Note it's not that number, but roughly the square root of that number, that matters. And they might be quite non-uniform. If the scheduler tick and the nanose

Note it's not that number, but roughly the square root of that number, that matters. And they might be quite non-uniform. If the scheduler tick and the nanosecond clock are synchronous, you could end up with a few thousand popular values instead of a billion. It's not a real concern today, and probably won't be a real concern in 10 years, but it's not so far removed from possibility that no one has to think about it.