From 3152053752a103ac13791fbaf2b93b2c2db30ca8 Mon Sep 17 00:00:00 2001
From: John Heffner <jheffner@psc.edu>
Date: Wed, 18 Oct 2006 20:36:48 -0700
Subject: [PATCH] --- yaml --- r: 40044 b: refs/heads/master c:
 ae8064ac32d07f609114d73928cdef803be87134 h: refs/heads/master v: v3

---
 [refs]                      |  2 +-
 trunk/include/linux/tcp.h   |  2 ++
 trunk/net/ipv4/tcp_output.c | 20 +++++++++++++++-----
 3 files changed, 18 insertions(+), 6 deletions(-)

diff --git a/[refs] b/[refs]
index 80f5a4c809af..5cf64d0997be 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: b52f070c9c3c09ed3b7f699280193aae7e25d816
+refs/heads/master: ae8064ac32d07f609114d73928cdef803be87134
diff --git a/trunk/include/linux/tcp.h b/trunk/include/linux/tcp.h
index 0e058a2d1c6d..2d36f6db3706 100644
--- a/trunk/include/linux/tcp.h
+++ b/trunk/include/linux/tcp.h
@@ -342,6 +342,8 @@ struct tcp_sock {
 
 	unsigned long last_synq_overflow; 
 
+	__u32	tso_deferred;
+
 /* Receiver side RTT estimation */
 	struct {
 		__u32	rtt;
diff --git a/trunk/net/ipv4/tcp_output.c b/trunk/net/ipv4/tcp_output.c
index f22536e32cb1..ca406157724c 100644
--- a/trunk/net/ipv4/tcp_output.c
+++ b/trunk/net/ipv4/tcp_output.c
@@ -1096,10 +1096,14 @@ static int tcp_tso_should_defer(struct sock *sk, struct tcp_sock *tp, struct sk_
 	u32 send_win, cong_win, limit, in_flight;
 
 	if (TCP_SKB_CB(skb)->flags & TCPCB_FLAG_FIN)
-		return 0;
+		goto send_now;
 
 	if (icsk->icsk_ca_state != TCP_CA_Open)
-		return 0;
+		goto send_now;
+
+	/* Defer for less than two clock ticks. */
+	if (!tp->tso_deferred && ((jiffies<<1)>>1) - (tp->tso_deferred>>1) > 1)
+		goto send_now;
 
 	in_flight = tcp_packets_in_flight(tp);
 
@@ -1115,7 +1119,7 @@ static int tcp_tso_should_defer(struct sock *sk, struct tcp_sock *tp, struct sk_
 
 	/* If a full-sized TSO skb can be sent, do it. */
 	if (limit >= 65536)
-		return 0;
+		goto send_now;
 
 	if (sysctl_tcp_tso_win_divisor) {
 		u32 chunk = min(tp->snd_wnd, tp->snd_cwnd * tp->mss_cache);
@@ -1125,7 +1129,7 @@ static int tcp_tso_should_defer(struct sock *sk, struct tcp_sock *tp, struct sk_
 		 */
 		chunk /= sysctl_tcp_tso_win_divisor;
 		if (limit >= chunk)
-			return 0;
+			goto send_now;
 	} else {
 		/* Different approach, try not to defer past a single
 		 * ACK.  Receiver should ACK every other full sized
@@ -1133,11 +1137,17 @@ static int tcp_tso_should_defer(struct sock *sk, struct tcp_sock *tp, struct sk_
 		 * then send now.
 		 */
 		if (limit > tcp_max_burst(tp) * tp->mss_cache)
-			return 0;
+			goto send_now;
 	}
 
 	/* Ok, it looks like it is advisable to defer.  */
+	tp->tso_deferred = 1 | (jiffies<<1);
+
 	return 1;
+
+send_now:
+	tp->tso_deferred = 0;
+	return 0;
 }
 
 /* Create a new MTU probe if we are ready.