On Fri, Oct 20, 2023 at 05:18:56PM +0900, Michael Paquier wrote: > On Fri, Oct 20, 2023 at 07:08:58AM +0000, Xiang Gao wrote: >> This patch uses a parallel computing optimization algorithm to >> improve crc32c computing performance on ARM. The algorithm comes >> from Intel whitepaper: >> crc-iscsi-polynomial-crc32-instruction-paper. Input data is divided >> into three equal-sized blocks.Three parallel blocks (crc0, crc1, >> crc2) for 1024 Bytes.One Block: 42(BLK_LENGTH) * 8(step length: >> crc32c_u64) bytes >> >> Crc32c unitest: >> https://gist.github.com/gaoxyt/138fd53ca1eead8102eeb9204067f7e4 >> Crc32c benchmark: >> https://gist.github.com/gaoxyt/4506c10fc06b3501445e32c4257113e9 >> It gets ~2x speedup compared to linear Arm crc32c instructions. > > Interesting. Could you attached to this thread the test files you > used and the results obtained please? If this data gets deleted from > github, then it would not be possible to refer back to what you did at > the related benchmark results. > > Note that your patch is forgetting about meson; it just patches > ./configure.
I'm able to reproduce the speedup with the provided benchmark on an Apple M1 Pro (which appears to have the required instructions). There was almost no change for the 512-byte case, but there was a ~60% speedup for the 4096-byte case. However, I couldn't produce any noticeable speedup with Heikki's pg_waldump benchmark [0]. I haven't had a chance to dig further, unfortunately. Assuming I'm not doing something wrong, I don't think such a result should necessarily disqualify this optimization, though. [0] https://postgr.es/m/ec487192-f6aa-509a-cacb-6642dad14209%40iki.fi -- Nathan Bossart Amazon Web Services: https://aws.amazon.com
