From: Cong Wang <amwang@redhat.com>
To: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: linux-kernel@vger.kernel.org, Tejun Heo <tj@kernel.org>,
Greg Kroah-Hartman <gregkh@suse.de>,
Peter Zijlstra <peterz@infradead.org>,
Miles Lane <miles.lane@gmail.com>,
Heiko Carstens <heiko.carstens@de.ibm.com>,
Benjamin Herrenschmidt <benh@kernel.crashing.org>,
Larry Finger <Larry.Finger@lwfinger.net>,
akpm@linux-foundation.org
Subject: Re: [Patch v2] sysfs: add lockdep class support to s_active
Date: Fri, 05 Feb 2010 17:37:00 +0800 [thread overview]
Message-ID: <4B6BE6BC.4070506@redhat.com> (raw)
In-Reply-To: <m1iqachx8k.fsf@fess.ebiederm.org>
Eric W. Biederman wrote:
> Amerigo Wang <amwang@redhat.com> writes:
>
>> Recently we met a lockdep warning from sysfs during s2ram or cpu hotplug.
>> As reported by several people, it is something like:
>
> The interesting case is the cpu hotplug is actually a problem. It isn't
> useful to get a complaint about the non-problems code paths triggered
> by pm. However my earlier review spotted a real deadlock case. Where
> in one of the sysfs attributes we iterate over the list of online cpus
> and that appeared to an attribute that removing a cpu would remove
> from sysfs...
>
You are referring this one:
http://marc.info/?l=linux-kernel&m=126474021428905&w=2
?
Hmm, yeah, I missed that the lock it is holding is not s_active, thus so
not be the case we are trying to fix here.
Thanks for pointing this out.
next prev parent reply other threads:[~2010-02-05 9:34 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-02-05 6:42 [Patch v2] sysfs: add lockdep class support to s_active Amerigo Wang
2010-02-05 7:09 ` Xiaotian Feng
2010-02-05 7:27 ` Cong Wang
2010-02-05 9:39 ` Eric W. Biederman
2010-02-05 9:48 ` Cong Wang
2010-02-05 10:00 ` Xiaotian Feng
2010-02-08 3:12 ` Cong Wang
2010-02-05 8:57 ` Eric W. Biederman
2010-02-05 9:29 ` Cong Wang
2010-02-05 9:01 ` Eric W. Biederman
2010-02-05 9:37 ` Cong Wang [this message]
2010-02-05 9:59 ` Eric W. Biederman
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