Re: Fw: potential /dev/urandom scalability improvement

[Andrew Morton]

Arjan van de Ven <arjanv@xxxxxxxxxx> wrote:
>
> > a) execute a prefetch at addresses which are not PREFETCH_STRIDE-aligned
>  >    and, as a consequence,
>  > 
>  > b) prefetch data from the next page, outside the range of the user's
>  >    (addr,len).
> 
>  well if you assume that cachelines (and prefetch stride) are proper
>  divisors of PAGE_SIZE is that still true ?

Probably not ;)

If someone does

	prefetch_range(4096, 1);

on 4k pagesize, what should we do?

Issuing a single

	prefetch 4090

sounds reasonable.

In that case I'm arranging for it to perform

	prefetch (4096 - 32)

in that case, which seems neater.
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