From: Alasdair G Kergon <agk@redhat.com>
To: device-mapper development <dm-devel@redhat.com>
Cc: Andrew Morton <akpm@osdl.org>,
linux-kernel@vger.kernel.org, Ingo Molnar <mingo@elte.hu>,
Eric Sandeen <sandeen@sandeen.net>,
Srinivasa DS <srinivasa@in.ibm.com>
Subject: Re: [dm-devel] [PATCH 2.6.19 5/5] fs: freeze_bdev with semaphore not mutex
Date: Tue, 7 Nov 2006 23:34:20 +0000 [thread overview]
Message-ID: <20061107233420.GC30653@agk.surrey.redhat.com> (raw)
In-Reply-To: <170fa0d20611071218t3c145ef9i5413e432597d78a5@mail.gmail.com>
On Tue, Nov 07, 2006 at 03:18:08PM -0500, Mike Snitzer wrote:
> Srinivasa's description of the patch just speaks to how freeze_bdev
> and thaw_bdev are used by DM but completely skips justification for
> switching from mutex to semaphore. Why is it beneficial and/or
> necessary to use a semaphore instead of a mutex here?
This used to be a semaphore; someone changed it to a mutex; we started
getting device-mapper bug reports from people because the usage breaks the
stated semantics for a mutex; this patch puts things back while we consider
if there's a better way of doing things.
Alasdair
--
agk@redhat.com
next prev parent reply other threads:[~2006-11-07 23:34 UTC|newest]
Thread overview: 69+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-11-07 18:34 Alasdair G Kergon
2006-11-07 20:18 ` [dm-devel] " Mike Snitzer
2006-11-07 20:22 ` Eric Sandeen
2006-11-07 23:34 ` Alasdair G Kergon [this message]
2006-11-07 20:28 ` Andrew Morton
2006-11-07 22:45 ` Eric Sandeen
2006-11-07 23:00 ` Andrew Morton
2006-11-08 9:54 ` Arjan van de Ven
2007-01-12 6:23 ` Srinivasa Ds
2007-01-12 10:16 ` Srinivasa Ds
2006-11-07 23:05 ` Rafael J. Wysocki
2006-11-07 23:18 ` Eric Sandeen
2006-11-07 23:42 ` Rafael J. Wysocki
2006-11-08 0:01 ` Alasdair G Kergon
2006-11-08 8:27 ` David Chinner
2006-11-08 14:25 ` Alasdair G Kergon
2006-11-08 14:43 ` Rafael J. Wysocki
2006-11-08 15:25 ` Alasdair G Kergon
2006-11-08 23:06 ` Rafael J. Wysocki
2006-11-07 23:49 ` Alasdair G Kergon
2006-11-08 0:00 ` Rafael J. Wysocki
2006-11-08 3:33 ` David Chinner
2006-11-08 2:30 ` Alasdair G Kergon
2006-11-08 12:10 ` Rafael J. Wysocki
2006-11-08 18:09 ` Pavel Machek
2006-11-09 15:52 ` Rafael J. Wysocki
2006-11-09 16:00 ` Pavel Machek
2006-11-09 19:59 ` Rafael J. Wysocki
2006-11-09 21:17 ` Pavel Machek
2006-11-09 21:18 ` Rafael J. Wysocki
2006-11-09 21:41 ` Pavel Machek
2006-11-09 22:21 ` Rafael J. Wysocki
2006-11-09 23:11 ` Pavel Machek
2006-11-09 23:24 ` Alasdair G Kergon
2006-11-09 23:32 ` Pavel Machek
2006-11-10 12:03 ` Rafael J. Wysocki
2006-11-12 18:43 ` Pavel Machek
2006-11-12 21:53 ` Rafael J. Wysocki
2006-11-12 23:30 ` David Chinner
2006-11-13 16:11 ` Rafael J. Wysocki
2006-11-15 18:50 ` Pavel Machek
2006-11-15 19:56 ` Rafael J. Wysocki
2006-11-15 20:00 ` Rafael J. Wysocki
2006-11-15 20:23 ` Pavel Machek
2006-11-15 21:58 ` Rafael J. Wysocki
2006-11-15 22:49 ` Pavel Machek
2006-11-16 23:20 ` David Chinner
2006-11-16 23:38 ` Pavel Machek
2006-11-13 7:35 ` Stefan Seyfried
2006-11-10 0:57 ` David Chinner
2006-11-10 10:39 ` Pavel Machek
2006-11-12 22:30 ` David Chinner
2006-11-12 22:43 ` Rafael J. Wysocki
2006-11-13 5:43 ` David Chinner
2006-11-13 16:22 ` Rafael J. Wysocki
2006-11-14 0:10 ` David Chinner
2006-11-16 23:23 ` David Chinner
2006-11-16 23:40 ` Pavel Machek
2006-11-17 1:40 ` David Chinner
2006-11-17 15:13 ` Pavel Machek
2006-11-10 0:54 ` David Chinner
2006-11-10 10:24 ` Alan Cox
2006-11-10 10:36 ` Pavel Machek
2006-11-10 0:33 ` David Chinner
2006-11-10 10:38 ` Pavel Machek
2006-11-08 20:48 ` Nigel Cunningham
2006-11-08 21:08 ` Rafael J. Wysocki
2006-11-07 23:23 ` Alasdair G Kergon
2006-11-07 23:39 ` Ingo Molnar
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