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Subject[tip:sched/core] sched: Optimize branch hint in pick_next_task_fair()
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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