1 files changed, 21 insertions, 0 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)
 {