[PATCH v3 0/2] KSM: Replace jhash2 with xxhash

[Timofey Titovets <nefelim4ag@gmail.com>]

ksm use jhash2 for hashing pages,
in 4.14 xxhash has been merged to mainline kernel.

xxhash much faster then jhash2 on big inputs (32 byte+)

xxhash has 2 versions, one with 32-bit hash and
one with 64-bit hash.

64-bit version works faster then 32-bit on 64-bit arch.

So lets get better from two worlds,
create arch dependent xxhash() function that will use
fastest algo for current arch.
This a first patch.

Performance info and ksm update can be found in second patch.

Changelog:
  v1 -> v2:
    - Move xxhash() to xxhash.h/c and separate patches

  v2 -> v3:
    - Move xxhash() xxhash.c -> xxhash.h
    - replace xxhash_t with 'unsigned long'
    - update kerneldoc above xxhash()

Timofey Titovets (2):
  xxHash: create arch dependent 32/64-bit xxhash()
  KSM: Replace jhash2 with xxhash

 include/linux/xxhash.h | 23 +++++++++++++++++++++++
 mm/Kconfig             |  1 +
 mm/ksm.c               | 14 +++++++-------
 3 files changed, 31 insertions(+), 7 deletions(-)

--
2.14.1