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| author | Peter Zijlstra <peterz@infradead.org> | 2008-10-08 09:16:04 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2008-10-08 12:20:26 +0200 |
| commit | 2fb7635c4cea310992a39580133099dd99ad151c (patch) | |
| tree | e898c690d05c3dfeaa733fb3472eff400669be3a /kernel/sched_fair.c | |
| parent | 990d0f2ced23052abc7efa09bd05bff34e00cf73 (diff) | |
| download | lwn-2fb7635c4cea310992a39580133099dd99ad151c.tar.gz lwn-2fb7635c4cea310992a39580133099dd99ad151c.zip | |
sched: sync wakeups vs avg_overlap
While looking at the code I wondered why we always do:
sync && avg_overlap < migration_cost
Which is a bit odd, since the overlap test was meant to detect sync wakeups
so using it to specialize sync wakeups doesn't make much sense.
Hence change the code to do:
sync || avg_overlap < migration_cost
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel/sched_fair.c')
| -rw-r--r-- | kernel/sched_fair.c | 18 |
1 files changed, 10 insertions, 8 deletions
diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index fcbe850a5a90..18fd17172eb6 100644 --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -1103,6 +1103,11 @@ wake_affine(struct sched_domain *this_sd, struct rq *this_rq, if (!(this_sd->flags & SD_WAKE_AFFINE) || !sched_feat(AFFINE_WAKEUPS)) return 0; + if (!sync && sched_feat(SYNC_WAKEUPS) && + curr->se.avg_overlap < sysctl_sched_migration_cost && + p->se.avg_overlap < sysctl_sched_migration_cost) + sync = 1; + /* * If sync wakeup then subtract the (maximum possible) * effect of the currently running task from the load @@ -1127,11 +1132,8 @@ wake_affine(struct sched_domain *this_sd, struct rq *this_rq, * a reasonable amount of time then attract this newly * woken task: */ - if (sync && balanced) { - if (curr->se.avg_overlap < sysctl_sched_migration_cost && - p->se.avg_overlap < sysctl_sched_migration_cost) - return 1; - } + if (sync && balanced) + return 1; schedstat_inc(p, se.nr_wakeups_affine_attempts); tl_per_task = cpu_avg_load_per_task(this_cpu); @@ -1268,9 +1270,9 @@ static void check_preempt_wakeup(struct rq *rq, struct task_struct *p, int sync) if (!sched_feat(WAKEUP_PREEMPT)) return; - if (sched_feat(WAKEUP_OVERLAP) && sync && - se->avg_overlap < sysctl_sched_migration_cost && - pse->avg_overlap < sysctl_sched_migration_cost) { + if (sched_feat(WAKEUP_OVERLAP) && (sync || + (se->avg_overlap < sysctl_sched_migration_cost && + pse->avg_overlap < sysctl_sched_migration_cost))) { resched_task(curr); return; } |