8 files changed, 32 insertions, 9 deletions

diff --git a/include/net/tcp.h b/include/net/tcp.h
index 96cc3b434e40..15bdbc6bd571 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 ae35e0609047..5af99b3ef5d7 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 bbf2d6624e89..0705b496c6b3 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 6acc04bde080..5e56ad368dd2 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 e47b37984e95..404a326ba345 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 77add63623df..40dbb3877510 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 b907456a79f4..998f6416ef8b 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 327770bf5522..a2fd25617d24 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) {