Re: discontiguous memory platforms

Daniel Phillips (phillips@bonn-fries.net)
Wed, 1 May 2002 15:21:39 +0200

On Thursday 02 May 2002 10:50, Roman Zippel wrote:
> Hi,
>
> 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.

Are you talking about mm_ptov and friends here? What are the loops for?
Could you please describe the most extreme case of physical discontiguity
you're handling?

> 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.

Yes, since logical and virtual kernel addresses in config_nonlinear differ
only by a constant (PAGE_OFFSET) then setting the constant to zero gives
me your case.

-- 
Daniel
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