[PATCH 40/49] firmware: pcsi: replace cpumask_weight with cpumask_weight_eq

Yury Norov yury.norov at gmail.com
Thu Feb 10 14:49:24 PST 2022


down_and_up_cpus() calls cpumask_weight() to compare the weight of
cpumask with a given number. We can do it more efficiently with
cpumask_weight_{eq, ...} because conditional cpumask_weight may stop
traversing the cpumask earlier, as soon as condition is (or can't be) met.

Signed-off-by: Yury Norov <yury.norov at gmail.com>
---
 drivers/firmware/psci/psci_checker.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/firmware/psci/psci_checker.c b/drivers/firmware/psci/psci_checker.c
index 116eb465cdb4..90c9473832a9 100644
--- a/drivers/firmware/psci/psci_checker.c
+++ b/drivers/firmware/psci/psci_checker.c
@@ -90,7 +90,7 @@ static unsigned int down_and_up_cpus(const struct cpumask *cpus,
 		 * cpu_down() checks the number of online CPUs before the TOS
 		 * resident CPU.
 		 */
-		if (cpumask_weight(offlined_cpus) + 1 == nb_available_cpus) {
+		if (cpumask_weight_eq(offlined_cpus, nb_available_cpus - 1)) {
 			if (ret != -EBUSY) {
 				pr_err("Unexpected return code %d while trying "
 				       "to power down last online CPU %d\n",
-- 
2.32.0




More information about the linux-arm-kernel mailing list