Re: MM with fragmented memory

Werner Almesberger (almesber@lrc.di.epfl.ch)
Tue, 27 Oct 1998 12:21:05 +0100 (MET)

Jamie Lokier wrote:
> You don't have to arrange the memory map this way. Try changing the
> definition of MAP_NR to use a small lookup table or even a calculation
> (if the memory layout is regular) for the upper page address bits.

Good point. Maybe I've chickened out a bit too quickly.

I've now written everything with a virtually linear kernel address space
and so far it looks good (kernel makes it to the point where it tries to
mount the root FS). I was pleased by how few changes were actually
necessary.

Maybe I'll retry a 1:1 mapping approach again once we have the system in
a more complete state and run some benchmarks to compare them. If the
difference is significant, it may be worth supporting a 1:1 mapped model
in spite of the inconvenient setup procedure.

Thanks,
- Werner

-- 
  _________________________________________________________________________
 / Werner Almesberger, DI-ICA,EPFL,CH   werner.almesberger@lrc.di.epfl.ch /
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