Commit cd1fc85b authored Dec 07, 2017 by Yuchung Cheng Committed by David S. Miller Dec 08, 2017

tcp: always evaluate losses in RACK upon undo



When sender detects spurious retransmission, all packets
marked lost are remarked to be in-flight. However some may
be considered lost based on its timestamps in RACK. This patch
forces RACK to re-evaluate, which may be skipped previously if
the ACK does not advance RACK timestamp.

Signed-off-by: Yuchung Cheng <ycheng@google.com>
Reviewed-by: Neal Cardwell <ncardwell@google.com>
Reviewed-by: Priyaranjan Jha <priyarjha@google.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent 0ce294d8

net/ipv4/tcp_input.c

+1 −0

Original line number	Diff line number	Diff line
		@@ -2329,6 +2329,7 @@ static void tcp_undo_cwnd_reduction(struct sock *sk, bool unmark_loss)
		}
		tp->snd_cwnd_stamp = tcp_jiffies32;
		tp->undo_marker = 0;
		tp->rack.advanced = 1; /* Force RACK to re-exam losses */
		}

		static inline bool tcp_may_undo(const struct tcp_sock *tp)