From: Chris Mason <chris.mason@oracle.com>
To: Dave Chinner <david@fromorbit.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>,
Andrew Morton <akpm@linux-foundation.org>,
Peter Zijlstra <a.p.zijlstra@chello.nl>,
"Li, Shaohua" <shaohua.li@intel.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"richard@rsk.demon.co.uk" <richard@rsk.demon.co.uk>,
"jens.axboe@oracle.com" <jens.axboe@oracle.com>
Subject: Re: regression in page writeback
Date: Thu, 24 Sep 2009 20:38:20 -0400 [thread overview]
Message-ID: <20090925003820.GK2662@think> (raw)
In-Reply-To: <20090925001117.GA9464@discord.disaster>
On Fri, Sep 25, 2009 at 10:11:17AM +1000, Dave Chinner wrote:
> On Thu, Sep 24, 2009 at 11:15:08AM +0800, Wu Fengguang wrote:
> > On Wed, Sep 23, 2009 at 10:00:58PM +0800, Chris Mason wrote:
> > > The only place that actually honors the congestion flag is pdflush.
> > > It's trivial to get pdflush backed up and make it sit down without
> > > making any progress because once the queue congests, pdflush goes away.
> >
> > Right. I guess that's more or less intentional - to give lowest priority
> > to periodic/background writeback.
>
> IMO, this is the wrong design. Background writeback should
> have higher CPU/scheduler priority than normal tasks. If there is
> sufficient dirty pages in the system for background writeback to
> be active, it should be running *now* to start as much IO as it can
> without being held up by other, lower priority tasks.
I'd say that an fsync from mutt or vi should be done at a higher prio
than a background streaming writer.
-chris
next prev parent reply other threads:[~2009-09-25 0:38 UTC|newest]
Thread overview: 79+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-09-22 5:49 regression in page writeback Shaohua Li
2009-09-22 6:40 ` Peter Zijlstra
2009-09-22 8:05 ` Wu Fengguang
2009-09-22 8:09 ` Peter Zijlstra
2009-09-22 8:24 ` Wu Fengguang
2009-09-22 8:32 ` Peter Zijlstra
2009-09-22 8:51 ` Wu Fengguang
2009-09-22 8:52 ` Richard Kennedy
2009-09-22 9:05 ` Wu Fengguang
2009-09-22 11:41 ` Shaohua Li
2009-09-22 15:52 ` Chris Mason
2009-09-23 0:22 ` Wu Fengguang
2009-09-23 0:54 ` Andrew Morton
2009-09-23 1:17 ` Wu Fengguang
2009-09-23 1:27 ` Wu Fengguang
2009-09-23 1:28 ` Andrew Morton
2009-09-23 1:32 ` Wu Fengguang
2009-09-23 1:47 ` Andrew Morton
2009-09-23 2:01 ` Wu Fengguang
2009-09-23 2:09 ` Andrew Morton
2009-09-23 3:07 ` Wu Fengguang
2009-09-23 1:45 ` Wu Fengguang
2009-09-23 1:59 ` Andrew Morton
2009-09-23 2:26 ` Wu Fengguang
2009-09-23 2:36 ` Andrew Morton
2009-09-23 2:49 ` Wu Fengguang
2009-09-23 2:56 ` Andrew Morton
2009-09-23 3:11 ` Wu Fengguang
2009-09-23 3:10 ` Shaohua Li
2009-09-23 3:14 ` Wu Fengguang
2009-09-23 3:25 ` Wu Fengguang
2009-09-23 14:00 ` Chris Mason
2009-09-24 3:15 ` Wu Fengguang
2009-09-24 12:10 ` Chris Mason
2009-09-25 3:26 ` Wu Fengguang
2009-09-25 0:11 ` Dave Chinner
2009-09-25 0:38 ` Chris Mason [this message]
2009-09-25 5:04 ` Dave Chinner
2009-09-25 6:45 ` Wu Fengguang
2009-09-28 1:07 ` Dave Chinner
2009-09-28 7:15 ` Wu Fengguang
2009-09-28 13:08 ` Christoph Hellwig
2009-09-28 14:07 ` Theodore Tso
2009-09-30 5:26 ` Wu Fengguang
2009-09-30 5:32 ` Wu Fengguang
2009-10-01 22:17 ` Jan Kara
2009-10-02 3:27 ` Wu Fengguang
2009-10-06 12:55 ` Jan Kara
2009-10-06 13:18 ` Wu Fengguang
2009-09-30 14:11 ` Theodore Tso
2009-10-01 15:14 ` Wu Fengguang
2009-10-01 21:54 ` Theodore Tso
2009-10-02 2:55 ` Wu Fengguang
2009-10-02 8:19 ` Wu Fengguang
2009-10-02 17:26 ` Theodore Tso
2009-10-03 6:10 ` Wu Fengguang
2009-09-29 2:32 ` Wu Fengguang
2009-09-29 14:00 ` Chris Mason
2009-09-29 14:21 ` Christoph Hellwig
2009-09-29 0:15 ` Wu Fengguang
2009-09-28 14:25 ` Chris Mason
2009-09-29 23:39 ` Dave Chinner
2009-09-30 1:30 ` Wu Fengguang
2009-09-25 12:06 ` Chris Mason
2009-09-25 3:19 ` Wu Fengguang
2009-09-26 1:47 ` Dave Chinner
2009-09-26 3:02 ` Wu Fengguang
2009-09-26 3:02 ` Wu Fengguang
2009-09-23 9:19 ` Richard Kennedy
2009-09-23 9:23 ` Peter Zijlstra
2009-09-23 9:37 ` Wu Fengguang
2009-09-23 10:30 ` Wu Fengguang
2009-09-23 6:41 ` Shaohua Li
2009-09-22 10:49 ` Wu Fengguang
2009-09-22 11:50 ` Shaohua Li
2009-09-22 13:39 ` Wu Fengguang
2009-09-23 1:52 ` Shaohua Li
2009-09-23 4:00 ` Wu Fengguang
2009-09-25 6:14 ` Wu Fengguang
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