Re: [PATCH 08/17] mm/sparse: mark memory sections present earlier

[Mike Rapoport]

> Upcoming HugeTLB bootmem changes need sparsemem section metadata before
> the HugeTLB bootmem allocation path runs. The memblock ranges are marked
> present from sparse_init(), which is called too late for that setup.
> 
> Move the code that marks memblock ranges present into
> mm_core_init_early(), before free_area_init() and the HugeTLB bootmem
> setup. Rename the helper to sparse_memblock_present() to make the new
> caller describe the sparsemem-specific initialization step.
> 
> This is a preparatory change.
> 
> Signed-off-by: Muchun Song <songmuchun@xxxxxxxxxxxxx>
>
> diff --git a/mm/internal.h b/mm/internal.h
> index 8ec8b447d75e..11844b40f47a 100644
> --- a/mm/internal.h
> +++ b/mm/internal.h
> @@ -960,6 +960,7 @@ void memmap_init_range(unsigned long, int, unsigned long, unsigned long,
>   * mm/sparse.c
>   */
>  #ifdef CONFIG_SPARSEMEM
> +void sparse_memblock_present(void);
>  void sparse_init(void);
>  int sparse_index_init(unsigned long section_nr, int nid);
>  
> @@ -997,6 +998,7 @@ static inline void __section_mark_present(struct mem_section *ms,
>  int section_nr_vmemmap_pages(unsigned long pfn, unsigned long nr_pages,
>  		struct vmem_altmap *altmap, struct dev_pagemap *pgmap);
>  #else
> +static inline void sparse_memblocks_present(void) {}

Sashiko found that this fail comilation with SPARSEMEM=n.

https://sashiko.dev/#/patchset/20260702093821.2740183-1-songmuchun%40bytedance.com?part=8

Please build test your changes with FLATMEM and with
SPARSEMEM_VMEMMAP=n.

-- 
Sincerely yours,
Mike.