Re: [Patch v3 2/2] mm/khugepaged: unify pmd folio installation with map_anon_folio_pmd()

[David Hildenbrand <david@redhat.com>]

On 08.10.25 11:54, Wei Yang wrote:
> Currently we install pmd folio with map_anon_folio_pmd() in
> __do_huge_pmd_anonymous_page() and do_huge_zero_wp_pmd(). While in
> collapse_huge_page(), it is done with identical code except statistics
> adjustment.
> 
> Unify the process with map_anon_folio_pmd() to install pmd folio. Split
> it to map_anon_folio_pmd_pf() and map_anon_folio_pmd_nopf() to be used
> in page fault or not respectively.
> 
> No functional change is intended.
> 
> Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
> Cc: David Hildenbrand <david@redhat.com>
> Cc: Lance Yang <lance.yang@linux.dev>
> Cc: Dev Jain <dev.jain@arm.com>
> Cc: Zi Yan <ziy@nvidia.com>
> Cc: Usama Arif <usamaarif642@gmail.com>
> Cc: Matthew Wilcox <willy@infradead.org>
> Acked-by: David Hildenbrand <david@redhat.com>
> Reviewed-by: Zi Yan <ziy@nvidia.com>
> Acked-by: Lance Yang <lance.yang@linux.dev>
> 
> ---
> v3:
>    * add static inline and put bracket into separate lines
>    * rebase on latest mm-new
> v2:
>    * split map_anon_folio_pmd_[no]pf() suggested by Matthew
> ---
>   include/linux/huge_mm.h |  7 +++++++
>   mm/huge_memory.c        | 14 ++++++++++----
>   mm/khugepaged.c         |  9 +--------
>   3 files changed, 18 insertions(+), 12 deletions(-)
> 
> diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h
> index bb48cb50c0ec..588e3522a1d0 100644
> --- a/include/linux/huge_mm.h
> +++ b/include/linux/huge_mm.h
> @@ -542,6 +542,8 @@ void split_huge_pmd_locked(struct vm_area_struct *vma, unsigned long address,
>   			   pmd_t *pmd, bool freeze);
>   bool unmap_huge_pmd_locked(struct vm_area_struct *vma, unsigned long addr,
>   			   pmd_t *pmdp, struct folio *folio);
> +void map_anon_folio_pmd_nopf(struct folio *folio, pmd_t *pmd,
> +		struct vm_area_struct *vma, unsigned long haddr);
>   
>   #else /* CONFIG_TRANSPARENT_HUGEPAGE */
>   
> @@ -633,6 +635,11 @@ static inline bool unmap_huge_pmd_locked(struct vm_area_struct *vma,
>   	return false;
>   }
>   
> +static inline void map_anon_folio_pmd_nopf(struct folio *folio, pmd_t *pmd,
> +		struct vm_area_struct *vma, unsigned long haddr)
> +{
> +}
> +

Thinking again, maybe you don't even need this stub? Any calling code 
should be guarded by CONFIG_TRANSPARENT_HUGEPAGE.

-- 
Cheers

David / dhildenb