diff mbox series

sched/fair: stabilize asym cpu capacity system idle cpu selection

Message ID 20230711081359.868862-1-vincent.guittot@linaro.org
State New
Headers
Series sched/fair: stabilize asym cpu capacity system idle cpu selection |

Commit Message

Vincent Guittot July 11, 2023, 8:13 a.m. UTC 
  select_idle_capacity() not only looks for an idle cpu that fits for the
waking task but also for cpu with highest bandwidth when no cpu fits.
Start the loop with target cpu so it will be selected 1st when no cpu fits
but several cpus shared the same bandwidth. Starting with target cpu
prevents the task to migrate between cpus with same bandwidth at every
wakeup when no cpu fits.

Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
---
 kernel/sched/fair.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index a80a73909dc2..0ee116f992f4 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -7065,7 +7065,7 @@  select_idle_capacity(struct task_struct *p, struct sched_domain *sd, int target)
 	util_min = uclamp_eff_value(p, UCLAMP_MIN);
 	util_max = uclamp_eff_value(p, UCLAMP_MAX);
 
-	for_each_cpu_wrap(cpu, cpus, target + 1) {
+	for_each_cpu_wrap(cpu, cpus, target) {
 		unsigned long cpu_cap = capacity_of(cpu);
 
 		if (!available_idle_cpu(cpu) && !sched_idle_cpu(cpu))