diff options
| author | Peter Zijlstra <a.p.zijlstra@chello.nl> | 2009-01-26 17:56:17 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2009-02-01 10:49:06 +0100 |
| commit | d942fb6c7d391baba3dddb566eb735fbf3df8528 (patch) | |
| tree | 0340b810c79f873b7aea34298aa22e2ebf740df3 /kernel | |
| parent | cpuset: fix possible deadlock in async_rebuild_sched_domains (diff) | |
| download | linux-d942fb6c7d391baba3dddb566eb735fbf3df8528.tar.xz linux-d942fb6c7d391baba3dddb566eb735fbf3df8528.zip | |
sched: fix sync wakeups
Pawel Dziekonski reported that the openssl benchmark and his
quantum chemistry application both show slowdowns due to the
scheduler under-parallelizing execution.
The reason are pipe wakeups still doing 'sync' wakeups which
overrides the normal buddy wakeup logic - even if waker and
wakee are loosely coupled.
Fix an inversion of logic in the buddy wakeup code.
Reported-by: Pawel Dziekonski <dzieko@gmail.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/sched.c | 4 | ||||
| -rw-r--r-- | kernel/sched_fair.c | 11 |
2 files changed, 6 insertions, 9 deletions
diff --git a/kernel/sched.c b/kernel/sched.c index 52bbf1c842a8..770b1f9ebe14 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -2266,6 +2266,10 @@ static int try_to_wake_up(struct task_struct *p, unsigned int state, int sync) if (!sched_feat(SYNC_WAKEUPS)) sync = 0; + if (!sync && (current->se.avg_overlap < sysctl_sched_migration_cost && + p->se.avg_overlap < sysctl_sched_migration_cost)) + sync = 1; + #ifdef CONFIG_SMP if (sched_feat(LB_WAKEUP_UPDATE)) { struct sched_domain *sd; diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index 5cc1c162044f..fdc417504681 100644 --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -1179,20 +1179,15 @@ wake_affine(struct sched_domain *this_sd, struct rq *this_rq, int idx, unsigned long load, unsigned long this_load, unsigned int imbalance) { - struct task_struct *curr = this_rq->curr; - struct task_group *tg; unsigned long tl = this_load; unsigned long tl_per_task; + struct task_group *tg; unsigned long weight; int balanced; if (!(this_sd->flags & SD_WAKE_AFFINE) || !sched_feat(AFFINE_WAKEUPS)) return 0; - if (sync && (curr->se.avg_overlap > sysctl_sched_migration_cost || - p->se.avg_overlap > sysctl_sched_migration_cost)) - sync = 0; - /* * If sync wakeup then subtract the (maximum possible) * effect of the currently running task from the load @@ -1419,9 +1414,7 @@ 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) { resched_task(curr); return; } |