On Wed, Dec 21, 2011 at 08:03:19PM +0100, Frederic Weisbecker wrote:

We don't need to hold the parent task_lock() on the
parent in cgroup_fork() because we are already synchronized
against the two places that may change the parent css_set
concurrently:

- cgroup_exit(), but the parent obviously can't exit concurrently
- cgroup migration: we are synchronized against threadgroup_lock()

So we can safely remove the task_lock() there.

Signed-off-by: Frederic Weisbecker <redacted>
Cc: Tejun Heo <redacted>
Cc: Li Zefan <redacted>
Cc: Containers <redacted>
Cc: Cgroups <redacted>
Cc: KAMEZAWA Hiroyuki <redacted>
Cc: Oleg Nesterov <redacted>
Cc: Andrew Morton <akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org>
Cc: Paul Menage <redacted>
Cc: Mandeep Singh Baines <redacted>

Applied both patches to cgroup/for-3.3 and pushed out to linux-next.

Thank you.

-- 
tejun