linux-sg2042/kernel/sched
Byungchul Park 6efdb105d3 sched/fair: Fix switched_to_fair()'s per entity load tracking
Where switched_from_fair() will remove the entity's load from the
runqueue, switched_to_fair() does not currently add it back. This
means that when a task leaves the fair class for a short duration; say
because of PI; we loose its load contribution.

This can ripple forward and disturb the load tracking because other
operations (enqueue, dequeue) assume its factored in. Only once the
runqueue empties will the load tracking recover.

When we add it back in, age the per entity average to match up with
the runqueue age. This has the obvious problem that if the task leaves
the fair class for a significant time, the load will age to 0.

Employ the normal migration rule for inter-runqueue moves in
task_move_group_fair(). Again, there is the obvious problem of the
task migrating while not in the fair class.

The alternative solution would be to to omit the chunk in
attach_entity_load_avg(), which would effectively reset the timestamp
and use whatever avg there was.

Signed-off-by: Byungchul Park <byungchul.park@lge.com>
[ Rewrote the changelog and comments. ]
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: yuyang.du@intel.com
Link: http://lkml.kernel.org/r/1440069720-27038-5-git-send-email-byungchul.park@lge.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-09-13 09:52:48 +02:00
..
Makefile sched: Move the loadavg code to a more obvious location 2015-05-08 12:04:12 +02:00
auto_group.c sched, timer: Convert usages of ACCESS_ONCE() in the scheduler to READ_ONCE()/WRITE_ONCE() 2015-05-08 12:11:32 +02:00
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 kernel/sched/clock.c: add another clock for use with the soft lockup watchdog 2015-02-12 18:54:13 -08:00
completion.c sched/completion: Serialize completion_done() with complete() 2015-02-18 14:27:40 +01:00
core.c Linux 4.3-rc1 2015-09-13 09:51:21 +02:00
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: Remove cpu_active_mask from cpudl_find() 2015-02-04 07:52:29 +01:00
cpudeadline.h sched/deadline: Modify cpudl::free_cpus to reflect rd->online 2015-01-30 19:39:16 +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/cputime: Guarantee stime + utime == rtime 2015-08-03 12:21:21 +02:00
deadline.c sched/deadline: Fix comment in enqueue_task_dl() 2015-08-12 12:06:10 +02:00
debug.c sched/fair: Provide runnable_load_avg back to cfs_rq 2015-08-03 12:24:31 +02:00
fair.c sched/fair: Fix switched_to_fair()'s per entity load tracking 2015-09-13 09:52:48 +02:00
features.h sched/numa: Prefer NUMA hotness over cache hotness 2015-07-07 08:46:10 +02:00
idle.c sched/idle: Move latency tracing stop/start calls deeper inside the idle loop 2015-07-21 08:18:51 +02:00
idle_task.c sched: Make sched_class::set_cpus_allowed() unconditional 2015-08-12 12:06:09 +02:00
loadavg.c sched: Move the loadavg code to a more obvious location 2015-05-08 12:04:12 +02:00
rt.c sched: Change the sched_class::set_cpus_allowed() calling context 2015-08-12 12:06:10 +02:00
sched.h sched: Make sched_class::set_cpus_allowed() unconditional 2015-08-12 12:06:09 +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/stat: Simplify the sched_info accounting dependency 2015-07-04 10:04:30 +02:00
stop_task.c sched: Make sched_class::set_cpus_allowed() unconditional 2015-08-12 12:06:09 +02:00
wait.c userfaultfd: waitqueue: add nr wake parameter to __wake_up_locked_key 2015-09-04 16:54:41 -07:00