diff --git a/kernel/cgroup.c b/kernel/cgroup.c index 771d1b8aaae9..8ab800c7bac0 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -1331,9 +1331,13 @@ static void cgroup_enable_task_cg_lists(void) * We should check if the process is exiting, otherwise * it will race with cgroup_exit() in that the list * entry won't be deleted though the process has exited. + * Do it while holding siglock so that we don't end up + * racing against cgroup_exit(). */ + spin_lock_irq(&p->sighand->siglock); if (!(p->flags & PF_EXITING)) list_add(&p->cg_list, &task_css_set(p)->tasks); + spin_unlock_irq(&p->sighand->siglock); task_unlock(p); } while_each_thread(g, p); @@ -3968,16 +3972,12 @@ static int __init cgroup_wq_init(void) /* * There isn't much point in executing destruction path in * parallel. Good chunk is serialized with cgroup_mutex anyway. - * - * XXX: Must be ordered to make sure parent is offlined after - * children. The ordering requirement is for memcg where a - * parent's offline may wait for a child's leading to deadlock. In - * the long term, this should be fixed from memcg side. + * Use 1 for @max_active. * * We would prefer to do this in cgroup_init() above, but that * is called before init_workqueues(): so leave this until after. */ - cgroup_destroy_wq = alloc_ordered_workqueue("cgroup_destroy", 0); + cgroup_destroy_wq = alloc_workqueue("cgroup_destroy", 0, 1); BUG_ON(!cgroup_destroy_wq); /*