public inbox for linux-kernel@vger.kernel.org
 help / color / mirror / Atom feed
From: Christoph Lameter <clameter@sgi.com>
To: akpm@osdl.org
Cc: Peter Williams <pwil3058@bigpond.net.au>,
	linux-kernel@vger.kernel.org,
	Nick Piggin <nickpiggin@yahoo.com.au>,
	Christoph Lameter <clameter@sgi.com>,
	KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>,
	Ingo Molnar <mingo@elte.hu>,
	"Siddha, Suresh B" <suresh.b.siddha@intel.com>
Subject: [PATCH 1/7] Avoid taking rq lock in wake_priority_sleeper
Date: Fri, 27 Oct 2006 19:41:17 -0700 (PDT)	[thread overview]
Message-ID: <20061028024117.10809.74875.sendpatchset@schroedinger.engr.sgi.com> (raw)
In-Reply-To: <20061028024112.10809.15841.sendpatchset@schroedinger.engr.sgi.com>

Avoid taking the rq lock in wake_priority sleeper

Avoid taking the request queue lock in wake_priority_sleeper if
there are no running processes.

Signed-off-by: Christoph Lameter <clameter@sgi.com>

Index: linux-2.6.19-rc3/kernel/sched.c
===================================================================
--- linux-2.6.19-rc3.orig/kernel/sched.c	2006-10-26 21:30:11.328325096 -0500
+++ linux-2.6.19-rc3/kernel/sched.c	2006-10-27 11:58:02.142767971 -0500
@@ -2898,6 +2898,9 @@ static inline int wake_priority_sleeper(
 	int ret = 0;
 
 #ifdef CONFIG_SCHED_SMT
+	if (!rq->nr_running)
+		return 0;
+
 	spin_lock(&rq->lock);
 	/*
 	 * If an SMT sibling task has been put to sleep for priority

  reply	other threads:[~2006-10-28  2:41 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2006-10-28  2:41 [PATCH 0/7] sched_domain balancing via tasklet V2 Christoph Lameter
2006-10-28  2:41 ` Christoph Lameter [this message]
2006-10-28  2:41 ` [PATCH 2/7] Disable interrupts for locking in load_balance() Christoph Lameter
2006-10-28  2:41 ` [PATCH 3/7] Extract load calculation from rebalance_tick Christoph Lameter
2006-10-28  2:41 ` [PATCH 4/7] Stagger load balancing in build_sched_domains Christoph Lameter
2006-10-28  2:41 ` [PATCH 5/7] Move idle stat calculation into rebalance_tick() Christoph Lameter
2006-10-28 17:57   ` Siddha, Suresh B
2006-10-29  1:05     ` Christoph Lameter
2006-10-28  2:41 ` [PATCH 6/7] Use tasklet to call balancing Christoph Lameter
2006-10-28  2:41 ` [PATCH 7/7] Call tasklet less frequently Christoph Lameter
  -- strict thread matches above, loose matches on Subject: below --
2006-11-03 20:46 [PATCH 0/7] sched_domain balancing via tasklet V3 Christoph Lameter
2006-11-03 20:46 ` [PATCH 1/7] Avoid taking rq lock in wake_priority_sleeper Christoph Lameter

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=20061028024117.10809.74875.sendpatchset@schroedinger.engr.sgi.com \
    --to=clameter@sgi.com \
    --cc=akpm@osdl.org \
    --cc=kamezawa.hiroyu@jp.fujitsu.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mingo@elte.hu \
    --cc=nickpiggin@yahoo.com.au \
    --cc=pwil3058@bigpond.net.au \
    --cc=suresh.b.siddha@intel.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