Messages in this thread Patch in this message | | | Date | Tue, 24 Nov 2009 16:56:36 GMT | From | tip-bot for Tim Blechmann <> | Subject | [tip:sched/core] sched: Optimize branch hint in pick_next_task_fair() |
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Commit-ID: 36ace27e3e60d44ea69ce394b2e45386ae98d9d9 Gitweb: http://git.kernel.org/tip/36ace27e3e60d44ea69ce394b2e45386ae98d9d9 Author: Tim Blechmann <tim@klingt.org> AuthorDate: Tue, 24 Nov 2009 11:55:45 +0100 Committer: Ingo Molnar <mingo@elte.hu> CommitDate: Tue, 24 Nov 2009 12:18:12 +0100
sched: Optimize branch hint in pick_next_task_fair()
Branch hint profiling on my nehalem machine showed 90% incorrect branch hints:
15728471 158903754 90 pick_next_task_fair sched_fair.c 1555
Signed-off-by: Tim Blechmann <tim@klingt.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> LKML-Reference: <4B0BBBB1.2050100@klingt.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> --- kernel/sched_fair.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-)
diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index f28a267..24086e7 100644 --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -1704,7 +1704,7 @@ static struct task_struct *pick_next_task_fair(struct rq *rq) struct cfs_rq *cfs_rq = &rq->cfs; struct sched_entity *se; - if (unlikely(!cfs_rq->nr_running)) + if (!cfs_rq->nr_running) return NULL; do {
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