Re: [PATCH v5 13/17] mm/sparse: remove section_map_size()

["David Hildenbrand (Arm)" <david@kernel.org>]

On 8/25/26 10:46, Muchun Song wrote:
> section_map_size() no longer provides any shared logic.
> 
> After the sparse-vmemmap changes, its only remaining user is the
> !CONFIG_SPARSEMEM_VMEMMAP path in __populate_section_memmap(), which can
> compute the size inline with PAGE_ALIGN(sizeof(struct page) *
> PAGES_PER_SECTION).
> 
> Remove section_map_size() and inline the remaining calculation.
> 
> Signed-off-by: Muchun Song <songmuchun@bytedance.com>
> Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
> ---
> v2:
> - Collect Acked-by from Mike Rapoport
> ---
>  include/linux/mm.h |  1 -
>  mm/sparse.c        | 15 ++-------------
>  2 files changed, 2 insertions(+), 14 deletions(-)
> 
> diff --git a/include/linux/mm.h b/include/linux/mm.h
> index 441bd39eab73..b19711b6dbc6 100644
> --- a/include/linux/mm.h
> +++ b/include/linux/mm.h
> @@ -5140,7 +5140,6 @@ static inline void print_vma_addr(char *prefix, unsigned long rip)
>  }
>  #endif
>  
> -unsigned long section_map_size(void);
>  struct page * __populate_section_memmap(unsigned long pfn,
>  		unsigned long nr_pages, int nid, struct vmem_altmap *altmap,
>  		struct dev_pagemap *pgmap);
> diff --git a/mm/sparse.c b/mm/sparse.c
> index 7096d8e13802..9349ed6326c0 100644
> --- a/mm/sparse.c
> +++ b/mm/sparse.c
> @@ -209,23 +209,12 @@ void __init sparse_sections_init(void)
>  		memory_present(nid, start, end);
>  }
>  
> -#ifdef CONFIG_SPARSEMEM_VMEMMAP
> -unsigned long __init section_map_size(void)
> -{
> -	return ALIGN(sizeof(struct page) * PAGES_PER_SECTION, PMD_SIZE);
> -}
> -
> -#else
> -unsigned long __init section_map_size(void)
> -{
> -	return PAGE_ALIGN(sizeof(struct page) * PAGES_PER_SECTION);
> -}
> -
> +#ifndef CONFIG_SPARSEMEM_VMEMMAP
>  struct page __init *__populate_section_memmap(unsigned long pfn,
>  		unsigned long nr_pages, int nid, struct vmem_altmap *altmap,
>  		struct dev_pagemap *pgmap)
>  {
> -	unsigned long size = section_map_size();
> +	unsigned long size = PAGE_ALIGN(sizeof(struct page) * PAGES_PER_SECTION);

While at it, I'd make that const.

Acked-by: David Hildenbrand (Arm) <david@kernel.org>

-- 
Cheers,

David