Riza Suminto has posted comments on this change. ( 
http://gerrit.cloudera.org:8080/17195 )

Change subject: IMPALA-10584: Defer advancing read page when reservation is 
tight.
......................................................................


Patch Set 3:

It looks like the solution of this problem is much more simple than I thought: 
just don't advance the read page.

The initial reason why we are advancing read page in the first place is 
explained in IMPALA-8890 (review is in https://gerrit.cloudera.org/c/14144/): a 
DCHECK hit in ExpectedPinCount() because we tried to unpin a fully exhausted 
and attached read_page_. IMPALA-8890 choose to advance the read iterator to 
avoid this DCHECK.

Patch set 3 in this review choose to NOT advance the read page, but instead 
skip the first page (that is the read page) when iterating pages_ to call 
UnpinPageIfNeeded.


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Gerrit-Project: Impala-ASF
Gerrit-Branch: master
Gerrit-MessageType: comment
Gerrit-Change-Id: I16137b6e423f190f60c3115a06ccd0f77e9f585a
Gerrit-Change-Number: 17195
Gerrit-PatchSet: 3
Gerrit-Owner: Riza Suminto <[email protected]>
Gerrit-Reviewer: Bikramjeet Vig <[email protected]>
Gerrit-Reviewer: Impala Public Jenkins <[email protected]>
Gerrit-Reviewer: Joe McDonnell <[email protected]>
Gerrit-Reviewer: Quanlong Huang <[email protected]>
Gerrit-Reviewer: Riza Suminto <[email protected]>
Gerrit-Comment-Date: Mon, 12 Apr 2021 20:18:24 +0000
Gerrit-HasComments: No

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