From d9071ecb313940fe1d8827fef48bbf9fdaf28a4c Mon Sep 17 00:00:00 2001 From: Andrea Righi Date: Sat, 4 Jan 2025 10:00:09 +0100 Subject: [PATCH] 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: Yury Norov Signed-off-by: Andrea Righi Signed-off-by: Tejun Heo --- kernel/sched/ext.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) diff --git a/kernel/sched/ext.c b/kernel/sched/ext.c index 926579624c41..0ce116e0f67c 100644 --- a/kernel/sched/ext.c +++ b/kernel/sched/ext.c @@ -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)) - return; - } + 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); -- 2.50.1