From: Andrea Arcangeli <aarcange@redhat.com>
To: Jan Kara <jack@suse.cz>
Cc: Boaz Harrosh <bharrosh@panasas.com>,
Mike Snitzer <snitzer@redhat.com>,
linux-scsi@vger.kernel.org, neilb@suse.de, dm-devel@redhat.com,
linux-fsdevel@vger.kernel.org, lsf-pc@lists.linux-foundation.org,
"Darrick J. Wong" <djwong@us.ibm.com>
Subject: Re: [Lsf-pc] [LSF/MM TOPIC] a few storage topics
Date: Mon, 23 Jan 2012 18:53:53 +0100 [thread overview]
Message-ID: <20120123175353.GD30782@redhat.com> (raw)
In-Reply-To: <20120123161857.GC28526@quack.suse.cz>
On Mon, Jan 23, 2012 at 05:18:57PM +0100, Jan Kara wrote:
> requst granularity. Sure, big requests will take longer to complete but
> maximum request size is relatively low (512k by default) so writing maximum
> sized request isn't that much slower than writing 4k. So it works OK in
> practice.
Totally unrelated to the writeback, but the merged big 512k requests
actually adds up some measurable I/O scheduler latencies and they in
turn slightly diminish the fairness that cfq could provide with
smaller max request size. Probably even more measurable with SSDs (but
then SSDs are even faster).
next prev parent reply other threads:[~2012-01-23 17:54 UTC|newest]
Thread overview: 76+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <CABE8wws67dn0fwhTCs_XqH0g_CxGuT+hPQH9cVFe1xx5t_O9Jw@mail.gmail.com>
2012-01-17 20:06 ` [LSF/MM TOPIC] a few storage topics Mike Snitzer
2012-01-17 21:36 ` [Lsf-pc] " Jan Kara
2012-01-18 22:58 ` Darrick J. Wong
2012-01-18 23:22 ` Jan Kara
2012-01-18 23:42 ` Boaz Harrosh
2012-01-19 9:46 ` Jan Kara
2012-01-19 15:08 ` Andrea Arcangeli
2012-01-19 20:52 ` Jan Kara
2012-01-19 21:39 ` Andrea Arcangeli
2012-01-22 11:31 ` Boaz Harrosh
2012-01-23 16:30 ` Jan Kara
2012-01-22 12:21 ` Boaz Harrosh
2012-01-23 16:18 ` Jan Kara
2012-01-23 17:53 ` Andrea Arcangeli [this message]
2012-01-23 18:28 ` Jeff Moyer
2012-01-23 18:56 ` Andrea Arcangeli
2012-01-23 19:19 ` Jeff Moyer
2012-01-24 15:15 ` Chris Mason
2012-01-24 16:56 ` [dm-devel] " Christoph Hellwig
2012-01-24 17:01 ` Andreas Dilger
2012-01-24 17:06 ` [Lsf-pc] [dm-devel] " Andrea Arcangeli
2012-01-24 17:08 ` Chris Mason
2012-01-24 17:08 ` [Lsf-pc] " Andreas Dilger
2012-01-24 18:05 ` [dm-devel] " Jeff Moyer
2012-01-24 18:40 ` Christoph Hellwig
2012-01-24 19:07 ` Chris Mason
2012-01-24 19:14 ` Jeff Moyer
2012-01-24 20:09 ` [Lsf-pc] [dm-devel] " Jan Kara
2012-01-24 20:13 ` [Lsf-pc] " Jeff Moyer
2012-01-24 20:39 ` [Lsf-pc] [dm-devel] " Jan Kara
2012-01-24 20:59 ` Jeff Moyer
2012-01-24 21:08 ` Jan Kara
2012-01-25 3:29 ` Wu Fengguang
2012-01-25 6:15 ` [Lsf-pc] " Andreas Dilger
2012-01-25 6:35 ` [Lsf-pc] [dm-devel] " Wu Fengguang
2012-01-25 14:00 ` Jan Kara
2012-01-26 12:29 ` Andreas Dilger
2012-01-27 17:03 ` Ted Ts'o
2012-01-26 16:25 ` Vivek Goyal
2012-01-26 20:37 ` Jan Kara
2012-01-26 22:34 ` Dave Chinner
2012-01-27 3:27 ` Wu Fengguang
2012-01-27 5:25 ` Andreas Dilger
2012-01-27 7:53 ` Wu Fengguang
2012-01-25 14:33 ` Steven Whitehouse
2012-01-25 14:45 ` Jan Kara
2012-01-25 16:22 ` Loke, Chetan
2012-01-25 16:40 ` Steven Whitehouse
2012-01-25 17:08 ` Loke, Chetan
2012-01-25 17:32 ` James Bottomley
2012-01-25 18:28 ` Loke, Chetan
2012-01-25 18:37 ` Loke, Chetan
2012-01-25 18:37 ` James Bottomley
2012-01-25 20:06 ` Chris Mason
2012-01-25 22:46 ` Andrea Arcangeli
2012-01-25 22:58 ` Jan Kara
2012-01-26 8:59 ` Boaz Harrosh
2012-01-26 16:40 ` Loke, Chetan
2012-01-26 17:00 ` Andreas Dilger
2012-01-26 17:16 ` Loke, Chetan
2012-02-03 12:37 ` Wu Fengguang
2012-01-26 22:38 ` Dave Chinner
2012-01-26 16:17 ` Loke, Chetan
2012-01-25 18:44 ` Boaz Harrosh
2012-02-03 12:55 ` Wu Fengguang
2012-01-24 19:11 ` [dm-devel] [Lsf-pc] " Jeff Moyer
2012-01-26 22:31 ` Dave Chinner
2012-01-24 17:12 ` Jeff Moyer
2012-01-24 17:32 ` Chris Mason
2012-01-24 18:14 ` Jeff Moyer
2012-01-25 0:23 ` NeilBrown
2012-01-25 6:11 ` Andreas Dilger
2012-01-18 23:39 ` Dan Williams
2012-01-24 17:59 ` Martin K. Petersen
2012-01-24 19:48 ` Douglas Gilbert
2012-01-24 20:04 ` Martin K. Petersen
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