From: Yao Dongdong <yaodongdong@huawei.com>
To: Ingo Molnar <mingo@redhat.com>, Peter Zijlstra <peterz@infradead.org>
Cc: LKML <linux-kernel@vger.kernel.org>,
Srikar Dronamraju <srikar@linux.vnet.ibm.com>,
<yaodongdong@huawei.com>
Subject: [PATCH v2]sched:add check of shallowest_idle_cpu before search for least_loaded_cpu
Date: Mon, 27 Oct 2014 17:41:28 +0800 [thread overview]
Message-ID: <544E1348.4050100@huawei.com> (raw)
Idle cpu is idler than non-idle cpu, so we needn't search for least_loaded_cpu
after we have found an idle cpu.
Signed-off-by:yaodongdong@huawei.com
Reviewed-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
---
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 0b069bf..2445a23 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -4446,7 +4446,7 @@ find_idlest_cpu(struct sched_group *group, struct task_struct *p, int this_cpu)
latest_idle_timestamp = rq->idle_stamp;
shallowest_idle_cpu = i;
}
- } else {
+ } else if (shallowest_idle_cpu == -1) {
load = weighted_cpuload(i);
if (load < min_load || (load == min_load && i == this_cpu)) {
min_load = load;
--
1.8.0.1
next reply other threads:[~2014-10-27 9:43 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-10-27 9:41 Yao Dongdong [this message]
2014-10-27 12:30 ` [PATCH v2]sched:add check of shallowest_idle_cpu before search for least_loaded_cpu Peter Zijlstra
2014-10-28 1:47 ` Yao Dongdong
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=544E1348.4050100@huawei.com \
--to=yaodongdong@huawei.com \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@redhat.com \
--cc=peterz@infradead.org \
--cc=srikar@linux.vnet.ibm.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox