From 8cd6d6162d998da579d40a1ee061bf8ce1610ff8 Mon Sep 17 00:00:00 2001
From: Neal Cardwell <ncardwell@google.com>
Date: Wed, 16 Nov 2011 08:58:05 +0000
Subject: [PATCH] tcp: skip cwnd moderation in TCP_CA_Open in tcp_try_to_open
The problem: Senders were overriding cwnd values picked during an undo
by calling tcp_moderate_cwnd() in tcp_try_to_open().
The fix: Don't moderate cwnd in tcp_try_to_open() if we're in
TCP_CA_Open, since doing so is generally unnecessary and specifically
would override a DSACK-based undo of a cwnd reduction made in fast
recovery.
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
net/ipv4/tcp_input.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index a4efdd7cf5a18..78dd38cd5496d 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -2881,7 +2881,8 @@ static void tcp_try_to_open(struct sock *sk, int flag)
if (inet_csk(sk)->icsk_ca_state != TCP_CA_CWR) {
tcp_try_keep_open(sk);
- tcp_moderate_cwnd(tp);
+ if (inet_csk(sk)->icsk_ca_state != TCP_CA_Open)
+ tcp_moderate_cwnd(tp);
} else {
tcp_cwnd_down(sk, flag);
}
--
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