RFR: 8310159: Bulk copy with Unsafe::arrayCopy is slower compared to memcpy [v4]
Steve Dohrmann
duke at openjdk.org
Thu Nov 16 21:26:47 UTC 2023
> Below is baseline data collected using a modified version of the java.lang.foreign.xor micro benchmark referenced by @mcimadamore in the bug report. I collected data on an Ubuntu 22.04 laptop with a Tigerlake i7-1185G7, which does support AVX512.
>
> Baseline data
> Benchmark (arrayKind) (sizeKind) Mode Cnt Score Error Units
> --------------------------------------------------------------------------------------
> XorTest.copy ELEMENTS SMALL avgt 30 584737355.767 ± 60414308.540 ns/op
> XorTest.copy ELEMENTS MEDIUM avgt 30 272248995.683 ± 2924954.498 ns/op
> XorTest.copy ELEMENTS LARGE avgt 30 1019200210.900 ± 28334453.652 ns/op
> XorTest.copy REGION SMALL avgt 30 7399944.164 ± 216821.819 ns/op
> XorTest.copy REGION MEDIUM avgt 30 20591454.558 ± 147398.572 ns/op
> XorTest.copy REGION LARGE avgt 30 21649266.051 ± 179263.875 ns/op
> XorTest.copy CRITICAL SMALL avgt 30 51079.357 ± 542.482 ns/op
> XorTest.copy CRITICAL MEDIUM avgt 30 2496.961 ± 11.375 ns/op
> XorTest.copy CRITICAL LARGE avgt 30 515.454 ± 5.831 ns/op
> XorTest.copy FOREIGN SMALL avgt 30 7558432.075 ± 79489.276 ns/op
> XorTest.copy FOREIGN MEDIUM avgt 30 19730666.341 ± 500505.099 ns/op
> XorTest.copy FOREIGN LARGE avgt 30 34616758.085 ± 340300.726 ns/op
> XorTest.xor ELEMENTS SMALL avgt 30 219832692.489 ± 2329417.319 ns/op
> XorTest.xor ELEMENTS MEDIUM avgt 30 505138197.167 ± 3818334.424 ns/op
> XorTest.xor ELEMENTS LARGE avgt 30 1189608474.667 ± 5877981.900 ns/op
> XorTest.xor REGION SMALL avgt 30 64093872.804 ± 599704.491 ns/op
> XorTest.xor REGION MEDIUM avgt 30 81544576.454 ± 1406342.118 ns/op
> XorTest.xor REGION LARGE avgt 30 90091424.883 ± 775577.613 ns/op
> XorTest.xor CRITICAL SMALL avgt 30 57231375.744 ± 438223.342 ns/op
> XorTest.xor CRITICAL MEDIUM avgt 30 58583884.930 ± 375355.215 ns/op
> XorTest.xor CRITICAL LARGE avgt 30 60644832.949 ± 588120.738 ns/op
> XorTest.xor FOREIGN SMALL avgt 30 73868679.405 ± 819965.524 ns/op
> XorTest.xor FOREIGN MEDIUM avgt 30 88156275.944 ± 1051257.152 ns/op
> XorTest.xor FOREIGN LARGE avgt 30 123115513...
Steve Dohrmann has updated the pull request incrementally with one additional commit since the last revision:
- fix whitespace error
-------------
Changes:
- all: https://git.openjdk.org/jdk/pull/16575/files
- new: https://git.openjdk.org/jdk/pull/16575/files/10313c9a..3dbf3d5a
Webrevs:
- full: https://webrevs.openjdk.org/?repo=jdk&pr=16575&range=03
- incr: https://webrevs.openjdk.org/?repo=jdk&pr=16575&range=02-03
Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod
Patch: https://git.openjdk.org/jdk/pull/16575.diff
Fetch: git fetch https://git.openjdk.org/jdk.git pull/16575/head:pull/16575
PR: https://git.openjdk.org/jdk/pull/16575
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