use GTop ();
my $gtop = GTop->new;
my $proc = $gtop->proc_mem($$);
print "size before:  ", $gtop->proc_mem($$)->size(), " B\n";
{
    my $x = 'a' x 10**7;
    print "size inside: ", $gtop->proc_mem($$)->size(), " B\n";
}
print "size  after: ", $gtop->proc_mem($$)->size(), " B\n";