diff options
| author | Eric Dumazet <edumazet@google.com> | 2012-07-18 08:11:12 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2012-07-18 11:28:46 -0700 |
| commit | ddbe503203855939946430e39bae58de11b70b69 (patch) | |
| tree | 1605a8d3b14a92819eb8ed47ae5a84c1b66e12f8 /include/net | |
| parent | dc9059512c09d09b99de6cd3a8bc842507934cbb (diff) | |
ipv6: add ipv6_addr_hash() helper
Introduce ipv6_addr_hash() helper doing a XOR on all bits
of an IPv6 address, with an optimized x86_64 version.
Use it in flow dissector, as suggested by Andrew McGregor,
to reduce hash collision probabilities in fq_codel (and other
users of flow dissector)
Use it in ip6_tunnel.c and use more bit shuffling, as suggested
by David Laight, as existing hash was ignoring most of them.
Use it in sunrpc and use more bit shuffling, using hash_32().
Use it in net/ipv6/addrconf.c, using hash_32() as well.
As a cleanup, use it in net/ipv4/tcp_metrics.c
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Andrew McGregor <andrewmcgr@gmail.com>
Cc: Dave Taht <dave.taht@gmail.com>
Cc: Tom Herbert <therbert@google.com>
Cc: David Laight <David.Laight@ACULAB.COM>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include/net')
| -rw-r--r-- | include/net/addrconf.h | 3 | ||||
| -rw-r--r-- | include/net/ipv6.h | 13 |
2 files changed, 15 insertions, 1 deletions
diff --git a/include/net/addrconf.h b/include/net/addrconf.h index f2b801c4b55..089a09d001d 100644 --- a/include/net/addrconf.h +++ b/include/net/addrconf.h @@ -46,7 +46,8 @@ struct prefix_info { #include <net/if_inet6.h> #include <net/ipv6.h> -#define IN6_ADDR_HSIZE 16 +#define IN6_ADDR_HSIZE_SHIFT 4 +#define IN6_ADDR_HSIZE (1 << IN6_ADDR_HSIZE_SHIFT) extern int addrconf_init(void); extern void addrconf_cleanup(void); diff --git a/include/net/ipv6.h b/include/net/ipv6.h index f695f39e892..01c34b363a3 100644 --- a/include/net/ipv6.h +++ b/include/net/ipv6.h @@ -419,6 +419,19 @@ static inline bool ipv6_addr_any(const struct in6_addr *a) #endif } +static inline u32 ipv6_addr_hash(const struct in6_addr *a) +{ +#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64 + const unsigned long *ul = (const unsigned long *)a; + unsigned long x = ul[0] ^ ul[1]; + + return (u32)(x ^ (x >> 32)); +#else + return (__force u32)(a->s6_addr32[0] ^ a->s6_addr32[1] ^ + a->s6_addr32[2] ^ a->s6_addr32[3]); +#endif +} + static inline bool ipv6_addr_loopback(const struct in6_addr *a) { return (a->s6_addr32[0] | a->s6_addr32[1] | |