RE: ERROR: "paddr_to_nid" [drivers/md/raid1.ko] undefined!

[Luck, Tony]

>> Exporting paddr_to_nid() in arch/ia64/mm/numa.c fixes all of these build errors.
>> Is there a problem with doing that?
>
> I don't see a problem with exporting it.

But I also don't see these build errors.  I'm using the same HEAD commit. I think the
same .config (derived from arch/ia64/configs/bigsur_defconfig.

Big difference is I'm doing a natinve build with a much older compiler (4.6.4)

-Tony