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| author | Peter Zijlstra <a.p.zijlstra@chello.nl> | 2008-09-20 23:38:02 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2008-09-22 16:28:32 +0200 |
| commit | 15afe09bf496ae10c989e1a375a6b5da7bd3e16e (patch) | |
| tree | 4565659d1084e357eea42e6321a4d304ac950faa /kernel/sched_rt.c | |
| parent | Merge commit 'v2.6.27-rc6' into sched/devel (diff) | |
| download | linux-15afe09bf496ae10c989e1a375a6b5da7bd3e16e.tar.xz linux-15afe09bf496ae10c989e1a375a6b5da7bd3e16e.zip | |
sched: wakeup preempt when small overlap
Lin Ming reported a 10% OLTP regression against 2.6.27-rc4.
The difference seems to come from different preemption agressiveness,
which affects the cache footprint of the workload and its effective
cache trashing.
Aggresively preempt a task if its avg overlap is very small, this should
avoid the task going to sleep and find it still running when we schedule
back to it - saving a wakeup.
Reported-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_rt.c')
| -rw-r--r-- | kernel/sched_rt.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/kernel/sched_rt.c b/kernel/sched_rt.c index 552310798dad..6d2d0a5d030b 100644 --- a/kernel/sched_rt.c +++ b/kernel/sched_rt.c @@ -783,7 +783,7 @@ static void check_preempt_equal_prio(struct rq *rq, struct task_struct *p) /* * Preempt the current task with a newly woken task if needed: */ -static void check_preempt_curr_rt(struct rq *rq, struct task_struct *p) +static void check_preempt_curr_rt(struct rq *rq, struct task_struct *p, int sync) { if (p->prio < rq->curr->prio) { resched_task(rq->curr); |