Re: [PATCH 3/9] mm: name pointers to copied PTE values ptentp

[Anshuman Khandual <anshuman.khandual@xxxxxxx>]

Subject line is very confusing. Perhaps something like the following.

mm: Rename pointers to copied PTE values as ptentp

But even 'copied PTE values' is not very clear as well.

On Thu, Aug 06, 2026 at 09:38:41AM +0100, Muhammad Usama Anjum wrote:
> The hw_pte_t conversion must retain pte_t * for pointers to standalone PTE

We need to explain what is `standalone PTE values` first.

> values. Name the value parameters ptentp in the install_pte callback,
> write_protect_page(), and guard_install_set_pte() so the later mechanical
> conversion can distinguish them from pointers to PTE table storage.
> 
> Some functions already use the ptentp name, including:
> - madvise_folio_pte_batch()
> - folio_pte_batch_flags()
> No need to convert them.
> 
> This is a naming-only change.

Small nit - s/naming-only/rename

The commit message needs rewrite clearly explaining the following details

- What are standalone PTE values
- How these are different from HW pgtable pointers
- Change is just a rename for pointers into such 'standalone PTE'
- These renamed 'ptentp' here would be used for skip or replaced during
  upcoming mechanical change via a script
- No functional changes intended

> 
> Signed-off-by: Muhammad Usama Anjum <usama.anjum@xxxxxxx>
> ---
> Changes since RFC v1:
> - Update the description for the architecture opt-in conversion.
> ---
>  include/linux/pagewalk.h | 2 +-
>  mm/ksm.c                 | 4 ++--
>  mm/madvise.c             | 4 ++--
>  3 files changed, 5 insertions(+), 5 deletions(-)
> 
> diff --git a/include/linux/pagewalk.h b/include/linux/pagewalk.h
> index b41d7265c01bc..c34d826c5e4a2 100644
> --- a/include/linux/pagewalk.h
> +++ b/include/linux/pagewalk.h
> @@ -89,7 +89,7 @@ struct mm_walk_ops {
>                      struct mm_walk *walk);
>       void (*post_vma)(struct mm_walk *walk);
>       int (*install_pte)(unsigned long addr, unsigned long next,
> -                        pte_t *ptep, struct mm_walk *walk);
> +                        pte_t *ptentp, struct mm_walk *walk);
>       enum page_walk_lock walk_lock;
>  };
>  
> diff --git a/mm/ksm.c b/mm/ksm.c
> index ad05d7791307e..11d50518d02e9 100644
> --- a/mm/ksm.c
> +++ b/mm/ksm.c
> @@ -1292,7 +1292,7 @@ static u32 calc_checksum(struct page *page)
>  }
>  
>  static int write_protect_page(struct vm_area_struct *vma, struct folio 
> *folio,
> -                           pte_t *orig_pte)
> +                           pte_t *ptentp)
>  {
>       struct mm_struct *mm = vma->vm_mm;
>       DEFINE_FOLIO_VMA_WALK(pvmw, folio, vma, 0, 0);
> @@ -1371,7 +1371,7 @@ static int write_protect_page(struct vm_area_struct 
> *vma, struct folio *folio,
>  
>               set_pte_at(mm, pvmw.address, pvmw.pte, entry);
>       }
> -     *orig_pte = entry;
> +     *ptentp = entry;
>       err = 0;
>  
>  out_unlock:
> diff --git a/mm/madvise.c b/mm/madvise.c
> index 07a21ca31bad4..c324cc991f841 100644
> --- a/mm/madvise.c
> +++ b/mm/madvise.c
> @@ -1101,12 +1101,12 @@ static int guard_install_pte_entry(pte_t *pte, 
> unsigned long addr,
>  }
>  
>  static int guard_install_set_pte(unsigned long addr, unsigned long next,
> -                              pte_t *ptep, struct mm_walk *walk)
> +                              pte_t *ptentp, struct mm_walk *walk)
>  {
>       unsigned long *nr_pages = (unsigned long *)walk->private;
>  
>       /* Simply install a PTE marker, this causes segfault on access. */
> -     *ptep = make_pte_marker(PTE_MARKER_GUARD);
> +     *ptentp = make_pte_marker(PTE_MARKER_GUARD);
>       (*nr_pages)++;
>  
>       return 0;
> -- 
> 2.47.3
>

How did we ensure that the above changes are comprehensive and nothing
else got left in here ?