[ http://issues.apache.org/jira/browse/LUCENE-639?page=comments#action_12425597 ] Yonik Seeley commented on LUCENE-639: -------------------------------------
Here's the simple TermDoc iteration test I used: http://svn.apache.org/viewvc/lucene/java/trunk/src/test/org/apache/lucene/index/TestTermdocPerf.java I think our attempts at optimization might be foiled by the larger method size, and the fact that so many vints are going to be a single byte (the term freqs are interleaved with the doc increments). Hotspot might have an easier time with the small method, and the branch predictor will have fewer branches to track, etc. who knows... If anyone else feels like running on a different processor or with different params, please have at it. For me, the "more real lucene" test on the P4 was enough to dissuade me from pursuing this further (yet again). > [PATCH] Slight performance improvement for readVInt() of IndexInput > ------------------------------------------------------------------- > > Key: LUCENE-639 > URL: http://issues.apache.org/jira/browse/LUCENE-639 > Project: Lucene - Java > Issue Type: Improvement > Components: Index > Affects Versions: 2.0.0 > Reporter: Johan Stuyts > Priority: Minor > Attachments: Lucene2ReadVIntPerformance.patch, readVInt performance > results.pdf, ReadVIntPerformanceMain.java > > > By unrolling the loop in readVInt() I was able to get a slight, about 1.8 %, > performance improvement for this method. The test program invoked the method > over 17 million times on each run. > I ran the performance tests on: > - Windows XP Pro SP2 > - Sun JDK 1.5.0_07 > - YourKit 5.5.4 > - Lucene trunk -- This message is automatically generated by JIRA. - If you think it was sent incorrectly contact one of the administrators: http://issues.apache.org/jira/secure/Administrators.jspa - For more information on JIRA, see: http://www.atlassian.com/software/jira --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
