Messages in this thread | | | Date | Tue, 27 Dec 2011 09:33:35 +0800 | From | Li Zefan <> | Subject | Re: [PATCH v2] cgroup: Remove task_lock() from cgroup_post_fork() |
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Tejun Heo wrote: > 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? >
Acked-by: Li Zefan <lizf@cn.fujitsu.com>
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