Re: discontiguous memory platforms

Daniel Phillips
2002-05-02T18:41:35Z

On Thursday 02 May 2002 20:35, Geert Uytterhoeven wrote:
> On Thu, 2 May 2002, Roman Zippel wrote:
> > On Thu, 2 May 2002, Andrea Arcangeli wrote:
> > > What I
> > > care about is not to clobber the common code with additional overlapping
> > > common code abstractions.
> >
> > Just to throw in an alternative: On m68k we map currently everything
> > together into a single virtual area. This means the virtual<->physical
> > conversion is a bit more expensive and mem_map is simply indexed by the
> > the virtual address.
> > It works nicely, it just needs two small patches in the initializition
> > code, which aren't integrated yet. I think it's very close to what Daniel
> > wants, only that the logical and virtual address are identical.
>
> I also want to add that the order (by address) of the virtual chunk is not
> necessarily the same as the order (by address) of the physical chunks.
>
> So it's perfect possible to put the kernel in the second physical chunk, in
> which case the first physical chunk (with a lower physical address) ends up in
> the virtual list behind the first physical chunk.
>
> IIRC (/me no Linux mm whizard), the above reason was the main reason why the
> current zone system doesn't work well for m68k boxes (mainly talking about
> Amiga).

Config_nonlinear will handle this situation without difficulty.

--
Daniel