Re: [PATCH] mm/dirty: Replace READ_ONCE() with pudp_get()

[Dev Jain]

On 06/10/25 11:22 am, Anshuman Khandual wrote:
> Replace READ_ONCE() with a standard page table accessor i.e pudp_get() that
> anyways defaults into READ_ONCE() in cases where platform does not override
>
> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
> Cc: David Hildenbrand <david@xxxxxxxxxx>
> Cc: linux-mm@xxxxxxxxx
> Cc: linux-kernel@xxxxxxxxxxxxxxx
> Signed-off-by: Anshuman Khandual <anshuman.khandual@xxxxxxx>
> ---
>   mm/mapping_dirty_helpers.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/mm/mapping_dirty_helpers.c b/mm/mapping_dirty_helpers.c
> index c193de6cb23a..737c407f4081 100644
> --- a/mm/mapping_dirty_helpers.c
> +++ b/mm/mapping_dirty_helpers.c
> @@ -149,7 +149,7 @@ static int wp_clean_pud_entry(pud_t *pud, unsigned long addr, unsigned long end,
>   			      struct mm_walk *walk)
>   {
>   #ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
> -	pud_t pudval = READ_ONCE(*pud);
> +	pud_t pudval = pudp_get(pud);
>   
>   	/* Do not split a huge pud */
>   	if (pud_trans_huge(pudval)) {

Talking about mm, why not also make changes for these READ_ONCE accesses
in gup, hmm, memory, mprotect, sparse-vmemmap?