-----Original Message-----
From: wikitech-l-bounces(a)lists.wikimedia.org
[mailto:wikitech-l-bounces@lists.wikimedia.org] On Behalf Of
Andrew Garrett
Sent: 04 October 2009 23:07
To: mak(a)aifb.uni-karlsruhe.de; Wikimedia developers
Subject: Re: [Wikitech-l] MediaWiki memory usage
On 04/10/2009, at 7:27 PM, Markus Krötzsch wrote:
> == How to do memory profiling? ==
>
> I tried to enable PHP memory profiling in xdebug, but all I got
> time data, and I gave up on this for now. The
aggregated outputs
profileinfo.php were not very useful for me either; in
particular, I
think that they do not take garbage collection
into
account, i.e. they
only show new memory allocations, but not the
freeing of
old memory.
So one piece of code may allocate 20M but never
need more
than 4M at a
time, while another consumes the same amount and
keeps it
due to some
mem leak. Especially, the sums and percentages do
apparently not show
the real impact that a piece of code has on using
PHP's memory.
So I based my memory estimations on the minimal PHP memory
limit that
> would not return a blank page when creating a page preview
> (ini_set('memory_limit',...);). This measure is rather coarse for
> debugging, but it might be the one number that matters most to the
user. The
results were reproducible.
For future reference, you can use the memory_get_usage
function:
http://php.net/manual-lookup.php?pattern=get+memory+usage&lang=en