From 710390d90f143a9ebb87a475215140f426792efd Mon Sep 17 00:00:00 2001 From: Tim Blechmann Date: Tue, 24 Nov 2009 11:55:27 +0100 Subject: [PATCH] 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 Cc: Peter Zijlstra Cc: Mike Galbraith Cc: Paul Mackerras Cc: Arnaldo Carvalho de Melo Cc: Frederic Weisbecker LKML-Reference: <4B0BBB9F.6080304@klingt.org> Signed-off-by: Ingo Molnar --- kernel/sched.c | 4 ++-- 1 file 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; } -- 2.39.5