From: Sasha Levin <sasha.levin@oracle.com>
To: Tejun Heo <tj@kernel.org>
Cc: lizefan@huawei.com, containers@lists.linux-foundation.org,
cgroups@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] cgroup: missing rcu read lock around task_css_set
Date: Mon, 03 Mar 2014 17:48:19 -0500 [thread overview]
Message-ID: <531506B3.5030004@oracle.com> (raw)
In-Reply-To: <20140303224505.GE26523@mtj.dyndns.org>
On 03/03/2014 05:45 PM, Tejun Heo wrote:
> On Mon, Mar 03, 2014 at 05:43:11PM -0500, Sasha Levin wrote:
>> On 03/03/2014 05:33 PM, Tejun Heo wrote:
>>> On Sat, Mar 01, 2014 at 10:00:11PM -0500, Sasha Levin wrote:
>>>> rcu read lock should be held when calling and working with task_css_set.
>>>>
>>>> This patch also fixes a related lockdep warning.
>>>
>>> Hmmm... PF_EXITING should be visible at that point and cset can't
>>> change anymore. We prolly need to update lockdep annotation rather
>>> than adding spurious rcu locking around it. Against which branch is
>>> it? Can you please post the lockdep warning?
>>
>> I see it on -next.
>
> I think the right thing to do is using task_css_set_check() with
> PF_EXITING check and add comment explaining that cset can no longer
> change. Can you please write up a patch?
Sure!
Thanks,
Sasha
next prev parent reply other threads:[~2014-03-03 22:48 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-03-02 3:00 [PATCH] cgroup: missing rcu read lock around task_css_set Sasha Levin
[not found] ` <1393729211-937-1-git-send-email-sasha.levin-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org>
2014-03-03 22:33 ` Tejun Heo
[not found] ` <20140303223327.GB26523-9pTldWuhBndy/B6EtB590w@public.gmane.org>
2014-03-03 22:43 ` Sasha Levin
[not found] ` <5315057F.3030602-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org>
2014-03-03 22:45 ` Tejun Heo
2014-03-03 22:48 ` Sasha Levin [this message]
[not found] ` <20140303224505.GE26523-9pTldWuhBndy/B6EtB590w@public.gmane.org>
2014-03-03 23:00 ` Sasha Levin
[not found] ` <53150989.70307-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org>
2014-03-04 17:20 ` Sasha Levin
[not found] ` <53160B6D.8020501-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org>
2014-03-04 19:47 ` Tejun Heo
[not found] ` <20140304194741.GA2204-Gd/HAXX7CRxy/B6EtB590w@public.gmane.org>
2014-03-05 0:57 ` Li Zefan
[not found] ` <53167662.5000801-hv44wF8Li93QT0dZR+AlfA@public.gmane.org>
2014-03-27 15:35 ` Sasha Levin
[not found] ` <5334452D.4080200-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org>
2014-03-28 2:48 ` Li Zefan
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