Programming Question: Memory Leak when accessing products

I’ve dramatically shortened my script and posted this version below.
It shows the same behavior as my original script. I’ve ran it with the following four configurations resulting in the specified memory usage increase per product:

1. Linux with caching: about 116KB per product
2. Linux without caching: about 180KB per product
3. Window with caching: about 10KB per product
4. Windows without caching: about 2KB per product

So Windows behaves as I would expect. But Linux behaves very strange.

<?php

function generateRandomString($length) {

    $characters = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ';
    $charactersLength = strlen($characters);
    $randomString = '';
    for ($i = 0; $i < $length; $i++) {
        $randomString .= $characters[rand(0, $charactersLength - 1)];
    }

    return $randomString;
}

function generateRandomPrice($min, $max, $decimals = 2){

    $randomfloat = $min + mt_rand() / mt_getrandmax() * ($max - $min);

    return number_format($randomfloat, $decimals);
}

function createRandomProductData() {

    $result = [ 'product' => [
        'title' => generateRandomString(10),
        'type' => 'simple',
        'status' => 'publish',
        'virtual' => false,
        'sku' => generateRandomString(4),
        'managing_stock' => false,
        'downloadable' => false,
        'review_allowed' => false,
        'short_description' => generateRandomString(20),
        'regular_price' => generateRandomPrice(10.0, 99.0)
    ] ];

    return $result;
}

function instantiateWooCommerce() {

    $wpLoadPath = 'C:/inetpub/wwwroot/wordpress/wp-load.php';
    //$wpLoadPath = '/opt/wordpress-3.9.1-1/apps/wordpress/htdocs/wp-load.php';
    require_once $wpLoadPath;

    $wooCommercePath = realpath(WP_PLUGIN_DIR . '/woocommerce/woocommerce.php');
    require_once $wooCommercePath;

    WC()->api->includes();
    WC()->api->register_resources(new WC_API_Server( '/' ));

    $credentials = [
        'user_login' => 'FP_product_uploader',
        'user_password' => '12345678'
    ];
    $user = wp_signon($credentials, false);
    wp_set_current_user($user->ID);
}

function printMemoryUsage($label) {

    $memoryUsage = memory_get_usage();
    echo $label . ': ' . $memoryUsage . "\n";
}

instantiateWooCommerce();
wp_suspend_cache_addition(true);

$api = WC()->api->WC_API_Products;

printMemoryUsage('before');
for($i = 0; $i < 10; ++$i) {
    printMemoryUsage($i);
    $productData = createRandomProductData();
    $api->create_product($productData);
}
printMemoryUsage('after');