Commit 7ebb66a1 authored Feb 13, 2018 by Mel Gorman Committed by Ingo Molnar Feb 21, 2018

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 <mgorman@techsingularity.net>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Giovanni Gherdovich <ggherdovich@suse.cz>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20180213133730.24064-2-mgorman@techsingularity.net


Signed-off-by: Ingo Molnar <mingo@kernel.org>

parent ed029343

kernel/sched/fair.c

+2 −3

Original line number	Diff line number	Diff line
		@@ -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)) {

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