[PATCH 21/54] kernel: replace cpumask_weight with cpumask_empty in padata.c

From: Yury Norov
Date: Sun Jan 23 2022 - 13:41:35 EST


padata_do_parallel() calls cpumask_weight() to check if any bit of a
given cpumask is set. We can do it 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>
---
kernel/padata.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/padata.c b/kernel/padata.c
index 18d3a5c699d8..e5819bb8bd1d 100644
--- a/kernel/padata.c
+++ b/kernel/padata.c
@@ -181,7 +181,7 @@ int padata_do_parallel(struct padata_shell *ps,
goto out;

if (!cpumask_test_cpu(*cb_cpu, pd->cpumask.cbcpu)) {
- if (!cpumask_weight(pd->cpumask.cbcpu))
+ if (cpumask_empty(pd->cpumask.cbcpu))
goto out;

/* Select an alternate fallback CPU and notify the caller. */
--
2.30.2