clocksource: Replace cpumask_weight() with cpumask_empty()

clocksource_verify_percpu() calls cpumask_weight() to check if any bit of a given cpumask is set. This can be done more efficiently with cpumask_empty() because cpumask_empty() stops traversing the cpumask as soon as it finds first set bit, while cpumask_weight() counts all bits unconditionally.

Yury Norov committed 4 years ago

Commit 8afbcaf1 parent efaa0221 file · +1 −1Browse files

Unified · Split

kernel/time/clocksource.c+1−1

@@ -343,7 +343,7 @@ void clocksource_verify_percpu(struct clocksource *cs) · 342 unmodified lines
343	cpus_read_lock();	343	cpus_read_lock();
344	preempt_disable();	344	preempt_disable();
345	clocksource_verify_choose_cpus();	345	clocksource_verify_choose_cpus();
346	if (cpumask_weight(&cpus_chosen) == 0) {	346	if (cpumask_empty(&cpus_chosen)) {
347	preempt_enable();	347	preempt_enable();
348	cpus_read_unlock();	348	cpus_read_unlock();
349	pr_warn("Not enough CPUs to check clocksource '%s'.\n", cs->name);	349	pr_warn("Not enough CPUs to check clocksource '%s'.\n", cs->name);