From: Pavel Machek <pavel@ucw.cz>
To: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>,
Alasdair G Kergon <agk@redhat.com>,
Eric Sandeen <sandeen@redhat.com>, Andrew Morton <akpm@osdl.org>,
linux-kernel@vger.kernel.org, dm-devel@redhat.com,
Srinivasa DS <srinivasa@in.ibm.com>,
Nigel Cunningham <nigel@suspend2.net>,
David Chinner <dgc@sgi.com>
Subject: Re: [PATCH 2.6.19 5/5] fs: freeze_bdev with semaphore not mutex
Date: Fri, 10 Nov 2006 11:36:50 +0100 [thread overview]
Message-ID: <20061110103650.GE3196@elf.ucw.cz> (raw)
In-Reply-To: <1163154249.7900.19.camel@localhost.localdomain>
HI!
> > Why not simply &~ PF_NOFREEZE on that particular process? Filesystems
> > are free to use threads/work queues/whatever, but refrigerator should
> > mean "no writes to filesystem" for them...
>
> You can't go around altering the flags of another process - what locking
> are you relying upon for this ?
Well, my idea was for process to &~ PF_NOFREEZE on itself.
We are currently (kernel/power/process.c) using &p->sighand->siglock
for some accesses, and no locking for others. There were some attempts
to fix this, but they led to problems, and we are not hitting any
problems... part of reason is that we hot-unplug non-boot cpus before
freezing processes, so we are running UP at that point.
Pavel
--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
next prev parent reply other threads:[~2006-11-10 10:37 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
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 [this message]
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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