From 7ebb66a12f85bc375beaf45ca900427fe47aa8f7 Mon Sep 17 00:00:00 2001 From: Mel Gorman Date: Tue, 13 Feb 2018 13:37:25 +0000 Subject: [PATCH] sched/fair: Avoid an unnecessary lookup of current CPU ID during wake_affine The only caller of wake_affine() knows the CPU ID. Pass it in instead of rechecking it. Signed-off-by: Mel Gorman Signed-off-by: Peter Zijlstra (Intel) Cc: Giovanni Gherdovich Cc: Linus Torvalds Cc: Matt Fleming Cc: Mike Galbraith Cc: Peter Zijlstra Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/20180213133730.24064-2-mgorman@techsingularity.net Signed-off-by: Ingo Molnar --- kernel/sched/fair.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 820f94c..0132572 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -5751,9 +5751,8 @@ wake_affine_weight(struct sched_domain *sd, struct task_struct *p, } static int wake_affine(struct sched_domain *sd, struct task_struct *p, - int prev_cpu, int sync) + int this_cpu, int prev_cpu, int sync) { - int this_cpu = smp_processor_id(); int target = nr_cpumask_bits; if (sched_feat(WA_IDLE)) @@ -6376,7 +6375,7 @@ select_task_rq_fair(struct task_struct *p, int prev_cpu, int sd_flag, int wake_f if (cpu == prev_cpu) goto pick_cpu; - new_cpu = wake_affine(affine_sd, p, prev_cpu, sync); + new_cpu = wake_affine(affine_sd, p, cpu, prev_cpu, sync); } if (sd && !(sd_flag & SD_BALANCE_FORK)) { -- 2.7.4