Wordpres Multisite Cron aware of system load

wp-multisite-cron.php

<?php
/**
 * Multisite Cron task. Hits the cron url for all enabled blogs so scheduled tasks function designed.
 * @see http://www.lucasrolff.com/wordpress/why-wp-cron-sucks/
 */
require('./wp-load.php');
//error_reporting(E_ALL);
//ini_set('display_errors',1);
ini_set('memory_limit','512M');
echo '<pre>';
global $wpdb;
$sql = $wpdb->prepare("SELECT domain, path FROM $wpdb->blogs WHERE archived = '0' and deleted = 0", '');
$blogs = $wpdb->get_results($sql); 
foreach($blogs as $blog) {
        set_time_limit(180); //3min per site max.
        $command = "http://" . $blog->domain . ($blog->path ? $blog->path : '/') . 'wp-cron.php?doing_wp_cron';
        //Consider system load before running cron.
        $load = sys_getloadavg();
        if ($load[0] <= 1) {
                echo 'Running cron for ' . $blog->path . "\n";
                $ch = curl_init($command);
                $rc = curl_setopt($ch, CURLOPT_RETURNTRANSFER, FALSE);
                $rc = curl_exec($ch);
                curl_close($ch);
        }else{
                echo 'Too busy. Skipped ' . $blog->path . "\n";
        }
}
echo '</pre>';