tcp: retire FACK loss detection

FACK loss detection has been disabled by default and the
successor RACK subsumed FACK and can handle reordering better.
This patch removes FACK to simplify TCP loss recovery.

Signed-off-by: Yuchung Cheng <ycheng@google.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Neal Cardwell <ncardwell@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>

1 files changed, 0 insertions, 2 deletions

diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index bc71a27d5ad9..337555076043 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -2509,8 +2509,6 @@ static int tcp_repair_options_est(struct sock *sk,
                                 return -EINVAL;
 
                         tp->rx_opt.sack_ok |= TCP_SACK_SEEN;
-                        if (sock_net(sk)->ipv4.sysctl_tcp_fack)
-                                tcp_enable_fack(tp);
                         break;
                 case TCPOPT_TIMESTAMP:
                         if (opt.opt_val != 0)