This is a note to let you know that I've just added the patch titled
clocksource: Replace cpumask_weight() with cpumask_empty()
to the 5.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
clocksource-replace-cpumask_weight-with-cpumask_empt.patch
and it can be found in the queue-5.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 028bcb4c53e50bf2f5220ec90ec1bd37d8bfb8c4
Author: Yury Norov <yury.norov@xxxxxxxxx>
Date: Thu Feb 10 14:49:07 2022 -0800
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@xxxxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20220210224933.379149-24-yury.norov@xxxxxxxxx
Stable-dep-of: 6bb05a33337b ("clocksource: Use migrate_disable() to avoid calling get_random_u32() in atomic context")
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c
index e44fb1e12a281..658b90755dd72 100644
--- 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);
