i think from my perspective it has nothing to do with cpus being 32-bit or 64-bit and more to do with the average length of terms in most languages being smaller than 8. for the languages with longer word length, its usually because of complex morphology that most users would stem away. so doing 4 bytes at a time seems optimal IMO. languages from nature don't care about your cpu.
On Tue, Apr 25, 2023 at 8:52 AM Michael McCandless <luc...@mikemccandless.com> wrote: > > For a truly "pure" indexing test I usually use a single thread for indexing, > and SerialMergeScheduler (using that single thread to also do single-threaded > merging). It makes the indexing take forever lol but it produces > "comparable" results. > > But ... this sounds like a great change anyway? Do we really need to gate it > on benchmark results? Do we think there could be a downside e.g. slower > indexing on (the dwindling) 32 bit CPUs? > > Mike McCandless > > http://blog.mikemccandless.com > > > On Tue, Apr 25, 2023 at 7:39 AM Robert Muir <rcm...@gmail.com> wrote: >> >> I think the results of the benchmark will depend on the properties of >> the indexed terms. For english wikipedia (luceneutil) the average word >> length is around 5 bytes so this optimization may not do much. >> >> On Tue, Apr 25, 2023 at 1:58 AM Patrick Zhai <zhai7...@gmail.com> wrote: >> > >> > I did a quick run with your patch, but since I turned on the CMS as well >> > as TieredMergePolicy I'm not sure how fair the comparison is. Here's the >> > result: >> > Candidate: >> > Indexer: indexing done (890209 msec); total 33332620 docs >> > Indexer: waitForMerges done (71622 msec) >> > Indexer: finished (961877 msec) >> > Baseline: >> > Indexer: indexing done (909706 msec); total 33332620 docs >> > Indexer: waitForMerges done (54775 msec) >> > Indexer: finished (964528 msec) >> > >> > For more accurate comparison I guess it's better to use LogxxMergePolicy >> > and turn off CMS? If you want to run it yourself you can find the lines I >> > quoted from the log file. >> > >> > Patrick >> > >> > On Mon, Apr 24, 2023 at 12:34 PM Thomas Dullien >> > <thomas.dull...@elastic.co.invalid> wrote: >> >> >> >> Hey all, >> >> >> >> I've been experimenting with fixing some low-hanging performance fruit in >> >> the ElasticSearch codebase, and came across the fact that the MurmurHash >> >> implementation that is used by ByteRef.hashCode() is reading 4 bytes per >> >> loop iteration (which is likely an artifact from 32-bit architectures, >> >> which are ever-less-important). I made a small fix to change the >> >> implementation to read 8 bytes per loop iteration; I expected a very >> >> small impact (2-3% CPU or so over an indexing run in ElasticSearch), but >> >> got a pretty nontrivial throughput improvement over a few indexing >> >> benchmarks. >> >> >> >> I tried running Lucene-only benchmarks, and succeeded in running the >> >> example from https://github.com/mikemccand/luceneutil - but I couldn't >> >> figure out how to run indexing benchmarks and how to interpret the >> >> results. >> >> >> >> Could someone help me in running the benchmarks for the attached patch? >> >> >> >> Cheers, >> >> Thomas >> >> >> >> --------------------------------------------------------------------- >> >> To unsubscribe, e-mail: dev-unsubscr...@lucene.apache.org >> >> For additional commands, e-mail: dev-h...@lucene.apache.org >> >> --------------------------------------------------------------------- >> To unsubscribe, e-mail: dev-unsubscr...@lucene.apache.org >> For additional commands, e-mail: dev-h...@lucene.apache.org >> --------------------------------------------------------------------- To unsubscribe, e-mail: dev-unsubscr...@lucene.apache.org For additional commands, e-mail: dev-h...@lucene.apache.org
