The following commit has been merged into the sched/core branch of tip:
Commit-ID: 55b39b0cf183b9c682717a55a2fba06da69bba6b
Gitweb: https://git.kernel.org/tip/55b39b0cf183b9c682717a55a2fba06da69bba6b
Author: Yury Norov (NVIDIA) <yury.norov@gmail.com>
AuthorDate: Sat, 06 Dec 2025 22:42:47 -05:00
Committer: Peter Zijlstra <peterz@infradead.org>
CommitterDate: Thu, 08 Jan 2026 12:43:56 +01:00
sched/fair: Use cpumask_weight_and() in sched_balance_find_dst_group()
In the group_has_spare case, the function creates a temporary cpumask
to just calculate weight of (p->cpus_ptr & sched_group_span(local)).
We've got a dedicated helper for it.
Signed-off-by: Yury Norov (NVIDIA) <yury.norov@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org>
Reviewed-by: K Prateek Nayak <kprateek.nayak@amd.com>
Reviewed-by: Fernand Sieber <sieberf@amazon.com>
Link: https://patch.msgid.link/20251207034247.402926-1-yury.norov@gmail.com
---
kernel/sched/fair.c | 7 +++----
1 file changed, 3 insertions(+), 4 deletions(-)
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 842a0f2..ebee20f 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -10974,10 +10974,9 @@ sched_balance_find_dst_group(struct sched_domain *sd, struct task_struct *p, int
* take care of it.
*/
if (p->nr_cpus_allowed != NR_CPUS) {
- struct cpumask *cpus = this_cpu_cpumask_var_ptr(select_rq_mask);
-
- cpumask_and(cpus, sched_group_span(local), p->cpus_ptr);
- imb_numa_nr = min(cpumask_weight(cpus), sd->imb_numa_nr);
+ unsigned int w = cpumask_weight_and(p->cpus_ptr,
+ sched_group_span(local));
+ imb_numa_nr = min(w, sd->imb_numa_nr);
}
imbalance = abs(local_sgs.idle_cpus - idlest_sgs.idle_cpus);