case that cfs_rq->runtime_used exceeds cfs_rq->runtime_assigned. Signed-off-by: Paul Turner <pjt@google.com> Signed-off-by: Nikhil Rao <ncrao@google.com> Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com> Reviewed-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110721184757.179386821@google.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-21 16:43:30 +00:00
cfs_b->runtime = quota;
sched: Introduce primitives to account for CFS bandwidth tracking In this patch we introduce the notion of CFS bandwidth, partitioned into globally unassigned bandwidth, and locally claimed bandwidth. - The global bandwidth is per task_group, it represents a pool of unclaimed bandwidth that cfs_rqs can allocate from. - The local bandwidth is tracked per-cfs_rq, this represents allotments from the global pool bandwidth assigned to a specific cpu. Bandwidth is managed via cgroupfs, adding two new interfaces to the cpu subsystem: - cpu.cfs_period_us : the bandwidth period in usecs - cpu.cfs_quota_us : the cpu bandwidth (in usecs) that this tg will be allowed to consume over period above. Signed-off-by: Paul Turner <pjt@google.com> Signed-off-by: Nikhil Rao <ncrao@google.com> Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com> Reviewed-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110721184756.972636699@google.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-21 16:43:28 +00:00
raw_spin_unlock_irq(&cfs_b->lock);
for_each_possible_cpu(i) {
struct cfs_rq *cfs_rq = tg->cfs_rq[i];
struct rq *rq = rq_of(cfs_rq);
raw_spin_lock_irq(&rq->lock);
cfs_rq->runtime_enabled = quota != RUNTIME_INF;
cfs_rq->runtime_remaining = 0;
raw_spin_unlock_irq(&rq->lock);
}
sched: Validate CFS quota hierarchies Add constraints validation for CFS bandwidth hierarchies. Validate that: max(child bandwidth) <= parent_bandwidth In a quota limited hierarchy, an unconstrained entity (e.g. bandwidth==RUNTIME_INF) inherits the bandwidth of its parent. This constraint is chosen over sum(child_bandwidth) as notion of over-commit is valuable within SCHED_OTHER. Some basic code from the RT case is re-factored for reuse. Signed-off-by: Paul Turner <pjt@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110721184757.083774572@google.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-21 16:43:29 +00:00
out_unlock:
mutex_unlock(&cfs_constraints_mutex);
sched: Introduce primitives to account for CFS bandwidth tracking In this patch we introduce the notion of CFS bandwidth, partitioned into globally unassigned bandwidth, and locally claimed bandwidth. - The global bandwidth is per task_group, it represents a pool of unclaimed bandwidth that cfs_rqs can allocate from. - The local bandwidth is tracked per-cfs_rq, this represents allotments from the global pool bandwidth assigned to a specific cpu. Bandwidth is managed via cgroupfs, adding two new interfaces to the cpu subsystem: - cpu.cfs_period_us : the bandwidth period in usecs - cpu.cfs_quota_us : the cpu bandwidth (in usecs) that this tg will be allowed to consume over period above. Signed-off-by: Paul Turner <pjt@google.com> Signed-off-by: Nikhil Rao <ncrao@google.com> Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com> Reviewed-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110721184756.972636699@google.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-21 16:43:28 +00:00
sched: Validate CFS quota hierarchies Add constraints validation for CFS bandwidth hierarchies. Validate that: max(child bandwidth) <= parent_bandwidth In a quota limited hierarchy, an unconstrained entity (e.g. bandwidth==RUNTIME_INF) inherits the bandwidth of its parent. This constraint is chosen over sum(child_bandwidth) as notion of over-commit is valuable within SCHED_OTHER. Some basic code from the RT case is re-factored for reuse. Signed-off-by: Paul Turner <pjt@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110721184757.083774572@google.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-21 16:43:29 +00:00
return ret;
sched: Introduce primitives to account for CFS bandwidth tracking In this patch we introduce the notion of CFS bandwidth, partitioned into globally unassigned bandwidth, and locally claimed bandwidth. - The global bandwidth is per task_group, it represents a pool of unclaimed bandwidth that cfs_rqs can allocate from. - The local bandwidth is tracked per-cfs_rq, this represents allotments from the global pool bandwidth assigned to a specific cpu. Bandwidth is managed via cgroupfs, adding two new interfaces to the cpu subsystem: - cpu.cfs_period_us : the bandwidth period in usecs - cpu.cfs_quota_us : the cpu bandwidth (in usecs) that this tg will be allowed to consume over period above. Signed-off-by: Paul Turner <pjt@google.com> Signed-off-by: Nikhil Rao <ncrao@google.com> Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com> Reviewed-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110721184756.972636699@google.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-21 16:43:28 +00:00
}
int tg_set_cfs_quota(struct task_group *tg, long cfs_quota_us)
{
u64 quota, period;
period = ktime_to_ns(tg_cfs_bandwidth(tg)->period);
if (cfs_quota_us < 0)
quota = RUNTIME_INF;
else
quota = (u64)cfs_quota_us * NSEC_PER_USEC;
return tg_set_cfs_bandwidth(tg, period, quota);
}
long tg_get_cfs_quota(struct task_group *tg)
{
u64 quota_us;
if (tg_cfs_bandwidth(tg)->quota == RUNTIME_INF)
return -1;
quota_us = tg_cfs_bandwidth(tg)->quota;
do_div(quota_us, NSEC_PER_USEC);
return quota_us;
}
int tg_set_cfs_period(struct task_group *tg, long cfs_period_us)
{
u64 quota, period;
period = (u64)cfs_period_us * NSEC_PER_USEC;
quota = tg_cfs_bandwidth(tg)->quota;
if (period <= 0)
return -EINVAL;
return tg_set_cfs_bandwidth(tg, period, quota);
}
long tg_get_cfs_period(struct task_group *tg)
{
u64 cfs_period_us;
cfs_period_us = ktime_to_ns(tg_cfs_bandwidth(tg)->period);
do_div(cfs_period_us, NSEC_PER_USEC);
return cfs_period_us;
}
static s64 cpu_cfs_quota_read_s64(struct cgroup *cgrp, struct cftype *cft)
{
return tg_get_cfs_quota(cgroup_tg(cgrp));
}
static int cpu_cfs_quota_write_s64(struct cgroup *cgrp, struct cftype *cftype,
s64 cfs_quota_us)
{
return tg_set_cfs_quota(cgroup_tg(cgrp), cfs_quota_us);
}
static u64 cpu_cfs_period_read_u64(struct cgroup *cgrp, struct cftype *cft)
{
return tg_get_cfs_period(cgroup_tg(cgrp));
}
static int cpu_cfs_period_write_u64(struct cgroup *cgrp, struct cftype *cftype,
u64 cfs_period_us)
{
return tg_set_cfs_period(cgroup_tg(cgrp), cfs_period_us);
}
sched: Validate CFS quota hierarchies Add constraints validation for CFS bandwidth hierarchies. Validate that: max(child bandwidth) <= parent_bandwidth In a quota limited hierarchy, an unconstrained entity (e.g. bandwidth==RUNTIME_INF) inherits the bandwidth of its parent. This constraint is chosen over sum(child_bandwidth) as notion of over-commit is valuable within SCHED_OTHER. Some basic code from the RT case is re-factored for reuse. Signed-off-by: Paul Turner <pjt@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110721184757.083774572@google.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-21 16:43:29 +00:00
struct cfs_schedulable_data {
struct task_group *tg;
u64 period, quota;
};
/*
* normalize group quota/period to be quota/max_period
* note: units are usecs
*/
static u64 normalize_cfs_quota(struct task_group *tg,
struct cfs_schedulable_data *d)
{
u64 quota, period;
if (tg == d->tg) {
period = d->period;
quota = d->quota;
} else {
period = tg_get_cfs_period(tg);
quota = tg_get_cfs_quota(tg);
}
/* note: these should typically be equivalent */
if (quota == RUNTIME_INF || quota == -1)
return RUNTIME_INF;
return to_ratio(period, quota);
}
static int tg_cfs_schedulable_down(struct task_group *tg, void *data)
{
struct cfs_schedulable_data *d = data;
struct cfs_bandwidth *cfs_b = tg_cfs_bandwidth(tg);
s64 quota = 0, parent_quota = -1;
if (!tg->parent) {
quota = RUNTIME_INF;
} else {
struct cfs_bandwidth *parent_b = tg_cfs_bandwidth(tg->parent);
quota = normalize_cfs_quota(tg, d);
parent_quota = parent_b->hierarchal_quota;
/*
* ensure max(child_quota) <= parent_quota, inherit when no
* limit is set
*/
if (quota == RUNTIME_INF)
quota = parent_quota;
else if (parent_quota != RUNTIME_INF && quota > parent_quota)
return -EINVAL;
}
cfs_b->hierarchal_quota = quota;
return 0;
}
static int __cfs_schedulable(struct task_group *tg, u64 period, u64 quota)
{
struct cfs_schedulable_data data = {
.tg = tg,
.period = period,
.quota = quota,
};
if (quota != RUNTIME_INF) {
do_div(data.period, NSEC_PER_USEC);
do_div(data.quota, NSEC_PER_USEC);
}
return walk_tg_tree(tg_cfs_schedulable_down, tg_nop, &data);
}
sched: Introduce primitives to account for CFS bandwidth tracking In this patch we introduce the notion of CFS bandwidth, partitioned into globally unassigned bandwidth, and locally claimed bandwidth. - The global bandwidth is per task_group, it represents a pool of unclaimed bandwidth that cfs_rqs can allocate from. - The local bandwidth is tracked per-cfs_rq, this represents allotments from the global pool bandwidth assigned to a specific cpu. Bandwidth is managed via cgroupfs, adding two new interfaces to the cpu subsystem: - cpu.cfs_period_us : the bandwidth period in usecs - cpu.cfs_quota_us : the cpu bandwidth (in usecs) that this tg will be allowed to consume over period above. Signed-off-by: Paul Turner <pjt@google.com> Signed-off-by: Nikhil Rao <ncrao@google.com> Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com> Reviewed-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110721184756.972636699@google.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-21 16:43:28 +00:00
#endif /* CONFIG_CFS_BANDWIDTH */
sched: add comments for ifdefs in sched.c make sched.c easier to read. Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-30 12:23:45 +00:00
#endif /* CONFIG_FAIR_GROUP_SCHED */
Hook up group scheduler with control groups Enable "cgroup" (formerly containers) based fair group scheduling. This will let administrator create arbitrary groups of tasks (using "cgroup" pseudo filesystem) and control their cpu bandwidth usage. [akpm@linux-foundation.org: fix cpp condition] Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Cc: Randy Dunlap <randy.dunlap@oracle.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Paul Menage <menage@google.com> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-19 06:41:03 +00:00
sched: rt-group: make rt groups scheduling configurable Make the rt group scheduler compile time configurable. Keep it experimental for now. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-13 14:45:40 +00:00
#ifdef CONFIG_RT_GROUP_SCHED
cgroups: fix compile warning Return type of cpu_rt_runtime_write() should be int instead of ssize_t. Signed-off-by: Mirco Tischler <mt-ml@gmx.de> Acked-by: Paul Menage <menage@google.com> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-05-14 23:05:46 +00:00
static int cpu_rt_runtime_write(struct cgroup *cgrp, struct cftype *cft,
CGroups _s64 files: use read_s64/write_s64 in CFS cgroup for rt_runtime file This removes some filesystem boilerplate from the CFS cgroup subsystem. Signed-off-by: Paul Menage <menage@google.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29 08:00:06 +00:00
s64 val)
sched: rt group scheduling Extend group scheduling to also cover the realtime classes. It uses the time limiting introduced by the previous patch to allow multiple realtime groups. The hard time limit is required to keep behaviour deterministic. The algorithms used make the realtime scheduler O(tg), linear scaling wrt the number of task groups. This is the worst case behaviour I can't seem to get out of, the avg. case of the algorithms can be improved, I focused on correctness and worst case. [ akpm@linux-foundation.org: move side-effects out of BUG_ON(). ] Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:30 +00:00
{
CGroups _s64 files: use read_s64/write_s64 in CFS cgroup for rt_runtime file This removes some filesystem boilerplate from the CFS cgroup subsystem. Signed-off-by: Paul Menage <menage@google.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29 08:00:06 +00:00
return sched_group_set_rt_runtime(cgroup_tg(cgrp), val);
sched: rt group scheduling Extend group scheduling to also cover the realtime classes. It uses the time limiting introduced by the previous patch to allow multiple realtime groups. The hard time limit is required to keep behaviour deterministic. The algorithms used make the realtime scheduler O(tg), linear scaling wrt the number of task groups. This is the worst case behaviour I can't seem to get out of, the avg. case of the algorithms can be improved, I focused on correctness and worst case. [ akpm@linux-foundation.org: move side-effects out of BUG_ON(). ] Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:30 +00:00
}
CGroups _s64 files: use read_s64/write_s64 in CFS cgroup for rt_runtime file This removes some filesystem boilerplate from the CFS cgroup subsystem. Signed-off-by: Paul Menage <menage@google.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29 08:00:06 +00:00
static s64 cpu_rt_runtime_read(struct cgroup *cgrp, struct cftype *cft)
sched: rt group scheduling Extend group scheduling to also cover the realtime classes. It uses the time limiting introduced by the previous patch to allow multiple realtime groups. The hard time limit is required to keep behaviour deterministic. The algorithms used make the realtime scheduler O(tg), linear scaling wrt the number of task groups. This is the worst case behaviour I can't seem to get out of, the avg. case of the algorithms can be improved, I focused on correctness and worst case. [ akpm@linux-foundation.org: move side-effects out of BUG_ON(). ] Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:30 +00:00
{
CGroups _s64 files: use read_s64/write_s64 in CFS cgroup for rt_runtime file This removes some filesystem boilerplate from the CFS cgroup subsystem. Signed-off-by: Paul Menage <menage@google.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29 08:00:06 +00:00
return sched_group_rt_runtime(cgroup_tg(cgrp));
sched: rt group scheduling Extend group scheduling to also cover the realtime classes. It uses the time limiting introduced by the previous patch to allow multiple realtime groups. The hard time limit is required to keep behaviour deterministic. The algorithms used make the realtime scheduler O(tg), linear scaling wrt the number of task groups. This is the worst case behaviour I can't seem to get out of, the avg. case of the algorithms can be improved, I focused on correctness and worst case. [ akpm@linux-foundation.org: move side-effects out of BUG_ON(). ] Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:30 +00:00
}
sched: rt-group: synchonised bandwidth period Various SMP balancing algorithms require that the bandwidth period run in sync. Possible improvements are moving the rt_bandwidth thing into root_domain and keeping a span per rt_bandwidth which marks throttled cpus. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 17:44:57 +00:00
static int cpu_rt_period_write_uint(struct cgroup *cgrp, struct cftype *cftype,
u64 rt_period_us)
{
return sched_group_set_rt_period(cgroup_tg(cgrp), rt_period_us);
}
static u64 cpu_rt_period_read_uint(struct cgroup *cgrp, struct cftype *cft)
{
return sched_group_rt_period(cgroup_tg(cgrp));
}
sched: add comments for ifdefs in sched.c make sched.c easier to read. Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-30 12:23:45 +00:00
#endif /* CONFIG_RT_GROUP_SCHED */
sched: rt group scheduling Extend group scheduling to also cover the realtime classes. It uses the time limiting introduced by the previous patch to allow multiple realtime groups. The hard time limit is required to keep behaviour deterministic. The algorithms used make the realtime scheduler O(tg), linear scaling wrt the number of task groups. This is the worst case behaviour I can't seem to get out of, the avg. case of the algorithms can be improved, I focused on correctness and worst case. [ akpm@linux-foundation.org: move side-effects out of BUG_ON(). ] Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:30 +00:00
sched: report CPU usage in CFS cgroup directories Adds a cpu.usage file to the CFS cgroup that reports CPU usage in milliseconds for that cgroup's tasks [ mingo@elte.hu: style cleanups. ] Signed-off-by: Paul Menage <menage@google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-29 20:18:11 +00:00
static struct cftype cpu_files[] = {
sched: rt-group: make rt groups scheduling configurable Make the rt group scheduler compile time configurable. Keep it experimental for now. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-13 14:45:40 +00:00
#ifdef CONFIG_FAIR_GROUP_SCHED
sched: report CPU usage in CFS cgroup directories Adds a cpu.usage file to the CFS cgroup that reports CPU usage in milliseconds for that cgroup's tasks [ mingo@elte.hu: style cleanups. ] Signed-off-by: Paul Menage <menage@google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-29 20:18:11 +00:00
{
.name = "shares",
CGroup API files: rename read/write_uint methods to read_write_u64 Several people have justifiably complained that the "_uint" suffix is inappropriate for functions that handle u64 values, so this patch just renames all these functions and their users to have the suffic _u64. [peterz@infradead.org: build fix] Signed-off-by: Paul Menage <menage@google.com> Cc: "Li Zefan" <lizf@cn.fujitsu.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Paul Jackson <pj@sgi.com> Cc: Pavel Emelyanov <xemul@openvz.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: "YAMAMOTO Takashi" <yamamoto@valinux.co.jp> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29 07:59:56 +00:00
.read_u64 = cpu_shares_read_u64,
.write_u64 = cpu_shares_write_u64,
sched: report CPU usage in CFS cgroup directories Adds a cpu.usage file to the CFS cgroup that reports CPU usage in milliseconds for that cgroup's tasks [ mingo@elte.hu: style cleanups. ] Signed-off-by: Paul Menage <menage@google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-29 20:18:11 +00:00
},
sched: rt-group: make rt groups scheduling configurable Make the rt group scheduler compile time configurable. Keep it experimental for now. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-13 14:45:40 +00:00
#endif
sched: Introduce primitives to account for CFS bandwidth tracking In this patch we introduce the notion of CFS bandwidth, partitioned into globally unassigned bandwidth, and locally claimed bandwidth. - The global bandwidth is per task_group, it represents a pool of unclaimed bandwidth that cfs_rqs can allocate from. - The local bandwidth is tracked per-cfs_rq, this represents allotments from the global pool bandwidth assigned to a specific cpu. Bandwidth is managed via cgroupfs, adding two new interfaces to the cpu subsystem: - cpu.cfs_period_us : the bandwidth period in usecs - cpu.cfs_quota_us : the cpu bandwidth (in usecs) that this tg will be allowed to consume over period above. Signed-off-by: Paul Turner <pjt@google.com> Signed-off-by: Nikhil Rao <ncrao@google.com> Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com> Reviewed-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110721184756.972636699@google.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-21 16:43:28 +00:00
#ifdef CONFIG_CFS_BANDWIDTH
{
.name = "cfs_quota_us",
.read_s64 = cpu_cfs_quota_read_s64,
.write_s64 = cpu_cfs_quota_write_s64,
},
{
.name = "cfs_period_us",
.read_u64 = cpu_cfs_period_read_u64,
.write_u64 = cpu_cfs_period_write_u64,
},
#endif
sched: rt-group: make rt groups scheduling configurable Make the rt group scheduler compile time configurable. Keep it experimental for now. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-13 14:45:40 +00:00
#ifdef CONFIG_RT_GROUP_SCHED
sched: rt group scheduling Extend group scheduling to also cover the realtime classes. It uses the time limiting introduced by the previous patch to allow multiple realtime groups. The hard time limit is required to keep behaviour deterministic. The algorithms used make the realtime scheduler O(tg), linear scaling wrt the number of task groups. This is the worst case behaviour I can't seem to get out of, the avg. case of the algorithms can be improved, I focused on correctness and worst case. [ akpm@linux-foundation.org: move side-effects out of BUG_ON(). ] Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:30 +00:00
{
sched: rt-group: interface Change the rt_ratio interface to rt_runtime_us, to match rt_period_us. This avoids picking a granularity for the ratio. Extend the /sys/kernel/uids/<uid>/ interface to allow setting the group's rt_runtime. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-13 14:45:39 +00:00
.name = "rt_runtime_us",
CGroups _s64 files: use read_s64/write_s64 in CFS cgroup for rt_runtime file This removes some filesystem boilerplate from the CFS cgroup subsystem. Signed-off-by: Paul Menage <menage@google.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29 08:00:06 +00:00
.read_s64 = cpu_rt_runtime_read,
.write_s64 = cpu_rt_runtime_write,
sched: rt group scheduling Extend group scheduling to also cover the realtime classes. It uses the time limiting introduced by the previous patch to allow multiple realtime groups. The hard time limit is required to keep behaviour deterministic. The algorithms used make the realtime scheduler O(tg), linear scaling wrt the number of task groups. This is the worst case behaviour I can't seem to get out of, the avg. case of the algorithms can be improved, I focused on correctness and worst case. [ akpm@linux-foundation.org: move side-effects out of BUG_ON(). ] Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 20:08:30 +00:00
},
sched: rt-group: synchonised bandwidth period Various SMP balancing algorithms require that the bandwidth period run in sync. Possible improvements are moving the rt_bandwidth thing into root_domain and keeping a span per rt_bandwidth which marks throttled cpus. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 17:44:57 +00:00
{
.name = "rt_period_us",
CGroup API files: rename read/write_uint methods to read_write_u64 Several people have justifiably complained that the "_uint" suffix is inappropriate for functions that handle u64 values, so this patch just renames all these functions and their users to have the suffic _u64. [peterz@infradead.org: build fix] Signed-off-by: Paul Menage <menage@google.com> Cc: "Li Zefan" <lizf@cn.fujitsu.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Paul Jackson <pj@sgi.com> Cc: Pavel Emelyanov <xemul@openvz.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: "YAMAMOTO Takashi" <yamamoto@valinux.co.jp> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29 07:59:56 +00:00
.read_u64 = cpu_rt_period_read_uint,
.write_u64 = cpu_rt_period_write_uint,
sched: rt-group: synchonised bandwidth period Various SMP balancing algorithms require that the bandwidth period run in sync. Possible improvements are moving the rt_bandwidth thing into root_domain and keeping a span per rt_bandwidth which marks throttled cpus. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 17:44:57 +00:00
},
sched: rt-group: make rt groups scheduling configurable Make the rt group scheduler compile time configurable. Keep it experimental for now. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-13 14:45:40 +00:00
#endif
Hook up group scheduler with control groups Enable "cgroup" (formerly containers) based fair group scheduling. This will let administrator create arbitrary groups of tasks (using "cgroup" pseudo filesystem) and control their cpu bandwidth usage. [akpm@linux-foundation.org: fix cpp condition] Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Cc: Randy Dunlap <randy.dunlap@oracle.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Paul Menage <menage@google.com> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-19 06:41:03 +00:00
};
static int cpu_cgroup_populate(struct cgroup_subsys *ss, struct cgroup *cont)
{
sched: report CPU usage in CFS cgroup directories Adds a cpu.usage file to the CFS cgroup that reports CPU usage in milliseconds for that cgroup's tasks [ mingo@elte.hu: style cleanups. ] Signed-off-by: Paul Menage <menage@google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-29 20:18:11 +00:00
return cgroup_add_files(cont, ss, cpu_files, ARRAY_SIZE(cpu_files));
Hook up group scheduler with control groups Enable "cgroup" (formerly containers) based fair group scheduling. This will let administrator create arbitrary groups of tasks (using "cgroup" pseudo filesystem) and control their cpu bandwidth usage. [akpm@linux-foundation.org: fix cpp condition] Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Cc: Randy Dunlap <randy.dunlap@oracle.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Paul Menage <menage@google.com> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-19 06:41:03 +00:00
}
struct cgroup_subsys cpu_cgroup_subsys = {
sched: fix style in kernel/sched.c fallout of recent commits: small coding style fixes. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-29 20:18:11 +00:00
.name = "cpu",
.create = cpu_cgroup_create,
.destroy = cpu_cgroup_destroy,
cgroups: add per-thread subsystem callbacks Add cgroup subsystem callbacks for per-thread attachment in atomic contexts Add can_attach_task(), pre_attach(), and attach_task() as new callbacks for cgroups's subsystem interface. Unlike can_attach and attach, these are for per-thread operations, to be called potentially many times when attaching an entire threadgroup. Also, the old "bool threadgroup" interface is removed, as replaced by this. All subsystems are modified for the new interface - of note is cpuset, which requires from/to nodemasks for attach to be globally scoped (though per-cpuset would work too) to persist from its pre_attach to attach_task and attach. This is a pre-patch for cgroup-procs-writable.patch. Signed-off-by: Ben Blum <bblum@andrew.cmu.edu> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Matt Helsley <matthltc@us.ibm.com> Reviewed-by: Paul Menage <menage@google.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: Miao Xie <miaox@cn.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-05-26 23:25:19 +00:00
.can_attach_task = cpu_cgroup_can_attach_task,
.attach_task = cpu_cgroup_attach_task,
sched, cgroup: Use exit hook to avoid use-after-free crash By not notifying the controller of the on-exit move back to init_css_set, we fail to move the task out of the previous cgroup's cfs_rq. This leads to an opportunity for a cgroup-destroy to come in and free the cgroup (there are no active tasks left in it after all) to which the not-quite dead task is still enqueued. Reported-by: Miklos Vajna <vmiklos@frugalware.org> Fixed-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: <stable@kernel.org> Cc: Mike Galbraith <efault@gmx.de> Signed-off-by: Ingo Molnar <mingo@elte.hu> LKML-Reference: <1293206353.29444.205.camel@laptop>
2011-01-19 11:26:11 +00:00
.exit = cpu_cgroup_exit,
sched: fix style in kernel/sched.c fallout of recent commits: small coding style fixes. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-29 20:18:11 +00:00
.populate = cpu_cgroup_populate,
.subsys_id = cpu_cgroup_subsys_id,
Hook up group scheduler with control groups Enable "cgroup" (formerly containers) based fair group scheduling. This will let administrator create arbitrary groups of tasks (using "cgroup" pseudo filesystem) and control their cpu bandwidth usage. [akpm@linux-foundation.org: fix cpp condition] Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Cc: Randy Dunlap <randy.dunlap@oracle.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Paul Menage <menage@google.com> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-19 06:41:03 +00:00
.early_init = 1,
};
sched: rt-group: make rt groups scheduling configurable Make the rt group scheduler compile time configurable. Keep it experimental for now. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-13 14:45:40 +00:00
#endif /* CONFIG_CGROUP_SCHED */
sched: cpu accounting controller (V2) Commit cfb5285660aad4931b2ebbfa902ea48a37dfffa1 removed a useful feature for us, which provided a cpu accounting resource controller. This feature would be useful if someone wants to group tasks only for accounting purpose and doesnt really want to exercise any control over their cpu consumption. The patch below reintroduces the feature. It is based on Paul Menage's original patch (Commit 62d0df64065e7c135d0002f069444fbdfc64768f), with these differences: - Removed load average information. I felt it needs more thought (esp to deal with SMP and virtualized platforms) and can be added for 2.6.25 after more discussions. - Convert group cpu usage to be nanosecond accurate (as rest of the cfs stats are) and invoke cpuacct_charge() from the respective scheduler classes - Make accounting scalable on SMP systems by splitting the usage counter to be per-cpu - Move the code from kernel/cpu_acct.c to kernel/sched.c (since the code is not big enough to warrant a new file and also this rightly needs to live inside the scheduler. Also things like accessing rq->lock while reading cpu usage becomes easier if the code lived in kernel/sched.c) The patch also modifies the cpu controller not to provide the same accounting information. Tested-by: Balbir Singh <balbir@linux.vnet.ibm.com> Tested the patches on top of 2.6.24-rc3. The patches work fine. Ran some simple tests like cpuspin (spin on the cpu), ran several tasks in the same group and timed them. Compared their time stamps with cpuacct.usage. Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-12-02 19:04:49 +00:00
#ifdef CONFIG_CGROUP_CPUACCT
/*
* CPU accounting code for task groups.
*
* Based on the work by Paul Menage (menage@google.com) and Balbir Singh
* (balbir@in.ibm.com).
*/
sched: add hierarchical accounting to cpu accounting controller Impact: improve CPU time accounting of tasks under the cpu accounting controller Add hierarchical accounting to cpu accounting controller and include cpuacct documentation. Currently, while charging the task's cputime to its accounting group, the accounting group hierarchy isn't updated. This patch charges the cputime of a task to its accounting group and all its parent accounting groups. Reported-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com> Reviewed-by: Paul Menage <menage@google.com> Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-10 15:11:13 +00:00
/* track cpu usage of a group of tasks and its child groups */
sched: cpu accounting controller (V2) Commit cfb5285660aad4931b2ebbfa902ea48a37dfffa1 removed a useful feature for us, which provided a cpu accounting resource controller. This feature would be useful if someone wants to group tasks only for accounting purpose and doesnt really want to exercise any control over their cpu consumption. The patch below reintroduces the feature. It is based on Paul Menage's original patch (Commit 62d0df64065e7c135d0002f069444fbdfc64768f), with these differences: - Removed load average information. I felt it needs more thought (esp to deal with SMP and virtualized platforms) and can be added for 2.6.25 after more discussions. - Convert group cpu usage to be nanosecond accurate (as rest of the cfs stats are) and invoke cpuacct_charge() from the respective scheduler classes - Make accounting scalable on SMP systems by splitting the usage counter to be per-cpu - Move the code from kernel/cpu_acct.c to kernel/sched.c (since the code is not big enough to warrant a new file and also this rightly needs to live inside the scheduler. Also things like accessing rq->lock while reading cpu usage becomes easier if the code lived in kernel/sched.c) The patch also modifies the cpu controller not to provide the same accounting information. Tested-by: Balbir Singh <balbir@linux.vnet.ibm.com> Tested the patches on top of 2.6.24-rc3. The patches work fine. Ran some simple tests like cpuspin (spin on the cpu), ran several tasks in the same group and timed them. Compared their time stamps with cpuacct.usage. Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-12-02 19:04:49 +00:00
struct cpuacct {
struct cgroup_subsys_state css;
/* cpuusage holds pointer to a u64-type object on every cpu */
percpu: add __percpu sparse annotations to core kernel subsystems Add __percpu sparse annotations to core subsystems. These annotations are to make sparse consider percpu variables to be in a different address space and warn if accessed without going through percpu accessors. This patch doesn't affect normal builds. Signed-off-by: Tejun Heo <tj@kernel.org> Reviewed-by: Christoph Lameter <cl@linux-foundation.org> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: linux-mm@kvack.org Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Dipankar Sarma <dipankar@in.ibm.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Eric Biederman <ebiederm@xmission.com>
2010-02-02 05:38:57 +00:00
u64 __percpu *cpuusage;
cpuacct: add per-cgroup utime/stime statistics Add per-cgroup cpuacct controller statistics like the system and user time consumed by the group of tasks. Changelog: v7 - Changed the name of the statistic from utime to user and from stime to system so that in future we could easily add other statistics like irq, softirq, steal times etc easily. v6 - Fixed a bug in the error path of cpuacct_create() (pointed by Li Zefan). v5 - In cpuacct_stats_show(), use cputime64_to_clock_t() since we are operating on a 64bit variable here. v4 - Remove comments in cpuacct_update_stats() which explained why rcu_read_lock() was needed (as per Peter Zijlstra's review comments). - Don't say that percpu_counter_read() is broken in Documentation/cpuacct.txt as per KAMEZAWA Hiroyuki's review comments. v3 - Fix a small race in the cpuacct hierarchy walk. v2 - stime and utime now exported in clock_t units instead of msecs. - Addressed the code review comments from Balbir and Li Zefan. - Moved to -tip tree. v1 - Moved the stime/utime accounting to cpuacct controller. Earlier versions - http://lkml.org/lkml/2009/2/25/129 Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com> Signed-off-by: Balaji Rao <balajirrao@gmail.com> Cc: Dhaval Giani <dhaval@linux.vnet.ibm.com> Cc: Paul Menage <menage@google.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Reviewed-by: Li Zefan <lizf@cn.fujitsu.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com> Tested-by: Balbir Singh <balbir@linux.vnet.ibm.com> LKML-Reference: <20090331043222.GA4093@in.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-31 04:32:22 +00:00
struct percpu_counter cpustat[CPUACCT_STAT_NSTATS];
sched: add hierarchical accounting to cpu accounting controller Impact: improve CPU time accounting of tasks under the cpu accounting controller Add hierarchical accounting to cpu accounting controller and include cpuacct documentation. Currently, while charging the task's cputime to its accounting group, the accounting group hierarchy isn't updated. This patch charges the cputime of a task to its accounting group and all its parent accounting groups. Reported-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com> Reviewed-by: Paul Menage <menage@google.com> Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-10 15:11:13 +00:00
struct cpuacct *parent;
sched: cpu accounting controller (V2) Commit cfb5285660aad4931b2ebbfa902ea48a37dfffa1 removed a useful feature for us, which provided a cpu accounting resource controller. This feature would be useful if someone wants to group tasks only for accounting purpose and doesnt really want to exercise any control over their cpu consumption. The patch below reintroduces the feature. It is based on Paul Menage's original patch (Commit 62d0df64065e7c135d0002f069444fbdfc64768f), with these differences: - Removed load average information. I felt it needs more thought (esp to deal with SMP and virtualized platforms) and can be added for 2.6.25 after more discussions. - Convert group cpu usage to be nanosecond accurate (as rest of the cfs stats are) and invoke cpuacct_charge() from the respective scheduler classes - Make accounting scalable on SMP systems by splitting the usage counter to be per-cpu - Move the code from kernel/cpu_acct.c to kernel/sched.c (since the code is not big enough to warrant a new file and also this rightly needs to live inside the scheduler. Also things like accessing rq->lock while reading cpu usage becomes easier if the code lived in kernel/sched.c) The patch also modifies the cpu controller not to provide the same accounting information. Tested-by: Balbir Singh <balbir@linux.vnet.ibm.com> Tested the patches on top of 2.6.24-rc3. The patches work fine. Ran some simple tests like cpuspin (spin on the cpu), ran several tasks in the same group and timed them. Compared their time stamps with cpuacct.usage. Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-12-02 19:04:49 +00:00
};
struct cgroup_subsys cpuacct_subsys;
/* return cpu accounting group corresponding to this container */
sched: cleanup cpuacct variable names Change the variable names to the common convention for the cpuacct subsystem. Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-29 04:32:43 +00:00
static inline struct cpuacct *cgroup_ca(struct cgroup *cgrp)
sched: cpu accounting controller (V2) Commit cfb5285660aad4931b2ebbfa902ea48a37dfffa1 removed a useful feature for us, which provided a cpu accounting resource controller. This feature would be useful if someone wants to group tasks only for accounting purpose and doesnt really want to exercise any control over their cpu consumption. The patch below reintroduces the feature. It is based on Paul Menage's original patch (Commit 62d0df64065e7c135d0002f069444fbdfc64768f), with these differences: - Removed load average information. I felt it needs more thought (esp to deal with SMP and virtualized platforms) and can be added for 2.6.25 after more discussions. - Convert group cpu usage to be nanosecond accurate (as rest of the cfs stats are) and invoke cpuacct_charge() from the respective scheduler classes - Make accounting scalable on SMP systems by splitting the usage counter to be per-cpu - Move the code from kernel/cpu_acct.c to kernel/sched.c (since the code is not big enough to warrant a new file and also this rightly needs to live inside the scheduler. Also things like accessing rq->lock while reading cpu usage becomes easier if the code lived in kernel/sched.c) The patch also modifies the cpu controller not to provide the same accounting information. Tested-by: Balbir Singh <balbir@linux.vnet.ibm.com> Tested the patches on top of 2.6.24-rc3. The patches work fine. Ran some simple tests like cpuspin (spin on the cpu), ran several tasks in the same group and timed them. Compared their time stamps with cpuacct.usage. Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-12-02 19:04:49 +00:00
{
sched: cleanup cpuacct variable names Change the variable names to the common convention for the cpuacct subsystem. Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-29 04:32:43 +00:00
return container_of(cgroup_subsys_state(cgrp, cpuacct_subsys_id),
sched: cpu accounting controller (V2) Commit cfb5285660aad4931b2ebbfa902ea48a37dfffa1 removed a useful feature for us, which provided a cpu accounting resource controller. This feature would be useful if someone wants to group tasks only for accounting purpose and doesnt really want to exercise any control over their cpu consumption. The patch below reintroduces the feature. It is based on Paul Menage's original patch (Commit 62d0df64065e7c135d0002f069444fbdfc64768f), with these differences: - Removed load average information. I felt it needs more thought (esp to deal with SMP and virtualized platforms) and can be added for 2.6.25 after more discussions. - Convert group cpu usage to be nanosecond accurate (as rest of the cfs stats are) and invoke cpuacct_charge() from the respective scheduler classes - Make accounting scalable on SMP systems by splitting the usage counter to be per-cpu - Move the code from kernel/cpu_acct.c to kernel/sched.c (since the code is not big enough to warrant a new file and also this rightly needs to live inside the scheduler. Also things like accessing rq->lock while reading cpu usage becomes easier if the code lived in kernel/sched.c) The patch also modifies the cpu controller not to provide the same accounting information. Tested-by: Balbir Singh <balbir@linux.vnet.ibm.com> Tested the patches on top of 2.6.24-rc3. The patches work fine. Ran some simple tests like cpuspin (spin on the cpu), ran several tasks in the same group and timed them. Compared their time stamps with cpuacct.usage. Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-12-02 19:04:49 +00:00
struct cpuacct, css);
}
/* return cpu accounting group to which this task belongs */
static inline struct cpuacct *task_ca(struct task_struct *tsk)
{
return container_of(task_subsys_state(tsk, cpuacct_subsys_id),
struct cpuacct, css);
}
/* create a new cpu accounting group */
static struct cgroup_subsys_state *cpuacct_create(
sched: cleanup cpuacct variable names Change the variable names to the common convention for the cpuacct subsystem. Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-29 04:32:43 +00:00
struct cgroup_subsys *ss, struct cgroup *cgrp)
sched: cpu accounting controller (V2) Commit cfb5285660aad4931b2ebbfa902ea48a37dfffa1 removed a useful feature for us, which provided a cpu accounting resource controller. This feature would be useful if someone wants to group tasks only for accounting purpose and doesnt really want to exercise any control over their cpu consumption. The patch below reintroduces the feature. It is based on Paul Menage's original patch (Commit 62d0df64065e7c135d0002f069444fbdfc64768f), with these differences: - Removed load average information. I felt it needs more thought (esp to deal with SMP and virtualized platforms) and can be added for 2.6.25 after more discussions. - Convert group cpu usage to be nanosecond accurate (as rest of the cfs stats are) and invoke cpuacct_charge() from the respective scheduler classes - Make accounting scalable on SMP systems by splitting the usage counter to be per-cpu - Move the code from kernel/cpu_acct.c to kernel/sched.c (since the code is not big enough to warrant a new file and also this rightly needs to live inside the scheduler. Also things like accessing rq->lock while reading cpu usage becomes easier if the code lived in kernel/sched.c) The patch also modifies the cpu controller not to provide the same accounting information. Tested-by: Balbir Singh <balbir@linux.vnet.ibm.com> Tested the patches on top of 2.6.24-rc3. The patches work fine. Ran some simple tests like cpuspin (spin on the cpu), ran several tasks in the same group and timed them. Compared their time stamps with cpuacct.usage. Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-12-02 19:04:49 +00:00
{
struct cpuacct *ca = kzalloc(sizeof(*ca), GFP_KERNEL);
cpuacct: add per-cgroup utime/stime statistics Add per-cgroup cpuacct controller statistics like the system and user time consumed by the group of tasks. Changelog: v7 - Changed the name of the statistic from utime to user and from stime to system so that in future we could easily add other statistics like irq, softirq, steal times etc easily. v6 - Fixed a bug in the error path of cpuacct_create() (pointed by Li Zefan). v5 - In cpuacct_stats_show(), use cputime64_to_clock_t() since we are operating on a 64bit variable here. v4 - Remove comments in cpuacct_update_stats() which explained why rcu_read_lock() was needed (as per Peter Zijlstra's review comments). - Don't say that percpu_counter_read() is broken in Documentation/cpuacct.txt as per KAMEZAWA Hiroyuki's review comments. v3 - Fix a small race in the cpuacct hierarchy walk. v2 - stime and utime now exported in clock_t units instead of msecs. - Addressed the code review comments from Balbir and Li Zefan. - Moved to -tip tree. v1 - Moved the stime/utime accounting to cpuacct controller. Earlier versions - http://lkml.org/lkml/2009/2/25/129 Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com> Signed-off-by: Balaji Rao <balajirrao@gmail.com> Cc: Dhaval Giani <dhaval@linux.vnet.ibm.com> Cc: Paul Menage <menage@google.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Reviewed-by: Li Zefan <lizf@cn.fujitsu.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com> Tested-by: Balbir Singh <balbir@linux.vnet.ibm.com> LKML-Reference: <20090331043222.GA4093@in.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-31 04:32:22 +00:00
int i;
sched: cpu accounting controller (V2) Commit cfb5285660aad4931b2ebbfa902ea48a37dfffa1 removed a useful feature for us, which provided a cpu accounting resource controller. This feature would be useful if someone wants to group tasks only for accounting purpose and doesnt really want to exercise any control over their cpu consumption. The patch below reintroduces the feature. It is based on Paul Menage's original patch (Commit 62d0df64065e7c135d0002f069444fbdfc64768f), with these differences: - Removed load average information. I felt it needs more thought (esp to deal with SMP and virtualized platforms) and can be added for 2.6.25 after more discussions. - Convert group cpu usage to be nanosecond accurate (as rest of the cfs stats are) and invoke cpuacct_charge() from the respective scheduler classes - Make accounting scalable on SMP systems by splitting the usage counter to be per-cpu - Move the code from kernel/cpu_acct.c to kernel/sched.c (since the code is not big enough to warrant a new file and also this rightly needs to live inside the scheduler. Also things like accessing rq->lock while reading cpu usage becomes easier if the code lived in kernel/sched.c) The patch also modifies the cpu controller not to provide the same accounting information. Tested-by: Balbir Singh <balbir@linux.vnet.ibm.com> Tested the patches on top of 2.6.24-rc3. The patches work fine. Ran some simple tests like cpuspin (spin on the cpu), ran several tasks in the same group and timed them. Compared their time stamps with cpuacct.usage. Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-12-02 19:04:49 +00:00
if (!ca)
cpuacct: add per-cgroup utime/stime statistics Add per-cgroup cpuacct controller statistics like the system and user time consumed by the group of tasks. Changelog: v7 - Changed the name of the statistic from utime to user and from stime to system so that in future we could easily add other statistics like irq, softirq, steal times etc easily. v6 - Fixed a bug in the error path of cpuacct_create() (pointed by Li Zefan). v5 - In cpuacct_stats_show(), use cputime64_to_clock_t() since we are operating on a 64bit variable here. v4 - Remove comments in cpuacct_update_stats() which explained why rcu_read_lock() was needed (as per Peter Zijlstra's review comments). - Don't say that percpu_counter_read() is broken in Documentation/cpuacct.txt as per KAMEZAWA Hiroyuki's review comments. v3 - Fix a small race in the cpuacct hierarchy walk. v2 - stime and utime now exported in clock_t units instead of msecs. - Addressed the code review comments from Balbir and Li Zefan. - Moved to -tip tree. v1 - Moved the stime/utime accounting to cpuacct controller. Earlier versions - http://lkml.org/lkml/2009/2/25/129 Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com> Signed-off-by: Balaji Rao <balajirrao@gmail.com> Cc: Dhaval Giani <dhaval@linux.vnet.ibm.com> Cc: Paul Menage <menage@google.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Reviewed-by: Li Zefan <lizf@cn.fujitsu.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com> Tested-by: Balbir Singh <balbir@linux.vnet.ibm.com> LKML-Reference: <20090331043222.GA4093@in.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-31 04:32:22 +00:00
goto out;
sched: cpu accounting controller (V2) Commit cfb5285660aad4931b2ebbfa902ea48a37dfffa1 removed a useful feature for us, which provided a cpu accounting resource controller. This feature would be useful if someone wants to group tasks only for accounting purpose and doesnt really want to exercise any control over their cpu consumption. The patch below reintroduces the feature. It is based on Paul Menage's original patch (Commit 62d0df64065e7c135d0002f069444fbdfc64768f), with these differences: - Removed load average information. I felt it needs more thought (esp to deal with SMP and virtualized platforms) and can be added for 2.6.25 after more discussions. - Convert group cpu usage to be nanosecond accurate (as rest of the cfs stats are) and invoke cpuacct_charge() from the respective scheduler classes - Make accounting scalable on SMP systems by splitting the usage counter to be per-cpu - Move the code from kernel/cpu_acct.c to kernel/sched.c (since the code is not big enough to warrant a new file and also this rightly needs to live inside the scheduler. Also things like accessing rq->lock while reading cpu usage becomes easier if the code lived in kernel/sched.c) The patch also modifies the cpu controller not to provide the same accounting information. Tested-by: Balbir Singh <balbir@linux.vnet.ibm.com> Tested the patches on top of 2.6.24-rc3. The patches work fine. Ran some simple tests like cpuspin (spin on the cpu), ran several tasks in the same group and timed them. Compared their time stamps with cpuacct.usage. Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-12-02 19:04:49 +00:00
ca->cpuusage = alloc_percpu(u64);
cpuacct: add per-cgroup utime/stime statistics Add per-cgroup cpuacct controller statistics like the system and user time consumed by the group of tasks. Changelog: v7 - Changed the name of the statistic from utime to user and from stime to system so that in future we could easily add other statistics like irq, softirq, steal times etc easily. v6 - Fixed a bug in the error path of cpuacct_create() (pointed by Li Zefan). v5 - In cpuacct_stats_show(), use cputime64_to_clock_t() since we are operating on a 64bit variable here. v4 - Remove comments in cpuacct_update_stats() which explained why rcu_read_lock() was needed (as per Peter Zijlstra's review comments). - Don't say that percpu_counter_read() is broken in Documentation/cpuacct.txt as per KAMEZAWA Hiroyuki's review comments. v3 - Fix a small race in the cpuacct hierarchy walk. v2 - stime and utime now exported in clock_t units instead of msecs. - Addressed the code review comments from Balbir and Li Zefan. - Moved to -tip tree. v1 - Moved the stime/utime accounting to cpuacct controller. Earlier versions - http://lkml.org/lkml/2009/2/25/129 Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com> Signed-off-by: Balaji Rao <balajirrao@gmail.com> Cc: Dhaval Giani <dhaval@linux.vnet.ibm.com> Cc: Paul Menage <menage@google.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Reviewed-by: Li Zefan <lizf@cn.fujitsu.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com> Tested-by: Balbir Singh <balbir@linux.vnet.ibm.com> LKML-Reference: <20090331043222.GA4093@in.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-31 04:32:22 +00:00
if (!ca->cpuusage)
goto out_free_ca;
for (i = 0; i < CPUACCT_STAT_NSTATS; i++)
if (percpu_counter_init(&ca->cpustat[i], 0))
goto out_free_counters;
sched: cpu accounting controller (V2) Commit cfb5285660aad4931b2ebbfa902ea48a37dfffa1 removed a useful feature for us, which provided a cpu accounting resource controller. This feature would be useful if someone wants to group tasks only for accounting purpose and doesnt really want to exercise any control over their cpu consumption. The patch below reintroduces the feature. It is based on Paul Menage's original patch (Commit 62d0df64065e7c135d0002f069444fbdfc64768f), with these differences: - Removed load average information. I felt it needs more thought (esp to deal with SMP and virtualized platforms) and can be added for 2.6.25 after more discussions. - Convert group cpu usage to be nanosecond accurate (as rest of the cfs stats are) and invoke cpuacct_charge() from the respective scheduler classes - Make accounting scalable on SMP systems by splitting the usage counter to be per-cpu - Move the code from kernel/cpu_acct.c to kernel/sched.c (since the code is not big enough to warrant a new file and also this rightly needs to live inside the scheduler. Also things like accessing rq->lock while reading cpu usage becomes easier if the code lived in kernel/sched.c) The patch also modifies the cpu controller not to provide the same accounting information. Tested-by: Balbir Singh <balbir@linux.vnet.ibm.com> Tested the patches on top of 2.6.24-rc3. The patches work fine. Ran some simple tests like cpuspin (spin on the cpu), ran several tasks in the same group and timed them. Compared their time stamps with cpuacct.usage. Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-12-02 19:04:49 +00:00
sched: add hierarchical accounting to cpu accounting controller Impact: improve CPU time accounting of tasks under the cpu accounting controller Add hierarchical accounting to cpu accounting controller and include cpuacct documentation. Currently, while charging the task's cputime to its accounting group, the accounting group hierarchy isn't updated. This patch charges the cputime of a task to its accounting group and all its parent accounting groups. Reported-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com> Reviewed-by: Paul Menage <menage@google.com> Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-10 15:11:13 +00:00
if (cgrp->parent)
ca->parent = cgroup_ca(cgrp->parent);
sched: cpu accounting controller (V2) Commit cfb5285660aad4931b2ebbfa902ea48a37dfffa1 removed a useful feature for us, which provided a cpu accounting resource controller. This feature would be useful if someone wants to group tasks only for accounting purpose and doesnt really want to exercise any control over their cpu consumption. The patch below reintroduces the feature. It is based on Paul Menage's original patch (Commit 62d0df64065e7c135d0002f069444fbdfc64768f), with these differences: - Removed load average information. I felt it needs more thought (esp to deal with SMP and virtualized platforms) and can be added for 2.6.25 after more discussions. - Convert group cpu usage to be nanosecond accurate (as rest of the cfs stats are) and invoke cpuacct_charge() from the respective scheduler classes - Make accounting scalable on SMP systems by splitting the usage counter to be per-cpu - Move the code from kernel/cpu_acct.c to kernel/sched.c (since the code is not big enough to warrant a new file and also this rightly needs to live inside the scheduler. Also things like accessing rq->lock while reading cpu usage becomes easier if the code lived in kernel/sched.c) The patch also modifies the cpu controller not to provide the same accounting information. Tested-by: Balbir Singh <balbir@linux.vnet.ibm.com> Tested the patches on top of 2.6.24-rc3. The patches work fine. Ran some simple tests like cpuspin (spin on the cpu), ran several tasks in the same group and timed them. Compared their time stamps with cpuacct.usage. Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-12-02 19:04:49 +00:00
return &ca->css;
cpuacct: add per-cgroup utime/stime statistics Add per-cgroup cpuacct controller statistics like the system and user time consumed by the group of tasks. Changelog: v7 - Changed the name of the statistic from utime to user and from stime to system so that in future we could easily add other statistics like irq, softirq, steal times etc easily. v6 - Fixed a bug in the error path of cpuacct_create() (pointed by Li Zefan). v5 - In cpuacct_stats_show(), use cputime64_to_clock_t() since we are operating on a 64bit variable here. v4 - Remove comments in cpuacct_update_stats() which explained why rcu_read_lock() was needed (as per Peter Zijlstra's review comments). - Don't say that percpu_counter_read() is broken in Documentation/cpuacct.txt as per KAMEZAWA Hiroyuki's review comments. v3 - Fix a small race in the cpuacct hierarchy walk. v2 - stime and utime now exported in clock_t units instead of msecs. - Addressed the code review comments from Balbir and Li Zefan. - Moved to -tip tree. v1 - Moved the stime/utime accounting to cpuacct controller. Earlier versions - http://lkml.org/lkml/2009/2/25/129 Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com> Signed-off-by: Balaji Rao <balajirrao@gmail.com> Cc: Dhaval Giani <dhaval@linux.vnet.ibm.com> Cc: Paul Menage <menage@google.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Reviewed-by: Li Zefan <lizf@cn.fujitsu.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com> Tested-by: Balbir Singh <balbir@linux.vnet.ibm.com> LKML-Reference: <20090331043222.GA4093@in.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-31 04:32:22 +00:00
out_free_counters:
while (--i >= 0)
percpu_counter_destroy(&ca->cpustat[i]);
free_percpu(ca->cpuusage);
out_free_ca:
kfree(ca);
out:
return ERR_PTR(-ENOMEM);
sched: cpu accounting controller (V2) Commit cfb5285660aad4931b2ebbfa902ea48a37dfffa1 removed a useful feature for us, which provided a cpu accounting resource controller. This feature would be useful if someone wants to group tasks only for accounting purpose and doesnt really want to exercise any control over their cpu consumption. The patch below reintroduces the feature. It is based on Paul Menage's original patch (Commit 62d0df64065e7c135d0002f069444fbdfc64768f), with these differences: - Removed load average information. I felt it needs more thought (esp to deal with SMP and virtualized platforms) and can be added for 2.6.25 after more discussions. - Convert group cpu usage to be nanosecond accurate (as rest of the cfs stats are) and invoke cpuacct_charge() from the respective scheduler classes - Make accounting scalable on SMP systems by splitting the usage counter to be per-cpu - Move the code from kernel/cpu_acct.c to kernel/sched.c (since the code is not big enough to warrant a new file and also this rightly needs to live inside the scheduler. Also things like accessing rq->lock while reading cpu usage becomes easier if the code lived in kernel/sched.c) The patch also modifies the cpu controller not to provide the same accounting information. Tested-by: Balbir Singh <balbir@linux.vnet.ibm.com> Tested the patches on top of 2.6.24-rc3. The patches work fine. Ran some simple tests like cpuspin (spin on the cpu), ran several tasks in the same group and timed them. Compared their time stamps with cpuacct.usage. Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-12-02 19:04:49 +00:00
}
/* destroy an existing cpu accounting group */
sched: style cleanups style cleanup of various changes that were done recently. no code changed: text data bss dec hex filename 23680 2542 28 26250 668a sched.o.before 23680 2542 28 26250 668a sched.o.after Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-12-05 14:46:09 +00:00
static void
sched: cleanup cpuacct variable names Change the variable names to the common convention for the cpuacct subsystem. Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-29 04:32:43 +00:00
cpuacct_destroy(struct cgroup_subsys *ss, struct cgroup *cgrp)
sched: cpu accounting controller (V2) Commit cfb5285660aad4931b2ebbfa902ea48a37dfffa1 removed a useful feature for us, which provided a cpu accounting resource controller. This feature would be useful if someone wants to group tasks only for accounting purpose and doesnt really want to exercise any control over their cpu consumption. The patch below reintroduces the feature. It is based on Paul Menage's original patch (Commit 62d0df64065e7c135d0002f069444fbdfc64768f), with these differences: - Removed load average information. I felt it needs more thought (esp to deal with SMP and virtualized platforms) and can be added for 2.6.25 after more discussions. - Convert group cpu usage to be nanosecond accurate (as rest of the cfs stats are) and invoke cpuacct_charge() from the respective scheduler classes - Make accounting scalable on SMP systems by splitting the usage counter to be per-cpu - Move the code from kernel/cpu_acct.c to kernel/sched.c (since the code is not big enough to warrant a new file and also this rightly needs to live inside the scheduler. Also things like accessing rq->lock while reading cpu usage becomes easier if the code lived in kernel/sched.c) The patch also modifies the cpu controller not to provide the same accounting information. Tested-by: Balbir Singh <balbir@linux.vnet.ibm.com> Tested the patches on top of 2.6.24-rc3. The patches work fine. Ran some simple tests like cpuspin (spin on the cpu), ran several tasks in the same group and timed them. Compared their time stamps with cpuacct.usage. Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-12-02 19:04:49 +00:00
{
sched: cleanup cpuacct variable names Change the variable names to the common convention for the cpuacct subsystem. Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-29 04:32:43 +00:00
struct cpuacct *ca = cgroup_ca(cgrp);
cpuacct: add per-cgroup utime/stime statistics Add per-cgroup cpuacct controller statistics like the system and user time consumed by the group of tasks. Changelog: v7 - Changed the name of the statistic from utime to user and from stime to system so that in future we could easily add other statistics like irq, softirq, steal times etc easily. v6 - Fixed a bug in the error path of cpuacct_create() (pointed by Li Zefan). v5 - In cpuacct_stats_show(), use cputime64_to_clock_t() since we are operating on a 64bit variable here. v4 - Remove comments in cpuacct_update_stats() which explained why rcu_read_lock() was needed (as per Peter Zijlstra's review comments). - Don't say that percpu_counter_read() is broken in Documentation/cpuacct.txt as per KAMEZAWA Hiroyuki's review comments. v3 - Fix a small race in the cpuacct hierarchy walk. v2 - stime and utime now exported in clock_t units instead of msecs. - Addressed the code review comments from Balbir and Li Zefan. - Moved to -tip tree. v1 - Moved the stime/utime accounting to cpuacct controller. Earlier versions - http://lkml.org/lkml/2009/2/25/129 Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com> Signed-off-by: Balaji Rao <balajirrao@gmail.com> Cc: Dhaval Giani <dhaval@linux.vnet.ibm.com> Cc: Paul Menage <menage@google.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Reviewed-by: Li Zefan <lizf@cn.fujitsu.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com> Tested-by: Balbir Singh <balbir@linux.vnet.ibm.com> LKML-Reference: <20090331043222.GA4093@in.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-31 04:32:22 +00:00
int i;
sched: cpu accounting controller (V2) Commit cfb5285660aad4931b2ebbfa902ea48a37dfffa1 removed a useful feature for us, which provided a cpu accounting resource controller. This feature would be useful if someone wants to group tasks only for accounting purpose and doesnt really want to exercise any control over their cpu consumption. The patch below reintroduces the feature. It is based on Paul Menage's original patch (Commit 62d0df64065e7c135d0002f069444fbdfc64768f), with these differences: - Removed load average information. I felt it needs more thought (esp to deal with SMP and virtualized platforms) and can be added for 2.6.25 after more discussions. - Convert group cpu usage to be nanosecond accurate (as rest of the cfs stats are) and invoke cpuacct_charge() from the respective scheduler classes - Make accounting scalable on SMP systems by splitting the usage counter to be per-cpu - Move the code from kernel/cpu_acct.c to kernel/sched.c (since the code is not big enough to warrant a new file and also this rightly needs to live inside the scheduler. Also things like accessing rq->lock while reading cpu usage becomes easier if the code lived in kernel/sched.c) The patch also modifies the cpu controller not to provide the same accounting information. Tested-by: Balbir Singh <balbir@linux.vnet.ibm.com> Tested the patches on top of 2.6.24-rc3. The patches work fine. Ran some simple tests like cpuspin (spin on the cpu), ran several tasks in the same group and timed them. Compared their time stamps with cpuacct.usage. Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-12-02 19:04:49 +00:00
cpuacct: add per-cgroup utime/stime statistics Add per-cgroup cpuacct controller statistics like the system and user time consumed by the group of tasks. Changelog: v7 - Changed the name of the statistic from utime to user and from stime to system so that in future we could easily add other statistics like irq, softirq, steal times etc easily. v6 - Fixed a bug in the error path of cpuacct_create() (pointed by Li Zefan). v5 - In cpuacct_stats_show(), use cputime64_to_clock_t() since we are operating on a 64bit variable here. v4 - Remove comments in cpuacct_update_stats() which explained why rcu_read_lock() was needed (as per Peter Zijlstra's review comments). - Don't say that percpu_counter_read() is broken in Documentation/cpuacct.txt as per KAMEZAWA Hiroyuki's review comments. v3 - Fix a small race in the cpuacct hierarchy walk. v2 - stime and utime now exported in clock_t units instead of msecs. - Addressed the code review comments from Balbir and Li Zefan. - Moved to -tip tree. v1 - Moved the stime/utime accounting to cpuacct controller. Earlier versions - http://lkml.org/lkml/2009/2/25/129 Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com> Signed-off-by: Balaji Rao <balajirrao@gmail.com> Cc: Dhaval Giani <dhaval@linux.vnet.ibm.com> Cc: Paul Menage <menage@google.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Reviewed-by: Li Zefan <lizf@cn.fujitsu.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com> Tested-by: Balbir Singh <balbir@linux.vnet.ibm.com> LKML-Reference: <20090331043222.GA4093@in.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-31 04:32:22 +00:00
for (i = 0; i < CPUACCT_STAT_NSTATS; i++)
percpu_counter_destroy(&ca->cpustat[i]);
sched: cpu accounting controller (V2) Commit cfb5285660aad4931b2ebbfa902ea48a37dfffa1 removed a useful feature for us, which provided a cpu accounting resource controller. This feature would be useful if someone wants to group tasks only for accounting purpose and doesnt really want to exercise any control over their cpu consumption. The patch below reintroduces the feature. It is based on Paul Menage's original patch (Commit 62d0df64065e7c135d0002f069444fbdfc64768f), with these differences: - Removed load average information. I felt it needs more thought (esp to deal with SMP and virtualized platforms) and can be added for 2.6.25 after more discussions. - Convert group cpu usage to be nanosecond accurate (as rest of the cfs stats are) and invoke cpuacct_charge() from the respective scheduler classes - Make accounting scalable on SMP systems by splitting the usage counter to be per-cpu - Move the code from kernel/cpu_acct.c to kernel/sched.c (since the code is not big enough to warrant a new file and also this rightly needs to live inside the scheduler. Also things like accessing rq->lock while reading cpu usage becomes easier if the code lived in kernel/sched.c) The patch also modifies the cpu controller not to provide the same accounting information. Tested-by: Balbir Singh <balbir@linux.vnet.ibm.com> Tested the patches on top of 2.6.24-rc3. The patches work fine. Ran some simple tests like cpuspin (spin on the cpu), ran several tasks in the same group and timed them. Compared their time stamps with cpuacct.usage. Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-12-02 19:04:49 +00:00
free_percpu(ca->cpuusage);
kfree(ca);
}
sched, cpuacct: refactoring cpuusage_read / cpuusage_write Impact: micro-optimize the code on 64-bit architectures In the thread regarding to 'export percpu cpuacct cgroup stats' http://lkml.org/lkml/2008/12/7/13 akpm pointed out that current cpuacct code is inefficient. This patch refactoring the following: * make cpu_rq locking only on 32-bit * change iterator to each_present_cpu instead of each_possible_cpu to make it hotplug friendly. It's a bit of code churn, but I was rewarded with 160 byte code size saving on x86-64 arch and zero code size change on i386. Signed-off-by: Ken Chen <kenchen@google.com> Cc: Paul Menage <menage@google.com> Cc: Li Zefan <lizf@cn.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-16 06:02:01 +00:00
static u64 cpuacct_cpuusage_read(struct cpuacct *ca, int cpu)
{
alloc_percpu: change percpu_ptr to per_cpu_ptr Impact: cleanup There are two allocated per-cpu accessor macros with almost identical spelling. The original and far more popular is per_cpu_ptr (44 files), so change over the other 4 files. tj: kill percpu_ptr() and update UP too Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: mingo@redhat.com Cc: lenb@kernel.org Cc: cpufreq@vger.kernel.org Signed-off-by: Tejun Heo <tj@kernel.org>
2009-02-20 07:29:08 +00:00
u64 *cpuusage = per_cpu_ptr(ca->cpuusage, cpu);
sched, cpuacct: refactoring cpuusage_read / cpuusage_write Impact: micro-optimize the code on 64-bit architectures In the thread regarding to 'export percpu cpuacct cgroup stats' http://lkml.org/lkml/2008/12/7/13 akpm pointed out that current cpuacct code is inefficient. This patch refactoring the following: * make cpu_rq locking only on 32-bit * change iterator to each_present_cpu instead of each_possible_cpu to make it hotplug friendly. It's a bit of code churn, but I was rewarded with 160 byte code size saving on x86-64 arch and zero code size change on i386. Signed-off-by: Ken Chen <kenchen@google.com> Cc: Paul Menage <menage@google.com> Cc: Li Zefan <lizf@cn.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-16 06:02:01 +00:00
u64 data;
#ifndef CONFIG_64BIT
/*
* Take rq->lock to make 64-bit read safe on 32-bit platforms.
*/
sched: Convert rq->lock to raw_spinlock Convert locks which cannot be sleeping locks in preempt-rt to raw_spinlocks. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Ingo Molnar <mingo@elte.hu>
2009-11-17 13:28:38 +00:00
raw_spin_lock_irq(&cpu_rq(cpu)->lock);
sched, cpuacct: refactoring cpuusage_read / cpuusage_write Impact: micro-optimize the code on 64-bit architectures In the thread regarding to 'export percpu cpuacct cgroup stats' http://lkml.org/lkml/2008/12/7/13 akpm pointed out that current cpuacct code is inefficient. This patch refactoring the following: * make cpu_rq locking only on 32-bit * change iterator to each_present_cpu instead of each_possible_cpu to make it hotplug friendly. It's a bit of code churn, but I was rewarded with 160 byte code size saving on x86-64 arch and zero code size change on i386. Signed-off-by: Ken Chen <kenchen@google.com> Cc: Paul Menage <menage@google.com> Cc: Li Zefan <lizf@cn.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-16 06:02:01 +00:00
data = *cpuusage;
sched: Convert rq->lock to raw_spinlock Convert locks which cannot be sleeping locks in preempt-rt to raw_spinlocks. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Ingo Molnar <mingo@elte.hu>
2009-11-17 13:28:38 +00:00
raw_spin_unlock_irq(&cpu_rq(cpu)->lock);
sched, cpuacct: refactoring cpuusage_read / cpuusage_write Impact: micro-optimize the code on 64-bit architectures In the thread regarding to 'export percpu cpuacct cgroup stats' http://lkml.org/lkml/2008/12/7/13 akpm pointed out that current cpuacct code is inefficient. This patch refactoring the following: * make cpu_rq locking only on 32-bit * change iterator to each_present_cpu instead of each_possible_cpu to make it hotplug friendly. It's a bit of code churn, but I was rewarded with 160 byte code size saving on x86-64 arch and zero code size change on i386. Signed-off-by: Ken Chen <kenchen@google.com> Cc: Paul Menage <menage@google.com> Cc: Li Zefan <lizf@cn.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-16 06:02:01 +00:00
#else
data = *cpuusage;
#endif
return data;
}
static void cpuacct_cpuusage_write(struct cpuacct *ca, int cpu, u64 val)
{
alloc_percpu: change percpu_ptr to per_cpu_ptr Impact: cleanup There are two allocated per-cpu accessor macros with almost identical spelling. The original and far more popular is per_cpu_ptr (44 files), so change over the other 4 files. tj: kill percpu_ptr() and update UP too Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: mingo@redhat.com Cc: lenb@kernel.org Cc: cpufreq@vger.kernel.org Signed-off-by: Tejun Heo <tj@kernel.org>
2009-02-20 07:29:08 +00:00
u64 *cpuusage = per_cpu_ptr(ca->cpuusage, cpu);
sched, cpuacct: refactoring cpuusage_read / cpuusage_write Impact: micro-optimize the code on 64-bit architectures In the thread regarding to 'export percpu cpuacct cgroup stats' http://lkml.org/lkml/2008/12/7/13 akpm pointed out that current cpuacct code is inefficient. This patch refactoring the following: * make cpu_rq locking only on 32-bit * change iterator to each_present_cpu instead of each_possible_cpu to make it hotplug friendly. It's a bit of code churn, but I was rewarded with 160 byte code size saving on x86-64 arch and zero code size change on i386. Signed-off-by: Ken Chen <kenchen@google.com> Cc: Paul Menage <menage@google.com> Cc: Li Zefan <lizf@cn.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-16 06:02:01 +00:00
#ifndef CONFIG_64BIT
/*
* Take rq->lock to make 64-bit write safe on 32-bit platforms.
*/
sched: Convert rq->lock to raw_spinlock Convert locks which cannot be sleeping locks in preempt-rt to raw_spinlocks. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Ingo Molnar <mingo@elte.hu>
2009-11-17 13:28:38 +00:00
raw_spin_lock_irq(&cpu_rq(cpu)->lock);
sched, cpuacct: refactoring cpuusage_read / cpuusage_write Impact: micro-optimize the code on 64-bit architectures In the thread regarding to 'export percpu cpuacct cgroup stats' http://lkml.org/lkml/2008/12/7/13 akpm pointed out that current cpuacct code is inefficient. This patch refactoring the following: * make cpu_rq locking only on 32-bit * change iterator to each_present_cpu instead of each_possible_cpu to make it hotplug friendly. It's a bit of code churn, but I was rewarded with 160 byte code size saving on x86-64 arch and zero code size change on i386. Signed-off-by: Ken Chen <kenchen@google.com> Cc: Paul Menage <menage@google.com> Cc: Li Zefan <lizf@cn.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-16 06:02:01 +00:00
*cpuusage = val;
sched: Convert rq->lock to raw_spinlock Convert locks which cannot be sleeping locks in preempt-rt to raw_spinlocks. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Ingo Molnar <mingo@elte.hu>
2009-11-17 13:28:38 +00:00
raw_spin_unlock_irq(&cpu_rq(cpu)->lock);
sched, cpuacct: refactoring cpuusage_read / cpuusage_write Impact: micro-optimize the code on 64-bit architectures In the thread regarding to 'export percpu cpuacct cgroup stats' http://lkml.org/lkml/2008/12/7/13 akpm pointed out that current cpuacct code is inefficient. This patch refactoring the following: * make cpu_rq locking only on 32-bit * change iterator to each_present_cpu instead of each_possible_cpu to make it hotplug friendly. It's a bit of code churn, but I was rewarded with 160 byte code size saving on x86-64 arch and zero code size change on i386. Signed-off-by: Ken Chen <kenchen@google.com> Cc: Paul Menage <menage@google.com> Cc: Li Zefan <lizf@cn.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-16 06:02:01 +00:00
#else
*cpuusage = val;
#endif
}
sched: cpu accounting controller (V2) Commit cfb5285660aad4931b2ebbfa902ea48a37dfffa1 removed a useful feature for us, which provided a cpu accounting resource controller. This feature would be useful if someone wants to group tasks only for accounting purpose and doesnt really want to exercise any control over their cpu consumption. The patch below reintroduces the feature. It is based on Paul Menage's original patch (Commit 62d0df64065e7c135d0002f069444fbdfc64768f), with these differences: - Removed load average information. I felt it needs more thought (esp to deal with SMP and virtualized platforms) and can be added for 2.6.25 after more discussions. - Convert group cpu usage to be nanosecond accurate (as rest of the cfs stats are) and invoke cpuacct_charge() from the respective scheduler classes - Make accounting scalable on SMP systems by splitting the usage counter to be per-cpu - Move the code from kernel/cpu_acct.c to kernel/sched.c (since the code is not big enough to warrant a new file and also this rightly needs to live inside the scheduler. Also things like accessing rq->lock while reading cpu usage becomes easier if the code lived in kernel/sched.c) The patch also modifies the cpu controller not to provide the same accounting information. Tested-by: Balbir Singh <balbir@linux.vnet.ibm.com> Tested the patches on top of 2.6.24-rc3. The patches work fine. Ran some simple tests like cpuspin (spin on the cpu), ran several tasks in the same group and timed them. Compared their time stamps with cpuacct.usage. Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-12-02 19:04:49 +00:00
/* return total cpu usage (in nanoseconds) of a group */
sched: cleanup cpuacct variable names Change the variable names to the common convention for the cpuacct subsystem. Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-29 04:32:43 +00:00
static u64 cpuusage_read(struct cgroup *cgrp, struct cftype *cft)
sched: cpu accounting controller (V2) Commit cfb5285660aad4931b2ebbfa902ea48a37dfffa1 removed a useful feature for us, which provided a cpu accounting resource controller. This feature would be useful if someone wants to group tasks only for accounting purpose and doesnt really want to exercise any control over their cpu consumption. The patch below reintroduces the feature. It is based on Paul Menage's original patch (Commit 62d0df64065e7c135d0002f069444fbdfc64768f), with these differences: - Removed load average information. I felt it needs more thought (esp to deal with SMP and virtualized platforms) and can be added for 2.6.25 after more discussions. - Convert group cpu usage to be nanosecond accurate (as rest of the cfs stats are) and invoke cpuacct_charge() from the respective scheduler classes - Make accounting scalable on SMP systems by splitting the usage counter to be per-cpu - Move the code from kernel/cpu_acct.c to kernel/sched.c (since the code is not big enough to warrant a new file and also this rightly needs to live inside the scheduler. Also things like accessing rq->lock while reading cpu usage becomes easier if the code lived in kernel/sched.c) The patch also modifies the cpu controller not to provide the same accounting information. Tested-by: Balbir Singh <balbir@linux.vnet.ibm.com> Tested the patches on top of 2.6.24-rc3. The patches work fine. Ran some simple tests like cpuspin (spin on the cpu), ran several tasks in the same group and timed them. Compared their time stamps with cpuacct.usage. Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-12-02 19:04:49 +00:00
{
sched: cleanup cpuacct variable names Change the variable names to the common convention for the cpuacct subsystem. Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-29 04:32:43 +00:00
struct cpuacct *ca = cgroup_ca(cgrp);
sched: cpu accounting controller (V2) Commit cfb5285660aad4931b2ebbfa902ea48a37dfffa1 removed a useful feature for us, which provided a cpu accounting resource controller. This feature would be useful if someone wants to group tasks only for accounting purpose and doesnt really want to exercise any control over their cpu consumption. The patch below reintroduces the feature. It is based on Paul Menage's original patch (Commit 62d0df64065e7c135d0002f069444fbdfc64768f), with these differences: - Removed load average information. I felt it needs more thought (esp to deal with SMP and virtualized platforms) and can be added for 2.6.25 after more discussions. - Convert group cpu usage to be nanosecond accurate (as rest of the cfs stats are) and invoke cpuacct_charge() from the respective scheduler classes - Make accounting scalable on SMP systems by splitting the usage counter to be per-cpu - Move the code from kernel/cpu_acct.c to kernel/sched.c (since the code is not big enough to warrant a new file and also this rightly needs to live inside the scheduler. Also things like accessing rq->lock while reading cpu usage becomes easier if the code lived in kernel/sched.c) The patch also modifies the cpu controller not to provide the same accounting information. Tested-by: Balbir Singh <balbir@linux.vnet.ibm.com> Tested the patches on top of 2.6.24-rc3. The patches work fine. Ran some simple tests like cpuspin (spin on the cpu), ran several tasks in the same group and timed them. Compared their time stamps with cpuacct.usage. Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-12-02 19:04:49 +00:00
u64 totalcpuusage = 0;
int i;
sched, cpuacct: refactoring cpuusage_read / cpuusage_write Impact: micro-optimize the code on 64-bit architectures In the thread regarding to 'export percpu cpuacct cgroup stats' http://lkml.org/lkml/2008/12/7/13 akpm pointed out that current cpuacct code is inefficient. This patch refactoring the following: * make cpu_rq locking only on 32-bit * change iterator to each_present_cpu instead of each_possible_cpu to make it hotplug friendly. It's a bit of code churn, but I was rewarded with 160 byte code size saving on x86-64 arch and zero code size change on i386. Signed-off-by: Ken Chen <kenchen@google.com> Cc: Paul Menage <menage@google.com> Cc: Li Zefan <lizf@cn.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-16 06:02:01 +00:00
for_each_present_cpu(i)
totalcpuusage += cpuacct_cpuusage_read(ca, i);
sched: cpu accounting controller (V2) Commit cfb5285660aad4931b2ebbfa902ea48a37dfffa1 removed a useful feature for us, which provided a cpu accounting resource controller. This feature would be useful if someone wants to group tasks only for accounting purpose and doesnt really want to exercise any control over their cpu consumption. The patch below reintroduces the feature. It is based on Paul Menage's original patch (Commit 62d0df64065e7c135d0002f069444fbdfc64768f), with these differences: - Removed load average information. I felt it needs more thought (esp to deal with SMP and virtualized platforms) and can be added for 2.6.25 after more discussions. - Convert group cpu usage to be nanosecond accurate (as rest of the cfs stats are) and invoke cpuacct_charge() from the respective scheduler classes - Make accounting scalable on SMP systems by splitting the usage counter to be per-cpu - Move the code from kernel/cpu_acct.c to kernel/sched.c (since the code is not big enough to warrant a new file and also this rightly needs to live inside the scheduler. Also things like accessing rq->lock while reading cpu usage becomes easier if the code lived in kernel/sched.c) The patch also modifies the cpu controller not to provide the same accounting information. Tested-by: Balbir Singh <balbir@linux.vnet.ibm.com> Tested the patches on top of 2.6.24-rc3. The patches work fine. Ran some simple tests like cpuspin (spin on the cpu), ran several tasks in the same group and timed them. Compared their time stamps with cpuacct.usage. Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-12-02 19:04:49 +00:00
return totalcpuusage;
}
sched: allow cpuacct stats to be reset Currently the schedstats implementation does not allow the statistics to be reset. This patch aims to allow that. echo 0 > cpuacct.usage resets the usage. Any other value is not allowed and returns -EINVAL. Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-29 04:32:44 +00:00
static int cpuusage_write(struct cgroup *cgrp, struct cftype *cftype,
u64 reset)
{
struct cpuacct *ca = cgroup_ca(cgrp);
int err = 0;
int i;
if (reset) {
err = -EINVAL;
goto out;
}
sched, cpuacct: refactoring cpuusage_read / cpuusage_write Impact: micro-optimize the code on 64-bit architectures In the thread regarding to 'export percpu cpuacct cgroup stats' http://lkml.org/lkml/2008/12/7/13 akpm pointed out that current cpuacct code is inefficient. This patch refactoring the following: * make cpu_rq locking only on 32-bit * change iterator to each_present_cpu instead of each_possible_cpu to make it hotplug friendly. It's a bit of code churn, but I was rewarded with 160 byte code size saving on x86-64 arch and zero code size change on i386. Signed-off-by: Ken Chen <kenchen@google.com> Cc: Paul Menage <menage@google.com> Cc: Li Zefan <lizf@cn.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-16 06:02:01 +00:00
for_each_present_cpu(i)
cpuacct_cpuusage_write(ca, i, 0);
sched: allow cpuacct stats to be reset Currently the schedstats implementation does not allow the statistics to be reset. This patch aims to allow that. echo 0 > cpuacct.usage resets the usage. Any other value is not allowed and returns -EINVAL. Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-29 04:32:44 +00:00
out:
return err;
}
sched, cpuacct: export percpu cpuacct cgroup stats This patch export per-cpu CPU cycle usage for a given cpuacct cgroup. There is a need for a user space monitor daemon to track group CPU usage on per-cpu base. It is also useful for monitoring CFS load balancer behavior by tracking per CPU group usage. Signed-off-by: Ken Chen <kenchen@google.com> Reviewed-by: Li Zefan <lizf@cn.fujitsu.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-16 06:04:15 +00:00
static int cpuacct_percpu_seq_read(struct cgroup *cgroup, struct cftype *cft,
struct seq_file *m)
{
struct cpuacct *ca = cgroup_ca(cgroup);
u64 percpu;
int i;
for_each_present_cpu(i) {
percpu = cpuacct_cpuusage_read(ca, i);
seq_printf(m, "%llu ", (unsigned long long) percpu);
}
seq_printf(m, "\n");
return 0;
}
cpuacct: add per-cgroup utime/stime statistics Add per-cgroup cpuacct controller statistics like the system and user time consumed by the group of tasks. Changelog: v7 - Changed the name of the statistic from utime to user and from stime to system so that in future we could easily add other statistics like irq, softirq, steal times etc easily. v6 - Fixed a bug in the error path of cpuacct_create() (pointed by Li Zefan). v5 - In cpuacct_stats_show(), use cputime64_to_clock_t() since we are operating on a 64bit variable here. v4 - Remove comments in cpuacct_update_stats() which explained why rcu_read_lock() was needed (as per Peter Zijlstra's review comments). - Don't say that percpu_counter_read() is broken in Documentation/cpuacct.txt as per KAMEZAWA Hiroyuki's review comments. v3 - Fix a small race in the cpuacct hierarchy walk. v2 - stime and utime now exported in clock_t units instead of msecs. - Addressed the code review comments from Balbir and Li Zefan. - Moved to -tip tree. v1 - Moved the stime/utime accounting to cpuacct controller. Earlier versions - http://lkml.org/lkml/2009/2/25/129 Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com> Signed-off-by: Balaji Rao <balajirrao@gmail.com> Cc: Dhaval Giani <dhaval@linux.vnet.ibm.com> Cc: Paul Menage <menage@google.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Reviewed-by: Li Zefan <lizf@cn.fujitsu.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com> Tested-by: Balbir Singh <balbir@linux.vnet.ibm.com> LKML-Reference: <20090331043222.GA4093@in.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-31 04:32:22 +00:00
static const char *cpuacct_stat_desc[] = {
[CPUACCT_STAT_USER] = "user",
[CPUACCT_STAT_SYSTEM] = "system",
};
static int cpuacct_stats_show(struct cgroup *cgrp, struct cftype *cft,
struct cgroup_map_cb *cb)
{
struct cpuacct *ca = cgroup_ca(cgrp);
int i;
for (i = 0; i < CPUACCT_STAT_NSTATS; i++) {
s64 val = percpu_counter_read(&ca->cpustat[i]);
val = cputime64_to_clock_t(val);
cb->fill(cb, cpuacct_stat_desc[i], val);
}
return 0;
}
sched: cpu accounting controller (V2) Commit cfb5285660aad4931b2ebbfa902ea48a37dfffa1 removed a useful feature for us, which provided a cpu accounting resource controller. This feature would be useful if someone wants to group tasks only for accounting purpose and doesnt really want to exercise any control over their cpu consumption. The patch below reintroduces the feature. It is based on Paul Menage's original patch (Commit 62d0df64065e7c135d0002f069444fbdfc64768f), with these differences: - Removed load average information. I felt it needs more thought (esp to deal with SMP and virtualized platforms) and can be added for 2.6.25 after more discussions. - Convert group cpu usage to be nanosecond accurate (as rest of the cfs stats are) and invoke cpuacct_charge() from the respective scheduler classes - Make accounting scalable on SMP systems by splitting the usage counter to be per-cpu - Move the code from kernel/cpu_acct.c to kernel/sched.c (since the code is not big enough to warrant a new file and also this rightly needs to live inside the scheduler. Also things like accessing rq->lock while reading cpu usage becomes easier if the code lived in kernel/sched.c) The patch also modifies the cpu controller not to provide the same accounting information. Tested-by: Balbir Singh <balbir@linux.vnet.ibm.com> Tested the patches on top of 2.6.24-rc3. The patches work fine. Ran some simple tests like cpuspin (spin on the cpu), ran several tasks in the same group and timed them. Compared their time stamps with cpuacct.usage. Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-12-02 19:04:49 +00:00
static struct cftype files[] = {
{
.name = "usage",
CGroup API files: rename read/write_uint methods to read_write_u64 Several people have justifiably complained that the "_uint" suffix is inappropriate for functions that handle u64 values, so this patch just renames all these functions and their users to have the suffic _u64. [peterz@infradead.org: build fix] Signed-off-by: Paul Menage <menage@google.com> Cc: "Li Zefan" <lizf@cn.fujitsu.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Paul Jackson <pj@sgi.com> Cc: Pavel Emelyanov <xemul@openvz.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: "YAMAMOTO Takashi" <yamamoto@valinux.co.jp> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29 07:59:56 +00:00
.read_u64 = cpuusage_read,
.write_u64 = cpuusage_write,
sched: cpu accounting controller (V2) Commit cfb5285660aad4931b2ebbfa902ea48a37dfffa1 removed a useful feature for us, which provided a cpu accounting resource controller. This feature would be useful if someone wants to group tasks only for accounting purpose and doesnt really want to exercise any control over their cpu consumption. The patch below reintroduces the feature. It is based on Paul Menage's original patch (Commit 62d0df64065e7c135d0002f069444fbdfc64768f), with these differences: - Removed load average information. I felt it needs more thought (esp to deal with SMP and virtualized platforms) and can be added for 2.6.25 after more discussions. - Convert group cpu usage to be nanosecond accurate (as rest of the cfs stats are) and invoke cpuacct_charge() from the respective scheduler classes - Make accounting scalable on SMP systems by splitting the usage counter to be per-cpu - Move the code from kernel/cpu_acct.c to kernel/sched.c (since the code is not big enough to warrant a new file and also this rightly needs to live inside the scheduler. Also things like accessing rq->lock while reading cpu usage becomes easier if the code lived in kernel/sched.c) The patch also modifies the cpu controller not to provide the same accounting information. Tested-by: Balbir Singh <balbir@linux.vnet.ibm.com> Tested the patches on top of 2.6.24-rc3. The patches work fine. Ran some simple tests like cpuspin (spin on the cpu), ran several tasks in the same group and timed them. Compared their time stamps with cpuacct.usage. Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-12-02 19:04:49 +00:00
},
sched, cpuacct: export percpu cpuacct cgroup stats This patch export per-cpu CPU cycle usage for a given cpuacct cgroup. There is a need for a user space monitor daemon to track group CPU usage on per-cpu base. It is also useful for monitoring CFS load balancer behavior by tracking per CPU group usage. Signed-off-by: Ken Chen <kenchen@google.com> Reviewed-by: Li Zefan <lizf@cn.fujitsu.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-16 06:04:15 +00:00
{
.name = "usage_percpu",
.read_seq_string = cpuacct_percpu_seq_read,
},
cpuacct: add per-cgroup utime/stime statistics Add per-cgroup cpuacct controller statistics like the system and user time consumed by the group of tasks. Changelog: v7 - Changed the name of the statistic from utime to user and from stime to system so that in future we could easily add other statistics like irq, softirq, steal times etc easily. v6 - Fixed a bug in the error path of cpuacct_create() (pointed by Li Zefan). v5 - In cpuacct_stats_show(), use cputime64_to_clock_t() since we are operating on a 64bit variable here. v4 - Remove comments in cpuacct_update_stats() which explained why rcu_read_lock() was needed (as per Peter Zijlstra's review comments). - Don't say that percpu_counter_read() is broken in Documentation/cpuacct.txt as per KAMEZAWA Hiroyuki's review comments. v3 - Fix a small race in the cpuacct hierarchy walk. v2 - stime and utime now exported in clock_t units instead of msecs. - Addressed the code review comments from Balbir and Li Zefan. - Moved to -tip tree. v1 - Moved the stime/utime accounting to cpuacct controller. Earlier versions - http://lkml.org/lkml/2009/2/25/129 Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com> Signed-off-by: Balaji Rao <balajirrao@gmail.com> Cc: Dhaval Giani <dhaval@linux.vnet.ibm.com> Cc: Paul Menage <menage@google.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Reviewed-by: Li Zefan <lizf@cn.fujitsu.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com> Tested-by: Balbir Singh <balbir@linux.vnet.ibm.com> LKML-Reference: <20090331043222.GA4093@in.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-31 04:32:22 +00:00
{
.name = "stat",
.read_map = cpuacct_stats_show,
},
sched: cpu accounting controller (V2) Commit cfb5285660aad4931b2ebbfa902ea48a37dfffa1 removed a useful feature for us, which provided a cpu accounting resource controller. This feature would be useful if someone wants to group tasks only for accounting purpose and doesnt really want to exercise any control over their cpu consumption. The patch below reintroduces the feature. It is based on Paul Menage's original patch (Commit 62d0df64065e7c135d0002f069444fbdfc64768f), with these differences: - Removed load average information. I felt it needs more thought (esp to deal with SMP and virtualized platforms) and can be added for 2.6.25 after more discussions. - Convert group cpu usage to be nanosecond accurate (as rest of the cfs stats are) and invoke cpuacct_charge() from the respective scheduler classes - Make accounting scalable on SMP systems by splitting the usage counter to be per-cpu - Move the code from kernel/cpu_acct.c to kernel/sched.c (since the code is not big enough to warrant a new file and also this rightly needs to live inside the scheduler. Also things like accessing rq->lock while reading cpu usage becomes easier if the code lived in kernel/sched.c) The patch also modifies the cpu controller not to provide the same accounting information. Tested-by: Balbir Singh <balbir@linux.vnet.ibm.com> Tested the patches on top of 2.6.24-rc3. The patches work fine. Ran some simple tests like cpuspin (spin on the cpu), ran several tasks in the same group and timed them. Compared their time stamps with cpuacct.usage. Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-12-02 19:04:49 +00:00
};
sched: cleanup cpuacct variable names Change the variable names to the common convention for the cpuacct subsystem. Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-29 04:32:43 +00:00
static int cpuacct_populate(struct cgroup_subsys *ss, struct cgroup *cgrp)
sched: cpu accounting controller (V2) Commit cfb5285660aad4931b2ebbfa902ea48a37dfffa1 removed a useful feature for us, which provided a cpu accounting resource controller. This feature would be useful if someone wants to group tasks only for accounting purpose and doesnt really want to exercise any control over their cpu consumption. The patch below reintroduces the feature. It is based on Paul Menage's original patch (Commit 62d0df64065e7c135d0002f069444fbdfc64768f), with these differences: - Removed load average information. I felt it needs more thought (esp to deal with SMP and virtualized platforms) and can be added for 2.6.25 after more discussions. - Convert group cpu usage to be nanosecond accurate (as rest of the cfs stats are) and invoke cpuacct_charge() from the respective scheduler classes - Make accounting scalable on SMP systems by splitting the usage counter to be per-cpu - Move the code from kernel/cpu_acct.c to kernel/sched.c (since the code is not big enough to warrant a new file and also this rightly needs to live inside the scheduler. Also things like accessing rq->lock while reading cpu usage becomes easier if the code lived in kernel/sched.c) The patch also modifies the cpu controller not to provide the same accounting information. Tested-by: Balbir Singh <balbir@linux.vnet.ibm.com> Tested the patches on top of 2.6.24-rc3. The patches work fine. Ran some simple tests like cpuspin (spin on the cpu), ran several tasks in the same group and timed them. Compared their time stamps with cpuacct.usage. Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-12-02 19:04:49 +00:00
{
sched: cleanup cpuacct variable names Change the variable names to the common convention for the cpuacct subsystem. Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-29 04:32:43 +00:00
return cgroup_add_files(cgrp, ss, files, ARRAY_SIZE(files));
sched: cpu accounting controller (V2) Commit cfb5285660aad4931b2ebbfa902ea48a37dfffa1 removed a useful feature for us, which provided a cpu accounting resource controller. This feature would be useful if someone wants to group tasks only for accounting purpose and doesnt really want to exercise any control over their cpu consumption. The patch below reintroduces the feature. It is based on Paul Menage's original patch (Commit 62d0df64065e7c135d0002f069444fbdfc64768f), with these differences: - Removed load average information. I felt it needs more thought (esp to deal with SMP and virtualized platforms) and can be added for 2.6.25 after more discussions. - Convert group cpu usage to be nanosecond accurate (as rest of the cfs stats are) and invoke cpuacct_charge() from the respective scheduler classes - Make accounting scalable on SMP systems by splitting the usage counter to be per-cpu - Move the code from kernel/cpu_acct.c to kernel/sched.c (since the code is not big enough to warrant a new file and also this rightly needs to live inside the scheduler. Also things like accessing rq->lock while reading cpu usage becomes easier if the code lived in kernel/sched.c) The patch also modifies the cpu controller not to provide the same accounting information. Tested-by: Balbir Singh <balbir@linux.vnet.ibm.com> Tested the patches on top of 2.6.24-rc3. The patches work fine. Ran some simple tests like cpuspin (spin on the cpu), ran several tasks in the same group and timed them. Compared their time stamps with cpuacct.usage. Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-12-02 19:04:49 +00:00
}
/*
* charge this task's execution time to its accounting group.
*
* called with rq->lock held.
*/
static void cpuacct_charge(struct task_struct *tsk, u64 cputime)
{
struct cpuacct *ca;
sched: add hierarchical accounting to cpu accounting controller Impact: improve CPU time accounting of tasks under the cpu accounting controller Add hierarchical accounting to cpu accounting controller and include cpuacct documentation. Currently, while charging the task's cputime to its accounting group, the accounting group hierarchy isn't updated. This patch charges the cputime of a task to its accounting group and all its parent accounting groups. Reported-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com> Reviewed-by: Paul Menage <menage@google.com> Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-10 15:11:13 +00:00
int cpu;
sched: cpu accounting controller (V2) Commit cfb5285660aad4931b2ebbfa902ea48a37dfffa1 removed a useful feature for us, which provided a cpu accounting resource controller. This feature would be useful if someone wants to group tasks only for accounting purpose and doesnt really want to exercise any control over their cpu consumption. The patch below reintroduces the feature. It is based on Paul Menage's original patch (Commit 62d0df64065e7c135d0002f069444fbdfc64768f), with these differences: - Removed load average information. I felt it needs more thought (esp to deal with SMP and virtualized platforms) and can be added for 2.6.25 after more discussions. - Convert group cpu usage to be nanosecond accurate (as rest of the cfs stats are) and invoke cpuacct_charge() from the respective scheduler classes - Make accounting scalable on SMP systems by splitting the usage counter to be per-cpu - Move the code from kernel/cpu_acct.c to kernel/sched.c (since the code is not big enough to warrant a new file and also this rightly needs to live inside the scheduler. Also things like accessing rq->lock while reading cpu usage becomes easier if the code lived in kernel/sched.c) The patch also modifies the cpu controller not to provide the same accounting information. Tested-by: Balbir Singh <balbir@linux.vnet.ibm.com> Tested the patches on top of 2.6.24-rc3. The patches work fine. Ran some simple tests like cpuspin (spin on the cpu), ran several tasks in the same group and timed them. Compared their time stamps with cpuacct.usage. Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-12-02 19:04:49 +00:00
cpuacct: add a branch prediction cpuacct_charge() is in fast-path, and checking of !cpuacct_susys.active always returns false after cpuacct has been initialized at system boot. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Paul Menage <menage@google.com> Cc: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-26 07:40:15 +00:00
if (unlikely(!cpuacct_subsys.active))
sched: cpu accounting controller (V2) Commit cfb5285660aad4931b2ebbfa902ea48a37dfffa1 removed a useful feature for us, which provided a cpu accounting resource controller. This feature would be useful if someone wants to group tasks only for accounting purpose and doesnt really want to exercise any control over their cpu consumption. The patch below reintroduces the feature. It is based on Paul Menage's original patch (Commit 62d0df64065e7c135d0002f069444fbdfc64768f), with these differences: - Removed load average information. I felt it needs more thought (esp to deal with SMP and virtualized platforms) and can be added for 2.6.25 after more discussions. - Convert group cpu usage to be nanosecond accurate (as rest of the cfs stats are) and invoke cpuacct_charge() from the respective scheduler classes - Make accounting scalable on SMP systems by splitting the usage counter to be per-cpu - Move the code from kernel/cpu_acct.c to kernel/sched.c (since the code is not big enough to warrant a new file and also this rightly needs to live inside the scheduler. Also things like accessing rq->lock while reading cpu usage becomes easier if the code lived in kernel/sched.c) The patch also modifies the cpu controller not to provide the same accounting information. Tested-by: Balbir Singh <balbir@linux.vnet.ibm.com> Tested the patches on top of 2.6.24-rc3. The patches work fine. Ran some simple tests like cpuspin (spin on the cpu), ran several tasks in the same group and timed them. Compared their time stamps with cpuacct.usage. Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-12-02 19:04:49 +00:00
return;
sched: add hierarchical accounting to cpu accounting controller Impact: improve CPU time accounting of tasks under the cpu accounting controller Add hierarchical accounting to cpu accounting controller and include cpuacct documentation. Currently, while charging the task's cputime to its accounting group, the accounting group hierarchy isn't updated. This patch charges the cputime of a task to its accounting group and all its parent accounting groups. Reported-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com> Reviewed-by: Paul Menage <menage@google.com> Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-10 15:11:13 +00:00
cpu = task_cpu(tsk);
cpuacct: make cpuacct hierarchy walk in cpuacct_charge() safe when rcupreempt is used -v2 Impact: fix cgroups race under rcu-preempt cpuacct_charge() obtains task's ca and does a hierarchy walk upwards. This can race with the task's movement between cgroups. This race can cause an access to freed ca pointer in cpuacct_charge() or access to invalid cgroups pointer of the task. This will not happen with rcu or tree rcu as cpuacct_charge() is called with preemption disabled. However if rcupreempt is used, the race is seen. Thanks to Li Zefan for explaining this. Fix this race by explicitly protecting ca and the hierarchy walk with rcu_read_lock(). Changes for v2: - Update patch descrition (as per Li Zefan's review comments). - Remove comments in cpuacct_charge() which explained why rcu_read_lock() was needed (as per Peter Zijlstra's review comments). Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com> Cc: Dhaval Giani <dhaval@linux.vnet.ibm.com> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Paul Menage <menage@google.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com> Tested-by: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-23 04:32:53 +00:00
rcu_read_lock();
sched: cpu accounting controller (V2) Commit cfb5285660aad4931b2ebbfa902ea48a37dfffa1 removed a useful feature for us, which provided a cpu accounting resource controller. This feature would be useful if someone wants to group tasks only for accounting purpose and doesnt really want to exercise any control over their cpu consumption. The patch below reintroduces the feature. It is based on Paul Menage's original patch (Commit 62d0df64065e7c135d0002f069444fbdfc64768f), with these differences: - Removed load average information. I felt it needs more thought (esp to deal with SMP and virtualized platforms) and can be added for 2.6.25 after more discussions. - Convert group cpu usage to be nanosecond accurate (as rest of the cfs stats are) and invoke cpuacct_charge() from the respective scheduler classes - Make accounting scalable on SMP systems by splitting the usage counter to be per-cpu - Move the code from kernel/cpu_acct.c to kernel/sched.c (since the code is not big enough to warrant a new file and also this rightly needs to live inside the scheduler. Also things like accessing rq->lock while reading cpu usage becomes easier if the code lived in kernel/sched.c) The patch also modifies the cpu controller not to provide the same accounting information. Tested-by: Balbir Singh <balbir@linux.vnet.ibm.com> Tested the patches on top of 2.6.24-rc3. The patches work fine. Ran some simple tests like cpuspin (spin on the cpu), ran several tasks in the same group and timed them. Compared their time stamps with cpuacct.usage. Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-12-02 19:04:49 +00:00
ca = task_ca(tsk);
sched: add hierarchical accounting to cpu accounting controller Impact: improve CPU time accounting of tasks under the cpu accounting controller Add hierarchical accounting to cpu accounting controller and include cpuacct documentation. Currently, while charging the task's cputime to its accounting group, the accounting group hierarchy isn't updated. This patch charges the cputime of a task to its accounting group and all its parent accounting groups. Reported-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com> Reviewed-by: Paul Menage <menage@google.com> Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-10 15:11:13 +00:00
for (; ca; ca = ca->parent) {
alloc_percpu: change percpu_ptr to per_cpu_ptr Impact: cleanup There are two allocated per-cpu accessor macros with almost identical spelling. The original and far more popular is per_cpu_ptr (44 files), so change over the other 4 files. tj: kill percpu_ptr() and update UP too Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: mingo@redhat.com Cc: lenb@kernel.org Cc: cpufreq@vger.kernel.org Signed-off-by: Tejun Heo <tj@kernel.org>
2009-02-20 07:29:08 +00:00
u64 *cpuusage = per_cpu_ptr(ca->cpuusage, cpu);
sched: cpu accounting controller (V2) Commit cfb5285660aad4931b2ebbfa902ea48a37dfffa1 removed a useful feature for us, which provided a cpu accounting resource controller. This feature would be useful if someone wants to group tasks only for accounting purpose and doesnt really want to exercise any control over their cpu consumption. The patch below reintroduces the feature. It is based on Paul Menage's original patch (Commit 62d0df64065e7c135d0002f069444fbdfc64768f), with these differences: - Removed load average information. I felt it needs more thought (esp to deal with SMP and virtualized platforms) and can be added for 2.6.25 after more discussions. - Convert group cpu usage to be nanosecond accurate (as rest of the cfs stats are) and invoke cpuacct_charge() from the respective scheduler classes - Make accounting scalable on SMP systems by splitting the usage counter to be per-cpu - Move the code from kernel/cpu_acct.c to kernel/sched.c (since the code is not big enough to warrant a new file and also this rightly needs to live inside the scheduler. Also things like accessing rq->lock while reading cpu usage becomes easier if the code lived in kernel/sched.c) The patch also modifies the cpu controller not to provide the same accounting information. Tested-by: Balbir Singh <balbir@linux.vnet.ibm.com> Tested the patches on top of 2.6.24-rc3. The patches work fine. Ran some simple tests like cpuspin (spin on the cpu), ran several tasks in the same group and timed them. Compared their time stamps with cpuacct.usage. Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-12-02 19:04:49 +00:00
*cpuusage += cputime;
}
cpuacct: make cpuacct hierarchy walk in cpuacct_charge() safe when rcupreempt is used -v2 Impact: fix cgroups race under rcu-preempt cpuacct_charge() obtains task's ca and does a hierarchy walk upwards. This can race with the task's movement between cgroups. This race can cause an access to freed ca pointer in cpuacct_charge() or access to invalid cgroups pointer of the task. This will not happen with rcu or tree rcu as cpuacct_charge() is called with preemption disabled. However if rcupreempt is used, the race is seen. Thanks to Li Zefan for explaining this. Fix this race by explicitly protecting ca and the hierarchy walk with rcu_read_lock(). Changes for v2: - Update patch descrition (as per Li Zefan's review comments). - Remove comments in cpuacct_charge() which explained why rcu_read_lock() was needed (as per Peter Zijlstra's review comments). Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com> Cc: Dhaval Giani <dhaval@linux.vnet.ibm.com> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Paul Menage <menage@google.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com> Tested-by: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-23 04:32:53 +00:00
rcu_read_unlock();
sched: cpu accounting controller (V2) Commit cfb5285660aad4931b2ebbfa902ea48a37dfffa1 removed a useful feature for us, which provided a cpu accounting resource controller. This feature would be useful if someone wants to group tasks only for accounting purpose and doesnt really want to exercise any control over their cpu consumption. The patch below reintroduces the feature. It is based on Paul Menage's original patch (Commit 62d0df64065e7c135d0002f069444fbdfc64768f), with these differences: - Removed load average information. I felt it needs more thought (esp to deal with SMP and virtualized platforms) and can be added for 2.6.25 after more discussions. - Convert group cpu usage to be nanosecond accurate (as rest of the cfs stats are) and invoke cpuacct_charge() from the respective scheduler classes - Make accounting scalable on SMP systems by splitting the usage counter to be per-cpu - Move the code from kernel/cpu_acct.c to kernel/sched.c (since the code is not big enough to warrant a new file and also this rightly needs to live inside the scheduler. Also things like accessing rq->lock while reading cpu usage becomes easier if the code lived in kernel/sched.c) The patch also modifies the cpu controller not to provide the same accounting information. Tested-by: Balbir Singh <balbir@linux.vnet.ibm.com> Tested the patches on top of 2.6.24-rc3. The patches work fine. Ran some simple tests like cpuspin (spin on the cpu), ran several tasks in the same group and timed them. Compared their time stamps with cpuacct.usage. Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-12-02 19:04:49 +00:00
}
sched: cpuacct: Use bigger percpu counter batch values for stats counters When CONFIG_VIRT_CPU_ACCOUNTING and CONFIG_CGROUP_CPUACCT are enabled we can call cpuacct_update_stats with values much larger than percpu_counter_batch. This means the call to percpu_counter_add will always add to the global count which is protected by a spinlock and we end up with a global spinlock in the scheduler. Based on an idea by KOSAKI Motohiro, this patch scales the batch value by cputime_one_jiffy such that we have the same batch limit as we would if CONFIG_VIRT_CPU_ACCOUNTING was disabled. His patch did this once at boot but that initialisation happened too early on PowerPC (before time_init) and it was never updated at runtime as a result of a hotplug cpu add/remove. This patch instead scales percpu_counter_batch by cputime_one_jiffy at runtime, which keeps the batch correct even after cpu hotplug operations. We cap it at INT_MAX in case of overflow. For architectures that do not support CONFIG_VIRT_CPU_ACCOUNTING, cputime_one_jiffy is the constant 1 and gcc is smart enough to optimise min(s32 percpu_counter_batch, INT_MAX) to just percpu_counter_batch at least on x86 and PowerPC. So there is no need to add an #ifdef. On a 64 thread PowerPC box with CONFIG_VIRT_CPU_ACCOUNTING and CONFIG_CGROUP_CPUACCT enabled, a context switch microbenchmark is 234x faster and almost matches a CONFIG_CGROUP_CPUACCT disabled kernel: CONFIG_CGROUP_CPUACCT disabled: 16906698 ctx switches/sec CONFIG_CGROUP_CPUACCT enabled: 61720 ctx switches/sec CONFIG_CGROUP_CPUACCT + patch: 16663217 ctx switches/sec Tested with: wget http://ozlabs.org/~anton/junkcode/context_switch.c make context_switch for i in `seq 0 63`; do taskset -c $i ./context_switch & done vmstat 1 Signed-off-by: Anton Blanchard <anton@samba.org> Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com> Tested-by: Balbir Singh <balbir@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: "Luck, Tony" <tony.luck@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-02-02 22:46:13 +00:00
/*
* When CONFIG_VIRT_CPU_ACCOUNTING is enabled one jiffy can be very large
* in cputime_t units. As a result, cpuacct_update_stats calls
* percpu_counter_add with values large enough to always overflow the
* per cpu batch limit causing bad SMP scalability.
*
* To fix this we scale percpu_counter_batch by cputime_one_jiffy so we
* batch the same amount of time with CONFIG_VIRT_CPU_ACCOUNTING disabled
* and enabled. We cap it at INT_MAX which is the largest allowed batch value.
*/
#ifdef CONFIG_SMP
#define CPUACCT_BATCH \
min_t(long, percpu_counter_batch * cputime_one_jiffy, INT_MAX)
#else
#define CPUACCT_BATCH 0
#endif
cpuacct: add per-cgroup utime/stime statistics Add per-cgroup cpuacct controller statistics like the system and user time consumed by the group of tasks. Changelog: v7 - Changed the name of the statistic from utime to user and from stime to system so that in future we could easily add other statistics like irq, softirq, steal times etc easily. v6 - Fixed a bug in the error path of cpuacct_create() (pointed by Li Zefan). v5 - In cpuacct_stats_show(), use cputime64_to_clock_t() since we are operating on a 64bit variable here. v4 - Remove comments in cpuacct_update_stats() which explained why rcu_read_lock() was needed (as per Peter Zijlstra's review comments). - Don't say that percpu_counter_read() is broken in Documentation/cpuacct.txt as per KAMEZAWA Hiroyuki's review comments. v3 - Fix a small race in the cpuacct hierarchy walk. v2 - stime and utime now exported in clock_t units instead of msecs. - Addressed the code review comments from Balbir and Li Zefan. - Moved to -tip tree. v1 - Moved the stime/utime accounting to cpuacct controller. Earlier versions - http://lkml.org/lkml/2009/2/25/129 Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com> Signed-off-by: Balaji Rao <balajirrao@gmail.com> Cc: Dhaval Giani <dhaval@linux.vnet.ibm.com> Cc: Paul Menage <menage@google.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Reviewed-by: Li Zefan <lizf@cn.fujitsu.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com> Tested-by: Balbir Singh <balbir@linux.vnet.ibm.com> LKML-Reference: <20090331043222.GA4093@in.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-31 04:32:22 +00:00
/*
* Charge the system/user time to the task's accounting group.
*/
static void cpuacct_update_stats(struct task_struct *tsk,
enum cpuacct_stat_index idx, cputime_t val)
{
struct cpuacct *ca;
sched: cpuacct: Use bigger percpu counter batch values for stats counters When CONFIG_VIRT_CPU_ACCOUNTING and CONFIG_CGROUP_CPUACCT are enabled we can call cpuacct_update_stats with values much larger than percpu_counter_batch. This means the call to percpu_counter_add will always add to the global count which is protected by a spinlock and we end up with a global spinlock in the scheduler. Based on an idea by KOSAKI Motohiro, this patch scales the batch value by cputime_one_jiffy such that we have the same batch limit as we would if CONFIG_VIRT_CPU_ACCOUNTING was disabled. His patch did this once at boot but that initialisation happened too early on PowerPC (before time_init) and it was never updated at runtime as a result of a hotplug cpu add/remove. This patch instead scales percpu_counter_batch by cputime_one_jiffy at runtime, which keeps the batch correct even after cpu hotplug operations. We cap it at INT_MAX in case of overflow. For architectures that do not support CONFIG_VIRT_CPU_ACCOUNTING, cputime_one_jiffy is the constant 1 and gcc is smart enough to optimise min(s32 percpu_counter_batch, INT_MAX) to just percpu_counter_batch at least on x86 and PowerPC. So there is no need to add an #ifdef. On a 64 thread PowerPC box with CONFIG_VIRT_CPU_ACCOUNTING and CONFIG_CGROUP_CPUACCT enabled, a context switch microbenchmark is 234x faster and almost matches a CONFIG_CGROUP_CPUACCT disabled kernel: CONFIG_CGROUP_CPUACCT disabled: 16906698 ctx switches/sec CONFIG_CGROUP_CPUACCT enabled: 61720 ctx switches/sec CONFIG_CGROUP_CPUACCT + patch: 16663217 ctx switches/sec Tested with: wget http://ozlabs.org/~anton/junkcode/context_switch.c make context_switch for i in `seq 0 63`; do taskset -c $i ./context_switch & done vmstat 1 Signed-off-by: Anton Blanchard <anton@samba.org> Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com> Tested-by: Balbir Singh <balbir@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: "Luck, Tony" <tony.luck@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-02-02 22:46:13 +00:00
int batch = CPUACCT_BATCH;
cpuacct: add per-cgroup utime/stime statistics Add per-cgroup cpuacct controller statistics like the system and user time consumed by the group of tasks. Changelog: v7 - Changed the name of the statistic from utime to user and from stime to system so that in future we could easily add other statistics like irq, softirq, steal times etc easily. v6 - Fixed a bug in the error path of cpuacct_create() (pointed by Li Zefan). v5 - In cpuacct_stats_show(), use cputime64_to_clock_t() since we are operating on a 64bit variable here. v4 - Remove comments in cpuacct_update_stats() which explained why rcu_read_lock() was needed (as per Peter Zijlstra's review comments). - Don't say that percpu_counter_read() is broken in Documentation/cpuacct.txt as per KAMEZAWA Hiroyuki's review comments. v3 - Fix a small race in the cpuacct hierarchy walk. v2 - stime and utime now exported in clock_t units instead of msecs. - Addressed the code review comments from Balbir and Li Zefan. - Moved to -tip tree. v1 - Moved the stime/utime accounting to cpuacct controller. Earlier versions - http://lkml.org/lkml/2009/2/25/129 Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com> Signed-off-by: Balaji Rao <balajirrao@gmail.com> Cc: Dhaval Giani <dhaval@linux.vnet.ibm.com> Cc: Paul Menage <menage@google.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Reviewed-by: Li Zefan <lizf@cn.fujitsu.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com> Tested-by: Balbir Singh <balbir@linux.vnet.ibm.com> LKML-Reference: <20090331043222.GA4093@in.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-31 04:32:22 +00:00
if (unlikely(!cpuacct_subsys.active))
return;
rcu_read_lock();
ca = task_ca(tsk);
do {
sched: cpuacct: Use bigger percpu counter batch values for stats counters When CONFIG_VIRT_CPU_ACCOUNTING and CONFIG_CGROUP_CPUACCT are enabled we can call cpuacct_update_stats with values much larger than percpu_counter_batch. This means the call to percpu_counter_add will always add to the global count which is protected by a spinlock and we end up with a global spinlock in the scheduler. Based on an idea by KOSAKI Motohiro, this patch scales the batch value by cputime_one_jiffy such that we have the same batch limit as we would if CONFIG_VIRT_CPU_ACCOUNTING was disabled. His patch did this once at boot but that initialisation happened too early on PowerPC (before time_init) and it was never updated at runtime as a result of a hotplug cpu add/remove. This patch instead scales percpu_counter_batch by cputime_one_jiffy at runtime, which keeps the batch correct even after cpu hotplug operations. We cap it at INT_MAX in case of overflow. For architectures that do not support CONFIG_VIRT_CPU_ACCOUNTING, cputime_one_jiffy is the constant 1 and gcc is smart enough to optimise min(s32 percpu_counter_batch, INT_MAX) to just percpu_counter_batch at least on x86 and PowerPC. So there is no need to add an #ifdef. On a 64 thread PowerPC box with CONFIG_VIRT_CPU_ACCOUNTING and CONFIG_CGROUP_CPUACCT enabled, a context switch microbenchmark is 234x faster and almost matches a CONFIG_CGROUP_CPUACCT disabled kernel: CONFIG_CGROUP_CPUACCT disabled: 16906698 ctx switches/sec CONFIG_CGROUP_CPUACCT enabled: 61720 ctx switches/sec CONFIG_CGROUP_CPUACCT + patch: 16663217 ctx switches/sec Tested with: wget http://ozlabs.org/~anton/junkcode/context_switch.c make context_switch for i in `seq 0 63`; do taskset -c $i ./context_switch & done vmstat 1 Signed-off-by: Anton Blanchard <anton@samba.org> Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com> Tested-by: Balbir Singh <balbir@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: "Luck, Tony" <tony.luck@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-02-02 22:46:13 +00:00
__percpu_counter_add(&ca->cpustat[idx], val, batch);
cpuacct: add per-cgroup utime/stime statistics Add per-cgroup cpuacct controller statistics like the system and user time consumed by the group of tasks. Changelog: v7 - Changed the name of the statistic from utime to user and from stime to system so that in future we could easily add other statistics like irq, softirq, steal times etc easily. v6 - Fixed a bug in the error path of cpuacct_create() (pointed by Li Zefan). v5 - In cpuacct_stats_show(), use cputime64_to_clock_t() since we are operating on a 64bit variable here. v4 - Remove comments in cpuacct_update_stats() which explained why rcu_read_lock() was needed (as per Peter Zijlstra's review comments). - Don't say that percpu_counter_read() is broken in Documentation/cpuacct.txt as per KAMEZAWA Hiroyuki's review comments. v3 - Fix a small race in the cpuacct hierarchy walk. v2 - stime and utime now exported in clock_t units instead of msecs. - Addressed the code review comments from Balbir and Li Zefan. - Moved to -tip tree. v1 - Moved the stime/utime accounting to cpuacct controller. Earlier versions - http://lkml.org/lkml/2009/2/25/129 Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com> Signed-off-by: Balaji Rao <balajirrao@gmail.com> Cc: Dhaval Giani <dhaval@linux.vnet.ibm.com> Cc: Paul Menage <menage@google.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Reviewed-by: Li Zefan <lizf@cn.fujitsu.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com> Tested-by: Balbir Singh <balbir@linux.vnet.ibm.com> LKML-Reference: <20090331043222.GA4093@in.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-31 04:32:22 +00:00
ca = ca->parent;
} while (ca);
rcu_read_unlock();
}
sched: cpu accounting controller (V2) Commit cfb5285660aad4931b2ebbfa902ea48a37dfffa1 removed a useful feature for us, which provided a cpu accounting resource controller. This feature would be useful if someone wants to group tasks only for accounting purpose and doesnt really want to exercise any control over their cpu consumption. The patch below reintroduces the feature. It is based on Paul Menage's original patch (Commit 62d0df64065e7c135d0002f069444fbdfc64768f), with these differences: - Removed load average information. I felt it needs more thought (esp to deal with SMP and virtualized platforms) and can be added for 2.6.25 after more discussions. - Convert group cpu usage to be nanosecond accurate (as rest of the cfs stats are) and invoke cpuacct_charge() from the respective scheduler classes - Make accounting scalable on SMP systems by splitting the usage counter to be per-cpu - Move the code from kernel/cpu_acct.c to kernel/sched.c (since the code is not big enough to warrant a new file and also this rightly needs to live inside the scheduler. Also things like accessing rq->lock while reading cpu usage becomes easier if the code lived in kernel/sched.c) The patch also modifies the cpu controller not to provide the same accounting information. Tested-by: Balbir Singh <balbir@linux.vnet.ibm.com> Tested the patches on top of 2.6.24-rc3. The patches work fine. Ran some simple tests like cpuspin (spin on the cpu), ran several tasks in the same group and timed them. Compared their time stamps with cpuacct.usage. Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-12-02 19:04:49 +00:00
struct cgroup_subsys cpuacct_subsys = {
.name = "cpuacct",
.create = cpuacct_create,
.destroy = cpuacct_destroy,
.populate = cpuacct_populate,
.subsys_id = cpuacct_subsys_id,
};
#endif /* CONFIG_CGROUP_CPUACCT */
Reference in a new issue Copy permalink