Re: Q: cgroup: Questions about possible issues in cgroup locking

[Frederic Weisbecker]

On Wed, Dec 21, 2011 at 02:08:48PM +0100, Oleg Nesterov wrote:
> On 12/21, Frederic Weisbecker wrote:
> > - By the time we call cgroup_post_fork(), it is ready to be woken up
> > and usable by the scheduler.
> 
> No, the new child can't run until do_fork()->wake_up_new_task().

Out of curiosity, why is it not possible for a task to kill and wake up the child
before that happens?

Understanding that could potentially let us remove the task_lock() in cgroup_post_fork()
(although I need to examine that more deeply).

Thanks!
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