Horton

Re: dsa_allocate() faliure

Tom Lane <tgl@sss.pgh.pa.us>

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From: Tom Lane <tgl@sss.pgh.pa.us>
To: Thomas Munro <thomas.munro@enterprisedb.com>
Cc: Robert Haas <robertmhaas@gmail.com>, Jakub Glapa <jakub.glapa@gmail.com>, Justin Pryzby <pryzby@telsasoft.com>, Fabio Isabettini <fisabettini@voipfuture.com>, Arne Roland <A.Roland@index.de>, Sand Stone <sand.m.stone@gmail.com>, Rick Otten <rottenwindfish@gmail.com>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Date: 2019-02-11T01:22:45Z
Lists: pgsql-hackers, pgsql-performance 
Thomas Munro <thomas.munro@enterprisedb.com> writes:
> On Mon, Feb 11, 2019 at 10:33 AM Tom Lane <tgl@sss.pgh.pa.us> wrote:
>> I observe from
>> https://coverage.postgresql.org/src/backend/utils/mmgr/freepage.c.gcov.html
>> that the edge cases in this function aren't too well exercised by
>> our regression tests, meaning that the buildfarm might not prove
>> much either way about the correctness of this patch.  That is one
>> factor pushing me to think we shouldn't risk it.  But, taking a
>> longer view, is that something that's practical to improve?

> Yeah.  This is a nice example of code that really deserves unit tests
> written in C.  Could be good motivation to built the infrastructure I
> mentioned here:
> https://www.postgresql.org/message-id/flat/CAEepm%3D2heu%2B5zwB65jWap3XY-UP6PpJZiKLQRSV2UQH9BmVRXQ%40mail.gmail.com

Meh.  I think if you hold out for that, you're going to be waiting a
long time.  I was thinking more along the lines of making a test API
in src/test/modules/, akin to what we've got for predtest or rbtree.

			regards, tom lane

Commits

  1. Fix rare dsa_allocate() failures due to freepage.c corruption.

  2. Release notes for 10.4, 9.6.9, 9.5.13, 9.4.18, 9.3.23.

  3. Fix crashes on plans with multiple Gather (Merge) nodes.