diff options
author | Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> | 2008-09-20 21:20:20 -0700 |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2008-09-20 21:20:20 -0700 |
commit | 006f582c73f4eda35e06fd323193c3df43fb3459 (patch) | |
tree | d82762cfb6fb5e6889a52d316fa263a80c4f9fb3 /net/ipv4/tcp_input.c | |
parent | 41ea36e35a0daa75377b3e70680e5c3a3f83fe27 (diff) | |
download | op-kernel-dev-006f582c73f4eda35e06fd323193c3df43fb3459.zip op-kernel-dev-006f582c73f4eda35e06fd323193c3df43fb3459.tar.gz |
tcp: convert retransmit_cnt_hint to seqno
Main benefit in this is that we can then freely point
the retransmit_skb_hint to anywhere we want to because
there's no longer need to know what would be the count
changes involve, and since this is really used only as a
terminator, unnecessary work is one time walk at most,
and if some retransmissions are necessary after that
point later on, the walk is not full waste of time
anyway.
Since retransmit_high must be kept valid, all lost
markers must ensure that.
Now I also have learned how those "holes" in the
rexmittable skbs can appear, mtu probe does them. So
I removed the misleading comment as well.
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/tcp_input.c')
-rw-r--r-- | net/ipv4/tcp_input.c | 34 |
1 files changed, 20 insertions, 14 deletions
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index 12512336..d271cc8 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -979,17 +979,17 @@ static void tcp_update_reordering(struct sock *sk, const int metric, } } -/* RFC: This is from the original, I doubt that this is necessary at all: - * clear xmit_retrans hint if seq of this skb is beyond hint. How could we - * retransmitted past LOST markings in the first place? I'm not fully sure - * about undo and end of connection cases, which can cause R without L? - */ +/* This must be called before lost_out is incremented */ static void tcp_verify_retransmit_hint(struct tcp_sock *tp, struct sk_buff *skb) { - if ((tp->retransmit_skb_hint != NULL) && + if ((tp->retransmit_skb_hint == NULL) || before(TCP_SKB_CB(skb)->seq, TCP_SKB_CB(tp->retransmit_skb_hint)->seq)) - tp->retransmit_skb_hint = NULL; + tp->retransmit_skb_hint = skb; + + if (!tp->lost_out || + after(TCP_SKB_CB(skb)->end_seq, tp->retransmit_high)) + tp->retransmit_high = TCP_SKB_CB(skb)->end_seq; } static void tcp_skb_mark_lost(struct tcp_sock *tp, struct sk_buff *skb) @@ -1002,6 +1002,16 @@ static void tcp_skb_mark_lost(struct tcp_sock *tp, struct sk_buff *skb) } } +void tcp_skb_mark_lost_uncond_verify(struct tcp_sock *tp, struct sk_buff *skb) +{ + tcp_verify_retransmit_hint(tp, skb); + + if (!(TCP_SKB_CB(skb)->sacked & (TCPCB_LOST|TCPCB_SACKED_ACKED))) { + tp->lost_out += tcp_skb_pcount(skb); + TCP_SKB_CB(skb)->sacked |= TCPCB_LOST; + } +} + /* This procedure tags the retransmission queue when SACKs arrive. * * We have three tag bits: SACKED(S), RETRANS(R) and LOST(L). @@ -1178,13 +1188,7 @@ static void tcp_mark_lost_retrans(struct sock *sk) TCP_SKB_CB(skb)->sacked &= ~TCPCB_SACKED_RETRANS; tp->retrans_out -= tcp_skb_pcount(skb); - /* clear lost hint */ - tp->retransmit_skb_hint = NULL; - - if (!(TCP_SKB_CB(skb)->sacked & (TCPCB_LOST|TCPCB_SACKED_ACKED))) { - tp->lost_out += tcp_skb_pcount(skb); - TCP_SKB_CB(skb)->sacked |= TCPCB_LOST; - } + tcp_skb_mark_lost_uncond_verify(tp, skb); NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPLOSTRETRANSMIT); } else { if (before(ack_seq, new_low_seq)) @@ -1890,6 +1894,7 @@ static void tcp_enter_frto_loss(struct sock *sk, int allowed_segments, int flag) if (!(TCP_SKB_CB(skb)->sacked & TCPCB_SACKED_ACKED)) { TCP_SKB_CB(skb)->sacked |= TCPCB_LOST; tp->lost_out += tcp_skb_pcount(skb); + tp->retransmit_high = TCP_SKB_CB(skb)->end_seq; } } tcp_verify_left_out(tp); @@ -1974,6 +1979,7 @@ void tcp_enter_loss(struct sock *sk, int how) TCP_SKB_CB(skb)->sacked &= ~TCPCB_SACKED_ACKED; TCP_SKB_CB(skb)->sacked |= TCPCB_LOST; tp->lost_out += tcp_skb_pcount(skb); + tp->retransmit_high = TCP_SKB_CB(skb)->end_seq; } } tcp_verify_left_out(tp); |