1 files changed, 43 insertions, 11 deletions

diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 602e7057e438..029c70dfb585 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -436,6 +436,8 @@ int tcp_fragment(struct sock *sk, struct sk_buff *skb, u32 len, unsigned int mss
         u16 flags;
 
         BUG_ON(len > skb->len);
+
+        clear_all_retrans_hints(tp);
         nsize = skb_headlen(skb) - len;
         if (nsize < 0)
                 nsize = 0;
@@ -1260,7 +1262,10 @@ static void tcp_retrans_try_collapse(struct sock *sk, struct sk_buff *skb, int m
                 BUG_ON(tcp_skb_pcount(skb) != 1 ||
                        tcp_skb_pcount(next_skb) != 1);
 
-                /* Ok.  We will be able to collapse the packet. */
+                /* changing transmit queue under us so clear hints */
+                clear_all_retrans_hints(tp);
+
+                /* Ok.  We will be able to collapse the packet. */
                 __skb_unlink(next_skb, &sk->sk_write_queue);
 
                 memcpy(skb_put(skb, next_skb_size), next_skb->data, next_skb_size);
@@ -1330,6 +1335,8 @@ void tcp_simple_retransmit(struct sock *sk)
                 }
         }
 
+        clear_all_retrans_hints(tp);
+
         if (!lost)
                 return;
 
@@ -1468,13 +1475,25 @@ void tcp_xmit_retransmit_queue(struct sock *sk)
         const struct inet_connection_sock *icsk = inet_csk(sk);
         struct tcp_sock *tp = tcp_sk(sk);
         struct sk_buff *skb;
-        int packet_cnt = tp->lost_out;
+        int packet_cnt;
+
+        if (tp->retransmit_skb_hint) {
+                skb = tp->retransmit_skb_hint;
+                packet_cnt = tp->retransmit_cnt_hint;
+        }else{
+                skb = sk->sk_write_queue.next;
+                packet_cnt = 0;
+        }
 
         /* First pass: retransmit lost packets. */
-        if (packet_cnt) {
-                sk_stream_for_retrans_queue(skb, sk) {
+        if (tp->lost_out) {
+                sk_stream_for_retrans_queue_from(skb, sk) {
                         __u8 sacked = TCP_SKB_CB(skb)->sacked;
 
+                        /* we could do better than to assign each time */
+                        tp->retransmit_skb_hint = skb;
+                        tp->retransmit_cnt_hint = packet_cnt;
+
                         /* Assume this retransmit will generate
                          * only one packet for congestion window
                          * calculation purposes.  This works because
@@ -1485,10 +1504,12 @@ void tcp_xmit_retransmit_queue(struct sock *sk)
                         if (tcp_packets_in_flight(tp) >= tp->snd_cwnd)
                                 return;
 
-                        if (sacked&TCPCB_LOST) {
+                        if (sacked & TCPCB_LOST) {
                                 if (!(sacked&(TCPCB_SACKED_ACKED|TCPCB_SACKED_RETRANS))) {
-                                        if (tcp_retransmit_skb(sk, skb))
+                                        if (tcp_retransmit_skb(sk, skb)) {
+                                                tp->retransmit_skb_hint = NULL;
                                                 return;
+                                        }
                                         if (icsk->icsk_ca_state != TCP_CA_Loss)
                                                 NET_INC_STATS_BH(LINUX_MIB_TCPFASTRETRANS);
                                         else
@@ -1501,8 +1522,8 @@ void tcp_xmit_retransmit_queue(struct sock *sk)
                                                                           TCP_RTO_MAX);
                                 }
 
-                                packet_cnt -= tcp_skb_pcount(skb);
-                                if (packet_cnt <= 0)
+                                packet_cnt += tcp_skb_pcount(skb);
+                                if (packet_cnt >= tp->lost_out)
                                         break;
                         }
                 }
@@ -1528,9 +1549,18 @@ void tcp_xmit_retransmit_queue(struct sock *sk)
         if (tcp_may_send_now(sk, tp))
                 return;
 
-        packet_cnt = 0;
+        if (tp->forward_skb_hint) {
+                skb = tp->forward_skb_hint;
+                packet_cnt = tp->forward_cnt_hint;
+        } else{
+                skb = sk->sk_write_queue.next;
+                packet_cnt = 0;
+        }
+
+        sk_stream_for_retrans_queue_from(skb, sk) {
+                tp->forward_cnt_hint = packet_cnt;
+                tp->forward_skb_hint = skb;
 
-        sk_stream_for_retrans_queue(skb, sk) {
                 /* Similar to the retransmit loop above we
                  * can pretend that the retransmitted SKB
                  * we send out here will be composed of one
@@ -1547,8 +1577,10 @@ void tcp_xmit_retransmit_queue(struct sock *sk)
                         continue;
 
                 /* Ok, retransmit it. */
-                if (tcp_retransmit_skb(sk, skb))
+                if (tcp_retransmit_skb(sk, skb)) {
+                        tp->forward_skb_hint = NULL;
                         break;
+                }
 
                 if (skb == skb_peek(&sk->sk_write_queue))
                         inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS,