[PATCH cgroup/for-3.7-fixes 1/2] Revert "cgroup: Remove task_lock() from cgroup_post_fork()"

Li Zefan lizefan at huawei.com
Fri Oct 19 08:51:02 UTC 2012


On 2012/10/19 8:59, Tejun Heo wrote:
>>From d935a5d6832a264ce52f4257e176f4f96cbaf048 Mon Sep 17 00:00:00 2001
> From: Tejun Heo <tj at kernel.org>
> Date: Thu, 18 Oct 2012 17:40:30 -0700
> 
> This reverts commit 7e3aa30ac8c904a706518b725c451bb486daaae9.
> 
> The commit incorrectly assumed that fork path always performed
> threadgroup_change_begin/end() and depended on that for
> synchronization against task exit and cgroup migration paths instead
> of explicitly grabbing task_lock().
> 
> threadgroup_change is not locked when forking a new process (as
> opposed to a new thread in the same process) and even if it were it
> wouldn't be effective as different processes use different threadgroup
> locks.
> 
> Revert the incorrect optimization.
> 
> Signed-off-by: Tejun Heo <tj at kernel.org>
> LKML-Reference: <20121008020000.GB2575 at localhost>
> Cc: Frederic Weisbecker <fweisbec at gmail.com>
> Cc: Li Zefan <lizefan at huawei.com>
> Cc: stable at vger.kernel.org

Acked-by: Li Zefan <lizefan at huawei.com>



More information about the Containers mailing list