Todd Lipcon has posted comments on this change.

Change subject: IMPALA-4654: KuduScanner must return when ReachedLimit()
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Patch Set 2:

(1 comment)

http://gerrit.cloudera.org:8080/#/c/5493/2/be/src/exec/kudu-scanner.cc
File be/src/exec/kudu-scanner.cc:

PS2, Line 200: scan_node_->ReachedLimit()
this isn't specific to Kudu, but it seems wrong that in this and other places, 
you're calling ReachedLimit() from a different thread than the one updating 
rows_returned. The compiler in theory is free to notice that you're not 
updating the rows_returned_ variable in this thread and hoist the load up out 
of loops, etc.

Apparently it's not happening, but it would probably be a good idea to make 
that a NoBarrier_Load(...).

</peanut-gallery>


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Gerrit-MessageType: comment
Gerrit-Change-Id: Iaddd51111a1b2647995d68e6d37d0500b3a322de
Gerrit-PatchSet: 2
Gerrit-Project: Impala-ASF
Gerrit-Branch: master
Gerrit-Owner: Matthew Jacobs <[email protected]>
Gerrit-Reviewer: Alex Behm <[email protected]>
Gerrit-Reviewer: Matthew Jacobs <[email protected]>
Gerrit-Reviewer: Sailesh Mukil <[email protected]>
Gerrit-Reviewer: Todd Lipcon <[email protected]>
Gerrit-HasComments: Yes

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