net: remove sock_poll_busy_loop

There is no point in hiding this logic in a helper.  Also remove the
useless events != 0 check and only busy loop once we know we actually
have a poll method.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/busy_poll.h

@@ -121,15 +121,6 @@ static inline void sk_busy_loop(struct sock *sk, int nonblock)
 #endif
 }
 
-static inline void sock_poll_busy_loop(struct socket *sock, __poll_t events)
-{
-	if (sk_can_busy_loop(sock->sk) &&
-	    events && (events & POLL_BUSY_LOOP)) {
-		/* once, only if requested by syscall */
-		sk_busy_loop(sock->sk, 1);
-	}
-}
-
 /* if this socket can poll_ll, tell the system call */
 static inline __poll_t sock_poll_busy_flag(struct socket *sock)
 {

net/socket.c

@@ -1132,9 +1132,12 @@ static __poll_t sock_poll(struct file *file, poll_table *wait)
 	struct socket *sock = file->private_data;
 	__poll_t events = poll_requested_events(wait);
 
-	sock_poll_busy_loop(sock, events);
 	if (!sock->ops->poll)
 		return 0;
+
+	/* poll once if requested by the syscall */
+	if (sk_can_busy_loop(sock->sk) && (events & POLL_BUSY_LOOP))
+		sk_busy_loop(sock->sk, 1);
 	return sock->ops->poll(file, sock, wait) | sock_poll_busy_flag(sock);
 }