1 files changed, 41 insertions, 18 deletions

diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index f5bd4bd3f7e6..f37ecf53ee8a 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -1524,6 +1524,27 @@ static bool tcp_nagle_check(bool partial, const struct tcp_sock *tp,
 		((nonagle & TCP_NAGLE_CORK) ||
 		 (!nonagle && tp->packets_out && tcp_minshall_check(tp)));
 }
+
+/* Return how many segs we'd like on a TSO packet,
+ * to send one TSO packet per ms
+ */
+static u32 tcp_tso_autosize(const struct sock *sk, unsigned int mss_now)
+{
+	u32 bytes, segs;
+
+	bytes = min(sk->sk_pacing_rate >> 10,
+		    sk->sk_gso_max_size - 1 - MAX_TCP_HEADER);
+
+	/* Goal is to send at least one packet per ms,
+	 * not one big TSO packet every 100 ms.
+	 * This preserves ACK clocking and is consistent
+	 * with tcp_tso_should_defer() heuristic.
+	 */
+	segs = max_t(u32, bytes / mss_now, sysctl_tcp_min_tso_segs);
+
+	return min_t(u32, segs, sk->sk_gso_max_segs);
+}
+
 /* Returns the portion of skb which can be sent right away */
 static unsigned int tcp_mss_split_point(const struct sock *sk,
 					const struct sk_buff *skb,
@@ -1731,7 +1752,7 @@ static int tso_fragment(struct sock *sk, struct sk_buff *skb, unsigned int len,
  * This algorithm is from John Heffner.
  */
 static bool tcp_tso_should_defer(struct sock *sk, struct sk_buff *skb,
-				 bool *is_cwnd_limited)
+				 bool *is_cwnd_limited, u32 max_segs)
 {
 	struct tcp_sock *tp = tcp_sk(sk);
 	const struct inet_connection_sock *icsk = inet_csk(sk);
@@ -1761,8 +1782,7 @@ static bool tcp_tso_should_defer(struct sock *sk, struct sk_buff *skb,
 	limit = min(send_win, cong_win);
 
 	/* If a full-sized TSO skb can be sent, do it. */
-	if (limit >= min_t(unsigned int, sk->sk_gso_max_size,
-			   tp->xmit_size_goal_segs * tp->mss_cache))
+	if (limit >= max_segs * tp->mss_cache)
 		goto send_now;
 
 	/* Middle in queue won't get any more data, full sendable already? */
@@ -1959,6 +1979,7 @@ static bool tcp_write_xmit(struct sock *sk, unsigned int mss_now, int nonagle,
 	int cwnd_quota;
 	int result;
 	bool is_cwnd_limited = false;
+	u32 max_segs;
 
 	sent_pkts = 0;
 
@@ -1972,6 +1993,7 @@ static bool tcp_write_xmit(struct sock *sk, unsigned int mss_now, int nonagle,
 		}
 	}
 
+	max_segs = tcp_tso_autosize(sk, mss_now);
 	while ((skb = tcp_send_head(sk))) {
 		unsigned int limit;
 
@@ -2004,10 +2026,23 @@ static bool tcp_write_xmit(struct sock *sk, unsigned int mss_now, int nonagle,
 				break;
 		} else {
 			if (!push_one &&
-			    tcp_tso_should_defer(sk, skb, &is_cwnd_limited))
+			    tcp_tso_should_defer(sk, skb, &is_cwnd_limited,
+						 max_segs))
 				break;
 		}
 
+		limit = mss_now;
+		if (tso_segs > 1 && !tcp_urg_mode(tp))
+			limit = tcp_mss_split_point(sk, skb, mss_now,
+						    min_t(unsigned int,
+							  cwnd_quota,
+							  max_segs),
+						    nonagle);
+
+		if (skb->len > limit &&
+		    unlikely(tso_fragment(sk, skb, limit, mss_now, gfp)))
+			break;
+
 		/* TCP Small Queues :
 		 * Control number of packets in qdisc/devices to two packets / or ~1 ms.
 		 * This allows for :
@@ -2018,8 +2053,8 @@ static bool tcp_write_xmit(struct sock *sk, unsigned int mss_now, int nonagle,
 		 * of queued bytes to ensure line rate.
 		 * One example is wifi aggregation (802.11 AMPDU)
 		 */
-		limit = max_t(unsigned int, sysctl_tcp_limit_output_bytes,
-			      sk->sk_pacing_rate >> 10);
+		limit = max(2 * skb->truesize, sk->sk_pacing_rate >> 10);
+		limit = min_t(u32, limit, sysctl_tcp_limit_output_bytes);
 
 		if (atomic_read(&sk->sk_wmem_alloc) > limit) {
 			set_bit(TSQ_THROTTLED, &tp->tsq_flags);
@@ -2032,18 +2067,6 @@ static bool tcp_write_xmit(struct sock *sk, unsigned int mss_now, int nonagle,
 				break;
 		}
 
-		limit = mss_now;
-		if (tso_segs > 1 && !tcp_urg_mode(tp))
-			limit = tcp_mss_split_point(sk, skb, mss_now,
-						    min_t(unsigned int,
-							  cwnd_quota,
-							  sk->sk_gso_max_segs),
-						    nonagle);
-
-		if (skb->len > limit &&
-		    unlikely(tso_fragment(sk, skb, limit, mss_now, gfp)))
-			break;
-
 		if (unlikely(tcp_transmit_skb(sk, skb, 1, gfp)))
 			break;