Re: [PATCH 1/2] mm: remove pfn_valid_within() and CONFIG_HOLES_IN_ZONE

[David Hildenbrand]

On 13.07.21 10:00, Mike Rapoport wrote:
> From: Mike Rapoport <rppt@xxxxxxxxxxxxx>
>
> After recent changes in freeing of the unused parts of the memory map and
> rework of pfn_valid() in arm and arm64 there are no architectures that can
> have holes in the memory map within a pageblock and so nothing can enable
> CONFIG_HOLES_IN_ZONE which guards non trivial implementation of
> pfn_valid_within().
>
> With that, pfn_valid_within() is always hardwired to 1 and can be
> completely removed.
>
> Remove calls to pfn_valid_within() and CONFIG_HOLES_IN_ZONE.
>
> Signed-off-by: Mike Rapoport <rppt@xxxxxxxxxxxxx>

There is currently the discussion to increase MAX_ORDER, for example, to 
cover 1GiB instead of 4MiB on x86-64. This would mean that we could 
suddenly, again, have holes insides MAX_ORDER - 1 pages.

So I assume if we ever go down that path, we'll need something like this 
again.

For now, this looks like the right thing to do

Acked-by: David Hildenbrand <david@xxxxxxxxxx>

--
Thanks,

David / dhildenb