Magento Memory Leak

memleak.php

<?php
ini_set('display_errors', 1);
ini_set('log_errors', 1);
error_reporting(E_ALL);
require 'app/Mage.php';
Mage::app('admin', 'store');
/* @var $customers Mage_Customer_Model_Resource_Customer_Collection */
$customers = Mage::getResourceModel('customer/customer_collection');
$customers->addAttributeToSelect('*');
$customers->setPageSize((isset($argv[1]) && is_numeric($argv[1]))?$argv[1]:2000);
$pages        = $customers->getLastPageNumber();
if (in_array('addresshack', $argv)) {
  echo "using address alternative...\n";
}
if (in_array('reflection', $argv)) {
  echo "using reflection...\n";
  $r = new ReflectionProperty(get_class($customers), '_itemsById');
  $r->setAccessible(true);
}

for ($currentPage  = 1; $currentPage <= $pages; $currentPage++) {
  echo "Page: $currentPage  ";// leaving in for debugging
  _echoMemoryUsage();
  $customers->setCurPage($currentPage);
  $customers->load();
  foreach ($customers as $key => $customer) {
    /* @var $customer Mage_Customer_Model_Customer */
    if (in_array('addresshack', $argv)) {
      $addresses  = $customer->getAddressCollection()->setCustomerFilter($customer)->addAttributeToSelect('city');
      $address    = $addresses->getItemById($customer->getData('default_billing'));
    } else {
      $address    = $customer->getPrimaryBillingAddress();
    }
    $city    = '';
    if ($address) {
        $city = $address->getCity();
        $address->clearInstance();
    }
    $customer->clearInstance();
    $customers->removeItemByKey($key);
  }
  
  //make the collection unload the data in memory so it will pick up the next page when load() is called.
  $customers->clear();
  if (isset($r)) {
    $r->setValue($customers, array());
  }
}
echo "Final usage: ";
_echoMemoryUsage();
function _echoMemoryUsage()
{
  $memUsage = memory_get_usage(true);
         
  if ($memUsage < 1024) {
    echo $memUsage." bytes";
  } elseif ($memUsage < 1048576) {
    echo round($memUsage/1024,2)." kilobytes";
  } else {
    echo round($memUsage/1048576,2)." megabytes";
  }
  echo "\n";
}

Insert between 47 and 48

unset($customers);
$customers = Mage::getResourceModel('customer/customer_collection');
$customers->addAttributeToSelect('*');
$customers->setPageSize((isset($argv[1]) && is_numeric($argv[1]))?$argv[1]:2000);