diff options
| author | Mike Galbraith <mgalbraith@suse.de> | 2011-11-22 15:21:26 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2011-12-06 09:06:24 +0100 |
| commit | 916671c08b7808aebec87cc56c85788e665b3c6b (patch) | |
| tree | b3cd42d8fc5ba64f3ee0bff332278758c656141c /kernel/sched | |
| parent | sched: Use rt.nr_cpus_allowed to recover select_task_rq() cycles (diff) | |
| download | linux-916671c08b7808aebec87cc56c85788e665b3c6b.tar.xz linux-916671c08b7808aebec87cc56c85788e665b3c6b.zip | |
sched: Set skip_clock_update in yield_task_fair()
This is another case where we are on our way to schedule(),
so can save a useless clock update and resulting microscopic
vruntime update.
Signed-off-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1321971686.6855.18.camel@marge.simson.net
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel/sched')
| -rw-r--r-- | kernel/sched/core.c | 7 | ||||
| -rw-r--r-- | kernel/sched/fair.c | 6 |
2 files changed, 13 insertions, 0 deletions
diff --git a/kernel/sched/core.c b/kernel/sched/core.c index ca8fd44145ac..db313c33af29 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -4547,6 +4547,13 @@ again: */ if (preempt && rq != p_rq) resched_task(p_rq->curr); + } else { + /* + * We might have set it in task_yield_fair(), but are + * not going to schedule(), so don't want to skip + * the next update. + */ + rq->skip_clock_update = 0; } out: diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 8e534a05e3ed..81ccb811afb4 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -3075,6 +3075,12 @@ static void yield_task_fair(struct rq *rq) * Update run-time statistics of the 'current'. */ update_curr(cfs_rq); + /* + * Tell update_rq_clock() that we've just updated, + * so we don't do microscopic update in schedule() + * and double the fastpath cost. + */ + rq->skip_clock_update = 1; } set_skip_buddy(se); |