The following commit has been merged into the sched/core branch of tip:
Commit-ID: b9bae70440d21e106fbc098803b5a190df65f2e0
Gitweb: https://git.kernel.org/tip/b9bae70440d21e106fbc098803b5a190df65f2e0
Author: Abel Wu <wuyun.abel@xxxxxxxxxxxxx>
AuthorDate: Wed, 07 Sep 2022 19:19:57 +08:00
Committer: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
CommitterDate: Wed, 07 Sep 2022 21:53:46 +02:00
sched/fair: Avoid double search on same cpu
The prev cpu is checked at the beginning of SIS, and it's unlikely
to be idle before the second check in select_idle_smt(). So we'd
better focus on its SMT siblings.
Signed-off-by: Abel Wu <wuyun.abel@xxxxxxxxxxxxx>
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Reviewed-by: Josh Don <joshdon@xxxxxxxxxx>
Acked-by: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20220907112000.1854-3-wuyun.abel@xxxxxxxxxxxxx
---
kernel/sched/fair.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 9657c7d..1ad79aa 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -6355,6 +6355,8 @@ static int select_idle_smt(struct task_struct *p, int target)
int cpu;
for_each_cpu_and(cpu, cpu_smt_mask(target), p->cpus_ptr) {
+ if (cpu == target)
+ continue;
if (available_idle_cpu(cpu) || sched_idle_cpu(cpu))
return cpu;
}
|