kernel_optimize_test/kernel/sched
Vincent Guittot a399d23307 sched/core: Fix incorrect utilization accounting when switching to fair class
When a task switches to fair scheduling class, the period between now
and the last update of its utilization is accounted as running time
whatever happened during this period. This incorrect accounting applies
to the task and also to the task group branch.

When changing the property of a running task like its list of allowed
CPUs or its scheduling class, we follow the sequence:

 - dequeue task
 - put task
 - change the property
 - set task as current task
 - enqueue task

The end of the sequence doesn't follow the normal sequence (as per
__schedule()) which is:

 - enqueue a task
 - then set the task as current task.

This incorrectordering is the root cause of incorrect utilization accounting.
Update the sequence to follow the right one:

 - dequeue task
 - put task
 - change the property
 - enqueue task
 - set task as current task

Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Morten.Rasmussen@arm.com
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: bsegall@google.com
Cc: dietmar.eggemann@arm.com
Cc: linaro-kernel@lists.linaro.org
Cc: pjt@google.com
Cc: yuyang.du@intel.com
Link: http://lkml.kernel.org/r/1473666472-13749-8-git-send-email-vincent.guittot@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-09-30 11:03:27 +02:00
..
auto_group.c sched/core: Move the sched_to_prio[] arrays out of line 2015-12-04 10:34:46 +01:00
auto_group.h sched, timer: Convert usages of ACCESS_ONCE() in the scheduler to READ_ONCE()/WRITE_ONCE() 2015-05-08 12:11:32 +02:00
clock.c sched/clock: Make local_clock()/cpu_clock() inline 2016-04-13 12:25:22 +02:00
completion.c sched/completion: Serialize completion_done() with complete() 2015-02-18 14:27:40 +01:00
core.c sched/core: Fix incorrect utilization accounting when switching to fair class 2016-09-30 11:03:27 +02:00
cpuacct.c sched/cpuacct: Introduce cpuacct.usage_all to show all CPU stats together 2016-07-09 13:56:15 +02:00
cpuacct.h sched/cpuacct: Simplify the cpuacct code 2016-03-21 11:00:28 +01:00
cpudeadline.c sched/deadline: Split cpudl_set() into cpudl_set() and cpudl_clear() 2016-09-05 13:29:43 +02:00
cpudeadline.h sched/deadline: Split cpudl_set() into cpudl_set() and cpudl_clear() 2016-09-05 13:29:43 +02:00
cpufreq_schedutil.c cpufreq: schedutil: map raw required frequency to driver frequency 2016-07-21 22:28:21 +02:00
cpufreq.c cpufreq: sched: Helpers to add and remove update_util hooks 2016-04-02 01:08:43 +02:00
cpupri.c sched/core: Use tsk_cpus_allowed() instead of accessing ->cpus_allowed 2016-05-12 09:55:35 +02:00
cpupri.h sched/cpupri: Remove unnecessary definitions in cpupri.h 2014-11-16 10:58:59 +01:00
cputime.c sched/cputime: Improve scalability by not accounting thread group tasks pending runtime 2016-08-18 11:53:46 +02:00
deadline.c sched/deadline: Fix the intention to re-evalute tick dependency for offline CPU 2016-09-05 13:29:45 +02:00
debug.c sched/debug: Remove several CONFIG_SCHEDSTATS guards 2016-09-05 13:29:47 +02:00
fair.c sched/core: Optimize SCHED_SMT 2016-09-30 11:03:26 +02:00
features.h sched/fair: Convert arch_scale_cpu_capacity() from weak function to #define 2015-09-13 09:52:55 +02:00
idle_task.c sched/core: Rewrite and improve select_idle_siblings() 2016-09-30 11:03:09 +02:00
idle.c Merge branch 'sched/urgent' into sched/core, to pick up fixes 2016-06-14 11:04:13 +02:00
loadavg.c sched/core: Correct off by one bug in load migration calculation 2016-07-13 14:58:20 +02:00
Makefile cpufreq: schedutil: New governor based on scheduler utilization data 2016-04-02 01:09:12 +02:00
rt.c sched/core: Provide a tsk_nr_cpus_allowed() helper 2016-05-12 09:55:36 +02:00
sched.h sched/core: Optimize SCHED_SMT 2016-09-30 11:03:26 +02:00
stats.c sched: use %*pb[l] to print bitmaps including cpumasks and nodemasks 2015-02-13 21:21:37 -08:00
stats.h sched/debug: Rename 'schedstat_val()' -> 'schedstat_val_or_zero()' 2016-09-05 13:29:46 +02:00
stop_task.c locking/lockdep, sched/core: Implement a better lock pinning scheme 2016-05-05 09:23:59 +02:00
swait.c wait.[ch]: Introduce the simple waitqueue (swait) implementation 2016-02-25 11:27:16 +01:00
wait.c sched/wait: Introduce init_wait_entry() 2016-09-30 10:54:03 +02:00