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| author | Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> | 2008-11-24 21:26:56 -0800 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2008-11-24 21:26:56 -0800 |
| commit | 92ee76b6d99bfcdab6162816c9025541ef7248eb (patch) | |
| tree | 84ff34e13792073b32e8e767f47598e373d2689d /net/ipv4 | |
| parent | 832d11c5cd076abc0aa1eaf7be96c81d1a59ce41 (diff) | |
| download | linux-92ee76b6d99bfcdab6162816c9025541ef7248eb.tar.gz linux-92ee76b6d99bfcdab6162816c9025541ef7248eb.tar.bz2 linux-92ee76b6d99bfcdab6162816c9025541ef7248eb.zip | |
tcp: Make shifting not clear the hints
The earlier version was just very basic one which is "playing
safe" by always clearing the hints. However, clearing of a hint
is extremely costly operation with large windows, so it must be
avoided at all cost whenever possible, there is a way with
shifting too achieve not-clearing.
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4')
| -rw-r--r-- | net/ipv4/tcp_input.c | 16 |
1 files changed, 14 insertions, 2 deletions
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index 97d57676b8ee..e6291dde3348 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -1379,6 +1379,11 @@ static int tcp_shifted_skb(struct sock *sk, struct sk_buff *prev, BUG_ON(!pcount); + /* Tweak before seqno plays */ + if (!tcp_is_fack(tp) && tcp_is_sack(tp) && tp->lost_skb_hint && + !before(TCP_SKB_CB(tp->lost_skb_hint)->seq, TCP_SKB_CB(skb)->seq)) + tp->lost_cnt_hint += pcount; + TCP_SKB_CB(prev)->end_seq += shifted; TCP_SKB_CB(skb)->seq += shifted; @@ -1408,8 +1413,6 @@ static int tcp_shifted_skb(struct sock *sk, struct sk_buff *prev, /* Difference in this won't matter, both ACKed by the same cumul. ACK */ TCP_SKB_CB(prev)->sacked |= (TCP_SKB_CB(skb)->sacked & TCPCB_EVER_RETRANS); - tcp_clear_all_retrans_hints(tp); - if (skb->len > 0) { BUG_ON(!tcp_skb_pcount(skb)); return 0; @@ -1417,6 +1420,15 @@ static int tcp_shifted_skb(struct sock *sk, struct sk_buff *prev, /* Whole SKB was eaten :-) */ + if (skb == tp->retransmit_skb_hint) + tp->retransmit_skb_hint = prev; + if (skb == tp->scoreboard_skb_hint) + tp->scoreboard_skb_hint = prev; + if (skb == tp->lost_skb_hint) { + tp->lost_skb_hint = prev; + tp->lost_cnt_hint -= tcp_skb_pcount(prev); + } + TCP_SKB_CB(skb)->flags |= TCP_SKB_CB(prev)->flags; if (skb == tcp_highest_sack(sk)) tcp_advance_highest_sack(sk, skb); |