Re: [PATCH v11 08/10] dt, numa: Add NUMA dt binding implementation.

[David Daney]

On 03/01/2016 08:47 AM, Rob Herring wrote:
> On Thu, Feb 25, 2016 at 7:26 PM, David Daney <ddaney@xxxxxxxxxxxxxxxxxx> wrote:
> > On 02/23/2016 11:36 AM, Rob Herring wrote:
> > > On Fri, Feb 19, 2016 at 05:13:17PM -0800, David Daney wrote:
> > > > From: Ganapatrao Kulkarni <gkulkarni@xxxxxxxxxxxxxxxxxx>
> > > >
> > > > ADD device tree node parsing for NUMA topology using device
> > > > "numa-node-id" property distance-map.
> > >
> > >
> > > I still want an adequate explanation why NUMA setup cannot be done with
> > > an unflattened tree. PowerPC manages to do that and should have a
> > > similar init flow being memblock based, so I would expect arm64 can too.
> >
> >
> > Many things could be done.  Really, we want to know what *should* be done.
> >
> > In the context of the current arm64 memory initialization we (more or less)
> > do:
> >
> >   1) early_init_fdt_scan_reserved_mem();
> >   2) memory_present()
> >   3) sparse_init()
> >   4) other things
> >   5) unflatten_device_tree()
> >
> > We are already reading information out of the FDT at #1.
> >
> > This patch set adds a step between 1 and 2 where we read NUMA information
> > out of the FDT.
>
> The dependency on unflattening is that memblock is up and we can
> allocate a chunk from it. Isn't that dependency met by step 1

No.

> or is
> there a dependency on sparsemem (or something else)?

Will Deacon talked about this over here:

https://lkml.org/lkml/2016/2/26/782

I am happy to modify the patch set, but I don't want to get stuck as an 
intermediary between two opposing blocs.

David Daney