diff options
| author | David S. Miller <davem@davemloft.net> | 2014-09-28 16:35:49 -0400 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2014-09-28 16:35:49 -0400 |
| commit | dc83d4d8f6c897022c974a00769b7a6efee6aed8 (patch) | |
| tree | 0d769e6155899c89ae95c3e31c79ce011eb96a39 /net/ipv6/tcp_ipv6.c | |
| parent | ff04a771ad25fc9ba91690e73465b4d34b6bf8b3 (diff) | |
| parent | 971f10eca186cab238c49daa91f703c5a001b0b1 (diff) | |
Merge branch 'tcp_skb_cb'
Eric Dumazet says:
====================
tcp: better TCP_SKB_CB layout
TCP had the assumption that IPCB and IP6CB are first members of skb->cb[]
This is fine, except that IPCB/IP6CB are used in TCP for a very short time
in input path.
What really matters for TCP stack is to get skb->next,
TCP_SKB_CB(skb)->seq, and TCP_SKB_CB(skb)->end_seq in the same cache line.
skb that are immediately consumed do not care because whole skb->cb[] is
hot in cpu cache, while skb that sit in wocket write queue or receive queues
do not need TCP_SKB_CB(skb)->header at all.
This patch set implements the prereq for IPv4, IPv6, and TCP to make this
possible. This makes TCP more efficient.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv6/tcp_ipv6.c')
| -rw-r--r-- | net/ipv6/tcp_ipv6.c | 12 |
1 files changed, 10 insertions, 2 deletions
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c index de51a88bec6..132bac137ae 100644 --- a/net/ipv6/tcp_ipv6.c +++ b/net/ipv6/tcp_ipv6.c @@ -742,7 +742,8 @@ static void tcp_v6_init_req(struct request_sock *req, struct sock *sk, ireq->ir_iif = inet6_iif(skb); if (!TCP_SKB_CB(skb)->tcp_tw_isn && - (ipv6_opt_accepted(sk, skb) || np->rxopt.bits.rxinfo || + (ipv6_opt_accepted(sk, skb, &TCP_SKB_CB(skb)->header.h6) || + np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo || np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim || np->repflow)) { atomic_inc(&skb->users); @@ -1367,7 +1368,7 @@ ipv6_pktoptions: np->rcv_flowinfo = ip6_flowinfo(ipv6_hdr(opt_skb)); if (np->repflow) np->flow_label = ip6_flowlabel(ipv6_hdr(opt_skb)); - if (ipv6_opt_accepted(sk, opt_skb)) { + if (ipv6_opt_accepted(sk, opt_skb, &TCP_SKB_CB(opt_skb)->header.h6)) { skb_set_owner_r(opt_skb, sk); opt_skb = xchg(&np->pktoptions, opt_skb); } else { @@ -1411,6 +1412,13 @@ static int tcp_v6_rcv(struct sk_buff *skb) th = tcp_hdr(skb); hdr = ipv6_hdr(skb); + /* This is tricky : We move IPCB at its correct location into TCP_SKB_CB() + * barrier() makes sure compiler wont play fool^Waliasing games. + */ + memmove(&TCP_SKB_CB(skb)->header.h6, IP6CB(skb), + sizeof(struct inet6_skb_parm)); + barrier(); + TCP_SKB_CB(skb)->seq = ntohl(th->seq); TCP_SKB_CB(skb)->end_seq = (TCP_SKB_CB(skb)->seq + th->syn + th->fin + skb->len - th->doff*4); |