Re: [PATCH v6] mm/pgmap: Use correct alignment when looking at first pfn from a region

Andrew Morton
2019-09-19T19:25:04Z

On Tue, 17 Sep 2019 21:01:29 +0530 "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com> wrote:

> vmem_altmap_offset() adjust the section aligned base_pfn offset.
> So we need to make sure we account for the same when computing base_pfn.
>
> ie, for altmap_valid case, our pfn_first should be:
>
> pfn_first = altmap->base_pfn + vmem_altmap_offset(altmap);

What are the user-visible runtime effects of this change?