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H A D | ksm.c | diff 59e1a2f4bf83744e748636415fde7d1e9f557e05 Fri Dec 28 09:34:05 CET 2018 Timofey Titovets <nefelim4ag@gmail.com> 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>
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H A D | Kconfig | diff 59e1a2f4bf83744e748636415fde7d1e9f557e05 Fri Dec 28 09:34:05 CET 2018 Timofey Titovets <nefelim4ag@gmail.com> 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>
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