my $x = "A" x 10_000_000;

##</code><code>##

  my $x = "AAAAA..[10_000_000 long]..";

##</code><code>##

  our $x;
  my $code = sub { $x = "A" x 10_000_000 };
  showmem("start");
  &$code;
  showmem("allocated");
  undef $x;
  showmem("var freed");
  undef $code;
  showmem("code freed");


##</code><code>##

  perl -DXt -we 'my $l = 100; my $a = "A" x $l;'