From: "Stephen C. Tweedie" <sct@redhat.com>
To: James Bottomley <James.Bottomley@steeleye.com>
Cc: "Stephen C. Tweedie" <sct@redhat.com>,
Chris Mason <mason@suse.com>,
Daniel Phillips <phillips@bonn-fries.net>,
linux-kernel@vger.kernel.org, linux-scsi@vger.kernel.org
Subject: Re: [PATCH] 2.4.x write barriers (updated for ext3)
Date: Mon, 4 Mar 2002 19:55:37 +0000 [thread overview]
Message-ID: <20020304195537.I1444@redhat.com> (raw)
In-Reply-To: <sct@redhat.com> <200203041828.g24ISJo09358@localhost.localdomain>
In-Reply-To: <200203041828.g24ISJo09358@localhost.localdomain>; from James.Bottomley@steeleye.com on Mon, Mar 04, 2002 at 12:28:19PM -0600
Hi,
On Mon, Mar 04, 2002 at 12:28:19PM -0600, James Bottomley wrote:
> There is one remaining curiosity I have, at least about the benchmarks: Since
> the linux elevator and tag queueing perform essentially similar function
> (except that the disk itself has a better notion of ordering because it knows
> its own geometry). Might we get better performance by reducing the number of
> tags we allow the device to use, thus forcing the writes to remain longer in
> the linux elevator?
Possibly, but my gut feeling says no and so do any benchmarks I've
seen regarding queue depths on adaptec controllers (not that I've seen
many). For relatively-closeby IOs, the disk will always have a better
idea of how to optimise a number of IOs than the Linux elevator can
have, especially if we have multiple IOs spanning multiple heads
within a single cylinder.
--Stephen
next prev parent reply other threads:[~2002-03-04 19:56 UTC|newest]
Thread overview: 73+ messages / expand[flat|nested] mbox.gz Atom feed top
2002-02-22 15:57 [PATCH] 2.4.x write barriers (updated for ext3) James Bottomley
2002-02-22 16:10 ` Chris Mason
2002-02-22 16:13 ` Stephen C. Tweedie
2002-02-22 17:36 ` James Bottomley
2002-02-22 18:14 ` Chris Mason
2002-02-28 15:36 ` James Bottomley
2002-02-28 15:55 ` Chris Mason
2002-02-28 17:58 ` Mike Anderson
2002-02-28 18:12 ` Chris Mason
2002-03-01 2:08 ` James Bottomley
2002-03-03 22:11 ` Daniel Phillips
2002-03-04 3:34 ` Chris Mason
2002-03-04 5:05 ` Daniel Phillips
2002-03-04 15:03 ` James Bottomley
2002-03-04 17:04 ` Stephen C. Tweedie
2002-03-04 17:16 ` Chris Mason
2002-03-04 18:05 ` Stephen C. Tweedie
2002-03-04 18:28 ` James Bottomley
2002-03-04 19:55 ` Stephen C. Tweedie [this message]
2002-03-04 19:48 ` Daniel Phillips
2002-03-04 19:57 ` Stephen C. Tweedie
2002-03-04 21:06 ` Daniel Phillips
2002-03-05 14:58 ` Stephen C. Tweedie
2002-03-05 7:48 ` Jens Axboe
2002-03-04 19:51 ` Daniel Phillips
2002-03-05 7:42 ` Jens Axboe
2002-03-04 17:35 ` James Bottomley
2002-03-04 17:48 ` Chris Mason
2002-03-04 18:11 ` James Bottomley
2002-03-04 18:41 ` Chris Mason
2002-03-04 21:34 ` Stephen C. Tweedie
2002-03-04 18:09 ` Stephen C. Tweedie
2002-03-04 8:19 ` Helge Hafting
2002-03-04 14:57 ` James Bottomley
2002-03-04 17:24 ` Chris Mason
2002-03-04 19:02 ` Daniel Phillips
2002-03-05 7:22 ` Jeremy Higdon
2002-03-05 23:01 ` Daniel Phillips
2002-03-04 4:21 ` Jeremy Higdon
2002-03-04 5:31 ` Daniel Phillips
2002-03-04 6:09 ` Jeremy Higdon
2002-03-04 7:57 ` Daniel Phillips
2002-03-05 7:09 ` Jeremy Higdon
2002-03-05 22:56 ` Daniel Phillips
2002-03-04 16:52 ` Stephen C. Tweedie
2002-03-04 18:15 ` Daniel Phillips
2002-03-05 7:40 ` Jens Axboe
2002-03-05 22:29 ` Daniel Phillips
2002-03-12 7:01 ` Jens Axboe
2002-03-10 5:24 ` Douglas Gilbert
2002-03-11 11:13 ` Kurt Garloff
2002-03-12 1:17 ` GOTO Masanori
2002-03-12 6:58 ` Jens Axboe
2002-03-13 22:37 ` Peter Osterlund
2002-03-11 11:34 ` Stephen C. Tweedie
2002-03-11 17:15 ` James Bottomley
2002-03-04 14:48 ` James Bottomley
2002-03-06 13:59 ` Daniel Phillips
2002-03-06 14:34 ` James Bottomley
2002-02-25 10:57 ` Helge Hafting
2002-02-25 15:04 ` James Bottomley
-- strict thread matches above, loose matches on Subject: below --
2002-03-01 15:26 Dieter Nützel
2002-03-01 16:00 ` James Bottomley
2002-02-21 23:30 Chris Mason
2002-02-22 14:19 ` Stephen C. Tweedie
2002-02-22 15:26 ` Chris Mason
2002-01-10 9:55 [ANNOUNCE] FUSE: Filesystem in Userspace 0.95 Miklos Szeredi
2002-01-13 3:10 ` Pavel Machek
2002-01-21 10:18 ` Miklos Szeredi
2002-01-23 10:47 ` Pavel Machek
2002-01-22 19:07 ` Daniel Phillips
2002-01-23 2:33 ` [Avfs] " Justin Mason
2002-01-23 5:26 ` Daniel Phillips
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