Maybe you and Jenda should avoid benchmarking tools that you don't really master.

Your first attempt was perfectly valid as a solution when performance is not an issue. But if it becomes one, then loading the entire document in memory when XML::Twig is specifically designed to avoid this, is kinda lame don't you think?

The code below is probably not faster than what you have, but a least it should not use too much memory.

#!/usr/bin/perl

use strict;
use warnings;

use XML::Twig;

my $t= XML::Twig->new( keep_spaces => 1, comments => 'drop',
                       twig_handlers => { _all_ => sub { $_[0]->flush 
+}}
                     )
                ->parsefile( "test_comments.xml")
    ;
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