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[TCP] FRTO: remove unnecessary fackets/sacked_out recounting

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F-RTO does not touch SACKED_ACKED bits at all, so there is no
need to recount them in tcp_enter_frto_loss. After removal of
the else branch, nested ifs can be combined.

This must also reset sacked_out when SACK is not in use as TCP
could have received some duplicate ACKs prior RTO. To achieve
that in a sane manner, tcp_reset_reno_sack was re-placed by the
previous patch.

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 2007-05-27 01:53:49 -07:00 committed by David S. Miller
parent 4ddf66769d
commit 9bff40fda0
1 changed files with 7 additions and 16 deletions
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23
net/ipv4/tcp_input.c
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@ -1474,17 +1474,15 @@ static void tcp_enter_frto_loss(struct sock *sk, int allowed_segments, int flag)
{
struct tcp_sock *tp = tcp_sk(sk);
struct sk_buff *skb;
int cnt = 0;
tp->sacked_out = 0;
tp->lost_out = 0;
tp->fackets_out = 0;
tp->retrans_out = 0;
if (IsReno(tp))
tcp_reset_reno_sack(tp);
tcp_for_write_queue(skb, sk) {
if (skb == tcp_send_head(sk))
break;
cnt += tcp_skb_pcount(skb);
/*
* Count the retransmission made on RTO correctly (only when
* waiting for the first ACK and did not get it)...
@ -1498,19 +1496,12 @@ static void tcp_enter_frto_loss(struct sock *sk, int allowed_segments, int flag)
} else {
TCP_SKB_CB(skb)->sacked &= ~(TCPCB_LOST|TCPCB_SACKED_RETRANS);
}
if (!(TCP_SKB_CB(skb)->sacked&TCPCB_SACKED_ACKED)) {
/* Do not mark those segments lost that were
* forward transmitted after RTO
*/
if (!after(TCP_SKB_CB(skb)->end_seq,
tp->frto_highmark)) {
TCP_SKB_CB(skb)->sacked |= TCPCB_LOST;
tp->lost_out += tcp_skb_pcount(skb);
}
} else {
tp->sacked_out += tcp_skb_pcount(skb);
tp->fackets_out = cnt;
/* Don't lost mark skbs that were fwd transmitted after RTO */
if (!(TCP_SKB_CB(skb)->sacked&TCPCB_SACKED_ACKED) &&
!after(TCP_SKB_CB(skb)->end_seq, tp->frto_highmark)) {
TCP_SKB_CB(skb)->sacked |= TCPCB_LOST;
tp->lost_out += tcp_skb_pcount(skb);
}
}
tcp_sync_left_out(tp);