From: Mel Gorman <mgorman@techsingularity.net>
To: LKML <linux-kernel@vger.kernel.org>
Cc: Ingo Molnar <mingo@kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
Vincent Guittot <vincent.guittot@linaro.org>,
Valentin Schneider <valentin.schneider@arm.com>,
Aubrey Li <aubrey.li@linux.intel.com>,
Mel Gorman <mgorman@techsingularity.net>
Subject: [PATCH 5/9] sched/fair: Avoid a second scan of target in select_idle_cpu
Date: Mon, 26 Jul 2021 11:22:43 +0100 [thread overview]
Message-ID: <20210726102247.21437-6-mgorman@techsingularity.net> (raw)
In-Reply-To: <20210726102247.21437-1-mgorman@techsingularity.net>
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 <mgorman@techsingularity.net>
---
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
next prev parent reply other threads:[~2021-07-26 10:23 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-26 10:22 [RFC PATCH 0/9] Modify and/or delete SIS_PROP Mel Gorman
2021-07-26 10:22 ` [PATCH 1/9] sched/fair: Track efficiency of select_idle_sibling Mel Gorman
2021-07-26 10:22 ` [PATCH 2/9] sched/fair: Track efficiency of task recent_used_cpu Mel Gorman
2021-07-26 10:22 ` [PATCH 3/9] sched/fair: Track efficiency of select_idle_core Mel Gorman
2021-07-26 10:22 ` [PATCH 4/9] sched/fair: Use prev instead of new target as recent_used_cpu Mel Gorman
2021-07-26 10:22 ` Mel Gorman [this message]
2021-07-26 10:22 ` [PATCH 6/9] sched/fair: Make select_idle_cpu() proportional to cores Mel Gorman
2021-07-26 10:22 ` [PATCH 7/9] sched/fair: Enforce proportional scan limits when scanning for an idle core Mel Gorman
2021-08-02 10:52 ` Song Bao Hua (Barry Song)
2021-08-04 10:22 ` Mel Gorman
2021-07-26 10:22 ` [PATCH 8/9] sched/fair: select idle cpu from idle cpumask for task wakeup Mel Gorman
2021-08-02 10:41 ` Song Bao Hua (Barry Song)
2021-08-04 10:26 ` Mel Gorman
2021-08-05 0:23 ` Aubrey Li
2021-09-17 3:44 ` Barry Song
2021-09-17 4:15 ` Barry Song
2021-09-17 9:11 ` Aubrey Li
2021-09-17 13:35 ` Mel Gorman
2021-07-26 10:22 ` [PATCH 9/9] sched/core: Delete SIS_PROP and rely on the idle cpu mask Mel Gorman
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