LKML Archive on lore.kernel.org
help / color / mirror / Atom feed
From: Nigel Cunningham <ncunningham@crca.org.au>
To: Alan Stern <stern@rowland.harvard.edu>
Cc: linux-pm@lists.linux-foundation.org,
	linux-kernel@vger.kernel.org, Miklos Szeredi <miklos@szeredi.hu>
Subject: Re: [linux-pm] Freezer: Don't count threads waiting for frozen filesystems.
Date: Fri, 31 Oct 2008 08:44:20 +1100	[thread overview]
Message-ID: <1225403060.6574.10.camel@nigel-laptop> (raw)
In-Reply-To: <Pine.LNX.4.44L0.0810300955020.2401-100000@iolanthe.rowland.org>

Hi Alan.

On Thu, 2008-10-30 at 09:56 -0400, Alan Stern wrote:
> On Fri, 31 Oct 2008, Nigel Cunningham wrote:
> 
> > > Well yeah, your patch handles the straightforward cases.  But it
> > > doesn't help with the more tricky cases, where one fuse filesystem is
> > > using another, and as those may become more widespread, this approach
> > > will fail.
> > 
> > At the moment, yes. But it's not impossible for us to modify the patch
> > to handle that as well.
> 
> It depends on what you mean.  The most direct reading of your statement
> is simply wrong: It is _theoretically_ impossible to find the correct
> order for freezing filesystems.  To do so would be equivalent to
> solving the halting problem.

I'm not sure that's true. You see, I'm thinking of this as not that
different to the problem of unmounting filesystems. There, too, we need
to unmount in a particular order, and let transactions on each
filesystem stop cleanly before we can unmount them. Even if there are
differences, perhaps looking at how we handle unmounting will help with
handling freezing.

Regards,

Nigel


  reply	other threads:[~2008-10-30 21:44 UTC|newest]

Thread overview: 59+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <1224886068.6478.21.camel@nigel-laptop>
2008-10-26 20:01 ` Rafael J. Wysocki
2008-10-27 11:12   ` Miklos Szeredi
2008-10-27 11:20     ` Nigel Cunningham
2008-10-27 11:37       ` Rafael J. Wysocki
2008-10-27 11:40         ` Nigel Cunningham
2008-10-27 12:38           ` Miklos Szeredi
2008-10-27 20:59             ` Nigel Cunningham
2008-10-27 21:09               ` Miklos Szeredi
2008-10-27 22:13                 ` Nigel Cunningham
2008-10-28 20:25                   ` Miklos Szeredi
2008-10-28 21:29                     ` Nigel Cunningham
2008-10-28 21:51                       ` Miklos Szeredi
2008-10-28 22:00                         ` Rafael J. Wysocki
2008-10-28 22:02                           ` Miklos Szeredi
2008-10-28 22:21                             ` Rafael J. Wysocki
2008-10-28 23:21                               ` Miklos Szeredi
2008-10-28 23:59                                 ` Rafael J. Wysocki
2008-10-29  8:10                                   ` Miklos Szeredi
2008-10-29 13:51                                     ` Alan Stern
2008-10-29 14:50                                       ` Miklos Szeredi
2008-10-29 15:28                                         ` Alan Stern
2008-10-29 15:50                                           ` Miklos Szeredi
2008-10-29 16:17                                             ` Alan Stern
2008-10-29 16:10                                           ` Miklos Szeredi
2008-10-29 20:37                                             ` Alan Stern
2008-10-29 21:11                                               ` Rafael J. Wysocki
2008-10-29 21:45                                                 ` Nigel Cunningham
2008-10-29 22:07                                                   ` Rafael J. Wysocki
2008-10-29 23:53                                                     ` Miklos Szeredi
2008-11-09 13:44                                                       ` Pavel Machek
2008-10-29 23:48                                                   ` Miklos Szeredi
2008-10-30 13:04                                                     ` Nigel Cunningham
2008-10-30 13:56                                                       ` Alan Stern
2008-10-30 21:44                                                         ` Nigel Cunningham [this message]
2008-10-31  8:49                                                           ` Miklos Szeredi
2008-10-31  9:10                                                             ` Nigel Cunningham
2008-10-31  9:16                                                               ` Miklos Szeredi
2008-10-31 11:28                                                                 ` Nigel Cunningham
2008-10-31 12:44                                                                   ` Miklos Szeredi
2008-10-31 21:11                                                                     ` Nigel Cunningham
2008-10-29 23:43                                               ` Miklos Szeredi
2008-10-30 13:54                                                 ` Alan Stern
2008-10-30 14:39                                                   ` Miklos Szeredi
2008-10-30 17:07                                                     ` Alan Stern
2008-10-30 17:43                                                       ` Miklos Szeredi
2008-10-30 20:17                                                     ` Rafael J. Wysocki
2008-11-15 16:58                                                     ` Pavel Machek
2008-10-29 23:56                                               ` Matthew Garrett
2008-10-28 22:03                         ` Nigel Cunningham
2008-10-28 23:04                     ` Nigel Cunningham
2008-10-28 23:12                       ` Miklos Szeredi
2008-10-28 23:17                         ` Nigel Cunningham
2008-10-28 23:24                           ` Miklos Szeredi
2008-10-28 23:41                             ` Nigel Cunningham
2008-10-28 23:45                               ` Miklos Szeredi
2008-10-28 23:50                                 ` Miklos Szeredi
2008-10-28 23:58                                   ` Nigel Cunningham
2008-10-28 23:54                                 ` Nigel Cunningham
2008-10-27 11:37       ` Miklos Szeredi

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=1225403060.6574.10.camel@nigel-laptop \
    --to=ncunningham@crca.org.au \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-pm@lists.linux-foundation.org \
    --cc=miklos@szeredi.hu \
    --cc=stern@rowland.harvard.edu \
    --subject='Re: [linux-pm] Freezer: Don'\''t count threads waiting for frozen filesystems.' \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).