static void unix_write_space(struct sock *sk)
{
	struct socket_wq *wq;

	rcu_read_lock();
	if (unix_writable(sk)) {
		wq = rcu_dereference(sk->sk_wq);
		if (skwq_has_sleeper(wq))
			wake_up_interruptible_sync_poll(&wq->wait,
				EPOLLOUT | EPOLLWRNORM | EPOLLWRBAND);
		sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
	}
	rcu_read_unlock();
}
static void unix_write_space(struct sock *sk)
{
	struct socket_wq *wq;

	rcu_read_lock();
	if (unix_writable(sk)) {
		wq = rcu_dereference(sk->sk_wq);
		if (skwq_has_sleeper(wq))
			wake_up_interruptible_sync_poll(&wq->wait,
				EPOLLOUT | EPOLLWRNORM | EPOLLWRBAND);
		sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
	}
	rcu_read_unlock();
}