Abhishek Rawat has posted comments on this change. ( http://gerrit.cloudera.org:8080/13178 )
Change subject: IMPALA-4658: Potential race if compiler reorders ReachedLimit() usage. ...................................................................... Patch Set 2: (1 comment) http://gerrit.cloudera.org:8080/#/c/13178/2/be/src/exec/exec-node.h File be/src/exec/exec-node.h: http://gerrit.cloudera.org:8080/#/c/13178/2/be/src/exec/exec-node.h@391 PS2, Line 391: AtomicInt64 num_rows_returned_shared_; > I made the change so that we only have a single variable. In the multi-thre It seems the tool did not send my response from yesterday to the reviewers. I also did some basic perf tests and I see that using LongAdder we regress the single threaded code-paths such as ExchangeNode::GetNext (evident from following result see 11:EXCHANGE stats below) (R) Regression: TPCH(50) TPCH-Q22 [parquet / none / none] (3.78s -> 3.98s [+5.29%]) +---------------------+------------+----------+----------+------------+------------+----------+----------+------------+--------+---------+-----------+ | Operator | % of Query | Avg | Base Avg | Delta(Avg) | StdDev(%) | Max | Base Max | Delta(Max) | #Hosts | #Rows | Est #Rows | +---------------------+------------+----------+----------+------------+------------+----------+----------+------------+--------+---------+-----------+ | 05:HASH JOIN | 44.01% | 2.51s | 2.52s | -0.36% | 3.56% | 2.75s | 2.67s | +2.93% | 3 | 318.22K | 750.00K | | 01:SCAN HDFS | 3.62% | 206.70ms | 198.37ms | +4.20% | 8.68% | 268.71ms | 286.23ms | -6.12% | 3 | 1.91M | 750.00K | | 11:EXCHANGE | 8.45% | 482.53ms | 275.75ms | +74.99% | 8.77% | 620.61ms | 355.22ms | +74.71% | 3 | 75.00M | 75.00M | | F00:EXCHANGE SENDER | 35.94% | 2.05s | 2.03s | +1.01% | * 12.67% * | 3.18s | 2.65s | +20.01% | 3 | -1 | -1 | | 03:SCAN HDFS | 3.20% | 183.07ms | 173.45ms | +5.55% | * 11.75% * | 254.60ms | 235.88ms | +7.94% | 3 | 75.00M | 75.00M | +---------------------+------------+----------+----------+------------+------------+----------+----------+------------+--------+---------+-----------+ The pre-review tests on the latest code with patch #4 is clean: https://jenkins.impala.io/job/ubuntu-16.04-from-scratch/5450/testReport/ -- To view, visit http://gerrit.cloudera.org:8080/13178 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-Project: Impala-ASF Gerrit-Branch: master Gerrit-MessageType: comment Gerrit-Change-Id: I4cbbfad80f7ab87dd6f192a24e2c68f7c66b047e Gerrit-Change-Number: 13178 Gerrit-PatchSet: 2 Gerrit-Owner: Abhishek Rawat <[email protected]> Gerrit-Reviewer: Abhishek Rawat <[email protected]> Gerrit-Reviewer: Impala Public Jenkins <[email protected]> Gerrit-Reviewer: Tim Armstrong <[email protected]> Gerrit-Reviewer: Todd Lipcon <[email protected]> Gerrit-Comment-Date: Wed, 01 May 2019 22:23:28 +0000 Gerrit-HasComments: Yes
