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
This commit is contained in:
Dietmar Eggemann 2020-05-20 15:42:39 +02:00 committed by Peter Zijlstra
parent 9b1b234bb8
commit c81b893299

View File

@ -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++;