Re: [Patch v2] mm/huge_memory: use end_folio to terminate anonymous folio remapping

[Barry Song <21cnbao@gmail.com>]

On Mon, Dec 15, 2025 at 8:49 AM Wei Yang <richard.weiyang@gmail.com> wrote:
>
> After splitting a large folio, it is necessary to remap the resulting
> anonymous folios.
>
> The current implementation determines the end of the remapping process
> by counting the number of pages that have been processed.
>
> Since the final folio in the sequence, end_folio, is already known and
> tracked, this commit refactors the remapping loop to leverage end_folio
> as the termination marker.
>
> Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
> Cc: Zi Yan <ziy@nvidia.com>
>
> ---
> v2: move folio assignment in loop
> ---
>  mm/huge_memory.c | 13 ++++---------
>  1 file changed, 4 insertions(+), 9 deletions(-)
>
> diff --git a/mm/huge_memory.c b/mm/huge_memory.c
> index 40cf59301c21..fe812d9c7807 100644
> --- a/mm/huge_memory.c
> +++ b/mm/huge_memory.c
> @@ -3423,20 +3423,15 @@ bool unmap_huge_pmd_locked(struct vm_area_struct *vma, unsigned long addr,
>         return __discard_anon_folio_pmd_locked(vma, addr, pmdp, folio);
>  }
>
> -static void remap_page(struct folio *folio, unsigned long nr, int flags)
> +static void remap_page(struct folio *folio, struct folio *end_folio, int flags)
>  {

Do we actually see an improvement in readability or performance?
The existing code feels a bit more readable to me; nr is clearly
the number of pages :-)

Thanks
Barry