Re: [PATCH v1] mm: convert folio_page() back to a macro

[Kiryl Shutsemau <kirill@shutemov.name>]

On Tue, Sep 23, 2025 at 04:00:58PM +0200, David Hildenbrand wrote:
> In commit 73b3294b1152 ("mm: simplify folio_page() and folio_page_idx()")
> we converted folio_page() into a static inline function. However
> briefly afterwards in commit a847b17009ec ("mm: constify highmem related
> functions for improved const-correctness") we had to add some nasty
> const-away casting to make the compiler happy when checking const
> correctness.
> 
> So let's just convert it back to a simple macro so the compiler can
> check const correctness properly. There is the alternative of
> using a _Generic() similar to page_folio(), but there is not a lot of
> benefit compared to just using a simple macro.
> 
> Cc: Andrew Morton <akpm@linux-foundation.org>
> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
> Cc: "Liam R. Howlett" <Liam.Howlett@oracle.com>
> Cc: Vlastimil Babka <vbabka@suse.cz>
> Cc: Mike Rapoport <rppt@kernel.org>
> Cc: Suren Baghdasaryan <surenb@google.com>
> Cc: Michal Hocko <mhocko@suse.com>
> Signed-off-by: David Hildenbrand <david@redhat.com>

Reviewed-by: Kiryl Shutsemau <kas@kernel.org>

-- 
  Kiryl Shutsemau / Kirill A. Shutemov