Commit d9071ecb authored by Andrea Righi's avatar Andrea Righi Committed by Tejun Heo
Browse files

sched_ext: idle: small CPU iteration refactoring 



Replace the loop to check if all SMT CPUs are idle with
cpumask_subset(). This simplifies the code and slightly improves
efficiency, while preserving the original behavior.

Note that idle_masks.smt handling remains racy, which is acceptable as
it serves as an optimization and is self-correcting.

Suggested-and-reviewed-by: default avatarYury Norov <yury.norov@gmail.com>
Signed-off-by: default avatarAndrea Righi <arighi@nvidia.com>
Signed-off-by: default avatarTejun Heo <tj@kernel.org>
parent c0cf3530

kernel/sched/ext.c

+2 −4
Original line number Diff line number Diff line
@@ -3671,10 +3671,8 @@ void __scx_update_idle(struct rq *rq, bool idle) 
			 * idle_masks.smt handling is racy but that's fine as

			 * it's only for optimization and self-correcting.

			 */

			for_each_cpu(cpu, smt) {

				if (!cpumask_test_cpu(cpu, idle_masks.cpu))

			if (!cpumask_subset(smt, idle_masks.cpu))

				return;

			}

			cpumask_or(idle_masks.smt, idle_masks.smt, smt);

		} else {

			cpumask_andnot(idle_masks.smt, idle_masks.smt, smt);