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author | Peter Zijlstra <a.p.zijlstra@chello.nl> | 2009-02-11 14:27:17 +0100 |
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committer | Ingo Molnar <mingo@elte.hu> | 2009-02-11 14:43:35 +0100 |
commit | fc631c82e1734d718ff0832558f64c8f5d185f26 (patch) | |
tree | 7bef1c5f3f2c3f454280026e1a528de526302827 /kernel/sched_fair.c | |
parent | 483b4ee60edbefdfbff0dd538fb81f368d9e7c0d (diff) | |
download | lwn-fc631c82e1734d718ff0832558f64c8f5d185f26.tar.gz lwn-fc631c82e1734d718ff0832558f64c8f5d185f26.zip |
sched: revert recent sync wakeup changes
Intel reported a 10% regression (mysql+sysbench) on a 16-way machine
with these patches:
1596e29: sched: symmetric sync vs avg_overlap
d942fb6: sched: fix sync wakeups
Revert them.
Reported-by: "Zhang, Yanmin" <yanmin_zhang@linux.intel.com>
Bisected-by: Lin Ming <ming.m.lin@intel.com>
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 | 11 |
1 files changed, 9 insertions, 2 deletions
diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index a7e50ba185ac..0566f2a03c42 100644 --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -1191,15 +1191,20 @@ 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 @@ -1426,7 +1431,9 @@ 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) { + if (sched_feat(WAKEUP_OVERLAP) && (sync || + (se->avg_overlap < sysctl_sched_migration_cost && + pse->avg_overlap < sysctl_sched_migration_cost))) { resched_task(curr); return; } |