diff options
| author | Yuchung Cheng <ycheng@google.com> | 2018-05-17 01:40:11 +0200 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2018-05-17 21:41:28 +0200 |
| commit | b38a51fec1c1f693f03b1aa19d0622123634d4b7 (patch) | |
| tree | 2dfede58dae59faf7da205143e3e00e1833e4bc7 | |
| parent | tcp: support DUPACK threshold in RACK (diff) | |
| download | linux-b38a51fec1c1f693f03b1aa19d0622123634d4b7.tar.xz linux-b38a51fec1c1f693f03b1aa19d0622123634d4b7.zip | |
tcp: disable RFC6675 loss detection
This patch disables RFC6675 loss detection and make sysctl
net.ipv4.tcp_recovery = 1 controls a binary choice between RACK
(1) or RFC6675 (0).
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Soheil Hassas Yeganeh <soheil@google.com>
Reviewed-by: Priyaranjan Jha <priyarjha@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to '')
| -rw-r--r-- | Documentation/networking/ip-sysctl.txt | 3 | ||||
| -rw-r--r-- | net/ipv4/tcp_input.c | 12 |
2 files changed, 10 insertions, 5 deletions
diff --git a/Documentation/networking/ip-sysctl.txt b/Documentation/networking/ip-sysctl.txt index 13bbac50dc8b..ea304a23c8d7 100644 --- a/Documentation/networking/ip-sysctl.txt +++ b/Documentation/networking/ip-sysctl.txt @@ -449,7 +449,8 @@ tcp_recovery - INTEGER features. RACK: 0x1 enables the RACK loss detection for fast detection of lost - retransmissions and tail drops. + retransmissions and tail drops. It also subsumes and disables + RFC6675 recovery for SACK connections. RACK: 0x2 makes RACK's reordering window static (min_rtt/4). RACK: 0x4 disables RACK's DUPACK threshold heuristic diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index b188e0d75edd..ccbe04f80040 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -2035,6 +2035,11 @@ static inline int tcp_dupack_heuristics(const struct tcp_sock *tp) return tp->sacked_out + 1; } +static bool tcp_is_rack(const struct sock *sk) +{ + return sock_net(sk)->ipv4.sysctl_tcp_recovery & TCP_RACK_LOSS_DETECTION; +} + /* Linux NewReno/SACK/ECN state machine. * -------------------------------------- * @@ -2141,7 +2146,7 @@ static bool tcp_time_to_recover(struct sock *sk, int flag) return true; /* Not-A-Trick#2 : Classic rule... */ - if (tcp_dupack_heuristics(tp) > tp->reordering) + if (!tcp_is_rack(sk) && tcp_dupack_heuristics(tp) > tp->reordering) return true; return false; @@ -2722,8 +2727,7 @@ static void tcp_rack_identify_loss(struct sock *sk, int *ack_flag) { struct tcp_sock *tp = tcp_sk(sk); - /* Use RACK to detect loss */ - if (sock_net(sk)->ipv4.sysctl_tcp_recovery & TCP_RACK_LOSS_DETECTION) { + if (tcp_is_rack(sk)) { u32 prior_retrans = tp->retrans_out; tcp_rack_mark_lost(sk); @@ -2862,7 +2866,7 @@ static void tcp_fastretrans_alert(struct sock *sk, const u32 prior_snd_una, fast_rexmit = 1; } - if (do_lost) + if (!tcp_is_rack(sk) && do_lost) tcp_update_scoreboard(sk, fast_rexmit); *rexmit = REXMIT_LOST; } |