mikemccand commented on issue #14671: URL: https://github.com/apache/lucene/issues/14671#issuecomment-2891105182
Oooh the nightly `knnPerfTest.py` benchy also noted a jump in `Visited Node Count (K)` chart: https://benchmarks.mikemccandless.com/knnResults.html#k_total_visited starting 2025-05-11. Does that align with the regression in this issue? > performance seems to have recovered on https://benchmarks.mikemccandless.com/PreFilteredVectorSearch.html but @mikemccand have you reverted this whlle playing around with java version? Oh sorry, yes, annotations `IG` (upgrade Java 23 -> 24, and Linux kernel 6.12.4 -> 6.14.4) showed a slowdown (we now think due to kernel upgrade, specifically the change to `HZ` kernel config, [see discussion here](https://github.com/apache/lucene/issues/14630)), `IH` (downgrade back to Java 23 and fix Lucene at commit just before the Java 24 upgrade, which I think reverted the Lucene change causing this regression, since perf recovered to the `IG` level), and then `II`, where I also reverted the Linux kernel back to 6.12.4 and recovered all the performance regression here. I've kicked off another Lucene nightly benchy run now ... with Lucene back to `main` tip, Java back to 24, and Linux kernel now further upgraded to 6.14.6 ... I expect this will show some regression to pre-filtered KNN, back to the `IG` level. I.e. we are accepting that [the Linux kernel HZ change (from 250 -> 1000) hurts performance of some Lucene tasks](https://github.com/apache/lucene/issues/14630#issuecomment-2887482208) and leaving these annotations to explain it to our future selves. Oh I'll also add an annotation for this issue's regression. So many moving parts!!! -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: issues-unsubscr...@lucene.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: issues-unsubscr...@lucene.apache.org For additional commands, e-mail: issues-h...@lucene.apache.org
