[PATCH] sched/fair: consider sched-idle CPU when selecting idle core

From: Jiang Biao
Date: Thu Jul 23 2020 - 20:27:11 EST


From: Jiang Biao <benbjiang@xxxxxxxxxxx>

Sched-idle CPU has been considered in select_idle_cpu and
select_idle_smt, it also needs to be considered in select_idle_core to
be consistent and keep the same *idle* policy.

Signed-off-by: Jiang Biao <benbjiang@xxxxxxxxxxx>
---
kernel/sched/fair.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 04fa8dbcfa4d..f430a9820d08 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -6014,7 +6014,7 @@ void __update_idle_core(struct rq *rq)
if (cpu == core)
continue;

- if (!available_idle_cpu(cpu))
+ if (!available_idle_cpu(cpu) && !sched_idle_cpu(cpu))
goto unlock;
}

@@ -6045,7 +6045,7 @@ static int select_idle_core(struct task_struct *p, struct sched_domain *sd, int
bool idle = true;

for_each_cpu(cpu, cpu_smt_mask(core)) {
- if (!available_idle_cpu(cpu)) {
+ if (!available_idle_cpu(cpu) && !sched_idle_cpu(cpu)) {
idle = false;
break;
}
--
2.21.0