This change enables congestion control to update cwnd based on not only packet cumulatively acked but also packets delivered out-of-order. This makes congestion control robust against packet reordering because it may raise cwnd as long as packets are being delivered once reordering has been detected (i.e., it only cares the amount of packets delivered, not the ordering among them).
Signed-off-by: Yuchung Cheng <ych...@google.com> Signed-off-by: Neal Cardwell <ncardw...@google.com> Signed-off-by: Eric Dumazet <ncardw...@google.com> --- net/ipv4/tcp_input.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index 2d6eaad..39c5326 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -3662,7 +3662,7 @@ static int tcp_ack(struct sock *sk, const struct sk_buff *skb, int flag) tcp_cwnd_reduction(sk, acked_sacked, flag); } else if (tcp_may_raise_cwnd(sk, flag)) { /* Advance cwnd if state allows */ - tcp_cong_avoid(sk, ack, acked); + tcp_cong_avoid(sk, ack, acked_sacked); } if ((flag & FLAG_FORWARD_PROGRESS) || !(flag & FLAG_NOT_DUP)) { -- 2.7.0.rc3.207.g0ac5344