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Subject[PATCH] sched: Optimize branch hint in context_switch()

Branch hint profiling on my nehalem machine showed 88%
incorrect branch hints:

42017484 326957902 88 context_switch sched.c 3043
42038493 326953687 88 context_switch sched.c 3050

Signed-off-by: Tim Blechmann <tim@klingt.org>
---
kernel/sched.c | 4 ++--
1 files changed, 2 insertions(+), 2 deletions(-)


diff --git a/kernel/sched.c b/kernel/sched.c
index 2a78b38..c78dcfe 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -3040,14 +3040,14 @@ context_switch(struct rq *rq, struct task_struct *prev,
*/
arch_start_context_switch(prev);

- if (likely(!mm)) {
+ if (unlikely(!mm)) {
next->active_mm = oldmm;
atomic_inc(&oldmm->mm_count);
enter_lazy_tlb(oldmm, next);
} else
switch_mm(oldmm, mm, next);

- if (likely(!prev->mm)) {
+ if (unlikely(!prev->mm)) {
prev->active_mm = NULL;
rq->prev_mm = oldmm;
}
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