On Thu, Feb 25, 2016 at 7:26 PM, David Daney [off-list ref] wrote:

On 02/23/2016 11:36 AM, Rob Herring wrote:

quoted

On Fri, Feb 19, 2016 at 05:13:17PM -0800, David Daney wrote:

quoted

From: Ganapatrao Kulkarni <redacted>

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

Rob