Re: [PATCH v2 07/22] numa: Introduce a generic memory_add_physaddr_to_nid()

[Dan Williams]

On Sun, Jul 12, 2020 at 11:58 PM Mike Rapoport <rppt@xxxxxxxxxxxxx> wrote:
>
> Hi Dan,
>
> On Sun, Jul 12, 2020 at 09:26:43AM -0700, Dan Williams wrote:
> > For architectures that opt into storing their numa data in memblock
> > (only ARM64 currently), add a memblock generic way to interrogate that
> > data for memory_add_physaddr_to_nid(). This requires ARCH_KEEP_MEMBLOCK
> > to keep memblock text and data around after boot.
>
> I afraid we are too far from using memblock as a generic placeholder for
> numa data. Although all architectures now have the numa info in
> memblock, only arm64 uses memblock as the primary source of that data.
>
> I'd rather prefer Jia's solution [1] to have a weak default for
> memory_add_physaddr_to_nid() and let architectures override it.

I'm ok with that as long as we do the same for phys_to_target_node().

Will had the concern about adding a generic numa-info facility the
last I tried this. I just don't see a practical way to get there in
the near term.