diff options
| author | George Spelvin <linux@sciencehorizons.net> | 2016-06-10 07:22:12 +0300 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-06-12 00:57:56 +0300 |
| commit | 703b5faf22fbddf984a361e6555f3a03fdba63d9 (patch) | |
| tree | 6bcfde71273dc055ba28abedd8305d6a829639f5 /include/linux/stringhash.h | |
| parent | 8387ff2577eb9ed245df9a39947f66976c6bcd02 (diff) | |
| download | linux-703b5faf22fbddf984a361e6555f3a03fdba63d9.tar.xz | |
fs/dcache.c: Save one 32-bit multiply in dcache lookup
Noe that we're mixing in the parent pointer earlier, we
don't need to use hash_32() to mix its bits. Instead, we can
just take the msbits of the hash value directly.
For those applications which use the partial_name_hash(),
move the multiply to end_name_hash.
Signed-off-by: George Spelvin <linux@sciencehorizons.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/linux/stringhash.h')
| -rw-r--r-- | include/linux/stringhash.h | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/include/linux/stringhash.h b/include/linux/stringhash.h index eb7debb280c0..7c2d95170d01 100644 --- a/include/linux/stringhash.h +++ b/include/linux/stringhash.h @@ -3,6 +3,7 @@ #include <linux/compiler.h> /* For __pure */ #include <linux/types.h> /* For u32, u64 */ +#include <linux/hash.h> /* * Routines for hashing strings of bytes to a 32-bit hash value. @@ -45,11 +46,12 @@ partial_name_hash(unsigned long c, unsigned long prevhash) /* * Finally: cut down the number of bits to a int value (and try to avoid - * losing bits) + * losing bits). This also has the property (wanted by the dcache) + * that the msbits make a good hash table index. */ static inline unsigned long end_name_hash(unsigned long hash) { - return (unsigned int)hash; + return __hash_32((unsigned int)hash); } /* |