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

[Mike Rapoport]

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.

[1] https://lore.kernel.org/lkml/20200710031619.18762-2-justin.he@xxxxxxx

> Cc: Mike Rapoport <rppt@xxxxxxxxxxxxx>
> Cc: Jia He <justin.he@xxxxxxx>
> Cc: Will Deacon <will@xxxxxxxxxx>
> Cc: David Hildenbrand <david@xxxxxxxxxx>
> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
> Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>
> ---
>  include/linux/mm.h |   11 +++++++++++
>  mm/Kconfig         |    6 ++++++
>  mm/page_alloc.c    |   23 ++++++++++++++++++++++-
>  3 files changed, 39 insertions(+), 1 deletion(-)
> 

-- 
Sincerely yours,
Mike.