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, 1 insertions, 3 deletions

diff --git a/net/ipv4/tcp_metrics.c b/net/ipv4/tcp_metrics.c
index 9d5ddebfd831..7097f92d16e5 100644
--- a/net/ipv4/tcp_metrics.c
+++ b/net/ipv4/tcp_metrics.c
@@ -470,10 +470,8 @@ void tcp_init_metrics(struct sock *sk)
                 tp->snd_ssthresh = TCP_INFINITE_SSTHRESH;
         }
         val = tcp_metric_get(tm, TCP_METRIC_REORDERING);
-        if (val && tp->reordering != val) {
-                tcp_disable_fack(tp);
+        if (val && tp->reordering != val)
                 tp->reordering = val;
-        }
 
         crtt = tcp_metric_get(tm, TCP_METRIC_RTT);
         rcu_read_unlock();