diff options
| author | Baruch Even <baruch@ev-en.org> | 2007-02-04 23:35:57 -0800 |
|---|---|---|
| committer | David S. Miller <davem@sunset.davemloft.net> | 2007-02-08 12:38:48 -0800 |
| commit | fda03fbb56bf88f1fb1c57b2474082e5addaa884 (patch) | |
| tree | b6067b0be2ee1bd65c704a1db893b45cd4920cc9 /net | |
| parent | ffbc61117d32dc4e768f999325ecfb2528d6b303 (diff) | |
[TCP]: Advance fast path pointer for first block only
Only advance the SACK fast-path pointer for the first block, the
fast-path assumes that only the first block advances next time so we
should not move the cached skb for the next sack blocks.
Signed-off-by: Baruch Even <baruch@ev-en.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
| -rw-r--r-- | net/ipv4/tcp_input.c | 34 |
1 files changed, 24 insertions, 10 deletions
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index c26076fb890..7670ef968dc 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -936,13 +936,16 @@ tcp_sacktag_write_queue(struct sock *sk, struct sk_buff *ack_skb, u32 prior_snd_ struct tcp_sock *tp = tcp_sk(sk); unsigned char *ptr = ack_skb->h.raw + TCP_SKB_CB(ack_skb)->sacked; struct tcp_sack_block_wire *sp = (struct tcp_sack_block_wire *)(ptr+2); + struct sk_buff *cached_skb; int num_sacks = (ptr[1] - TCPOLEN_SACK_BASE)>>3; int reord = tp->packets_out; int prior_fackets; u32 lost_retrans = 0; int flag = 0; int dup_sack = 0; + int cached_fack_count; int i; + int first_sack_index; if (!tp->sacked_out) tp->fackets_out = 0; @@ -1000,6 +1003,7 @@ tcp_sacktag_write_queue(struct sock *sk, struct sk_buff *ack_skb, u32 prior_snd_ } } + first_sack_index = 0; if (flag) num_sacks = 1; else { @@ -1016,6 +1020,10 @@ tcp_sacktag_write_queue(struct sock *sk, struct sk_buff *ack_skb, u32 prior_snd_ tmp = sp[j]; sp[j] = sp[j+1]; sp[j+1] = tmp; + + /* Track where the first SACK block goes to */ + if (j == first_sack_index) + first_sack_index = j+1; } } @@ -1025,20 +1033,22 @@ tcp_sacktag_write_queue(struct sock *sk, struct sk_buff *ack_skb, u32 prior_snd_ /* clear flag as used for different purpose in following code */ flag = 0; + /* Use SACK fastpath hint if valid */ + cached_skb = tp->fastpath_skb_hint; + cached_fack_count = tp->fastpath_cnt_hint; + if (!cached_skb) { + cached_skb = sk->sk_write_queue.next; + cached_fack_count = 0; + } + for (i=0; i<num_sacks; i++, sp++) { struct sk_buff *skb; __u32 start_seq = ntohl(sp->start_seq); __u32 end_seq = ntohl(sp->end_seq); int fack_count; - /* Use SACK fastpath hint if valid */ - if (tp->fastpath_skb_hint) { - skb = tp->fastpath_skb_hint; - fack_count = tp->fastpath_cnt_hint; - } else { - skb = sk->sk_write_queue.next; - fack_count = 0; - } + skb = cached_skb; + fack_count = cached_fack_count; /* Event "B" in the comment above. */ if (after(end_seq, tp->high_seq)) @@ -1048,8 +1058,12 @@ tcp_sacktag_write_queue(struct sock *sk, struct sk_buff *ack_skb, u32 prior_snd_ int in_sack, pcount; u8 sacked; - tp->fastpath_skb_hint = skb; - tp->fastpath_cnt_hint = fack_count; + cached_skb = skb; + cached_fack_count = fack_count; + if (i == first_sack_index) { + tp->fastpath_skb_hint = skb; + tp->fastpath_cnt_hint = fack_count; + } /* The retransmission queue is always in order, so * we can short-circuit the walk early. |