[tip: timers/core] clocksource: Replace cpumask_weight() with cpumask_empty()

[tip-bot2 for Yury Norov]

The following commit has been merged into the timers/core branch of tip:

Commit-ID:     8afbcaf8690dac19ebf570a4e4fef9c59c75bf8e
Gitweb:        https://git.kernel.org/tip/8afbcaf8690dac19ebf570a4e4fef9c59c75bf8e
Author:        Yury Norov <yury.norov@xxxxxxxxx>
AuthorDate:    Thu, 10 Feb 2022 14:49:07 -08:00
Committer:     Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitterDate: Sun, 10 Apr 2022 22:30:04 +02:00

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.

Signed-off-by: Yury Norov <yury.norov@xxxxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20220210224933.379149-24-yury.norov@xxxxxxxxx

---
 kernel/time/clocksource.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c
index 95d7ca3..cee5da1 100644
--- a/kernel/time/clocksource.c
+++ b/kernel/time/clocksource.c
@@ -343,7 +343,7 @@ void clocksource_verify_percpu(struct clocksource *cs)
 	cpus_read_lock();
 	preempt_disable();
 	clocksource_verify_choose_cpus();
-	if (cpumask_weight(&cpus_chosen) == 0) {
+	if (cpumask_empty(&cpus_chosen)) {
 		preempt_enable();
 		cpus_read_unlock();
 		pr_warn("Not enough CPUs to check clocksource '%s'.\n", cs->name);