diff options
| author | Tim Blechmann <tim@klingt.org> | 2009-11-24 13:55:27 +0300 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2009-11-24 14:18:42 +0300 |
| commit | 710390d90f143a9ebb87a475215140f426792efd (patch) | |
| tree | 53b2019edf0d25f3530e0c169ec01e7e115125d1 | |
| parent | 36ace27e3e60d44ea69ce394b2e45386ae98d9d9 (diff) | |
| download | linux-710390d90f143a9ebb87a475215140f426792efd.tar.xz | |
sched: Optimize branch hint in context_switch()
Branch hint profiling on my nehalem machine showed over 90%
incorrect branch hints:
10420275 170645395 94 context_switch sched.c
3043
10408421 171098521 94 context_switch sched.c
3050
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: <4B0BBB9F.6080304@klingt.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
| -rw-r--r-- | kernel/sched.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/kernel/sched.c b/kernel/sched.c index 93474a7935ae..010d5e16b4c5 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -2829,14 +2829,14 @@ context_switch(struct rq *rq, struct task_struct *prev, */ arch_start_context_switch(prev); - if (unlikely(!mm)) { + if (likely(!mm)) { next->active_mm = oldmm; atomic_inc(&oldmm->mm_count); enter_lazy_tlb(oldmm, next); } else switch_mm(oldmm, mm, next); - if (unlikely(!prev->mm)) { + if (likely(!prev->mm)) { prev->active_mm = NULL; rq->prev_mm = oldmm; } |