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| author | Viresh Kumar <viresh.kumar@linaro.org> | 2017-05-24 10:59:55 +0530 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2017-08-10 12:18:11 +0200 |
| commit | 9674f5cad22a590c865a330ce333026b9f9c078b (patch) | |
| tree | ebd0367c4b73382f18ed50ea0b35feabf6f0c104 /kernel/sched | |
| parent | c7132dd6f0e3b07bd4541cda9040897cc460d855 (diff) | |
| download | linux-9674f5cad22a590c865a330ce333026b9f9c078b.tar.gz linux-9674f5cad22a590c865a330ce333026b9f9c078b.tar.bz2 linux-9674f5cad22a590c865a330ce333026b9f9c078b.zip | |
sched/fair: Avoid checking cfs_rq->nr_running twice
Rearrange pick_next_task_fair() a bit to avoid checking
cfs_rq->nr_running twice for the case where FAIR_GROUP_SCHED is enabled
and the previous task doesn't belong to the fair class.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vincent Guittot <vincent.guittot@linaro.org>
Cc: linaro-kernel@lists.linaro.org
Link: http://lkml.kernel.org/r/000903ab3df3350943d3271c53615893a230dc95.1495603536.git.viresh.kumar@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel/sched')
| -rw-r--r-- | kernel/sched/fair.c | 16 |
1 files changed, 9 insertions, 7 deletions
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 27d425eccaad..30fd196c0cde 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -6187,10 +6187,10 @@ pick_next_task_fair(struct rq *rq, struct task_struct *prev, struct rq_flags *rf int new_tasks; again: -#ifdef CONFIG_FAIR_GROUP_SCHED if (!cfs_rq->nr_running) goto idle; +#ifdef CONFIG_FAIR_GROUP_SCHED if (prev->sched_class != &fair_sched_class) goto simple; @@ -6220,11 +6220,17 @@ again: /* * This call to check_cfs_rq_runtime() will do the * throttle and dequeue its entity in the parent(s). - * Therefore the 'simple' nr_running test will indeed + * Therefore the nr_running test will indeed * be correct. */ - if (unlikely(check_cfs_rq_runtime(cfs_rq))) + if (unlikely(check_cfs_rq_runtime(cfs_rq))) { + cfs_rq = &rq->cfs; + + if (!cfs_rq->nr_running) + goto idle; + goto simple; + } } se = pick_next_entity(cfs_rq, curr); @@ -6264,12 +6270,8 @@ again: return p; simple: - cfs_rq = &rq->cfs; #endif - if (!cfs_rq->nr_running) - goto idle; - put_prev_task(rq, prev); do { |