From: Pavel Machek <pavel@ucw.cz>
To: Colin Cross <ccross@android.com>
Cc: linux-kernel@vger.kernel.org, "Rafael J. Wysocki" <rjw@sisk.pl>,
Peter Zijlstra <peterz@infradead.org>,
Ingo Molnar <mingo@redhat.com>,
Andrew Morton <akpm@linux-foundation.org>,
Mandeep Singh Baines <msb@chromium.org>,
Oleg Nesterov <oleg@redhat.com>,
linux-nfs@vger.kernel.org, linux-pm@vger.kernel.org,
netdev@vger.kernel.org,
Linus Torvalds <torvalds@linux-foundation.org>,
Tejun Heo <tj@kernel.org>, Ben Chan <benchan@chromium.org>,
Len Brown <len.brown@intel.com>
Subject: Re: [PATCH v3 04/16] lockdep: check that no locks held at freeze time
Date: Tue, 7 May 2013 14:29:07 +0200 [thread overview]
Message-ID: <20130507122906.GC2585@elf.ucw.cz> (raw)
In-Reply-To: <1367884221-20462-5-git-send-email-ccross@android.com>
On Mon 2013-05-06 16:50:09, Colin Cross wrote:
> From: Mandeep Singh Baines <msb@chromium.org>
>
> We shouldn't try_to_freeze if locks are held. Holding a lock can cause a
> deadlock if the lock is later acquired in the suspend or hibernate path
> (e.g. by dpm). Holding a lock can also cause a deadlock in the case of
> cgroup_freezer if a lock is held inside a frozen cgroup that is later
> acquired by a process outside that group.
>
> History:
> This patch was originally applied as 6aa9707099c and reverted in
> dbf520a9d7d4 because NFS was freezing with locks held. It was
> deemed better to keep the bad freeze point in NFS to allow laptops
> to suspend consistently. The previous patch in this series converts
> NFS to call _unsafe versions of the freezable helpers so that
> lockdep doesn't complain about them until a more correct fix
> can be applied.
>
> [akpm@linux-foundation.org: export debug_check_no_locks_held]
> Signed-off-by: Mandeep Singh Baines <msb@chromium.org>
> Cc: Ben Chan <benchan@chromium.org>
> Cc: Oleg Nesterov <oleg@redhat.com>
> Cc: Tejun Heo <tj@kernel.org>
> Cc: Rafael J. Wysocki <rjw@sisk.pl>
> Cc: Ingo Molnar <mingo@redhat.com>
> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
> [ccross@android.com: don't warn if try_to_freeze_unsafe is called]
> Signed-off-by: Colin Cross <ccross@android.com>
Acked-by: Pavel Machek <pavel@ucw.cz>
--
(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:[~2013-05-07 12:29 UTC|newest]
Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-05-06 23:50 [PATCH v2 00/10] optimize freezing tasks by reducing task wakeups Colin Cross
2013-05-06 23:50 ` [PATCH v3 01/16] freezer: add unsafe versions of freezable helpers for NFS Colin Cross
2013-05-06 23:50 ` [PATCH v3 02/16] freezer: add unsafe versions of freezable helpers for CIFS Colin Cross
2013-05-07 10:07 ` Jeff Layton
2013-05-07 17:47 ` Colin Cross
2013-05-07 17:52 ` [PATCH v4 " Colin Cross
2013-05-07 18:11 ` Jeff Layton
2013-05-07 12:28 ` [PATCH v3 " Pavel Machek
2013-05-06 23:50 ` [PATCH v3 03/16] lockdep: remove task argument from debug_check_no_locks_held Colin Cross
2013-05-07 12:28 ` Pavel Machek
2013-05-06 23:50 ` [PATCH v3 04/16] lockdep: check that no locks held at freeze time Colin Cross
2013-05-07 12:29 ` Pavel Machek [this message]
2013-05-06 23:50 ` [PATCH v3 05/16] freezer: shorten freezer sleep time using exponential backoff Colin Cross
2013-05-06 23:50 ` [PATCH v3 06/16] freezer: skip waking up tasks with PF_FREEZER_SKIP set Colin Cross
2013-05-06 23:50 ` [PATCH v3 07/16] freezer: convert freezable helpers to freezer_do_not_count() Colin Cross
2013-05-06 23:50 ` [PATCH v3 08/16] freezer: convert freezable helpers to static inline where possible Colin Cross
2013-05-06 23:50 ` [PATCH v3 09/16] freezer: add new freezable helpers using freezer_do_not_count() Colin Cross
2013-05-06 23:50 ` [PATCH v3 10/16] binder: use freezable blocking calls Colin Cross
2013-05-06 23:50 ` [PATCH v3 11/16] epoll: use freezable blocking call Colin Cross
2013-05-06 23:50 ` [PATCH v3 12/16] select: " Colin Cross
2013-05-06 23:50 ` [PATCH v3 13/16] futex: " Colin Cross
2013-07-22 23:02 ` 3.11-rc regression bisected: s2disk does not work (was Re: [PATCH v3 13/16] futex: use freezable blocking call) Michael Leun
2013-07-22 23:55 ` Colin Cross
2013-07-23 0:32 ` Linus Torvalds
2013-07-23 0:42 ` Colin Cross
2013-07-23 1:41 ` Rafael J. Wysocki
2013-07-23 6:28 ` Colin Cross
2013-07-23 20:31 ` Colin Cross
2013-07-23 21:58 ` Michael Leun
2013-07-23 18:08 ` Michael Leun
2013-07-23 18:24 ` Darren Hart
2013-07-23 18:29 ` Colin Cross
2013-07-23 19:16 ` Michael Leun
2013-07-23 19:29 ` Colin Cross
2013-07-23 19:58 ` Michael Leun
2013-07-23 21:43 ` Rafael J. Wysocki
2013-07-23 0:26 ` Pavel Machek
2013-05-06 23:50 ` [PATCH v3 14/16] nanosleep: use freezable blocking call Colin Cross
2013-05-06 23:50 ` [PATCH v3 15/16] sigtimedwait: " Colin Cross
2013-05-06 23:50 ` [PATCH v3 16/16] af_unix: use freezable blocking calls in read Colin Cross
2013-05-07 18:12 ` [PATCH v2 00/10] optimize freezing tasks by reducing task wakeups Tejun Heo
2013-05-08 0:02 ` Rafael J. Wysocki
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=20130507122906.GC2585@elf.ucw.cz \
--to=pavel@ucw.cz \
--cc=akpm@linux-foundation.org \
--cc=benchan@chromium.org \
--cc=ccross@android.com \
--cc=len.brown@intel.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-nfs@vger.kernel.org \
--cc=linux-pm@vger.kernel.org \
--cc=mingo@redhat.com \
--cc=msb@chromium.org \
--cc=netdev@vger.kernel.org \
--cc=oleg@redhat.com \
--cc=peterz@infradead.org \
--cc=rjw@sisk.pl \
--cc=tj@kernel.org \
--cc=torvalds@linux-foundation.org \
/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
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
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).