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| author | Chris Redpath <chris.redpath@arm.com> | 2017-05-30 14:51:53 +0100 |
|---|---|---|
| committer | Chris Redpath <chris.redpath@arm.com> | 2017-10-27 13:30:32 +0100 |
| commit | 792510d9b392b392c763c5e395f046d5c246c66e (patch) | |
| tree | c63ae429b13f328fbb0b9c96b4b0f93fbad9728c /kernel/sched/sched.h | |
| parent | fac311be26e5af64612c386f5a041984fe7c59a2 (diff) | |
BACKPORT: sched/fair: Make it possible to account fair load avg consistently
While set_task_rq_fair() is introduced in mainline by commit ad936d8658fd
("sched/fair: Make it possible to account fair load avg consistently"),
the function results to be introduced here by the backport of
commit 09a43ace1f98 ("sched/fair: Propagate load during synchronous
attach/detach"). The problem (apart from the confusion introduced by the
backport) is actually that set_task_rq_fair() is currently not called at
all.
Fix the problem by backporting again commit ad936d8658fd
("sched/fair: Make it possible to account fair load avg consistently").
Original change log:
The current code accounts for the time a task was absent from the fair
class (per ATTACH_AGE_LOAD). However it does not work correctly when a
task got migrated or moved to another cgroup while outside of the fair
class.
This patch tries to address that by aging on migration. We locklessly
read the 'last_update_time' stamp from both the old and new cfs_rq,
ages the load upto the old time, and sets it to the new time.
These timestamps should in general not be more than 1 tick apart from
one another, so there is a definite bound on things.
Signed-off-by: Byungchul Park <byungchul.park@lge.com>
[ Changelog, a few edits and !SMP build fix ]
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>
Link: http://lkml.kernel.org/r/1445616981-29904-2-git-send-email-byungchul.park@lge.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
(cherry-picked from ad936d8658fd348338cb7d42c577dac77892b074)
Signed-off-by: Juri Lelli <juri.lelli@arm.com>
Signed-off-by: Chris Redpath <chris.redpath@arm.com>
Change-Id: I17294ab0ada3901d35895014715fd60952949358
Signed-off-by: Brendan Jackman <brendan.jackman@arm.com>
Diffstat (limited to 'kernel/sched/sched.h')
| -rw-r--r-- | kernel/sched/sched.h | 11 |
1 files changed, 10 insertions, 1 deletions
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index 5256f05a26e8..1d52ca8a613c 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -335,7 +335,15 @@ extern void sched_move_task(struct task_struct *tsk); #ifdef CONFIG_FAIR_GROUP_SCHED extern int sched_group_set_shares(struct task_group *tg, unsigned long shares); -#endif + +#ifdef CONFIG_SMP +extern void set_task_rq_fair(struct sched_entity *se, + struct cfs_rq *prev, struct cfs_rq *next); +#else /* !CONFIG_SMP */ +static inline void set_task_rq_fair(struct sched_entity *se, + struct cfs_rq *prev, struct cfs_rq *next) { } +#endif /* CONFIG_SMP */ +#endif /* CONFIG_FAIR_GROUP_SCHED */ #else /* CONFIG_CGROUP_SCHED */ @@ -987,6 +995,7 @@ static inline void set_task_rq(struct task_struct *p, unsigned int cpu) #endif #ifdef CONFIG_FAIR_GROUP_SCHED + set_task_rq_fair(&p->se, p->se.cfs_rq, tg->cfs_rq[cpu]); p->se.cfs_rq = tg->cfs_rq[cpu]; p->se.parent = tg->se[cpu]; #endif |