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| author |   Dietmar Eggemann <dietmar.eggemann@arm.com> | 2020-05-20 15:42:39 +0200 |
|---|---|---|
| committer |   Peter Zijlstra <peterz@infradead.org> | 2020-06-15 14:10:04 +0200 |
| commit | c81b89329933c6c0be809d4c0d2cb57c49153ee3 (patch) | |
| tree | 61e691ce0cd1a84035ecb5f7cf64fba8457a5c72 /kernel/sched/deadline.c | |
| parent | sched: correct SD_flags returned by tl->sd_flags() (diff) | |
| download | linux-dev-c81b89329933c6c0be809d4c0d2cb57c49153ee3.tar.xz linux-dev-c81b89329933c6c0be809d4c0d2cb57c49153ee3.zip | |
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
Diffstat (limited to 'kernel/sched/deadline.c')
| -rw-r--r-- | kernel/sched/deadline.c | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c index f31964ad9c2e..ec90265e9d8e 100644 --- a/kernel/sched/deadline.c +++ b/kernel/sched/deadline.c @@ -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++; |