void TestMallocPrivate::updatePeak()
{
    if (now_usable.load() > peak_usable.load()) {
        peak_usable.fetchAndStoreOrdered(now_usable.load());
    }
    if (now_usable.load() + now_overhead.load() > peak_total.load()) {
        peak_total.fetchAndStoreOrdered(now_usable.load() + now_overhead.load());
    }
}