jpountz opened a new pull request, #13381: URL: https://github.com/apache/lucene/pull/13381
As Robert pointed out and benchmarks confirmed, there is some (small) overhead to calling `madvise` via the foreign function API, benchmarks suggest it is in the order of 1-2us. This is not much for a single call, but may become non-negligible across many calls. Until now, we only looked into using prefetch() for terms, skip data and postings start pointers which are a single prefetch() operation per segment per term. But we may want to start using it in cases that could result into more calls to `madvise`, e.g. if we start using it for stored fields and a user requests 10k documents. In #13337, Robert wondered if we could take advantage of `mincore()` to reduce the overhead of `IndexInput#prefetch()`, which is what this PR is doing. For now, this is trying to not add new APIs. Instead, `IndexInput#prefetch` tracks consecutive hits on the page cache and calls `madvise` less and less frequently under the hood as the number of cache hits increases. -- 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
