Re: udev and devfs - The final word

Maciej Zenczykowski
2004-01-02T00:18:09Z

> Solve 90% of the problem space and have a human deal with the exceptions.
> How big's the unique number being exported, anyway? (If it's 32 bits, the
> exceptions are 1 in 4 billion. It may never be seen in the wild...)

Wouldn't this be a classical birthday problem with 50% collision chance
popping up in and around a few hundred devices? [20 for 8 bits, 23 for
365, 302 for 16 bits, 77163 for 32 bits], and that's only in a single
system - with hundreds of thousands of systems even a 0.1% collision rate
is deadly. [0.1% collision rate at 32 bits with 2932 devices] Even with
only 300 devices per system, you'll still get a collision (at 32 bits) on
more than 1 system in a hundred thousand.

Cheers,
MaZe.