diff options
| author | Yuchung Cheng <ycheng@google.com> | 2012-05-02 17:30:04 +0400 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2012-05-03 04:56:10 +0400 |
| commit | 750ea2bafa55aaed208b2583470ecd7122225634 (patch) | |
| tree | 7656d7697566b0cecc7fbbdd8dbae288bca6d7e3 /net/ipv4/tcp_timer.c | |
| parent | eed530b6c67624db3f2cf477bac7c4d005d8f7ba (diff) | |
| download | linux-750ea2bafa55aaed208b2583470ecd7122225634.tar.xz | |
tcp: early retransmit: delayed fast retransmit
Implementing the advanced early retransmit (sysctl_tcp_early_retrans==2).
Delays the fast retransmit by an interval of RTT/4. We borrow the
RTO timer to implement the delay. If we receive another ACK or send
a new packet, the timer is cancelled and restored to original RTO
value offset by time elapsed. When the delayed-ER timer fires,
we enter fast recovery and perform fast retransmit.
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/tcp_timer.c')
| -rw-r--r-- | net/ipv4/tcp_timer.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/net/ipv4/tcp_timer.c b/net/ipv4/tcp_timer.c index 34d4a02c2f16..e911e6c523ec 100644 --- a/net/ipv4/tcp_timer.c +++ b/net/ipv4/tcp_timer.c @@ -319,6 +319,11 @@ void tcp_retransmit_timer(struct sock *sk) struct tcp_sock *tp = tcp_sk(sk); struct inet_connection_sock *icsk = inet_csk(sk); + if (tp->early_retrans_delayed) { + tcp_resume_early_retransmit(sk); + return; + } + if (!tp->packets_out) goto out; |