Messages in this thread | | | Date | Fri, 23 Dec 2011 15:00:13 -0800 | From | Tejun Heo <> | Subject | Re: [PATCH v2] cgroup: Remove task_lock() from cgroup_post_fork() |
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On Fri, Dec 23, 2011 at 04:25:23AM +0100, Frederic Weisbecker wrote: > cgroup_post_fork() is protected between threadgroup_change_begin() > and threadgroup_change_end() against concurrent changes of the > child's css_set in cgroup_task_migrate(). Also the child can't > exit and call cgroup_exit() at this stage, this means it's css_set > can't be changed with init_css_set concurrently. > > For these reasons, we don't need to hold task_lock() on the child > because it's css_set can only remain stable in this place. > > Let's remove the lock there. > > v2: Update comment to explain that we are safe against > cgroup_exit() > > Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> > Cc: Li Zefan <lizf@cn.fujitsu.com> > Cc: Tejun Heo <tj@kernel.org> > Cc: Containers <containers@lists.linux-foundation.org> > Cc: Cgroups <cgroups@vger.kernel.org> > Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> > Cc: Oleg Nesterov <oleg@redhat.com> > Cc: Andrew Morton <akpm@linux-foundation.org> > Cc: Paul Menage <paul@paulmenage.org> > Cc: Mandeep Singh Baines <msb@chromium.org>
Li, does this look good to you?
Thanks.
-- tejun
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