On Wed, Apr 16, 2008 at 9:11 PM, Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> wrote: > > I don't fully understand the race. Both paths hold css_set_lock. > > Can you describe it in more detail please? Task A starts exiting, passes the check for unlinking current->cg_list. Before it completely exits task B does the very first cgroup_iter_begin() call (via reading a cgroups tasks file) which links all tasks in to their css_set objects via tsk->cg_list. Then task A finishes exiting and is freed, but doesn't unlink from the cg_list. > > afacit the task at *p could set PF_EXITING immediately after this code has > tested PF_EXITING and then the task at *p could proceed until we hit the > same race (whatever that is). The important fact there is that the task sets PF_EXITING *before* it checks whether it needs to unlink from current->cg_list. Paul _______________________________________________ Containers mailing list Containers@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/containers