From: "Rafael J. Wysocki" <rjw@sisk.pl>
To: Matt Reimer <mattjreimer@gmail.com>
Cc: "linux-kernel" <linux-kernel@vger.kernel.org>,
Alan Stern <stern@rowland.harvard.edu>,
Jens Axboe <jens.axboe@oracle.com>,
Maxim Levitsky <maximlevitsky@gmail.com>,
"linux-pm" <linux-pm@lists.linux-foundation.org>,
Andrew Morton <akpm@linux-foundation.org>,
Pavel Machek <pavel@ucw.cz>
Subject: Re: [linux-pm] Is it supposed to be ok to call del_gendisk while userspace is frozen?
Date: Fri, 23 Apr 2010 07:17:07 +0200 [thread overview]
Message-ID: <201004230717.07086.rjw@sisk.pl> (raw)
In-Reply-To: <y2yf383264b1004221640rd1fca614zfa15d7e7984ab3ba@mail.gmail.com>
On Friday 23 April 2010, Matt Reimer wrote:
> On Thu, Mar 4, 2010 at 1:15 PM, Pavel Machek <pavel@ucw.cz> wrote:
> > Hi!
> >
> >> > My thought exactly. This is the only approach that also solves the
> >> > following race:
> >> >
> >> > A driver is unloaded at the same time as a suspend starts.
> >> >
> >> > The writeback thread gets frozen.
> >> >
> >> > Then before the rmmod thread is frozen, it calls del_gendisk.
> >> >
> >> > Delaying things by means of a workqueue (or the equivalent) might also
> >> > work, but it doesn't seem as safe. For example, some important
> >> > writebacks might end up getting delayed until too late.
> >
> > Delaying writebacks during sleep should be ok... That's why we do
> > sync() after userspace is frozen -- nothing really important should be
> > waiting for writeback after that point.
>
> Has this been fixed,
No, it hasn't.
> or has a consensus about how to fix this been
> achieved? I'm hitting the same problem and have some time to work on a
> fix.
Generally, it looks like del_gendisk should thaw writeback threads, but not
during suspend, only during resume.
Rafael
next prev parent reply other threads:[~2010-04-23 5:17 UTC|newest]
Thread overview: 118+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-02-13 13:29 Is it supposed to be ok to call del_gendisk while userspace is frozen? Maxim Levitsky
2010-02-13 13:29 ` Maxim Levitsky
2010-02-15 16:00 ` Maxim Levitsky
2010-02-15 16:00 ` Maxim Levitsky
2010-02-15 21:04 ` Rafael J. Wysocki
2010-02-15 21:04 ` Rafael J. Wysocki
2010-02-16 16:27 ` Alan Stern
2010-02-16 16:27 ` [linux-pm] " Alan Stern
2010-02-20 22:22 ` Maxim Levitsky
2010-02-20 22:22 ` [linux-pm] " Maxim Levitsky
2010-02-23 12:33 ` Jens Axboe
2010-02-23 15:29 ` Alan Stern
2010-02-23 15:29 ` [linux-pm] " Alan Stern
2010-02-23 15:58 ` Jens Axboe
2010-02-23 15:58 ` [linux-pm] " Jens Axboe
2010-02-23 16:33 ` Alan Stern
2010-02-23 22:16 ` Jens Axboe
2010-02-24 15:59 ` Alan Stern
2010-02-24 15:59 ` [linux-pm] " Alan Stern
2010-02-24 19:12 ` Jens Axboe
2010-02-24 19:12 ` [linux-pm] " Jens Axboe
2010-02-24 20:19 ` Alan Stern
2010-02-24 20:19 ` [linux-pm] " Alan Stern
2010-02-23 22:16 ` Jens Axboe
2010-02-23 16:33 ` Alan Stern
2010-02-23 16:42 ` Testing for dirty buffers on a block device Alan Stern
2010-02-23 16:42 ` Alan Stern
2010-02-23 22:13 ` Jens Axboe
2010-02-23 22:13 ` Jens Axboe
2010-02-24 15:51 ` Alan Stern
2010-02-24 19:09 ` Jens Axboe
2010-02-24 19:09 ` Jens Axboe
2010-02-24 20:09 ` Alan Stern
2010-02-25 8:20 ` Jens Axboe
2010-02-25 8:20 ` Jens Axboe
2010-02-25 22:19 ` Dave Chinner
2010-02-25 22:19 ` Dave Chinner
2010-02-24 20:09 ` Alan Stern
2010-02-24 15:51 ` Alan Stern
2010-03-01 6:35 ` [linux-pm] Is it supposed to be ok to call del_gendisk while userspace is frozen? Pavel Machek
2010-03-01 15:23 ` Alan Stern
2010-03-03 21:50 ` Pavel Machek
2010-03-03 21:50 ` [linux-pm] " Pavel Machek
2010-03-03 22:23 ` Alan Stern
2010-03-03 22:23 ` [linux-pm] " Alan Stern
2010-03-04 0:23 ` Rafael J. Wysocki
2010-03-04 2:48 ` Alan Stern
2010-03-04 19:26 ` Rafael J. Wysocki
2010-03-04 19:36 ` Alan Stern
2010-03-04 19:36 ` [linux-pm] " Alan Stern
2010-03-04 20:04 ` Rafael J. Wysocki
2010-03-04 20:04 ` Rafael J. Wysocki
2010-03-04 20:15 ` Pavel Machek
2010-03-04 20:15 ` [linux-pm] " Pavel Machek
2010-04-22 23:40 ` Matt Reimer
2010-04-22 23:40 ` [linux-pm] " Matt Reimer
2010-04-23 5:17 ` Rafael J. Wysocki
2010-04-23 5:17 ` Rafael J. Wysocki [this message]
2010-05-11 23:55 ` [linux-pm] " Matt Reimer
2010-05-12 14:50 ` Alan Stern
2010-05-12 14:50 ` [linux-pm] " Alan Stern
2010-05-13 21:44 ` Matt Reimer
2010-05-13 21:54 ` Alan Stern
2010-05-13 22:20 ` Matt Reimer
2010-05-13 22:20 ` [linux-pm] " Matt Reimer
2010-05-13 22:47 ` Nigel Cunningham
2010-05-13 22:47 ` [linux-pm] " Nigel Cunningham
2010-05-15 2:37 ` Alan Stern
2010-05-15 2:53 ` Nigel Cunningham
2010-05-16 19:35 ` Rafael J. Wysocki
2010-05-16 19:35 ` Rafael J. Wysocki
2010-05-15 2:53 ` Nigel Cunningham
2010-05-15 2:37 ` Alan Stern
2010-05-15 2:32 ` Alan Stern
2010-05-15 2:32 ` [linux-pm] " Alan Stern
2010-05-15 20:30 ` Rafael J. Wysocki
2010-05-16 7:49 ` Nigel Cunningham
2010-05-16 19:38 ` Rafael J. Wysocki
2010-05-16 21:32 ` Nigel Cunningham
2010-05-17 2:22 ` Alan Stern
2010-05-17 7:45 ` Nigel Cunningham
2010-05-17 7:45 ` [linux-pm] " Nigel Cunningham
2010-05-17 20:35 ` Rafael J. Wysocki
2010-05-17 22:51 ` Nigel Cunningham
2010-05-17 22:51 ` [linux-pm] " Nigel Cunningham
2010-05-18 19:43 ` Rafael J. Wysocki
2010-05-18 19:43 ` [linux-pm] " Rafael J. Wysocki
2010-05-18 20:06 ` Alan Stern
2010-05-18 20:06 ` [linux-pm] " Alan Stern
2010-05-24 19:02 ` Pavel Machek
2010-05-24 21:21 ` Nigel Cunningham
2010-05-24 21:21 ` [linux-pm] " Nigel Cunningham
2010-05-24 19:02 ` Pavel Machek
2010-05-17 20:35 ` Rafael J. Wysocki
2010-05-17 2:22 ` Alan Stern
2010-05-16 21:32 ` Nigel Cunningham
2010-05-16 19:38 ` Rafael J. Wysocki
2010-05-16 7:49 ` Nigel Cunningham
2010-05-15 20:30 ` Rafael J. Wysocki
2010-05-13 21:54 ` Alan Stern
2010-05-13 21:44 ` Matt Reimer
2010-05-11 23:55 ` Matt Reimer
2010-03-04 19:26 ` Rafael J. Wysocki
2010-03-04 2:48 ` Alan Stern
2010-03-04 0:23 ` Rafael J. Wysocki
2010-03-04 13:53 ` Pavel Machek
2010-03-04 13:53 ` [linux-pm] " Pavel Machek
2010-06-04 11:20 ` Maxim Levitsky
2010-06-04 14:59 ` Alan Stern
2010-06-04 14:59 ` [linux-pm] " Alan Stern
2010-06-04 15:19 ` Maxim Levitsky
2010-06-04 17:52 ` Alan Stern
2010-06-04 17:52 ` Alan Stern
2010-06-04 15:19 ` Maxim Levitsky
2010-06-04 11:20 ` Maxim Levitsky
2010-03-01 15:23 ` Alan Stern
2010-03-01 6:35 ` Pavel Machek
2010-02-23 12:33 ` Jens Axboe
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