From: Lai Jiangshan <laijs@cn.fujitsu.com>
To: <linux-kernel@vger.kernel.org>
Cc: Tejun Heo <tj@kernel.org>, Lai Jiangshan <laijs@cn.fujitsu.com>
Subject: [PATCH 1/2] workqueue: remove unneeded test before wake up next worker
Date: Wed, 16 Jul 2014 18:09:58 +0800 [thread overview]
Message-ID: <1405505409-12058-1-git-send-email-laijs@cn.fujitsu.com> (raw)
In this code:
if ((worker->flags & WORKER_UNBOUND) && need_more_worker(pool))
wake_up_worker(pool);
the first test is unneeded. Even the first test is removed, it doesn't affect
the wake-up logic when WORKER_UNBOUND. And it will not introduce any useless
wake-up when !WORKER_UNBOUND since the nr_running >= 1 except only one case.
It will introduce useless/redundant wake-up when cpu_intensive, but this
case is rare and next patch will also remove this redundant wake-up.
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
---
kernel/workqueue.c | 7 ++-----
1 files changed, 2 insertions(+), 5 deletions(-)
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index f8d54c1..6d11b9a 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -2047,11 +2047,8 @@ __acquires(&pool->lock)
if (unlikely(cpu_intensive))
worker_set_flags(worker, WORKER_CPU_INTENSIVE, true);
- /*
- * Unbound pool isn't concurrency managed and work items should be
- * executed ASAP. Wake up another worker if necessary.
- */
- if ((worker->flags & WORKER_UNBOUND) && need_more_worker(pool))
+ /* Wake up another worker if necessary. */
+ if (need_more_worker(pool))
wake_up_worker(pool);
/*
--
1.7.4.4
next reply other threads:[~2014-07-16 10:09 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-07-16 10:09 Lai Jiangshan [this message]
2014-07-16 10:09 ` [PATCH 2/2] workqueue: remove the argument @wakeup from worker_set_flags() Lai Jiangshan
2014-07-18 22:38 ` Tejun Heo
2014-07-18 22:53 ` Tejun Heo
2014-07-18 22:05 ` [PATCH 1/2] workqueue: remove unneeded test before wake up next worker Tejun Heo
2014-07-18 22:53 ` Tejun Heo
2014-07-22 5:01 ` [PATCH 1/2 V2] " Lai Jiangshan
2014-07-22 5:02 ` [PATCH 2/2 V2] workqueue: remove the argument @wakeup from worker_set_flags() Lai Jiangshan
2014-07-22 14:38 ` Tejun Heo
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=1405505409-12058-1-git-send-email-laijs@cn.fujitsu.com \
--to=laijs@cn.fujitsu.com \
--cc=linux-kernel@vger.kernel.org \
--cc=tj@kernel.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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox
all inboxes | Powered by JetHome®