static int io_req_task_work_add(struct io_kiocb *req, struct callback_head *cb)
{
	struct task_struct *tsk = req->task;
	struct io_ring_ctx *ctx = req->ctx;
	int ret, notify;

	/*
	 * SQPOLL kernel thread doesn't need notification, just a wakeup. For
	 * all other cases, use TWA_SIGNAL unconditionally to ensure we're
	 * processing task_work. There's no reliable way to tell if TWA_RESUME
	 * will do the job.
	 */
	notify = 0;
	if (!(ctx->flags & IORING_SETUP_SQPOLL))
		notify = TWA_SIGNAL;

	ret = task_work_add(tsk, cb, notify);
	if (!ret)
		wake_up_process(tsk);

	return ret;
}
static int io_req_task_work_add(struct io_kiocb *req, struct callback_head *cb)
{
	struct task_struct *tsk = req->task;
	struct io_ring_ctx *ctx = req->ctx;
	int ret, notify;

	 
	notify = 0;
	if (!(ctx->flags & IORING_SETUP_SQPOLL))
		notify = TWA_SIGNAL;

	ret = task_work_add(tsk, cb, notify);
	if (!ret)
		wake_up_process(tsk);

	return ret;
}