From: Tejun Heo <tj@kernel.org>
To: Christoph Hellwig <hch@infradead.org>
Cc: "Darrick J. Wong" <djwong@us.ibm.com>, "Ted Ts'o" <tytso@mit.edu>,
Mingming Cao <cmm@us.ibm.com>, Ric Wheeler <rwheeler@redhat.com>,
linux-ext4 <linux-ext4@vger.kernel.org>,
linux-kernel <linux-kernel@vger.kernel.org>,
Keith Mannthey <kmannth@us.ibm.com>,
Mingming Cao <mcao@us.ibm.com>
Subject: Re: [RFC v3] ext4: Combine barrier requests coming from fsync
Date: Thu, 19 Aug 2010 17:48:39 +0200 [thread overview]
Message-ID: <4C6D5257.9040305@kernel.org> (raw)
In-Reply-To: <4C6CF6BC.3030804@kernel.org>
Hello, again.
On 08/19/2010 11:17 AM, Tejun Heo wrote:
> What was the configuration? If dm was involved, both md and dm can
> only process single flush request at a time. Supporing multiple
> flushes in flight wouldn't be too difficult. It's just the way things
> are implemented with the previous barrier implementation. It can
> definitely be improved.
Oh, I just realized that the current bio-based dm implementation
doesn't allow other bio's to be processed if a flush is in progress.
So, it's not about not being able to handle multiple flushes. The
queue just stalls while flush is in progress and because it also waits
for flush completion by waiting for all commands in progress to
finish. It basically ends up draining and stalling everything.
Shouldn't be too hard to make it better.
Thanks.
--
tejun
next prev parent reply other threads:[~2010-08-19 15:52 UTC|newest]
Thread overview: 55+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-04-29 23:51 [RFC] ext4: Don't send extra barrier during fsync if there are no dirty pages Darrick J. Wong
2010-05-04 0:57 ` Mingming Cao
2010-05-04 14:16 ` Ric Wheeler
2010-05-04 15:45 ` Christoph Hellwig
2010-06-30 12:48 ` tytso
2010-06-30 13:21 ` Ric Wheeler
2010-06-30 13:44 ` tytso
2010-06-30 13:54 ` Ric Wheeler
2010-06-30 19:05 ` Andreas Dilger
2010-07-21 17:16 ` Jan Kara
2010-08-03 0:09 ` Darrick J. Wong
2010-08-03 9:01 ` Christoph Hellwig
2010-08-04 18:16 ` Darrick J. Wong
2010-08-03 13:21 ` Jan Kara
2010-08-03 13:24 ` Avi Kivity
2010-08-04 23:32 ` Ted Ts'o
2010-08-05 2:20 ` Avi Kivity
2010-08-05 16:17 ` Ted Ts'o
2010-08-05 19:13 ` Jeff Moyer
2010-08-05 20:39 ` Ted Ts'o
2010-08-05 20:44 ` Jeff Moyer
2010-05-04 19:49 ` Mingming Cao
2010-06-29 20:51 ` [RFC v2] " Darrick J. Wong
2010-08-05 16:40 ` Ted Ts'o
2010-08-05 16:45 ` Ted Ts'o
2010-08-06 7:04 ` Darrick J. Wong
2010-08-06 10:17 ` Ric Wheeler
2010-08-09 19:53 ` [RFC v3] ext4: Combine barrier requests coming from fsync Darrick J. Wong
2010-08-09 21:07 ` Christoph Hellwig
2010-08-16 16:14 ` Darrick J. Wong
2010-08-19 2:07 ` Darrick J. Wong
2010-08-19 8:53 ` Christoph Hellwig
2010-08-19 9:17 ` Tejun Heo
2010-08-19 15:48 ` Tejun Heo [this message]
2010-08-09 21:19 ` Andreas Dilger
2010-08-09 23:38 ` Darrick J. Wong
2010-08-19 2:14 ` [RFC v4] ext4: Coordinate fsync requests Darrick J. Wong
2010-08-23 18:31 ` Performance testing of various barrier reduction patches [was: Re: [RFC v4] ext4: Coordinate fsync requests] Darrick J. Wong
2010-09-23 23:25 ` Darrick J. Wong
2010-09-24 6:24 ` Andreas Dilger
2010-09-24 11:44 ` Ric Wheeler
2010-09-27 23:01 ` Darrick J. Wong
2010-10-08 21:26 ` Darrick J. Wong
2010-10-08 21:56 ` Ric Wheeler
2010-10-11 20:20 ` Darrick J. Wong
2010-10-12 14:14 ` Christoph Hellwig
2010-10-15 23:39 ` Darrick J. Wong
2010-10-15 23:40 ` Christoph Hellwig
2010-10-16 0:02 ` Darrick J. Wong
2010-10-11 14:33 ` Ted Ts'o
2010-10-18 22:49 ` Darrick J. Wong
2010-10-19 18:28 ` Christoph Hellwig
2010-08-06 7:13 ` [RFC v2] ext4: Don't send extra barrier during fsync if there are no dirty pages Darrick J. Wong
2010-08-06 18:04 ` Ted Ts'o
2010-08-09 19:36 ` Darrick J. Wong
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