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[NETFILTER]: nf_conntrack: optimize hash_conntrack() 

Avoid calling jhash three times and hash the entire tuple in one go.

  __hash_conntrack | -485 # 760 -> 275, # inlines: 3 -> 1, size inlines: 717 -> 252
 1 function changed, 485 bytes removed

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Patrick McHardy 2008-01-31 04:40:52 -08:00 committed by David S. Miller
parent 380517dead
commit 0794935e21
1 changed files with 11 additions and 7 deletions
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18
net/netfilter/nf_conntrack_core.c
View File

@ -73,15 +73,19 @@ static unsigned int nf_conntrack_hash_rnd;
static u_int32_t __hash_conntrack(const struct nf_conntrack_tuple *tuple,
unsigned int size, unsigned int rnd)
{
unsigned int a, b;
unsigned int n;
u_int32_t h;
a = jhash2(tuple->src.u3.all, ARRAY_SIZE(tuple->src.u3.all),
(tuple->src.l3num << 16) | tuple->dst.protonum);
b = jhash2(tuple->dst.u3.all, ARRAY_SIZE(tuple->dst.u3.all),
((__force __u16)tuple->src.u.all << 16) |
(__force __u16)tuple->dst.u.all);
/* The direction must be ignored, so we hash everything up to the
* destination ports (which is a multiple of 4) and treat the last
* three bytes manually.
*/
n = (sizeof(tuple->src) + sizeof(tuple->dst.u3)) / sizeof(u32);
h = jhash2((u32 *)tuple, n,
rnd ^ (((__force __u16)tuple->dst.u.all << 16) |
tuple->dst.protonum));
return ((u64)jhash_2words(a, b, rnd) * size) >> 32;
return ((u64)h * size) >> 32;
}
static inline u_int32_t hash_conntrack(const struct nf_conntrack_tuple *tuple)