1 files changed, 8 insertions, 4 deletions

diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 0b88158dd4a7..eb73a1dccf56 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -1562,7 +1562,7 @@ static unsigned int tcp_mss_split_point(const struct sock *sk,
 static inline unsigned int tcp_cwnd_test(const struct tcp_sock *tp,
                                          const struct sk_buff *skb)
 {
-        u32 in_flight, cwnd;
+        u32 in_flight, cwnd, halfcwnd;
 
         /* Don't be strict about the congestion window for the final FIN.  */
         if ((TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN) &&
@@ -1571,10 +1571,14 @@ static inline unsigned int tcp_cwnd_test(const struct tcp_sock *tp,
 
         in_flight = tcp_packets_in_flight(tp);
         cwnd = tp->snd_cwnd;
-        if (in_flight < cwnd)
-                return (cwnd - in_flight);
+        if (in_flight >= cwnd)
+                return 0;
 
-        return 0;
+        /* For better scheduling, ensure we have at least
+         * 2 GSO packets in flight.
+         */
+        halfcwnd = max(cwnd >> 1, 1U);
+        return min(halfcwnd, cwnd - in_flight);
 }
 
 /* Initialize TSO state of a skb.