From perldoc XML::Simple:

You can dictate which parser module is used by setting either the envi
+-
ronment variable 'XML_SIMPLE_PREFERRED_PARSER' or the package variable
$XML::Simple::PREFERRED_PARSER to contain the module name.

[download]

$XML::Simple::PREFERRED_PARSER = 'XML::LibXML::SAX'; should do the trick.

Update: Results after changing parser (Debian unstable, P4 2.8G, 1G RAM): 

#!/usr/bin/perl
use warnings;
use strict;
use XML::Simple qw/XMLin XMLout/;

my $file = shift || die "Must supply xml file";
open FH, '<', $file or die "Cannot open $file for reading: $!";
my $document = do { local $/; <FH> };
$XML::Simple::PREFERRED_PARSER = 'XML::LibXML::SAX';
my $ref = XMLin( $document );

__END__
Output:
8787248
real    0m1.293s
user    0m0.752s
sys     0m0.526s

[download]

In reply to Re^3: XML::Simple hangs by bmann
in thread XML::Simple hangs by Ovid

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.