From ef9da47c7cc64d69526331f315e76b5680d4048f Mon Sep 17 00:00:00 2001 From: =?utf8?q?Ilpo=20J=C3=A4rvinen?= Date: Sat, 20 Sep 2008 21:25:15 -0700 Subject: [PATCH] tcp: don't clear retransmit_skb_hint when not necessary MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Most importantly avoid doing it with cumulative ACK. Not clearing means that we no longer need n^2 processing in resolution of each fast recovery. Signed-off-by: Ilpo Järvinen Signed-off-by: David S. Miller --- include/net/tcp.h | 7 ++++++- net/ipv4/tcp_input.c | 4 +++- net/ipv4/tcp_output.c | 8 +++++--- 3 files changed, 14 insertions(+), 5 deletions(-) diff --git a/include/net/tcp.h b/include/net/tcp.h index 220f54cf42ec..ea815723d414 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -1037,10 +1037,15 @@ static inline void tcp_mib_init(struct net *net) } /* from STCP */ -static inline void tcp_clear_all_retrans_hints(struct tcp_sock *tp) +static inline void tcp_clear_retrans_hints_partial(struct tcp_sock *tp) { tp->lost_skb_hint = NULL; tp->scoreboard_skb_hint = NULL; +} + +static inline void tcp_clear_all_retrans_hints(struct tcp_sock *tp) +{ + tcp_clear_retrans_hints_partial(tp); tp->retransmit_skb_hint = NULL; } diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index d017aed6edd7..44a4fffc2cc3 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -2925,7 +2925,9 @@ 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); + tcp_clear_retrans_hints_partial(tp); + if (skb == tp->retransmit_skb_hint) + tp->retransmit_skb_hint = NULL; } if (skb && (TCP_SKB_CB(skb)->sacked & TCPCB_SACKED_ACKED)) diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index f900fae8b87e..239cea7b6c0e 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -750,7 +750,7 @@ int tcp_fragment(struct sock *sk, struct sk_buff *skb, u32 len, BUG_ON(len > skb->len); - tcp_clear_all_retrans_hints(tp); + tcp_clear_retrans_hints_partial(tp); nsize = skb_headlen(skb) - len; if (nsize < 0) nsize = 0; @@ -1823,7 +1823,9 @@ static void tcp_retrans_try_collapse(struct sock *sk, struct sk_buff *skb, tp->packets_out -= tcp_skb_pcount(next_skb); /* changed transmit queue under us so clear hints */ - tcp_clear_all_retrans_hints(tp); + tcp_clear_retrans_hints_partial(tp); + if (next_skb == tp->retransmit_skb_hint) + tp->retransmit_skb_hint = skb; sk_wmem_free_skb(sk, next_skb); } @@ -1853,7 +1855,7 @@ void tcp_simple_retransmit(struct sock *sk) } } - tcp_clear_all_retrans_hints(tp); + tcp_clear_retrans_hints_partial(tp); if (prior_lost == tp->lost_out) return; -- 2.20.1