diff options
| author |   Eric Dumazet <edumazet@google.com> | 2018-04-16 10:33:36 -0700 |
|---|---|---|
| committer |   David S. Miller <davem@davemloft.net> | 2018-04-16 18:26:37 -0400 |
| commit | 796f82eafcd96629c2f9a0332dbb4f474854aaf8 (patch) | |
| tree | d758c4141548f9a997602c3beb25e1ca26bad54e /net/ipv4/tcp_input.c | |
| parent | tcp: fix SO_RCVLOWAT and RCVBUF autotuning (diff) | |
| download | linux-dev-796f82eafcd96629c2f9a0332dbb4f474854aaf8.tar.xz linux-dev-796f82eafcd96629c2f9a0332dbb4f474854aaf8.zip | |
tcp: fix delayed acks behavior for SO_RCVLOWAT
We should not delay acks if there are not enough bytes
in receive queue to satisfy SO_RCVLOWAT.
Since [E]POLLIN event is not going to be generated, there is little
hope for a delayed ack to be useful.
In fact, delaying ACK prevents sender from completing
the transfer.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/tcp_input.c')
| -rw-r--r-- | net/ipv4/tcp_input.c | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index 367def6ddeda..d854363a4387 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -5026,9 +5026,12 @@ static void __tcp_ack_snd_check(struct sock *sk, int ofo_possible) /* More than one full frame received... */ if (((tp->rcv_nxt - tp->rcv_wup) > inet_csk(sk)->icsk_ack.rcv_mss && /* ... and right edge of window advances far enough. - * (tcp_recvmsg() will send ACK otherwise). Or... + * (tcp_recvmsg() will send ACK otherwise). + * If application uses SO_RCVLOWAT, we want send ack now if + * we have not received enough bytes to satisfy the condition. */ - __tcp_select_window(sk) >= tp->rcv_wnd) || + (tp->rcv_nxt - tp->copied_seq < sk->sk_rcvlowat || + __tcp_select_window(sk) >= tp->rcv_wnd)) || /* We ACK each frame or... */ tcp_in_quickack_mode(sk) || /* We have out of order data. */ |