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author | Eric Dumazet <edumazet@google.com> | 2012-07-18 08:11:12 +0000 |
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committer | David S. Miller <davem@davemloft.net> | 2012-07-18 11:28:46 -0700 |
commit | ddbe503203855939946430e39bae58de11b70b69 (patch) | |
tree | 1605a8d3b14a92819eb8ed47ae5a84c1b66e12f8 /include/net/ipv6.h | |
parent | dc9059512c09d09b99de6cd3a8bc842507934cbb (diff) | |
download | kernel_goldelico_gta04-ddbe503203855939946430e39bae58de11b70b69.zip kernel_goldelico_gta04-ddbe503203855939946430e39bae58de11b70b69.tar.gz kernel_goldelico_gta04-ddbe503203855939946430e39bae58de11b70b69.tar.bz2 |
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/ipv6.h')
-rw-r--r-- | include/net/ipv6.h | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/include/net/ipv6.h b/include/net/ipv6.h index f695f39..01c34b3 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] | |