Re: [PATCH v3 02/14] arm64: drop ranges in definition of ARCH_FORCE_MAX_ORDER

[Kefeng Wang]

On 2023/3/25 14:08, Mike Rapoport wrote:
> From: "Mike Rapoport (IBM)" <rppt@xxxxxxxxxx>
>
> It is not a good idea to change fundamental parameters of core memory
> management. Having predefined ranges suggests that the values within
> those ranges are sensible, but one has to *really* understand
> implications of changing MAX_ORDER before actually amending it and
> ranges don't help here.
>
> Drop ranges in definition of ARCH_FORCE_MAX_ORDER and make its prompt
> visible only if EXPERT=y
>
> Acked-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
> Reviewed-by: Zi Yan <ziy@xxxxxxxxxx>
> Signed-off-by: Mike Rapoport (IBM) <rppt@xxxxxxxxxx>

Reviewed-by: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx>

> ---
>   arch/arm64/Kconfig | 4 +---
>   1 file changed, 1 insertion(+), 3 deletions(-)
>
> diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
> index e60baf7859d1..7324032af859 100644
> --- a/arch/arm64/Kconfig
> +++ b/arch/arm64/Kconfig
> @@ -1487,11 +1487,9 @@ config XEN
>   # 16K |       27          |      14      |       13        |         11         |
>   # 64K |       29          |      16      |       13        |         13         |
>   config ARCH_FORCE_MAX_ORDER
> -	int "Maximum zone order" if ARM64_4K_PAGES || ARM64_16K_PAGES
> +	int "Maximum zone order" if EXPERT && (ARM64_4K_PAGES || ARM64_16K_PAGES)
>   	default "13" if ARM64_64K_PAGES
> -	range 11 13 if ARM64_16K_PAGES
>   	default "11" if ARM64_16K_PAGES
> -	range 10 15 if ARM64_4K_PAGES
>   	default "10"
>   	help
>   	  The kernel memory allocator divides physically contiguous memory