The attached patch adds the can_wait_task() and
can_wait_task_ptrace() functions by splitting out the
checks from wait_consider_task().

		int ret = wait_consider_task(wo, 0, p);

gets then replaced by

		ret = can_wait_task(wo, p);
		if (!ret)
			continue;
		ret = wait_consider_task(wo, 0, p);