| commit | e2f82ac3fcffffca59751b65124544d11ed8be4a | |
| author | Eric Dumazet <dada1@cosmosbay.com> | |
| Tue, 18 Dec 2007 06:45:13 +0000 (17 22:45 -0800) | ||
| committer | David S. Miller <davem@davemloft.net> | |
| Mon, 28 Jan 2008 22:59:10 +0000 (28 14:59 -0800) | ||
| tree | 9eba528eb094b79da8c471c3980c6a6b90f371b4 | treesnapshot (tar.gz zip) |
| parent | 22c2d8bca212a655c120fd6617328ffa3480afad | commitdiff |
[NETFILTER]: xt_hashlimit: speedup hash_dst()
1) Using jhash2() instead of jhash() is a litle bit faster if applicable.
2) Thanks to jhash, hash value uses full 32 bits.
Instead of returning hash % size (implying a divide)
we return the high 32 bits of the (hash * size) that will
give results between [0 and size-1] and same hash distribution.
On most cpus, a multiply is less expensive than a divide, by an order
of magnitude.
Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
1) Using jhash2() instead of jhash() is a litle bit faster if applicable.
2) Thanks to jhash, hash value uses full 32 bits.
Instead of returning hash % size (implying a divide)
we return the high 32 bits of the (hash * size) that will
give results between [0 and size-1] and same hash distribution.
On most cpus, a multiply is less expensive than a divide, by an order
of magnitude.
Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
| net/netfilter/xt_hashlimit.c | diffblobblamehistory |