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authorPeter Zijlstra <a.p.zijlstra@chello.nl>2009-02-11 14:27:17 +0100
committerIngo Molnar <mingo@elte.hu>2009-02-11 14:43:35 +0100
commitfc631c82e1734d718ff0832558f64c8f5d185f26 (patch)
tree7bef1c5f3f2c3f454280026e1a528de526302827
parent483b4ee60edbefdfbff0dd538fb81f368d9e7c0d (diff)
downloadop-kernel-dev-fc631c82e1734d718ff0832558f64c8f5d185f26.zip
op-kernel-dev-fc631c82e1734d718ff0832558f64c8f5d185f26.tar.gz
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>
-rw-r--r--kernel/sched.c10
-rw-r--r--kernel/sched_fair.c11
2 files changed, 9 insertions, 12 deletions
diff --git a/kernel/sched.c b/kernel/sched.c
index e1fc67d..f11c02b 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -2266,16 +2266,6 @@ static int try_to_wake_up(struct task_struct *p, unsigned int state, int sync)
if (!sched_feat(SYNC_WAKEUPS))
sync = 0;
- if (!sync) {
- if (current->se.avg_overlap < sysctl_sched_migration_cost &&
- p->se.avg_overlap < sysctl_sched_migration_cost)
- sync = 1;
- } else {
- if (current->se.avg_overlap >= sysctl_sched_migration_cost ||
- p->se.avg_overlap >= sysctl_sched_migration_cost)
- sync = 0;
- }
-
#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 a7e50ba..0566f2a 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;
}
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