clocksource: Replace cpumask_weight() with cpumask_empty()

[ Upstream commit 8afbcaf8690dac19ebf570a4e4fef9c59c75bf8e ]

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@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20220210224933.379149-24-yury.norov@gmail.com
Stable-dep-of: 6bb05a33337b ("clocksource: Use migrate_disable() to avoid calling get_random_u32() in atomic context")
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c
index e44fb1e12a2816ac0b535c14c2a2b6514813636b..658b90755dd723f182963942637305c5786c3ff5 100644 (file)
--- a/kernel/time/clocksource.c
+++ b/kernel/time/clocksource.c
@@ -338,7 +338,7 @@ static 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);