Re: Re: [COMMITTERS] pgsql: Get rid of the need for manual maintenance of the initial

Stefan Kaltenbrunner <stefan@kaltenbrunner.cc>

From: Stefan Kaltenbrunner <stefan@kaltenbrunner.cc>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Robert Haas <robertmhaas@gmail.com>, PostgreSQL-development <pgsql-hackers@postgresql.org>
Date: 2010-01-05T19:23:15Z
Lists: pgsql-hackers

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Tom Lane wrote:
> Stefan Kaltenbrunner <stefan@kaltenbrunner.cc> writes:
>> did that and it seems the problem is in the loop that does:
> 
>> foreach my $row (@$data)
>> {
> 
>>      # To construct fmgroids.h and fmgrtab.c, we need to inspect some
>>      # of the individual data fields.  Just splitting on whitespace
> 
> Huh.  It's weird that I don't see a leak in either 5.8.7 or 5.10.1,
> which are the two closest perl versions I have handy here.  I think
> this may be a platform-specific Perl bug.  Still, it would be nice
> to work around it if we can.

yeah it is probably some strange platform specific issue - however with 
some help from the IRC channel I came up with the following patch that
considerable reduces the memory bloat (but still needs ~55MB max) and 
allows the build to succeed.


> 
> I'm not nearly good enough in Perl to be sure about the semantics
> of this loop.  Is it possible that it's changing the global contents
> of the @$data structure, rather than just hacking a local copy of
> each row before pushing some values into @fmgr?

hmm it is leaking a constant amount of 240kbyte per loop iteration with 
the original code but yeah very weird issue...


Stefan