Re: [PATCH 1/2] Generic Virtual Memmap suport for SPARSEMEM

Dave Hansen
2007-04-02T22:05:15Z

On Mon, 2007-04-02 at 14:53 -0700, Christoph Lameter wrote:
> > > Well think about how to handle the case that the allocatiopn of a page
> > > table page or a vmemmap block fails. Once we have that sorted out then we
> > > can cleanup the higher layers.
> >
> > I think it is best to just completely replace
> > sparse_early_mem_map_alloc() for the vmemmap case. It really is a
> > completely different beast. You'd never, for instance, have
> > alloc_remap() come into play.
>
> What is the purpose of alloc_remap? Could not figure that one out.

That's what we use on i386 to get some lowmem area for non-zero NUMA
nodes. Otherwise, all of ZONE_NORMAL is on node 0. It's a bit hokey,
and stuff like virt_to_phys() probably doesn't work on it, but it has
worked pretty well for a long time.

-- Dave