tcp: don't clear lost_skb_hint when not necessary

[linux-2.6-omap-h63xx.git] / net / ipv4 / tcp_input.c

diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 28e93f1e421743b823466e2c1be682d0feb41151..85627f83665fa23b40aca36c600c827b3f462dc5 100644 (file)
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -1298,9 +1298,6 @@ static int tcp_sacktag_one(struct sk_buff *skb, struct sock *sk,
                                        ~(TCPCB_LOST|TCPCB_SACKED_RETRANS);
                                tp->lost_out -= tcp_skb_pcount(skb);
                                tp->retrans_out -= tcp_skb_pcount(skb);
-
-                               /* clear lost hint */
-                               tp->retransmit_skb_hint = NULL;
                        }
                } else {
                        if (!(sacked & TCPCB_RETRANS)) {
@@ -1319,9 +1316,6 @@ static int tcp_sacktag_one(struct sk_buff *skb, struct sock *sk,
                        if (sacked & TCPCB_LOST) {
                                TCP_SKB_CB(skb)->sacked &= ~TCPCB_LOST;
                                tp->lost_out -= tcp_skb_pcount(skb);
-
-                               /* clear lost hint */
-                               tp->retransmit_skb_hint = NULL;
                        }
                }
 
@@ -1351,7 +1345,6 @@ static int tcp_sacktag_one(struct sk_buff *skb, struct sock *sk,
        if (dup_sack && (TCP_SKB_CB(skb)->sacked & TCPCB_SACKED_RETRANS)) {
                TCP_SKB_CB(skb)->sacked &= ~TCPCB_SACKED_RETRANS;
                tp->retrans_out -= tcp_skb_pcount(skb);
-               tp->retransmit_skb_hint = NULL;
        }
 
        return flag;
@@ -2851,6 +2844,7 @@ static int tcp_clean_rtx_queue(struct sock *sk, int prior_fackets)
        int flag = 0;
        u32 pkts_acked = 0;
        u32 reord = tp->packets_out;
+       u32 prior_sacked = tp->sacked_out;
        s32 seq_rtt = -1;
        s32 ca_seq_rtt = -1;
        ktime_t last_ackt = net_invalid_timestamp();
@@ -2932,7 +2926,11 @@ static int tcp_clean_rtx_queue(struct sock *sk, int prior_fackets)
 
                tcp_unlink_write_queue(skb, sk);
                sk_wmem_free_skb(sk, skb);
-               tcp_clear_all_retrans_hints(tp);
+               tp->scoreboard_skb_hint = NULL;
+               if (skb == tp->retransmit_skb_hint)
+                       tp->retransmit_skb_hint = NULL;
+               if (skb == tp->lost_skb_hint)
+                       tp->lost_skb_hint = NULL;
        }
 
        if (skb && (TCP_SKB_CB(skb)->sacked & TCPCB_SACKED_ACKED))
@@ -2951,6 +2949,15 @@ static int tcp_clean_rtx_queue(struct sock *sk, int prior_fackets)
                        /* Non-retransmitted hole got filled? That's reordering */
                        if (reord < prior_fackets)
                                tcp_update_reordering(sk, tp->fackets_out - reord, 0);
+
+                       /* No need to care for underflows here because
+                        * the lost_skb_hint gets NULLed if we're past it
+                        * (or something non-trivial happened)
+                        */
+                       if (tcp_is_fack(tp))
+                               tp->lost_cnt_hint -= pkts_acked;
+                       else
+                               tp->lost_cnt_hint -= prior_sacked - tp->sacked_out;
                }
 
                tp->fackets_out -= min(pkts_acked, tp->fackets_out);