All of lore.kernel.org
 help / color / mirror / Atom feed
From: qianjun.kernel@gmail.com
To: mingo@redhat.com, peterz@infradead.org, juri.lelli@redhat.com,
	vincent.guittot@linaro.org, dietmar.eggemann@arm.com,
	rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de
Cc: linux-kernel@vger.kernel.org, jun qian <qianjun.kernel@gmail.com>
Subject: [PATCH 1/1] sched/fair:Reduce unnecessary check preempt in the sched tick
Date: Tue, 13 Apr 2021 21:18:42 +0800	[thread overview]
Message-ID: <20210413131842.44430-1-qianjun.kernel@gmail.com> (raw)

From: jun qian <qianjun.kernel@gmail.com>

If it has been determined that the current cpu need resched in the
early stage of for_each_sched_entity, then there is no need to check
preempt in the subsequent se->parent entity_tick.

Signed-off-by: jun qian <qianjun.kernel@gmail.com>
---
 kernel/sched/fair.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 1a68a0536add..c0d135100d54 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -4352,8 +4352,13 @@ check_preempt_tick(struct cfs_rq *cfs_rq, struct sched_entity *curr)
 {
 	unsigned long ideal_runtime, delta_exec;
 	struct sched_entity *se;
+	struct rq *rq = rq_of(cfs_rq);
 	s64 delta;
 
+	/* If the TIF_NEED_RESCHED has been set, it is no need to check again */
+	if (test_tsk_need_resched(rq->curr))
+		return;
+
 	ideal_runtime = sched_slice(cfs_rq, curr);
 	delta_exec = curr->sum_exec_runtime - curr->prev_sum_exec_runtime;
 	if (delta_exec > ideal_runtime) {
-- 
2.18.2


             reply	other threads:[~2021-04-13 13:19 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-04-13 13:18 qianjun.kernel [this message]
2021-04-13 14:24 ` [PATCH 1/1] sched/fair:Reduce unnecessary check preempt in the sched tick Peter Zijlstra
2021-04-14  2:10   ` jun qian
2021-04-13 17:30 ` kernel test robot
2021-04-13 17:30   ` kernel test robot

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=20210413131842.44430-1-qianjun.kernel@gmail.com \
    --to=qianjun.kernel@gmail.com \
    --cc=bsegall@google.com \
    --cc=dietmar.eggemann@arm.com \
    --cc=juri.lelli@redhat.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mgorman@suse.de \
    --cc=mingo@redhat.com \
    --cc=peterz@infradead.org \
    --cc=rostedt@goodmis.org \
    --cc=vincent.guittot@linaro.org \
    /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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.