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| author | Eric Dumazet <eric.dumazet@gmail.com> | 2011-11-29 00:30:35 +0400 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2011-11-29 22:17:03 +0400 |
| commit | 4d77d2b567ec66a443792d99e96ac760991d80d0 (patch) | |
| tree | 8724a150e73cf33fd8a2f36f2b2432af3a78a3e8 | |
| parent | c3940999b29ca7d6ad9b37b827a058c90fd51992 (diff) | |
| download | linux-4d77d2b567ec66a443792d99e96ac760991d80d0.tar.xz | |
flow_dissector: use a 64bit load/store
Le lundi 28 novembre 2011 à 19:06 -0500, David Miller a écrit :
> From: Dimitris Michailidis <dm@chelsio.com>
> Date: Mon, 28 Nov 2011 08:25:39 -0800
>
> >> +bool skb_flow_dissect(const struct sk_buff *skb, struct flow_keys
> >> *flow)
> >> +{
> >> + int poff, nhoff = skb_network_offset(skb);
> >> + u8 ip_proto;
> >> + u16 proto = skb->protocol;
> >
> > __be16 instead of u16 for proto?
>
> I'll take care of this when I apply these patches.
( CC trimmed )
Thanks David !
Here is a small patch to use one 64bit load/store on x86_64 instead of
two 32bit load/stores.
[PATCH net-next] flow_dissector: use a 64bit load/store
gcc compiler is smart enough to use a single load/store if we
memcpy(dptr, sptr, 8) on x86_64, regardless of
CONFIG_CC_OPTIMIZE_FOR_SIZE
In IP header, daddr immediately follows saddr, this wont change in the
future. We only need to make sure our flow_keys (src,dst) fields wont
break the rule.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | include/net/flow_keys.h | 1 | ||||
| -rw-r--r-- | net/core/flow_dissector.c | 13 |
2 files changed, 12 insertions, 2 deletions
diff --git a/include/net/flow_keys.h b/include/net/flow_keys.h index e4cb28526563..80461c1ae9ef 100644 --- a/include/net/flow_keys.h +++ b/include/net/flow_keys.h @@ -2,6 +2,7 @@ #define _NET_FLOW_KEYS_H struct flow_keys { + /* (src,dst) must be grouped, in the same way than in IP header */ __be32 src; __be32 dst; union { diff --git a/net/core/flow_dissector.c b/net/core/flow_dissector.c index f0516d9280c3..0985b9b14b80 100644 --- a/net/core/flow_dissector.c +++ b/net/core/flow_dissector.c @@ -8,6 +8,16 @@ #include <linux/ppp_defs.h> #include <net/flow_keys.h> +/* copy saddr & daddr, possibly using 64bit load/store + * Equivalent to : flow->src = iph->saddr; + * flow->dst = iph->daddr; + */ +static void iph_to_flow_copy_addrs(struct flow_keys *flow, const struct iphdr *iph) +{ + BUILD_BUG_ON(offsetof(typeof(*flow), dst) != + offsetof(typeof(*flow), src) + sizeof(flow->src)); + memcpy(&flow->src, &iph->saddr, sizeof(flow->src) + sizeof(flow->dst)); +} bool skb_flow_dissect(const struct sk_buff *skb, struct flow_keys *flow) { @@ -31,8 +41,7 @@ ip: ip_proto = 0; else ip_proto = iph->protocol; - flow->src = iph->saddr; - flow->dst = iph->daddr; + iph_to_flow_copy_addrs(flow, iph); nhoff += iph->ihl * 4; break; } |