Re: [patch 0/4] ia64 SPARSEMEM

Bob Picco
2005-05-26T22:04:54Z

David Mosberger wrote: [Thu May 26 2005, 04:09:06PM EDT]
> >>>>> On Tue, 24 May 2005 12:27:39 -0400, Bob Picco <bob.picco@hp.com> said:
>
> >> + * SECTION_SIZE_BITS 2^N: how big each section will be
>
> Bob> I don't perceive VIRTUAL_MEM_MAP as a nicer solution. Actually
> Bob> SPARSEMEM is a very elegant solution for memory holes and
> Bob> hotplug memory.
>
> Except that it requires configuration? What happens if
> SECTION_SIZE_BITS is chosen wrong or poorly for a given (perhaps new)
> platform?
>
> --david
> -
Yes I suppose this is a valid point. Choosing a bad value for a very
sparse address address space or machine with small quantity of memory could
consume lots of useless memory for section_map and/or reserved page
structures.

I'd prefer not to have a platform specific solution. This needs to be given
some more thought.

bob