net: add scheduler sync hint to tcp_prequeue().

Decreases the odds wakee will suffer from frequent cache misses.

Signed-off-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/include/net/tcp.h b/include/net/tcp.h
index 56f0aec..75be5a2 100644 (file)
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -939,7 +939,7 @@ static inline int tcp_prequeue(struct sock *sk, struct sk_buff *skb)
 
                tp->ucopy.memory = 0;
        } else if (skb_queue_len(&tp->ucopy.prequeue) == 1) {
-               wake_up_interruptible_poll(sk->sk_sleep,
+               wake_up_interruptible_sync_poll(sk->sk_sleep,
                                           POLLIN | POLLRDNORM | POLLRDBAND);
                if (!inet_csk_ack_scheduled(sk))
                        inet_csk_reset_xmit_timer(sk, ICSK_TIME_DACK,