Commit 2d14a4de authored Feb 02, 2016 by Yuchung Cheng Committed by David S. Miller Feb 07, 2016

tcp: make congestion control more robust against reordering



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 <ycheng@google.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Eric Dumazet <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent 3ebd8871

net/ipv4/tcp_input.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -3660,7 +3660,7 @@ 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)) {

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