Commit bae4ec13 authored by Mel Gorman's avatar Mel Gorman Committed by Peter Zijlstra
Browse files

sched/fair: Move avg_scan_cost calculations under SIS_PROP 



As noted by Vincent Guittot, avg_scan_costs are calculated for SIS_PROP
even if SIS_PROP is disabled. Move the time calculations under a SIS_PROP
check and while we are at it, exclude the cost of initialising the CPU
mask from the average scan cost.

Signed-off-by: default avatarMel Gorman <mgorman@techsingularity.net>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: default avatarVincent Guittot <vincent.guittot@linaro.org>
Link: https://lkml.kernel.org/r/20210125085909.4600-3-mgorman@techsingularity.net
parent e6e0dc2d

kernel/sched/fair.c

+8 −6
Original line number Diff line number Diff line
@@ -6166,6 +6166,8 @@ static int select_idle_cpu(struct task_struct *p, struct sched_domain *sd, int t 
	if (!this_sd)

		return -1;



	cpumask_and(cpus, sched_domain_span(sd), p->cpus_ptr);



	if (sched_feat(SIS_PROP)) {

		u64 avg_cost, avg_idle, span_avg;
@@ -6181,11 +6183,9 @@ static int select_idle_cpu(struct task_struct *p, struct sched_domain *sd, int t 
			nr = div_u64(span_avg, avg_cost);

		else

			nr = 4;

	}



		time = cpu_clock(this);



	cpumask_and(cpus, sched_domain_span(sd), p->cpus_ptr);

	}



	for_each_cpu_wrap(cpu, cpus, target) {

		if (!--nr)
@@ -6194,8 +6194,10 @@ static int select_idle_cpu(struct task_struct *p, struct sched_domain *sd, int t 
			break;

	}



	if (sched_feat(SIS_PROP)) {

		time = cpu_clock(this) - time;

		update_avg(&this_sd->avg_scan_cost, time);

	}



	return cpu;

}