Alexey Serbin has posted comments on this change. ( http://gerrit.cloudera.org:8080/5905 )
Change subject: KUDU-1865 (part 1): reduce some cross-thread allocations ...................................................................... Patch Set 8: > Without positive (statistically significant) perf results I'm not > sure it's worth doing this patch (at least the std::function struct > stuff which is somewhat "weird" looking). > > I seem to recall that I did this work originally as part of the > integration of KRPC into Impala, and Impala was suffering majorly > from the "AllocLarge" bottleneck on older versions of tcmalloc > (fixed in the versions we use today). Impala did a lot of >1M > allocations which went throuhg the AllocLarge slow path while > holding the page heap lock, so any time that the RPC threads had to > go through the central free list, they were likely to get blocked > behind some other thread holding that lock. This made the > cross-thread allocations really bad. > > Now with more modern tcmalloc, it's still preferable to avoid the > central free lists, but I don't think it's worth being too crazy > without showing a real benefit. Thank you for the information, Todd. Yep, it seems this patch doesn't add a lot of improvement with current version of gperftools, etc. I posted the latest version with benchmark results just for posterity. -- To view, visit http://gerrit.cloudera.org:8080/5905 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-Project: kudu Gerrit-Branch: master Gerrit-MessageType: comment Gerrit-Change-Id: I7d4d5f14fb302196b1797c712b21cfce81f157c1 Gerrit-Change-Number: 5905 Gerrit-PatchSet: 8 Gerrit-Owner: Todd Lipcon <[email protected]> Gerrit-Reviewer: Alexey Serbin <[email protected]> Gerrit-Reviewer: Andrew Wong <[email protected]> Gerrit-Reviewer: Bankim Bhavsar <[email protected]> Gerrit-Reviewer: David Ribeiro Alves <[email protected]> Gerrit-Reviewer: Grant Henke <[email protected]> Gerrit-Reviewer: Kudu Jenkins (120) Gerrit-Reviewer: Michael Ho <[email protected]> Gerrit-Reviewer: Sailesh Mukil <[email protected]> Gerrit-Reviewer: Tidy Bot (241) Gerrit-Reviewer: Todd Lipcon <[email protected]> Gerrit-Comment-Date: Wed, 27 May 2020 04:25:51 +0000 Gerrit-HasComments: No
