1 files changed, 24 insertions, 11 deletions

diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 65632f827eea..bd134e3a0473 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -1902,7 +1902,9 @@ 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;
@@ -1910,9 +1912,6 @@ 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;
 
@@ -1971,10 +1970,27 @@ 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;
 
@@ -2338,11 +2354,8 @@ 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;