Re: [PATCH v4 0/4] arm64: drop pfn_valid_within() and simplify pfn_valid()

[Kefeng Wang]

On 2021/5/11 18:05, Mike Rapoport wrote:
> From: Mike Rapoport <rppt@xxxxxxxxxxxxx>
>
> Hi,
>
> These patches aim to remove CONFIG_HOLES_IN_ZONE and essentially hardwire
> pfn_valid_within() to 1.
>
> The idea is to mark NOMAP pages as reserved in the memory map and restore
> the intended semantics of pfn_valid() to designate availability of struct
> page for a pfn.
>
> With this the core mm will be able to cope with the fact that it cannot use
> NOMAP pages and the holes created by NOMAP ranges within MAX_ORDER blocks
> will be treated correctly even without the need for pfn_valid_within.
>
> The patches are boot tested on qemu-system-aarch64.
>
> I beleive it would be best to route these via mmotm tree.

Reviewed-by: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx>