Commit Graph

18 Commits

Author SHA1 Message Date
Linus Torvalds d3ec4844d4 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (43 commits)
  fs: Merge split strings
  treewide: fix potentially dangerous trailing ';' in #defined values/expressions
  uwb: Fix misspelling of neighbourhood in comment
  net, netfilter: Remove redundant goto in ebt_ulog_packet
  trivial: don't touch files that are removed in the staging tree
  lib/vsprintf: replace link to Draft by final RFC number
  doc: Kconfig: `to be' -> `be'
  doc: Kconfig: Typo: square -> squared
  doc: Konfig: Documentation/power/{pm => apm-acpi}.txt
  drivers/net: static should be at beginning of declaration
  drivers/media: static should be at beginning of declaration
  drivers/i2c: static should be at beginning of declaration
  XTENSA: static should be at beginning of declaration
  SH: static should be at beginning of declaration
  MIPS: static should be at beginning of declaration
  ARM: static should be at beginning of declaration
  rcu: treewide: Do not use rcu_read_lock_held when calling rcu_dereference_check
  Update my e-mail address
  PCIe ASPM: forcedly -> forcibly
  gma500: push through device driver tree
  ...

Fix up trivial conflicts:
 - arch/arm/mach-ep93xx/dma-m2p.c (deleted)
 - drivers/gpio/gpio-ep93xx.c (renamed and context nearby)
 - drivers/net/r8169.c (just context changes)
2011-07-25 13:56:39 -07:00
Suresh Siddha 192d885742 x86, mtrr: use stop_machine APIs for doing MTRR rendezvous
MTRR rendezvous sequence is not implemened using stop_machine() before, as this
gets called both from the process context aswell as the cpu online paths
(where the cpu has not come online and the interrupts are disabled etc).

Now that we have a new stop_machine_from_inactive_cpu() API, use it for
rendezvous during mtrr init of a logical processor that is coming online.

For the rest (runtime MTRR modification, system boot, resume paths), use
stop_machine() to implement the rendezvous sequence. This will consolidate and
cleanup the code.

Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Link: http://lkml.kernel.org/r/20110623182057.076997177@sbsiddha-MOBL3.sc.intel.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2011-06-27 15:17:13 -07:00
Tejun Heo f740e6cd0c stop_machine: implement stop_machine_from_inactive_cpu()
Currently, mtrr wants stop_machine functionality while a CPU is being
brought up.  As stop_machine() requires the calling CPU to be active,
mtrr implements its own stop_machine using stop_one_cpu() on each
online CPU.  This doesn't only unnecessarily duplicate complex logic
but also introduces a possibility of deadlock when it races against
the generic stop_machine().

This patch implements stop_machine_from_inactive_cpu() to serve such
use cases.  Its functionality is basically the same as stop_machine();
however, it should be called from a CPU which isn't active and doesn't
depend on working scheduling on the calling CPU.

This is achieved by using busy loops for synchronization and
open-coding stop_cpus queuing and waiting with direct invocation of
fn() for local CPU inbetween.

Signed-off-by: Tejun Heo <tj@kernel.org>
Link: http://lkml.kernel.org/r/20110623182056.982526827@sbsiddha-MOBL3.sc.intel.com
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2011-06-27 15:17:08 -07:00
Suresh Siddha 6d3321e8e2 x86, mtrr: lock stop machine during MTRR rendezvous sequence
MTRR rendezvous sequence using stop_one_cpu_nowait() can potentially
happen in parallel with another system wide rendezvous using
stop_machine(). This can lead to deadlock (The order in which
works are queued can be different on different cpu's. Some cpu's
will be running the first rendezvous handler and others will be running
the second rendezvous handler. Each set waiting for the other set to join
for the system wide rendezvous, leading to a deadlock).

MTRR rendezvous sequence is not implemented using stop_machine() as this
gets called both from the process context aswell as the cpu online paths
(where the cpu has not come online and the interrupts are disabled etc).
stop_machine() works with only online cpus.

For now, take the stop_machine mutex in the MTRR rendezvous sequence that
gets called from an online cpu (here we are in the process context
and can potentially sleep while taking the mutex). And the MTRR rendezvous
that gets triggered during cpu online doesn't need to take this stop_machine
lock (as the stop_machine() already ensures that there is no cpu hotplug
going on in parallel by doing get_online_cpus())

    TBD: Pursue a cleaner solution of extending the stop_machine()
         infrastructure to handle the case where the calling cpu is
         still not online and use this for MTRR rendezvous sequence.

fixes: https://bugzilla.novell.com/show_bug.cgi?id=672008

Reported-by: Vadim Kotelnikov <vadimuzzz@inbox.ru>
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Link: http://lkml.kernel.org/r/20110623182056.807230326@sbsiddha-MOBL3.sc.intel.com
Cc: stable@kernel.org # 2.6.35+, backport a week or two after this gets more testing in mainline
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2011-06-27 14:00:46 -07:00
Jonathan Neuschäfer 1816315b10 stop_machine.h: "disables preeempt" -> "disables preemption"
Use the noun instead of a misspelled verb.

Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2011-06-20 15:52:33 +02:00
Lucas De Marchi 25985edced Fix common misspellings
Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
2011-03-31 11:26:23 -03:00
Masami Hiramatsu 087a4eb559 stopmachine: Define __stop_machine when CONFIG_STOP_MACHINE=n
Define dummy __stop_machine() function even when
CONFIG_STOP_MACHINE=n. This getcpu-required version of
stop_machine() will be used from poke_text_smp().

Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Acked-by: Tejun Heo <tj@kernel.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: 2nddept-manager@sdl.hitachi.co.jp
Cc: Peter Zijlstra <peterz@infradead.org>
LKML-Reference: <20101014031030.4100.34156.stgit@ltc236.sdl.hitachi.co.jp>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-14 08:55:28 +02:00
Tejun Heo bbf1bb3eee cpu_stop: add dummy implementation for UP
When !CONFIG_SMP, cpu_stop functions weren't defined at all which
could lead to build failures if UP code uses cpu_stop facility.  Add
dummy cpu_stop implementation for UP.  The waiting variants execute
the work function directly with preempt disabled and
stop_one_cpu_nowait() schedules a workqueue work.

Makefile and ifdefs around stop_machine implementation are updated to
accomodate CONFIG_SMP && !CONFIG_STOP_MACHINE case.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Ingo Molnar <mingo@elte.hu>
2010-05-08 17:12:33 +02:00
Tejun Heo 3fc1f1e27a stop_machine: reimplement using cpu_stop
Reimplement stop_machine using cpu_stop.  As cpu stoppers are
guaranteed to be available for all online cpus,
stop_machine_create/destroy() are no longer necessary and removed.

With resource management and synchronization handled by cpu_stop, the
new implementation is much simpler.  Asking the cpu_stop to execute
the stop_cpu() state machine on all online cpus with cpu hotplug
disabled is enough.

stop_machine itself doesn't need to manage any global resources
anymore, so all per-instance information is rolled into struct
stop_machine_data and the mutex and all static data variables are
removed.

The previous implementation created and destroyed RT workqueues as
necessary which made stop_machine() calls highly expensive on very
large machines.  According to Dimitri Sivanich, preventing the dynamic
creation/destruction makes booting faster more than twice on very
large machines.  cpu_stop resources are preallocated for all online
cpus and should have the same effect.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Dimitri Sivanich <sivanich@sgi.com>
2010-05-06 18:49:20 +02:00
Tejun Heo 1142d81029 cpu_stop: implement stop_cpu[s]()
Implement a simplistic per-cpu maximum priority cpu monopolization
mechanism.  A non-sleeping callback can be scheduled to run on one or
multiple cpus with maximum priority monopolozing those cpus.  This is
primarily to replace and unify RT workqueue usage in stop_machine and
scheduler migration_thread which currently is serving multiple
purposes.

Four functions are provided - stop_one_cpu(), stop_one_cpu_nowait(),
stop_cpus() and try_stop_cpus().

This is to allow clean sharing of resources among stop_cpu and all the
migration thread users.  One stopper thread per cpu is created which
is currently named "stopper/CPU".  This will eventually replace the
migration thread and take on its name.

* This facility was originally named cpuhog and lived in separate
  files but Peter Zijlstra nacked the name and thus got renamed to
  cpu_stop and moved into stop_machine.c.

* Better reporting of preemption leak as per Peter's suggestion.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Dimitri Sivanich <sivanich@sgi.com>
2010-05-06 18:49:20 +02:00
Heiko Carstens 9ea09af3bd stop_machine: introduce stop_machine_create/destroy.
Introduce stop_machine_create/destroy. With this interface subsystems
that need a non-failing stop_machine environment can create the
stop_machine machine threads before actually calling stop_machine.
When the threads aren't needed anymore they can be killed with
stop_machine_destroy again.

When stop_machine gets called and the threads aren't present they
will be created and destroyed automatically. This restores the old
behaviour of stop_machine.

This patch also converts cpu hotplug to the new interface since it
is special: cpu_down calls __stop_machine instead of stop_machine.
However the kstop threads will only be created when stop_machine
gets called.

Changing the code so that the threads would be created automatically
on __stop_machine is currently not possible: when __stop_machine gets
called we hold cpu_add_remove_lock, which is the same lock that
create_rt_workqueue would take. So the workqueue needs to be created
before the cpu hotplug code locks cpu_add_remove_lock.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2009-01-05 08:40:14 +10:30
Rusty Russell 41c7bb9588 cpumask: convert rest of files in kernel/
Impact: Reduce stack usage, use new cpumask API.

Mainly changing cpumask_t to 'struct cpumask' and similar simple API
conversion.  Two conversions worth mentioning:

1) we use cpumask_any_but to avoid a temporary in kernel/softlockup.c,
2) Use cpumask_var_t in taskstats_user_cmd().

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Mike Travis <travis@sgi.com>
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@redhat.com>
2009-01-01 10:12:28 +10:30
Rusty Russell bf20029677 stop_machine: Remove deprecated stop_machine_run
Everyone should be using stop_machine() now.  The staged API
transition helped life in linux-next.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-08-26 00:19:27 +10:00
Rusty Russell eeec4fad96 stop_machine(): stop_machine_run() changed to use cpu mask
Instead of a "cpu" arg with magic values NR_CPUS (any cpu) and ~0 (all
cpus), pass a cpumask_t.  Allow NULL for the common case (where we
don't care which CPU the function is run on): temporary cpumask_t's
are usually considered bad for stack space.

This deprecates stop_machine_run, to be removed soon when all the
callers are dead.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-07-28 12:16:30 +10:00
Rusty Russell ffdb5976c4 Simplify stop_machine
stop_machine creates a kthread which creates kernel threads.  We can
create those threads directly and simplify things a little.  Some care
must be taken with CPU hotunplug, which has special needs, but that code
seems more robust than it was in the past.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
2008-07-28 12:16:29 +10:00
Jason Baron 5c2aed6225 stop_machine: add ALL_CPUS option
-allow stop_mahcine_run() to call a function on all cpus. Calling
 stop_machine_run() with a 'ALL_CPUS' invokes this new behavior.
 stop_machine_run() proceeds as normal until the calling cpu has
 invoked 'fn'. Then, we tell all the other cpus to call 'fn'.

Signed-off-by: Jason Baron <jbaron@redhat.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
CC: Adrian Bunk <bunk@stusta.de>
CC: Andi Kleen <andi@firstfloor.org>
CC: Alexey Dobriyan <adobriyan@gmail.com>
CC: Christoph Hellwig <hch@infradead.org>
CC: mingo@elte.hu
CC: akpm@osdl.org
2008-07-28 12:16:28 +10:00
David Woodhouse 62c4f0a2d5 Don't include linux/config.h from anywhere else in include/
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
2006-04-26 12:56:16 +01:00
Linus Torvalds 1da177e4c3 Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!
2005-04-16 15:20:36 -07:00