Re: [RESEND PATCH 1/2] arm64: change from CONT_PMD_SHIFT to CONT_PTE_SHIFT

From: Ard Biesheuvel
Date: Wed Dec 14 2016 - 09:46:33 EST


On 14 December 2016 at 14:19, zhongjiang <zhongjiang@xxxxxxxxxx> wrote:
> From: zhong jiang <zhongjiang@xxxxxxxxxx>
>
> I think that CONT_PTE_SHIFT is more reasonable even if they are some
> value. and the patch is not any functional change.
>

This may be the case for 64k pages, but not for 16k pages, and I
actually think add_default_hugepagesz() could be made unconditional,
given that both 64k on 4k kernels and 2 MB on 16k kernels are useful
hugepage sizes that are not otherwise available by default.

> Signed-off-by: zhong jiang <zhongjiang@xxxxxxxxxx>

Reviewed-by: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx>

> ---
> arch/arm64/mm/hugetlbpage.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/arm64/mm/hugetlbpage.c b/arch/arm64/mm/hugetlbpage.c
> index 2e49bd2..0a4c97b 100644
> --- a/arch/arm64/mm/hugetlbpage.c
> +++ b/arch/arm64/mm/hugetlbpage.c
> @@ -323,7 +323,7 @@ static __init int setup_hugepagesz(char *opt)
> static __init int add_default_hugepagesz(void)
> {
> if (size_to_hstate(CONT_PTES * PAGE_SIZE) == NULL)
> - hugetlb_add_hstate(CONT_PMD_SHIFT);
> + hugetlb_add_hstate(CONT_PTE_SHIFT);
> return 0;
> }
> arch_initcall(add_default_hugepagesz);
> --
> 1.8.3.1
>