2021-07-26 10:25:13

by Mel Gorman

[permalink] [raw]
Subject: [PATCH 5/9] sched/fair: Avoid a second scan of target in select_idle_cpu

When select_idle_cpu starts scanning for an idle CPU, it starts with
a target CPU that has already been checked by select_idle_sibling.
This patch starts with the next CPU instead.

Signed-off-by: Mel Gorman <[email protected]>
---
kernel/sched/fair.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 75ff991a460a..125c020746b8 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -6254,7 +6254,7 @@ static int select_idle_cpu(struct task_struct *p, struct sched_domain *sd, bool
time = cpu_clock(this);
}

- for_each_cpu_wrap(cpu, cpus, target) {
+ for_each_cpu_wrap(cpu, cpus, target + 1) {
if (has_idle_core) {
i = select_idle_core(p, cpu, cpus, &idle_cpu);
if ((unsigned int)i < nr_cpumask_bits)
--
2.26.2