Message ID | 1359918785.30177.111.camel@edumazet-glaptop |
---|---|
State | Accepted, archived |
Delegated to: | David Miller |
Headers | show |
From: Eric Dumazet <eric.dumazet@gmail.com> Date: Sun, 03 Feb 2013 11:13:05 -0800 > From: Eric Dumazet <edumazet@google.com> > > Commit 9dc274151a548 (tcp: fix ABC in tcp_slow_start()) > uncovered a bug in FRTO code : > tcp_process_frto() is setting snd_cwnd to 0 if the number > of in flight packets is 0. > > As Neal pointed out, if no packet is in flight we lost our > chance to disambiguate whether a loss timeout was spurious. > > We should assume it was a proper loss. > > Reported-by: Pasi Kärkkäinen <pasik@iki.fi> > Signed-off-by: Neal Cardwell <ncardwell@google.com> > Signed-off-by: Eric Dumazet <edumazet@google.com> Applied. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index 8aca4ee..680c422 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -3484,7 +3484,8 @@ static bool tcp_process_frto(struct sock *sk, int flag) ((tp->frto_counter >= 2) && (flag & FLAG_RETRANS_DATA_ACKED))) tp->undo_marker = 0; - if (!before(tp->snd_una, tp->frto_highmark)) { + if (!before(tp->snd_una, tp->frto_highmark) || + !tcp_packets_in_flight(tp)) { tcp_enter_frto_loss(sk, (tp->frto_counter == 1 ? 2 : 3), flag); return true; }