Re: [RFC PATCH v2 09/12] mm: Make MAX_ORDER of buddy allocator configurable via Kconfig SET_MAX_ORDER.

From: Randy Dunlap
Date: Fri Aug 12 2022 - 21:11:52 EST


Hi--

On 8/11/22 16:16, Zi Yan wrote:

> diff --git a/mm/Kconfig b/mm/Kconfig
> index bbe31e85afee..e558f5679707 100644
> --- a/mm/Kconfig
> +++ b/mm/Kconfig
> @@ -441,6 +441,20 @@ config SPARSEMEM_VMEMMAP
> pfn_to_page and page_to_pfn operations. This is the most
> efficient option when sufficient kernel resources are available.
>
> +config SET_MAX_ORDER
> + int "Set maximum order of buddy allocator"
> + depends on SPARSEMEM_VMEMMAP && (ARCH_FORCE_MAX_ORDER = 0)
> + range 10 255
> + default "10"
> + help
> + The kernel memory allocator divides physically contiguous memory
> + blocks into "zones", where each zone is a power of two number of
> + pages. This option selects the largest power of two that the kernel
> + keeps in the memory allocator. If you need to allocate very large
> + blocks of physically contiguous memory, then you may need to
> + increase this value. A value of 10 means that the largest free memory
> + block is 2^10 pages.

Please make sure that all lines of help text are indented with one tab + 2 spaces,
as specified in Documentation/process/coding-style.rst.

thanks.
--
~Randy