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@xxxxxxxxx> > Cc: Li Zefan <lizf@xxxxxxxxxxxxxx> > Cc: Tejun Heo <tj@xxxxxxxxxx> > Cc: Containers <containers@xxxxxxxxxxxxxxxxxxxxxxxxxx> > Cc: Cgroups <cgroups@xxxxxxxxxxxxxxx> > Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx> > Cc: Oleg Nesterov <oleg@xxxxxxxxxx> > Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> > Cc: Paul Menage <paul@xxxxxxxxxxxxxx> > Cc: Mandeep Singh Baines <msb@xxxxxxxxxxxx> Applied to cgroup/for-3.3. Thank you. -- tejun -- To unsubscribe from this list: send the line "unsubscribe cgroups" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
