Commit b9bae704 authored by Abel Wu's avatar Abel Wu Committed by Peter Zijlstra
Browse files

sched/fair: Avoid double search on same cpu 



The prev cpu is checked at the beginning of SIS, and it's unlikely
to be idle before the second check in select_idle_smt(). So we'd
better focus on its SMT siblings.

Signed-off-by: default avatarAbel Wu <wuyun.abel@bytedance.com>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: default avatarJosh Don <joshdon@google.com>
Acked-by: default avatarMel Gorman <mgorman@techsingularity.net>
Link: https://lore.kernel.org/r/20220907112000.1854-3-wuyun.abel@bytedance.com
parent 3e6efe87

kernel/sched/fair.c

+2 −0
Original line number Diff line number Diff line
@@ -6355,6 +6355,8 @@ static int select_idle_smt(struct task_struct *p, int target) 
	int cpu;



	for_each_cpu_and(cpu, cpu_smt_mask(target), p->cpus_ptr) {

		if (cpu == target)

			continue;

		if (available_idle_cpu(cpu) || sched_idle_cpu(cpu))

			return cpu;

	}