From: Andrew Morton <akpm@linux-foundation.org>
To: Mandeep Singh Baines <msb@chromium.org>
Cc: linux-kernel@vger.kernel.org, Ingo Molnar <mingo@redhat.com>,
Oleg Nesterov <oleg@redhat.com>, Tejun Heo <tj@kernel.org>,
"Rafael J. Wysocki" <rjw@sisk.pl>
Subject: Re: [PATCH v6] lockdep: check that no locks held at freeze time
Date: Thu, 21 Feb 2013 13:42:27 -0800 [thread overview]
Message-ID: <20130221134227.33679567.akpm@linux-foundation.org> (raw)
In-Reply-To: <1361465501-19744-1-git-send-email-msb@chromium.org>
On Thu, 21 Feb 2013 08:51:41 -0800
Mandeep Singh Baines <msb@chromium.org> wrote:
> 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.
>
> ...
>
> --- a/include/linux/freezer.h
> +++ b/include/linux/freezer.h
>
> ...
>
> @@ -43,6 +44,8 @@ extern void thaw_kernel_threads(void);
>
> static inline bool try_to_freeze(void)
> {
> + if (!(current->flags & PF_NOFREEZE))
> + debug_check_no_locks_held();
> might_sleep();
> if (likely(!freezing(current)))
> return false;
>
> ...
>
It still needs
http://ozlabs.org/~akpm/mmots/broken-out/lockdep-check-that-no-locks-held-at-freeze-time-fix.patch
next prev parent reply other threads:[~2013-02-21 21:42 UTC|newest]
Thread overview: 45+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-02-16 9:53 [PATCH 1/5] vfork: don't freezer_count() for in-kernel users of CLONE_VFORK Mandeep Singh Baines
2013-02-16 9:53 ` [PATCH 2/5] lockdep: check that no locks held at freeze time Mandeep Singh Baines
2013-02-16 17:06 ` Oleg Nesterov
2013-02-20 1:57 ` [PATCH v3] " Mandeep Singh Baines
2013-02-20 10:37 ` Ingo Molnar
2013-02-20 12:55 ` Rafael J. Wysocki
2013-02-20 13:52 ` Ingo Molnar
2013-02-20 22:30 ` Oleg Nesterov
2013-02-20 23:11 ` Mandeep Singh Baines
2013-02-20 23:17 ` [PATCH v4] " Mandeep Singh Baines
2013-02-20 23:24 ` Andrew Morton
2013-02-21 0:17 ` Mandeep Singh Baines
2013-02-21 0:20 ` Andrew Morton
2013-02-21 0:28 ` Mandeep Singh Baines
2013-02-21 0:42 ` Andrew Morton
2013-02-21 3:19 ` Mandeep Singh Baines
2013-02-21 3:17 ` [PATCH v5] " Mandeep Singh Baines
2013-02-21 15:42 ` Rafael J. Wysocki
2013-02-21 16:24 ` Mandeep Singh Baines
2013-02-21 16:51 ` [PATCH v6] " Mandeep Singh Baines
2013-02-21 21:42 ` Andrew Morton [this message]
2013-02-21 21:57 ` Mandeep Singh Baines
2013-02-16 9:53 ` [PATCH 3/5] coredump: use a freezable_schedule for the coredump_finish wait Mandeep Singh Baines
2013-02-16 17:17 ` Oleg Nesterov
2013-02-16 9:53 ` [PATCH 4/5] freezer: clear fake signal on exit from __refrigerator Mandeep Singh Baines
2013-02-16 17:06 ` Oleg Nesterov
2013-02-16 17:12 ` Oleg Nesterov
2013-02-20 18:09 ` Mandeep Singh Baines
2013-02-23 19:41 ` Oleg Nesterov
2013-02-23 19:59 ` Oleg Nesterov
2013-02-16 9:53 ` [PATCH 5/5] coredump: ignore non-fatal signals when core dumping to a pipe Mandeep Singh Baines
2013-02-16 17:10 ` Oleg Nesterov
2013-02-16 19:46 ` Oleg Nesterov
2013-02-18 23:55 ` Mandeep Singh Baines
2013-02-19 14:18 ` Oleg Nesterov
2013-02-19 5:19 ` Mandeep Singh Baines
2013-02-19 14:27 ` Oleg Nesterov
2013-02-19 19:33 ` Mandeep Singh Baines
2013-02-19 19:45 ` Oleg Nesterov
2013-02-19 20:20 ` Mandeep Singh Baines
2013-02-20 23:30 ` Mandeep Singh Baines
2013-02-23 19:21 ` Oleg Nesterov
2013-02-16 17:05 ` [PATCH 1/5] vfork: don't freezer_count() for in-kernel users of CLONE_VFORK Oleg Nesterov
2013-02-20 0:07 ` Mandeep Singh Baines
2013-02-20 1:41 ` Mandeep Singh Baines
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=20130221134227.33679567.akpm@linux-foundation.org \
--to=akpm@linux-foundation.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@redhat.com \
--cc=msb@chromium.org \
--cc=oleg@redhat.com \
--cc=rjw@sisk.pl \
--cc=tj@kernel.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
all inboxes | Powered by JetHome®