Tim Armstrong has posted comments on this change. ( http://gerrit.cloudera.org:8080/15244 )
Change subject: IMPALA-5904: (part 2) Fix more TSAN bugs ...................................................................... Patch Set 4: (1 comment) Thanks for the fixes. One last issue.. http://gerrit.cloudera.org:8080/#/c/15244/4/bin/tsan-suppressions.txt File bin/tsan-suppressions.txt: http://gerrit.cloudera.org:8080/#/c/15244/4/bin/tsan-suppressions.txt@34 PS4, Line 34: # Accesses to KuduScanNode::done_ are intentionally racey; see IMPALA-4880 and the > Yeah, we could, but looking at IMPALA-4880 it seems to be done this way int I think the argument about optimistic checking also works for atomic. I think it's fine with the volatile, it would just be better to get it TSAN-clean at the same time as everything else. Just to confirm, I checked that atomic operations with store/release generate the same instructions: https://godbolt.org/z/qA3KF2 If the functions are inlined into a bigger function the atomic operations will come with different compiler barriers, but even if the generated code was different, I doubt any perf effects would be significant when the check is done once per scan range. -- To view, visit http://gerrit.cloudera.org:8080/15244 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-Project: Impala-ASF Gerrit-Branch: master Gerrit-MessageType: comment Gerrit-Change-Id: I01feb40417dc5ea64ccb0c1044cfc3eed8508476 Gerrit-Change-Number: 15244 Gerrit-PatchSet: 4 Gerrit-Owner: Sahil Takiar <[email protected]> Gerrit-Reviewer: Impala Public Jenkins <[email protected]> Gerrit-Reviewer: Sahil Takiar <[email protected]> Gerrit-Reviewer: Tim Armstrong <[email protected]> Gerrit-Comment-Date: Tue, 25 Feb 2020 20:02:06 +0000 Gerrit-HasComments: Yes
