1 files changed, 24 insertions, 11 deletions

diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 5aa600900695..d1676d8a6ed7 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -1904,7 +1904,9 @@ static int tso_fragment(struct sock *sk, enum tcp_queue tcp_queue,
  * This algorithm is from John Heffner.
  */
 static bool tcp_tso_should_defer(struct sock *sk, struct sk_buff *skb,
-                                 bool *is_cwnd_limited, u32 max_segs)
+                                 bool *is_cwnd_limited,
+                                 bool *is_rwnd_limited,
+                                 u32 max_segs)
 {
         const struct inet_connection_sock *icsk = inet_csk(sk);
         u32 age, send_win, cong_win, limit, in_flight;
@@ -1912,9 +1914,6 @@ static bool tcp_tso_should_defer(struct sock *sk, struct sk_buff *skb,
         struct sk_buff *head;
         int win_divisor;
 
-        if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN)
-                goto send_now;
-
         if (icsk->icsk_ca_state >= TCP_CA_Recovery)
                 goto send_now;
 
@@ -1973,10 +1972,27 @@ static bool tcp_tso_should_defer(struct sock *sk, struct sk_buff *skb,
         if (age < (tp->srtt_us >> 4))
                 goto send_now;
 
-        /* Ok, it looks like it is advisable to defer. */
+        /* Ok, it looks like it is advisable to defer.
+         * Three cases are tracked :
+         * 1) We are cwnd-limited
+         * 2) We are rwnd-limited
+         * 3) We are application limited.
+         */
+        if (cong_win < send_win) {
+                if (cong_win <= skb->len) {
+                        *is_cwnd_limited = true;
+                        return true;
+                }
+        } else {
+                if (send_win <= skb->len) {
+                        *is_rwnd_limited = true;
+                        return true;
+                }
+        }
 
-        if (cong_win < send_win && cong_win <= skb->len)
-                *is_cwnd_limited = true;
+        /* If this packet won't get more data, do not wait. */
+        if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN)
+                goto send_now;
 
         return true;
 
@@ -2356,11 +2372,8 @@ static bool tcp_write_xmit(struct sock *sk, unsigned int mss_now, int nonagle,
                 } else {
                         if (!push_one &&
                             tcp_tso_should_defer(sk, skb, &is_cwnd_limited,
-                                                 max_segs)) {
-                                if (!is_cwnd_limited)
-                                        is_rwnd_limited = true;
+                                                 &is_rwnd_limited, max_segs))
                                 break;
-                        }
                 }
 
                 limit = mss_now;