Subject: Re: [PATCH v3 22/26] mm: numa_memblks: use memblock_{start,end}_of_DRAM() when sanitizing meminfo

From: Mike Rapoport <[email-masked]>
Date: Mon, 5 Aug 2024 23:33:39 +0300

On Mon, Aug 05, 2024 at 01:21:02PM -0700, Dan Williams wrote:
> Mike Rapoport wrote:
> > From: "Mike Rapoport (Microsoft)" <[email-masked]>
> > 
> > numa_cleanup_meminfo() moves blocks outside system RAM to
> > numa_reserved_meminfo and it uses 0 and PFN_PHYS(max_pfn) to determine
> > the memory boundaries.
> > 
> > Replace the memory range boundaries with more portable
> > memblock_start_of_DRAM() and memblock_end_of_DRAM().
> 
> Can you say a bit more about why this is more portable? Is there any
> scenario for which (0, max_pfn) does the wrong thing?

arm64 may have DRAM starting at addresses other than 0.
And max_pfn seems to me a redundant global variable that I'd love to see
gone.

-- 
Sincerely yours,
Mike.