From: Eric Dumazet <edumazet@google.com>
Date: Mon, 16 Apr 2012 23:28:07 +0000 (+0000)
Subject: tcp: fix tcp_grow_window() for large incoming frames
X-Git-Tag: MMI-PSA29.97-13-9~16940^2~16
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=4d846f02392a710f9604892ac3329e628e60a230;p=GitHub%2FMotorolaMobilityLLC%2Fkernel-slsi.git

tcp: fix tcp_grow_window() for large incoming frames

tcp_grow_window() has to grow rcv_ssthresh up to window_clamp, allowing
sender to increase its window.

tcp_grow_window() still assumes a tcp frame is under MSS, but its no
longer true with LRO/GRO.

This patch fixes one of the performance issue we noticed with GRO on.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Neal Cardwell <ncardwell@google.com>
Cc: Tom Herbert <therbert@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 9944c1d9a218..3ff364065376 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -335,6 +335,7 @@ static void tcp_grow_window(struct sock *sk, const struct sk_buff *skb)
 			incr = __tcp_grow_window(sk, skb);
 
 		if (incr) {
+			incr = max_t(int, incr, 2 * skb->len);
 			tp->rcv_ssthresh = min(tp->rcv_ssthresh + incr,
 					       tp->window_clamp);
 			inet_csk(sk)->icsk_ack.quick |= 1;