From e97991832a4ea4a5f47d65f068a4c966a2eb5730 Mon Sep 17 00:00:00 2001 From: Florian Westphal Date: Mon, 21 Nov 2016 14:18:38 +0100 Subject: tcp: make undo_cwnd mandatory for congestion modules The undo_cwnd fallback in the stack doubles cwnd based on ssthresh, which un-does reno halving behaviour. It seems more appropriate to let congctl algorithms pair .ssthresh and .undo_cwnd properly. Add a 'tcp_reno_undo_cwnd' function and wire it up for all congestion algorithms that used to rely on the fallback. Cc: Eric Dumazet Cc: Yuchung Cheng Cc: Neal Cardwell Signed-off-by: Florian Westphal Signed-off-by: David S. Miller --- net/ipv4/tcp_input.c | 5 +---- 1 file changed, 1 insertion(+), 4 deletions(-) (limited to 'net/ipv4/tcp_input.c') diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index a70046fea0e8..22e6a2097ff6 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -2394,10 +2394,7 @@ static void tcp_undo_cwnd_reduction(struct sock *sk, bool unmark_loss) if (tp->prior_ssthresh) { const struct inet_connection_sock *icsk = inet_csk(sk); - if (icsk->icsk_ca_ops->undo_cwnd) - tp->snd_cwnd = icsk->icsk_ca_ops->undo_cwnd(sk); - else - tp->snd_cwnd = max(tp->snd_cwnd, tp->snd_ssthresh << 1); + tp->snd_cwnd = icsk->icsk_ca_ops->undo_cwnd(sk); if (tp->prior_ssthresh > tp->snd_ssthresh) { tp->snd_ssthresh = tp->prior_ssthresh; -- cgit v1.2.3