note flexvault <p>Under Debian Linux the real memory was returned to the system, but under AIX 5.2, the real memory increased after the 'undef $x;'. I used <code> `ps -o "rssize" -p $$` </code> </p><p>to determine the real memory used. So it looks like it is system dependent code as <a href="http://www.perlmonks.org/?node_id=715263">zwon</a> pointed out. </p> <div class="pmsig"><div class="pmsig-733061"> <p><b>"Well done is better than well said." - Benjamin Franklin</b></p> </div></div> 1014100 1014172