diff --git a/include/net/tcp.h b/include/net/tcp.h
index 96cc3b434e40f7f3e68ccd1f6b06a5c564736777..15bdbc6bd571cbeec4de4b6c077df222461d71cb 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -810,6 +810,27 @@ static __inline__ __u32 tcp_max_burst(const struct tcp_sock *tp)
 	return 3;
 }
 
+/* RFC2861 Check whether we are limited by application or congestion window
+ * This is the inverse of cwnd check in tcp_tso_should_defer
+ */
+static inline int tcp_is_cwnd_limited(const struct sock *sk, u32 in_flight)
+{
+	const struct tcp_sock *tp = tcp_sk(sk);
+	u32 left;
+
+	if (in_flight >= tp->snd_cwnd)
+		return 1;
+
+	if (!(sk->sk_route_caps & NETIF_F_TSO))
+		return 0;
+
+	left = tp->snd_cwnd - in_flight;
+	if (sysctl_tcp_tso_win_divisor)
+		return left * sysctl_tcp_tso_win_divisor < tp->snd_cwnd;
+	else
+		return left <= tcp_max_burst(tp);
+}
+
 static __inline__ void tcp_minshall_update(struct tcp_sock *tp, int mss, 
 					   const struct sk_buff *skb)
 {
diff --git a/net/ipv4/tcp_bic.c b/net/ipv4/tcp_bic.c
index ae35e06090476a88bc9b6b6a4ba963d1aff9af9b..5af99b3ef5d706b62c95027667fc8a7e64e0f05f 100644
--- a/net/ipv4/tcp_bic.c
+++ b/net/ipv4/tcp_bic.c
@@ -217,7 +217,7 @@ static void bictcp_cong_avoid(struct sock *sk, u32 ack,
 
 	bictcp_low_utilization(sk, data_acked);
 
-	if (in_flight < tp->snd_cwnd)
+	if (!tcp_is_cwnd_limited(sk, in_flight))
 		return;
 
 	if (tp->snd_cwnd <= tp->snd_ssthresh) {
diff --git a/net/ipv4/tcp_cong.c b/net/ipv4/tcp_cong.c
index bbf2d6624e894b927a169d92ae2be882c851b91a..0705b496c6b3117de49e34b99f86731664a109ed 100644
--- a/net/ipv4/tcp_cong.c
+++ b/net/ipv4/tcp_cong.c
@@ -186,7 +186,7 @@ void tcp_reno_cong_avoid(struct sock *sk, u32 ack, u32 rtt, u32 in_flight,
 {
 	struct tcp_sock *tp = tcp_sk(sk);
 
-	if (in_flight < tp->snd_cwnd)
+	if (!tcp_is_cwnd_limited(sk, in_flight))
 		return;
 
         if (tp->snd_cwnd <= tp->snd_ssthresh) {
diff --git a/net/ipv4/tcp_highspeed.c b/net/ipv4/tcp_highspeed.c
index 6acc04bde08099c598e633a21518ed51e5b75bd2..5e56ad368dd260a819c636eb1733e0877ad37ffa 100644
--- a/net/ipv4/tcp_highspeed.c
+++ b/net/ipv4/tcp_highspeed.c
@@ -111,12 +111,12 @@ static void hstcp_init(struct sock *sk)
 }
 
 static void hstcp_cong_avoid(struct sock *sk, u32 adk, u32 rtt,
-			     u32 in_flight, int good)
+			     u32 in_flight, u32 pkts_acked)
 {
 	struct tcp_sock *tp = tcp_sk(sk);
 	struct hstcp *ca = inet_csk_ca(sk);
 
-	if (in_flight < tp->snd_cwnd)
+	if (!tcp_is_cwnd_limited(sk, in_flight))
 		return;
 
 	if (tp->snd_cwnd <= tp->snd_ssthresh) {
diff --git a/net/ipv4/tcp_htcp.c b/net/ipv4/tcp_htcp.c
index e47b37984e951e087cc2185b97336a5e3dadc21f..404a326ba3457ced90ef06b983c13625a1d93a66 100644
--- a/net/ipv4/tcp_htcp.c
+++ b/net/ipv4/tcp_htcp.c
@@ -207,7 +207,7 @@ static void htcp_cong_avoid(struct sock *sk, u32 ack, u32 rtt,
 	struct tcp_sock *tp = tcp_sk(sk);
 	struct htcp *ca = inet_csk_ca(sk);
 
-	if (in_flight < tp->snd_cwnd)
+	if (!tcp_is_cwnd_limited(sk, in_flight))
 		return;
 
         if (tp->snd_cwnd <= tp->snd_ssthresh) {
diff --git a/net/ipv4/tcp_hybla.c b/net/ipv4/tcp_hybla.c
index 77add63623df2a1034a21bfdb6fbaddf82385a71..40dbb38775101c02b4c285b887f13d1ff0aecebb 100644
--- a/net/ipv4/tcp_hybla.c
+++ b/net/ipv4/tcp_hybla.c
@@ -100,12 +100,12 @@ static void hybla_cong_avoid(struct sock *sk, u32 ack, u32 rtt,
 		ca->minrtt = tp->srtt;
 	}
 
+	if (!tcp_is_cwnd_limited(sk, in_flight))
+		return;
+
 	if (!ca->hybla_en)
 		return tcp_reno_cong_avoid(sk, ack, rtt, in_flight, flag);
 
-	if (in_flight < tp->snd_cwnd)
-		return;
-
 	if (ca->rho == 0)
 		hybla_recalc_param(sk);
 
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index b907456a79f46373bb81aac30ff9123910901952..998f6416ef8b59e308af1b23b01b654405219691 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -2058,3 +2058,4 @@ EXPORT_SYMBOL(tcp_connect);
 EXPORT_SYMBOL(tcp_make_synack);
 EXPORT_SYMBOL(tcp_simple_retransmit);
 EXPORT_SYMBOL(tcp_sync_mss);
+EXPORT_SYMBOL(sysctl_tcp_tso_win_divisor);
diff --git a/net/ipv4/tcp_scalable.c b/net/ipv4/tcp_scalable.c
index 327770bf552230211f2db5d799183fa08dd7e440..a2fd25617d241179345c7883ca62decd93f5ee6c 100644
--- a/net/ipv4/tcp_scalable.c
+++ b/net/ipv4/tcp_scalable.c
@@ -20,7 +20,8 @@ static void tcp_scalable_cong_avoid(struct sock *sk, u32 ack, u32 rtt,
 				    u32 in_flight, int flag)
 {
 	struct tcp_sock *tp = tcp_sk(sk);
-	if (in_flight < tp->snd_cwnd)
+
+	if (!tcp_is_cwnd_limited(sk, in_flight))
 		return;
 
 	if (tp->snd_cwnd <= tp->snd_ssthresh) {