Re: [PATCH v2 2/4] arm64: hugetlb: Fix huge_ptep_get_and_clear() for non-present ptes

[Catalin Marinas]

On Mon, Feb 17, 2025 at 02:04:15PM +0000, Ryan Roberts wrote:
> diff --git a/arch/arm64/mm/hugetlbpage.c b/arch/arm64/mm/hugetlbpage.c
> index 06db4649af91..614b2feddba2 100644
> --- a/arch/arm64/mm/hugetlbpage.c
> +++ b/arch/arm64/mm/hugetlbpage.c
> @@ -163,24 +163,23 @@ static pte_t get_clear_contig(struct mm_struct *mm,
>  			     unsigned long pgsize,
>  			     unsigned long ncontig)
>  {
> -	pte_t orig_pte = __ptep_get(ptep);
> -	unsigned long i;
> -
> -	for (i = 0; i < ncontig; i++, addr += pgsize, ptep++) {
> -		pte_t pte = __ptep_get_and_clear(mm, addr, ptep);
> -
> -		/*
> -		 * If HW_AFDBM is enabled, then the HW could turn on
> -		 * the dirty or accessed bit for any page in the set,
> -		 * so check them all.
> -		 */
> -		if (pte_dirty(pte))
> -			orig_pte = pte_mkdirty(orig_pte);
> -
> -		if (pte_young(pte))
> -			orig_pte = pte_mkyoung(orig_pte);
> +	pte_t pte, tmp_pte;
> +	bool present;
> +
> +	pte = __ptep_get_and_clear(mm, addr, ptep);
> +	present = pte_present(pte);
> +	while (--ncontig) {

A 'for' loop may be more consistent with the rest of the file but I
really don't mind the 'while' loop.

Reviewed-by: Catalin Marinas <catalin.marinas@xxxxxxx>