Commit 29fbc26e authored by Eric Dumazet's avatar Eric Dumazet Committed by David S. Miller
Browse files

tcp: do not call tcp_cleanup_rbuf() if we have a backlog 



Under pressure, tcp recvmsg() has logic to process the socket backlog,
but calls tcp_cleanup_rbuf() right before.

Avoiding sending ACK right before processing new segments makes
a lot of sense, as this decrease the number of ACK packets,
with no impact on effective ACK clocking.

Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 8bd172b7

net/ipv4/tcp.c

+1 −2
Original line number Diff line number Diff line
@@ -2436,12 +2436,11 @@ static int tcp_recvmsg_locked(struct sock *sk, struct msghdr *msg, size_t len, 
			}

		}



		tcp_cleanup_rbuf(sk, copied);



		if (copied >= target) {

			/* Do not sleep, just process backlog. */

			__sk_flush_backlog(sk);

		} else {

			tcp_cleanup_rbuf(sk, copied);

			sk_defer_free_flush(sk);

			sk_wait_data(sk, &timeo, last);

		}