Re: [RFC/RFT PATCH 1/3] memblock: update initialization of reserved pages

From: Mike Rapoport
Date: Fri Apr 16 2021 - 07:44:38 EST


On Thu, Apr 15, 2021 at 11:30:12AM +0200, David Hildenbrand wrote:
> > Not sure we really need a new pagetype here, PG_Reserved seems to be quite
> > enough to say "don't touch this". I generally agree that we could make
> > PG_Reserved a PageType and then have several sub-types for reserved memory.
> > This definitely will add clarity but I'm not sure that this justifies
> > amount of churn and effort required to audit uses of PageResrved().
> > > Then, we could mostly avoid having to query memblock at runtime to figure
> > > out that this is special memory. This would obviously be an extension to
> > > this series. Just a thought.
> >
> > Stop pushing memblock out of kernel! ;-)
>
> Can't stop. Won't stop. :D
>
> It's lovely for booting up a kernel until we have other data-structures in
> place ;)

A bit more seriously, we don't have any data structure that reliably
represents physical memory layout and arch-independent fashion.
memblock is probably the best starting point for eventually having one.

--
Sincerely yours,
Mike.