Michael Smith has posted comments on this change. ( http://gerrit.cloudera.org:8080/24940 )
Change subject: IMPALA-11917: Upgrade to GCC 15 and LLVM 22 ...................................................................... Patch Set 15: > Patch Set 15: > > > Patch Set 14: > > > > > Patch Set 14: > > > > > > > Patch Set 14: > > > > > > > > > (2 comments) > > > > > > > > Interesting, on the whole the diff seems to be around noise level, but > > > > some queries (TPCDS-Q99) have serious diff. This is a very short query, > > > > my guess is that the comes from codegen compilation times. > > > > > > TPCDS-Q99 sees a 10% reduction with and without codegen. So I don't think > > > codegen time is much of a factor. > > > > > > The main difference seems to be in execution time of the generated code > > > itself during joins and aggregation. I'll see if I can reproduce locally > > > and do some more targeted analysis. I think the difference is small > > > enough overall we could handle it in a follow-up ticket. > > > > Found an attribute that affects inlining, testing it out. > > Setting tune-cpu fixed a lot of the regression in Q99, and I added an > additional patch that optimizes simple SlotRef reads that preserves the LLVM > 5 code generation there. That should bring Q99 inline, and maybe improve some > others. Re-running with both changes at > https://jenkins.impala.io/job/perf-AB-test-ub2204/48/. Those two changes bring it to a slight improvement +-----------+-----------------------+---------+------------+------------+----------------+ | Workload | File Format | Avg (s) | Delta(Avg) | GeoMean(s) | Delta(GeoMean) | +-----------+-----------------------+---------+------------+------------+----------------+ | TPCDS(20) | parquet / none / none | 0.89 | -1.32% | 0.41 | -0.06% | +-----------+-----------------------+---------+------------+------------+----------------+ -- To view, visit http://gerrit.cloudera.org:8080/24940 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-Project: Impala-ASF Gerrit-Branch: master Gerrit-MessageType: comment Gerrit-Change-Id: I7dda730fa98ebe3825969265627a560b0c3095f9 Gerrit-Change-Number: 24940 Gerrit-PatchSet: 15 Gerrit-Owner: Michael Smith <[email protected]> Gerrit-Reviewer: Balazs Hevele <[email protected]> Gerrit-Reviewer: Csaba Ringhofer <[email protected]> Gerrit-Reviewer: Impala Public Jenkins <[email protected]> Gerrit-Reviewer: Joe McDonnell <[email protected]> Gerrit-Reviewer: Laszlo Gaal <[email protected]> Gerrit-Reviewer: Michael Smith <[email protected]> Gerrit-Comment-Date: Thu, 01 Oct 2026 21:35:22 +0000 Gerrit-HasComments: No
