diff options
author | Sage Weil <sage@newdream.net> | 2009-11-06 16:39:26 -0800 |
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committer | Sage Weil <sage@newdream.net> | 2009-11-06 16:39:26 -0800 |
commit | c6cf726316abd613cfb7c325d950f3629f964ec6 (patch) | |
tree | 446a686988656a355ee7ff94a43912c94f36ac63 /fs/ceph/crush/hash.c | |
parent | 1bdb70e59026838a79f77c440f8fe480a66e65e8 (diff) |
ceph: make CRUSH hash functions non-inline
These are way to big to be inline. I missed crush/* when doing the inline
audit for akpm's review.
Signed-off-by: Sage Weil <sage@newdream.net>
Diffstat (limited to 'fs/ceph/crush/hash.c')
-rw-r--r-- | fs/ceph/crush/hash.c | 86 |
1 files changed, 86 insertions, 0 deletions
diff --git a/fs/ceph/crush/hash.c b/fs/ceph/crush/hash.c new file mode 100644 index 00000000000..b438c5d2781 --- /dev/null +++ b/fs/ceph/crush/hash.c @@ -0,0 +1,86 @@ + +#include <linux/types.h> + +/* + * Robert Jenkins' function for mixing 32-bit values + * http://burtleburtle.net/bob/hash/evahash.html + * a, b = random bits, c = input and output + */ +#define crush_hashmix(a, b, c) do { \ + a = a-b; a = a-c; a = a^(c>>13); \ + b = b-c; b = b-a; b = b^(a<<8); \ + c = c-a; c = c-b; c = c^(b>>13); \ + a = a-b; a = a-c; a = a^(c>>12); \ + b = b-c; b = b-a; b = b^(a<<16); \ + c = c-a; c = c-b; c = c^(b>>5); \ + a = a-b; a = a-c; a = a^(c>>3); \ + b = b-c; b = b-a; b = b^(a<<10); \ + c = c-a; c = c-b; c = c^(b>>15); \ + } while (0) + +#define crush_hash_seed 1315423911 + +__u32 crush_hash32(__u32 a) +{ + __u32 hash = crush_hash_seed ^ a; + __u32 b = a; + __u32 x = 231232; + __u32 y = 1232; + crush_hashmix(b, x, hash); + crush_hashmix(y, a, hash); + return hash; +} + +__u32 crush_hash32_2(__u32 a, __u32 b) +{ + __u32 hash = crush_hash_seed ^ a ^ b; + __u32 x = 231232; + __u32 y = 1232; + crush_hashmix(a, b, hash); + crush_hashmix(x, a, hash); + crush_hashmix(b, y, hash); + return hash; +} + +__u32 crush_hash32_3(__u32 a, __u32 b, __u32 c) +{ + __u32 hash = crush_hash_seed ^ a ^ b ^ c; + __u32 x = 231232; + __u32 y = 1232; + crush_hashmix(a, b, hash); + crush_hashmix(c, x, hash); + crush_hashmix(y, a, hash); + crush_hashmix(b, x, hash); + crush_hashmix(y, c, hash); + return hash; +} + +__u32 crush_hash32_4(__u32 a, __u32 b, __u32 c, __u32 d) +{ + __u32 hash = crush_hash_seed ^ a ^ b ^ c ^ d; + __u32 x = 231232; + __u32 y = 1232; + crush_hashmix(a, b, hash); + crush_hashmix(c, d, hash); + crush_hashmix(a, x, hash); + crush_hashmix(y, b, hash); + crush_hashmix(c, x, hash); + crush_hashmix(y, d, hash); + return hash; +} + +__u32 crush_hash32_5(__u32 a, __u32 b, __u32 c, __u32 d, __u32 e) +{ + __u32 hash = crush_hash_seed ^ a ^ b ^ c ^ d ^ e; + __u32 x = 231232; + __u32 y = 1232; + crush_hashmix(a, b, hash); + crush_hashmix(c, d, hash); + crush_hashmix(e, x, hash); + crush_hashmix(y, a, hash); + crush_hashmix(b, x, hash); + crush_hashmix(y, c, hash); + crush_hashmix(d, x, hash); + crush_hashmix(y, e, hash); + return hash; +} |