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authorIlpo Järvinen <ilpo.jarvinen@helsinki.fi>2007-04-30 00:39:55 -0700
committerDavid S. Miller <davem@sunset.davemloft.net>2007-04-30 00:58:12 -0700
commit575ee7140dabe9b9c4f66f4f867039b97e548867 (patch)
tree035923b29490a85ea7e77c2b0751280f8b7a0ba4 /net
parent[XFRM]: Restrict upper layer information by bundle. (diff)
downloadlinux-dev-575ee7140dabe9b9c4f66f4f867039b97e548867.tar.xz
linux-dev-575ee7140dabe9b9c4f66f4f867039b97e548867.zip
[TCP] FRTO: Delay skb available check until it's mandatory
No new data is needed until the first ACK comes, so no need to check for application limitedness until then. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
-rw-r--r--net/ipv4/tcp_input.c19
1 files changed, 11 insertions, 8 deletions
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 051f0f815f17..6b669898b197 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -1265,20 +1265,15 @@ tcp_sacktag_write_queue(struct sock *sk, struct sk_buff *ack_skb, u32 prior_snd_
return flag;
}
-/* F-RTO can only be used if these conditions are satisfied:
- * - there must be some unsent new data
- * - the advertised window should allow sending it
- * - TCP has never retransmitted anything other than head (SACK enhanced
- * variant from Appendix B of RFC4138 is more robust here)
+/* F-RTO can only be used if TCP has never retransmitted anything other than
+ * head (SACK enhanced variant from Appendix B of RFC4138 is more robust here)
*/
int tcp_use_frto(struct sock *sk)
{
const struct tcp_sock *tp = tcp_sk(sk);
struct sk_buff *skb;
- if (!sysctl_tcp_frto || !tcp_send_head(sk) ||
- after(TCP_SKB_CB(tcp_send_head(sk))->end_seq,
- tp->snd_una + tp->snd_wnd))
+ if (!sysctl_tcp_frto)
return 0;
if (IsSackFrto())
@@ -2710,6 +2705,14 @@ static int tcp_process_frto(struct sock *sk, u32 prior_snd_una, int flag)
}
if (tp->frto_counter == 1) {
+ /* Sending of the next skb must be allowed or no FRTO */
+ if (!tcp_send_head(sk) ||
+ after(TCP_SKB_CB(tcp_send_head(sk))->end_seq,
+ tp->snd_una + tp->snd_wnd)) {
+ tcp_enter_frto_loss(sk, tp->frto_counter + 1, flag);
+ return 1;
+ }
+
tp->snd_cwnd = tcp_packets_in_flight(tp) + 2;
tp->frto_counter = 2;
return 1;