On 12/21, Frederic Weisbecker wrote: > > 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? Because it is not possible to wake it up. Please note that copy_process() creates the "deactivated" child, iow it is not on rq. But, at the same time its ->state == TASK_RUNNING. This "fools" try_to_wake_up() or anything else which in theory could place it on the runqueue. Except, of course, wake_up_new_task() does activate_task(). And note that it does this unconditionally, exactly because we know that this task can't be woken. Oleg. _______________________________________________ Containers mailing list Containers@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/containers
