예제 #1
0
static void
autogroup_move_group(struct task_struct *p, struct autogroup *ag)
{
	struct autogroup *prev;
	struct task_struct *t;
	unsigned long flags;

	BUG_ON(!lock_task_sighand(p, &flags));

	prev = p->signal->autogroup;
	if (prev == ag) {
		unlock_task_sighand(p, &flags);
		return;
	}

	p->signal->autogroup = autogroup_kref_get(ag);
	/*
	 * We can't avoid sched_move_task() after we changed signal->autogroup,
	 * this process can already run with task_group() == prev->tg or we can
	 * race with cgroup code which can read autogroup = prev under rq->lock.
	 * In the latter case for_each_thread() can not miss a migrating thread,
	 * cpu_cgroup_attach() must not be possible after cgroup_exit() and it
	 * can't be removed from thread list, we hold ->siglock.
	 *
	 * If an exiting thread was already removed from thread list we rely on
	 * sched_autogroup_exit_task().
	 */
	for_each_thread(p, t)
		sched_move_task(t);

	unlock_task_sighand(p, &flags);
	autogroup_kref_put(prev);
}
예제 #2
0
static void
autogroup_move_group(struct task_struct *p, struct autogroup *ag)
{
	struct autogroup *prev;
	struct task_struct *t;
	unsigned long flags;

	BUG_ON(!lock_task_sighand(p, &flags));

	prev = p->signal->autogroup;
	if (prev == ag) {
		unlock_task_sighand(p, &flags);
		return;
	}

	p->signal->autogroup = autogroup_kref_get(ag);

	if (!ACCESS_ONCE(sysctl_sched_autogroup_enabled))
                goto out;

	t = p;
	do {
		sched_move_task(t);
	} while_each_thread(p, t);

out:
	unlock_task_sighand(p, &flags);
	autogroup_kref_put(prev);
}
예제 #3
0
void sched_autogroup_exit_task(struct task_struct *p)
{
	/*
	 * We are going to call exit_notify() and autogroup_move_group() can't
	 * see this thread after that: we can no longer use signal->autogroup.
	 * See the PF_EXITING check in task_wants_autogroup().
	 */
	sched_move_task(p);
}