$ perl -MLinux::Smaps -Mstrict -le '
  my $s=Linux::Smaps->new;
  my $p;
  sub p {
    $s->update;
    my $c=$s->private_dirty+$s->private_clean;
    print $_[0], ": ", $c-$p;
    $p=$c;
  }
  p "start";
  p "start2";
  require CGI;
  p "required";
  CGI->compile(":all");
  p "compiled";
  p "end"
'
start: 1296
start2: 8
required: 1036
compiled: 2240
end: 0