Re: discontiguous memory platforms

From: Daniel Phillips (
Date: Wed May 01 2002 - 09:08:11 EST

On Thursday 02 May 2002 16:00, Roman Zippel wrote:
> Hi,
> On Wed, 1 May 2002, Daniel Phillips wrote:
> > > 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?
> It simply searches through all memory nodes, it's not really efficient.
> > Could you please describe the most extreme case of physical discontiguity
> > you're handling?
> I can't assume anything. I'm thinking about calculating the table
> dynamically and patching the kernel at bootup, we are already doing
> something similiar in the Amiga/ppc kernel.

Maybe this is a good place to try out a hash table variant of
config_nonlinear. It's got to be more efficient than searching all the
nodes, don't you think?

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