diff options
| author | Peter Zijlstra <a.p.zijlstra@chello.nl> | 2008-09-20 23:38:02 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2010-04-01 15:52:21 -0700 |
| commit | ecfb7fb9b13c617447a7f6b5925da26798c1a8a1 (patch) | |
| tree | 7242d25bc9fef033284cee5d9343484f1eacb124 /include | |
| parent | aa7659a10684907bec7c0c6887f8755767fb8dea (diff) | |
sched: wakeup preempt when small overlap
commit 15afe09bf496ae10c989e1a375a6b5da7bd3e16e upstream.
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/sched.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/include/linux/sched.h b/include/linux/sched.h index 20d6dd59cb0b..6d32974f3c1a 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -901,7 +901,7 @@ struct sched_class { void (*yield_task) (struct rq *rq); int (*select_task_rq)(struct task_struct *p, int sync); - void (*check_preempt_curr) (struct rq *rq, struct task_struct *p); + void (*check_preempt_curr) (struct rq *rq, struct task_struct *p, int sync); struct task_struct * (*pick_next_task) (struct rq *rq); void (*put_prev_task) (struct rq *rq, struct task_struct *p); |