diff options
| author | Yuchung Cheng <ycheng@google.com> | 2017-01-12 22:11:39 -0800 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2017-01-13 22:37:16 -0500 |
| commit | bec41a11dd3dc8c54f766b4f494140ca92ba7c10 (patch) | |
| tree | 62a888654cc55636c2ab85adf331db2361aae118 /net/ipv4/tcp_output.c | |
| parent | 840a3cbe89694fad75578856976f180e852e69aa (diff) | |
| download | linux-bec41a11dd3dc8c54f766b4f494140ca92ba7c10.tar.bz2 | |
tcp: remove early retransmit
This patch removes the support of RFC5827 early retransmit (i.e.,
fast recovery on small inflight with <3 dupacks) because it is
subsumed by the new RACK loss detection. More specifically when
RACK receives DUPACKs, it'll arm a reordering timer to start fast
recovery after a quarter of (min)RTT, hence it covers the early
retransmit except RACK does not limit itself to specific inflight
or dupack numbers.
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/tcp_output.c')
| -rw-r--r-- | net/ipv4/tcp_output.c | 11 |
1 files changed, 4 insertions, 7 deletions
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index 6327e4d368a4..9a1a1494b9dd 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -76,10 +76,8 @@ static void tcp_event_new_data_sent(struct sock *sk, const struct sk_buff *skb) tp->snd_nxt = TCP_SKB_CB(skb)->end_seq; tp->packets_out += tcp_skb_pcount(skb); - if (!prior_packets || icsk->icsk_pending == ICSK_TIME_EARLY_RETRANS || - icsk->icsk_pending == ICSK_TIME_LOSS_PROBE) { + if (!prior_packets || icsk->icsk_pending == ICSK_TIME_LOSS_PROBE) tcp_rearm_rto(sk); - } NET_ADD_STATS(sock_net(sk), LINUX_MIB_TCPORIGDATASENT, tcp_skb_pcount(skb)); @@ -2289,8 +2287,6 @@ bool tcp_schedule_loss_probe(struct sock *sk) u32 timeout, tlp_time_stamp, rto_time_stamp; u32 rtt = usecs_to_jiffies(tp->srtt_us >> 3); - if (WARN_ON(icsk->icsk_pending == ICSK_TIME_EARLY_RETRANS)) - return false; /* No consecutive loss probes. */ if (WARN_ON(icsk->icsk_pending == ICSK_TIME_LOSS_PROBE)) { tcp_rearm_rto(sk); @@ -2309,8 +2305,9 @@ bool tcp_schedule_loss_probe(struct sock *sk) /* Schedule a loss probe in 2*RTT for SACK capable connections * in Open state, that are either limited by cwnd or application. */ - if (sysctl_tcp_early_retrans < 3 || !tp->packets_out || - !tcp_is_sack(tp) || inet_csk(sk)->icsk_ca_state != TCP_CA_Open) + if ((sysctl_tcp_early_retrans != 3 && sysctl_tcp_early_retrans != 4) || + !tp->packets_out || !tcp_is_sack(tp) || + icsk->icsk_ca_state != TCP_CA_Open) return false; if ((tp->snd_cwnd > tcp_packets_in_flight(tp)) && |