On 8/5/21 9:02 PM, Zi Yan wrote:

From: Zi Yan <ziy@nvidia.com>

Patch 3 restores the pfn_valid_within() check when buddy allocator can merge
pages across memory sections. The check was removed when ARM64 gets rid of holes
in zones, but holes can appear in zones again after this patchset.

To me that's most unwelcome resurrection. I kinda missed it was going away and
now I can't even rejoice? I assume the systems that will be bumping max_order
have a lot of memory. Are they going to have many holes? What if we just
sacrificed the memory that would have a hole and don't add it to buddy at all?