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| author |   Quentin Perret <qperret@google.com> | 2020-11-12 11:12:01 +0000 |
|---|---|---|
| committer |   Peter Zijlstra <peterz@infradead.org> | 2020-11-17 13:15:27 +0100 |
| commit | 8e1ac4299a6e8726de42310d9c1379f188140c71 (patch) | |
| tree | 8eb8454794c58a9978cc4f09886fbe5af764fd7f /kernel | |
| parent | sched/debug: Fix memory corruption caused by multiple small reads of flags (diff) | |
| download | linux-dev-8e1ac4299a6e8726de42310d9c1379f188140c71.tar.xz linux-dev-8e1ac4299a6e8726de42310d9c1379f188140c71.zip | |
sched/fair: Fix overutilized update in enqueue_task_fair()
enqueue_task_fair() attempts to skip the overutilized update for new
tasks as their util_avg is not accurate yet. However, the flag we check
to do so is overwritten earlier on in the function, which makes the
condition pretty much a nop.
Fix this by saving the flag early on.
Fixes: 2802bf3cd936 ("sched/fair: Add over-utilization/tipping point indicator")
Reported-by: Rick Yiu <rickyiu@google.com>
Signed-off-by: Quentin Perret <qperret@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org>
Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Link: https://lkml.kernel.org/r/20201112111201.2081902-1-qperret@google.com
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/sched/fair.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 8e563cf2b5e7..56a8ca93a971 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -5477,6 +5477,7 @@ enqueue_task_fair(struct rq *rq, struct task_struct *p, int flags) struct cfs_rq *cfs_rq; struct sched_entity *se = &p->se; int idle_h_nr_running = task_has_idle_policy(p); + int task_new = !(flags & ENQUEUE_WAKEUP); /* * The code below (indirectly) updates schedutil which looks at @@ -5549,7 +5550,7 @@ enqueue_task_fair(struct rq *rq, struct task_struct *p, int flags) * into account, but that is not straightforward to implement, * and the following generally works well enough in practice. */ - if (flags & ENQUEUE_WAKEUP) + if (!task_new) update_overutilized_status(rq); enqueue_throttle: |