Re: [PATCH v6 1/6] arm64/hugetlb: Extend batching of multiple CONT_PTE in a single PTE setup

[Anshuman Khandual <anshuman.khandual@arm.com>]

On 09/07/26 1:08 PM, Wen Jiang wrote:
> From: "Barry Song (Xiaomi)" <baohua@kernel.org>
> 
> For sizes aligned to CONT_PTE_SIZE and smaller than PMD_SIZE,
> we can handle CONT_PTE_SIZE groups together.
> 
> Signed-off-by: Barry Song (Xiaomi) <baohua@kernel.org>
> Signed-off-by: Wen Jiang <jiangwen6@xiaomi.com>
> Tested-by: Xueyuan Chen <xueyuan.chen21@gmail.com>
> Tested-by: Leo Yan <leo.yan@arm.com>
> Reviewed-by: Dev Jain <dev.jain@arm.com>
> ---
>  arch/arm64/mm/hugetlbpage.c | 10 ++++++++++
>  1 file changed, 10 insertions(+)
> 
> diff --git a/arch/arm64/mm/hugetlbpage.c b/arch/arm64/mm/hugetlbpage.c
> index a42c05cf56408..0da746f729388 100644
> --- a/arch/arm64/mm/hugetlbpage.c
> +++ b/arch/arm64/mm/hugetlbpage.c
> @@ -110,6 +110,12 @@ static inline int num_contig_ptes(unsigned long size, size_t *pgsize)
>  		contig_ptes = CONT_PTES;
>  		break;
>  	default:
> +		if (size > 0 && size < PMD_SIZE &&

Is there a possibility for size <= 0 ? If not then
the above conditional check might be redundant.
> +				IS_ALIGNED(size, CONT_PTE_SIZE)) {
> +			*pgsize = PAGE_SIZE;
> +			contig_ptes = size >> PAGE_SHIFT;
> +			break;
> +		}
>  		WARN_ON(!__hugetlb_valid_size(size));

Would not these CONT_PTE_SIZE aligned sizes upto PMD_SIZE
trigger warning here because __hugetlb_valid_size() still
does not enumerate them ?
>  	}
>  
> @@ -359,6 +365,10 @@ pte_t arch_make_huge_pte(pte_t entry, unsigned int shift, vm_flags_t flags)
>  	case CONT_PTE_SIZE:
>  		return pte_mkcont(entry);
>  	default:
> +		if (pagesize > 0 && pagesize < PMD_SIZE &&
> +				IS_ALIGNED(pagesize, CONT_PTE_SIZE))
> +			return pte_mkcont(entry);
> +
>  		break;
>  	}
>  	pr_warn("%s: unrecognized huge page size 0x%lx\n",