linux-stable/kernel/sched
Peter Zijlstra 9edfbfed3f sched/core: Rework rq->clock update skips
The original purpose of rq::skip_clock_update was to avoid 'costly' clock
updates for back to back wakeup-preempt pairs. The big problem with it
has always been that the rq variable is unaware of the context and
causes indiscrimiate clock skips.

Rework the entire thing and create a sense of context by only allowing
schedule() to skip clock updates. (XXX can we measure the cost of the
added store?)

By ensuring only schedule can ever skip an update, we guarantee we're
never more than 1 tick behind on the update.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: umgwanakikbuti@gmail.com
Link: http://lkml.kernel.org/r/20150105103554.432381549@infradead.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-01-14 13:34:20 +01:00
..
auto_group.c sched: Change autogroup_move_group() to use for_each_thread() 2014-08-20 09:47:18 +02:00
auto_group.h Revert "sched/autogroup: Fix crash on reboot when autogroup is disabled" 2012-12-11 10:23:45 +01:00
clock.c time: Replace __get_cpu_var uses 2014-08-26 13:45:44 -04:00
completion.c sched/completion: Document when to use wait_for_completion_io_*() 2014-11-16 10:58:54 +01:00
core.c sched/core: Rework rq->clock update skips 2015-01-14 13:34:20 +01:00
cpuacct.c cgroup: rename cgroup_subsys->base_cftypes to ->legacy_cftypes 2014-07-15 11:05:09 -04:00
cpuacct.h sched/cpuacct: Initialize root cpuacct earlier 2013-04-10 13:54:20 +02:00
cpudeadline.c sched/deadline: Fix inter- exclusive cpusets migrations 2014-09-24 14:46:57 +02:00
cpudeadline.h sched/deadline: Remove unnecessary definitions in cpudeadline.h 2014-11-16 10:59:00 +01:00
cpupri.c Merge commit '3cf2f34' into sched/core, to fix build error 2014-06-12 13:46:37 +02:00
cpupri.h sched/cpupri: Remove unnecessary definitions in cpupri.h 2014-11-16 10:58:59 +01:00
cputime.c sched, time: Fix build error with 64 bit cputime_t on 32 bit systems 2014-10-03 05:46:55 +02:00
deadline.c sched/deadline: Avoid double-accounting in case of missed deadlines 2015-01-09 11:18:57 +01:00
debug.c sched: Refactor task_struct to use numa_faults instead of numa_* pointers 2014-11-04 07:17:57 +01:00
fair.c sched/core: Rework rq->clock update skips 2015-01-14 13:34:20 +01:00
features.h sched: Rename capacity related flags 2014-06-05 11:52:32 +02:00
idle.c sched: Let the scheduler see CPU idle states 2014-09-24 14:46:58 +02:00
idle_task.c sched: Provide update_curr callbacks for stop/idle scheduling classes 2014-11-23 14:14:40 -08:00
Makefile sched/idle: Move cpu/idle.c to sched/idle.c 2014-02-11 09:58:30 +01:00
proc.c cpuidle: menu: Lookup CPU runqueues less 2014-08-06 21:17:45 +02:00
rt.c sched/core: Rework rq->clock update skips 2015-01-14 13:34:20 +01:00
sched.h sched/core: Rework rq->clock update skips 2015-01-14 13:34:20 +01:00
stats.c kernel: audit/fix non-modular users of module_init in core code 2014-04-03 16:21:07 -07:00
stats.h sched: Micro-optimize by dropping unnecessary task_rq() calls 2013-09-25 13:51:06 +02:00
stop_task.c sched: Provide update_curr callbacks for stop/idle scheduling classes 2014-11-23 14:14:40 -08:00
wait.c sched/wait: Fix a kthread race with wait_woken() 2014-11-04 07:17:44 +01:00