Re: adjust prefetch in free_one_pgd()

[Alan Cox]

On Fri, 2002-08-02 at 17:38, David Mosberger wrote:
> >>>>> On 02 Aug 2002 18:49:27 +0100, Alan Cox <[e-mail]> said:
> 
>   Alan> I can't think of anything cachable with nasty side effects we
>   Alan> might encounter right now but one day someone will do it just
>   Alan> to be annoying.
> 
> Cacheable and side-effects don't go together.  Even without explicit
> software prefetches, most modern CPUs will happily and aggressively
> prefetch stuff from cacheable translations.

Yes we got burned on that with the latest AMD processors. They prefetch
into an area we accidentally have marked with differing cachabilities
between kernel and user space when using the nv binary driver stuff (but
its our bug not theirs). There's a horrid hack in 2.4.19rc to deal with
it pending merging the proper patches