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| author | Timofey Titovets | 2018-12-28 09:34:05 +0100 |
|---|---|---|
| committer | Linus Torvalds | 2018-12-28 21:11:46 +0100 |
| commit | 59e1a2f4bf83744e748636415fde7d1e9f557e05 (patch) | |
| tree | cc25e2343b4d9be364d9fbd04de37a7326d796cd /mm/mmap.c | |
| parent | xxHash: create arch dependent 32/64-bit xxhash() (diff) | |
| download | kernel-qcow2-linux-59e1a2f4bf83744e748636415fde7d1e9f557e05.tar.gz kernel-qcow2-linux-59e1a2f4bf83744e748636415fde7d1e9f557e05.tar.xz kernel-qcow2-linux-59e1a2f4bf83744e748636415fde7d1e9f557e05.zip | |
ksm: replace jhash2 with xxhash
Replace jhash2 with xxhash.
Perf numbers:
Intel(R) Xeon(R) CPU E5-2420 v2 @ 2.20GHz
ksm: crc32c hash() 12081 MB/s
ksm: xxh64 hash() 8770 MB/s
ksm: xxh32 hash() 4529 MB/s
ksm: jhash2 hash() 1569 MB/s
Sioh Lee did some testing:
crc32c_intel: 1084.10ns
crc32c (no hardware acceleration): 7012.51ns
xxhash32: 2227.75ns
xxhash64: 1413.16ns
jhash2: 5128.30ns
As jhash2 always will be slower (for data size like PAGE_SIZE). Don't use
it in ksm at all.
Use only xxhash for now, because for using crc32c, cryptoapi must be
initialized first - that requires some tricky solution to work well in all
situations.
Link: http://lkml.kernel.org/r/20181023182554.23464-3-nefelim4ag@gmail.com
Signed-off-by: Timofey Titovets <nefelim4ag@gmail.com>
Signed-off-by: leesioh <solee@os.korea.ac.kr>
Reviewed-by: Pavel Tatashin <pavel.tatashin@microsoft.com>
Reviewed-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/mmap.c')
0 files changed, 0 insertions, 0 deletions