Re: [Dri-devel] Re: [adaplas@pol.net: Re: [Linux-fbdev-devel] Fwd: Re: [Dri-devel] future of DRI?]

[Alan C. <al...@lx...>]

On Mon, 2003-03-03 at 00:01, Antonino Daplas wrote:
> > For some cases. The truth is a bit more horrible, and current fbdev has
> > the same problem here. Any early Athlon, and almost any PII/PIII derived
> > chip allows the user to bring the box down if they have access to 
> > a mix of cached and uncached RAM.
> > 
> 
> I do not understand.  Do you mean such as writing to framebuffer memory
> and making it execute?

On early athlon you prefetch non cached memory and the cpu corrupts its
cache, on PII, PII mmap frame buffer against a cached page, but the
right kind of instruction in a loop with the instruction bridging the
two memory types and run it in a tight loop