Horton

Re: dsa_allocate() faliure

Robert Haas <robertmhaas@gmail.com>

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From: Robert Haas <robertmhaas@gmail.com>
To: Thomas Munro <thomas.munro@enterprisedb.com>
Cc: 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: 2019-02-10T06:26:14Z
Lists: pgsql-hackers, pgsql-performance 
On Sun, Feb 10, 2019 at 1:55 AM Thomas Munro
<thomas.munro@enterprisedb.com> wrote:
> Bleugh.  Yeah.  What I said before wasn't quite right.  The value
> returned by FreePageManagerPutInternal() is actually correct at the
> moment it is returned, but it ceases to be correct immediately
> afterwards if the following call to FreePageBtreeCleanup() happens to
> reduce the size of that particular span.  The problem is that we
> clobber fpm->contiguous_pages with the earlier (and by now incorrect)
> value that we were holding in a local variable.

Yeah, I had similar bugs to that during the initial development work I
did on freepage.c, and that's why I got rid of some lazy recomputation
thing that I had tried at some point.  The version that got committed
brought that back again, but possibly it's got the same kind of
problem.

-- 
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company

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.