Re: page fault scalability patch V11 [0/7]: overview

Linus Torvalds
2004-11-20T01:56:43Z

On Sat, 20 Nov 2004, Nick Piggin wrote:
>
> The per thread rss may wrap (maybe not 64-bit counters), but even so,
> the summation over all threads should still end up being correct I
> think.

Yes. As long as the total rss fits in an int, it doesn't matter if any of
them wrap. Addition is still associative in twos-complement arithmetic
even in the presense of overflows.

If you actually want to make it proper standard C, I guess you'd have to
make the thing unsigned, which gives you the mod-2**n guarantees even if
somebody were to ever make a non-twos-complement machine.

Linus