Commit c81b8932 authored May 20, 2020 by Dietmar Eggemann Committed by Peter Zijlstra Jun 15, 2020

sched/deadline: Optimize dl_bw_cpus()



Return the weight of the root domain (rd) span in case it is a subset
of the cpu_active_mask.

Continue to compute the number of CPUs over rd span and cpu_active_mask
when in hotplug.

Signed-off-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Juri Lelli <juri.lelli@redhat.com>
Link: https://lkml.kernel.org/r/20200520134243.19352-2-dietmar.eggemann@arm.com

parent 9b1b234b

kernel/sched/deadline.c

+7 −1

Original line number	Diff line number	Diff line
		@@ -54,10 +54,16 @@ static inline struct dl_bw *dl_bw_of(int i)
		static inline int dl_bw_cpus(int i)
		{
		struct root_domain *rd = cpu_rq(i)->rd;
		int cpus = 0;
		int cpus;

		RCU_LOCKDEP_WARN(!rcu_read_lock_sched_held(),
		"sched RCU must be held");

		if (cpumask_subset(rd->span, cpu_active_mask))
		return cpumask_weight(rd->span);

		cpus = 0;

		for_each_cpu_and(i, rd->span, cpu_active_mask)
		cpus++;

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