tcp: don't clear retransmit_skb_hint when not necessary

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 <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Ilpo Järvinen 2008-09-20 21:25:15 -07:00 committed by David S. Miller
parent f0ceb0ed86
commit ef9da47c7c
3 changed files with 14 additions and 5 deletions

View File

@ -1037,10 +1037,15 @@ static inline void tcp_mib_init(struct net *net)
} }
/* from STCP */ /* 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->lost_skb_hint = NULL;
tp->scoreboard_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; tp->retransmit_skb_hint = NULL;
} }

View File

@ -2925,7 +2925,9 @@ static int tcp_clean_rtx_queue(struct sock *sk, int prior_fackets)
tcp_unlink_write_queue(skb, sk); tcp_unlink_write_queue(skb, sk);
sk_wmem_free_skb(sk, skb); 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)) if (skb && (TCP_SKB_CB(skb)->sacked & TCPCB_SACKED_ACKED))

View File

@ -750,7 +750,7 @@ int tcp_fragment(struct sock *sk, struct sk_buff *skb, u32 len,
BUG_ON(len > skb->len); BUG_ON(len > skb->len);
tcp_clear_all_retrans_hints(tp); tcp_clear_retrans_hints_partial(tp);
nsize = skb_headlen(skb) - len; nsize = skb_headlen(skb) - len;
if (nsize < 0) if (nsize < 0)
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); tp->packets_out -= tcp_skb_pcount(next_skb);
/* changed transmit queue under us so clear hints */ /* 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); 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) if (prior_lost == tp->lost_out)
return; return;