From 31915ab4cbf507aadab40847cf9989da5e88b090 Mon Sep 17 00:00:00 2001 From: Heiko Carstens Date: Thu, 16 Sep 2010 14:42:25 +0200 Subject: [PATCH] sched: Remove branch hints within context_switch() With 710390d9 "sched: Optimize branch hint in context_switch()" the branch hint logic within context_switch() got inversed. In fact the hints "if (likely(!mm))" and "if (likely(!prev->mm))" mean that it is likely that the previous and next task are kernel threads. That assumption is certainly counter intuitive, but Tim has shown that at least with his workload this is true. Nevertheless the truth is: it depends on the current workload. So just remove the annotations which also improves readability. Reported-by: Tim Blechmann Signed-off-by: Heiko Carstens Cc: Peter Zijlstra Cc: Mike Galbraith LKML-Reference: <20100916124225.GA2209@osiris.boeblingen.de.ibm.com> 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 b40b82e33590d..16a1129f51ec4 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -2845,14 +2845,14 @@ context_switch(struct rq *rq, struct task_struct *prev, */ arch_start_context_switch(prev); - if (likely(!mm)) { + if (!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 (!prev->mm) { prev->active_mm = NULL; rq->prev_mm = oldmm; }