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| author | Pablo Neira Ayuso <pablo@netfilter.org> | 2008-10-21 19:05:02 +0200 |
|---|---|---|
| committer | Pablo Neira Ayuso <pablo@netfilter.org> | 2008-10-21 19:05:02 +0200 |
| commit | 6d6ebd1247076c88ceeb8d9528d62cd38a5e909a (patch) | |
| tree | b3f871f627f6ab55908fdb9fdff8c204c7793064 /src/cache.c | |
| parent | 705435f574e45348f5613672588b453d6285ef20 (diff) | |
| download | conntrack-tools-6d6ebd1247076c88ceeb8d9528d62cd38a5e909a.tar.gz conntrack-tools-6d6ebd1247076c88ceeb8d9528d62cd38a5e909a.zip | |
cache: use jhash2 instead of double jhash+jhash_2words
Currently, oprofile reports ~17% of sample in the hashing. With
this patch, that uses jhash2 instead of a double call to jhash
and one to jhash_2words, it goes down to ~11%.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Diffstat (limited to 'src/cache.c')
| -rw-r--r-- | src/cache.c | 36 |
1 files changed, 17 insertions, 19 deletions
diff --git a/src/cache.c b/src/cache.c index 63a8cff..1d39fd5 100644 --- a/src/cache.c +++ b/src/cache.c @@ -30,15 +30,14 @@ static uint32_t __hash4(const struct nf_conntrack *ct, struct hashtable *table) { - unsigned int a, b; - - a = jhash(nfct_get_attr(ct, ATTR_ORIG_IPV4_SRC), sizeof(uint32_t), - ((nfct_get_attr_u8(ct, ATTR_ORIG_L3PROTO) << 16) | - (nfct_get_attr_u8(ct, ATTR_ORIG_L4PROTO)))); - - b = jhash(nfct_get_attr(ct, ATTR_ORIG_IPV4_DST), sizeof(uint32_t), - ((nfct_get_attr_u16(ct, ATTR_ORIG_PORT_SRC) << 16) | - (nfct_get_attr_u16(ct, ATTR_ORIG_PORT_DST)))); + uint32_t a[4] = { + [0] = nfct_get_attr_u32(ct, ATTR_IPV4_SRC), + [1] = nfct_get_attr_u32(ct, ATTR_IPV4_DST), + [2] = nfct_get_attr_u8(ct, ATTR_L3PROTO) << 16 | + nfct_get_attr_u8(ct, ATTR_L4PROTO), + [3] = nfct_get_attr_u16(ct, ATTR_PORT_SRC) << 16 | + nfct_get_attr_u16(ct, ATTR_PORT_DST), + }; /* * Instead of returning hash % table->hashsize (implying a divide) @@ -47,22 +46,21 @@ static uint32_t __hash4(const struct nf_conntrack *ct, struct hashtable *table) * but using a multiply, less expensive than a divide. See: * http://www.mail-archive.com/netdev@vger.kernel.org/msg56623.html */ - return ((uint64_t)jhash_2words(a, b, 0) * table->hashsize) >> 32; + return ((uint64_t)jhash2(a, 4, 0) * table->hashsize) >> 32; } static uint32_t __hash6(const struct nf_conntrack *ct, struct hashtable *table) { - unsigned int a, b; - - a = jhash(nfct_get_attr(ct, ATTR_ORIG_IPV6_SRC), sizeof(uint32_t)*4, - ((nfct_get_attr_u8(ct, ATTR_ORIG_L3PROTO) << 16) | - (nfct_get_attr_u8(ct, ATTR_ORIG_L4PROTO)))); + uint32_t a[10]; - b = jhash(nfct_get_attr(ct, ATTR_ORIG_IPV6_DST), sizeof(uint32_t)*4, - ((nfct_get_attr_u16(ct, ATTR_ORIG_PORT_SRC) << 16) | - (nfct_get_attr_u16(ct, ATTR_ORIG_PORT_DST)))); + memcpy(&a[0], nfct_get_attr(ct, ATTR_IPV6_SRC), sizeof(uint32_t)*4); + memcpy(&a[4], nfct_get_attr(ct, ATTR_IPV6_SRC), sizeof(uint32_t)*4); + a[8] = nfct_get_attr_u8(ct, ATTR_ORIG_L3PROTO) << 16 | + nfct_get_attr_u8(ct, ATTR_ORIG_L4PROTO); + a[9] = nfct_get_attr_u16(ct, ATTR_ORIG_PORT_SRC) << 16 | + nfct_get_attr_u16(ct, ATTR_ORIG_PORT_DST); - return ((uint64_t)jhash_2words(a, b, 0) * table->hashsize) >> 32; + return ((uint64_t)jhash2(a, 10, 0) * table->hashsize) >> 32; } static uint32_t hash(const void *data, struct hashtable *table) |