fat_hash() is using the algorithm known as bad. Instead of it, this
uses hash_32(). The following is the summary of test.
old hash:
hash func (1000 times): 33489 cycles
total inodes in hash table: 70926
largest bucket contains: 696
smallest bucket contains: 54
new hash:
hash func (1000 times): 33129 cycles
total inodes in hash table: 70926
largest bucket contains: 315
smallest bucket contains: 236
Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
d3dfa8228f