[PATCH 4/4] smp: Defer check for local execution in smp_call_function_many_cond()

From: Yury Norov
Date: Fri Jun 06 2025 - 16:28:28 EST


From: "Yury Norov [NVIDIA]" <yury.norov@xxxxxxxxx>

Defer check for local execution to the actual place where it is needed,
and save some stack on a useless local variable.

Signed-off-by: Yury Norov [NVIDIA] <yury.norov@xxxxxxxxx>
---
kernel/smp.c | 10 +++-------
1 file changed, 3 insertions(+), 7 deletions(-)

diff --git a/kernel/smp.c b/kernel/smp.c
index 715190669e94..867f79689684 100644
--- a/kernel/smp.c
+++ b/kernel/smp.c
@@ -779,7 +779,6 @@ static void smp_call_function_many_cond(const struct cpumask *mask,
bool wait = scf_flags & SCF_WAIT;
int nr_cpus = 0;
bool run_remote = false;
- bool run_local = false;

lockdep_assert_preemption_disabled();

@@ -801,11 +800,6 @@ static void smp_call_function_many_cond(const struct cpumask *mask,
*/
WARN_ON_ONCE(!in_task());

- /* Check if we need local execution. */
- if ((scf_flags & SCF_RUN_LOCAL) && cpumask_test_cpu(this_cpu, mask) &&
- (!cond_func || cond_func(this_cpu, info)))
- run_local = true;
-
/* Check if we need remote execution, i.e., any CPU excluding this one. */
if (cpumask_any_and_but(mask, cpu_online_mask, this_cpu) < nr_cpu_ids) {
run_remote = true;
@@ -853,7 +847,9 @@ static void smp_call_function_many_cond(const struct cpumask *mask,
run_remote = false;
}

- if (run_local) {
+ /* Check if we need local execution. */
+ if ((scf_flags & SCF_RUN_LOCAL) & cpumask_test_cpu(this_cpu, mask) &&
+ (!cond_func || cond_func(this_cpu, info))) {
unsigned long flags;

local_irq_save(flags);
--
2.43.0