tcp: tcp_prequeue() can use keyed wakeups

We can avoid waking up tasks not interested in receive notifications,
using wake_up_interruptible_poll() instead of wake_up_interruptible()

Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 2 insertions, 1 deletions

diff --git a/include/net/tcp.h b/include/net/tcp.h
index ac37228b7001..87d210bb12a4 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -908,7 +908,8 @@ 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(sk->sk_sleep);
+                wake_up_interruptible_poll(sk->sk_sleep,
+                                           POLLIN | POLLRDNORM | POLLRDBAND);
                 if (!inet_csk_ack_scheduled(sk))
                         inet_csk_reset_xmit_timer(sk, ICSK_TIME_DACK,
                                                   (3 * TCP_RTO_MIN) / 4,