Re: [PATCH] vmcoreinfo: export SECTION_HAS_MEM_MAP

From: Anshuman Khandual

Date: Tue Sep 29 2026 - 01:05:23 EST


On Mon, Sep 28, 2026 at 10:48:21AM +0200, David Hildenbrand (Arm) wrote:
> The crash tool currently hardcodes SECTION_HAS_MEM_MAP, and makedumpfile
> needs similar information (although still relying on
> SECTION_MARKED_PRESENT, it should switch to SECTION_HAS_MEM_MAP).
>
> Let's just export the value instead, so tools that work on vmcoreinfo
> will not have to guess.
>
> Signed-off-by: David Hildenbrand (Arm) <david@xxxxxxxxxx>

Reviewed-by: Anshuman Khandual <anshuman.khandual@xxxxxxx>

> ---
> Result of the discussion in reply to "[PATCH v2 00/13] mm/sparse: remove
> SECTION_MARKED_PRESENT and further cleanups" [1]
>
> This patch can go in independently. It would be preferable if both
> go into the same kernel release ;)
>
> [1] https://lore.kernel.org/r/20260921-b4-sparsemem_cleanups-v2-0-54d81d65e125@xxxxxxxxxx
> ---
> kernel/vmcore_info.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/kernel/vmcore_info.c b/kernel/vmcore_info.c
> index 5a417f8a922a..7833a36064a8 100644
> --- a/kernel/vmcore_info.c
> +++ b/kernel/vmcore_info.c
> @@ -182,6 +182,7 @@ static int __init crash_save_vmcoreinfo_init(void)
> VMCOREINFO_STRUCT_SIZE(mem_section);
> VMCOREINFO_OFFSET(mem_section, section_mem_map);
> VMCOREINFO_NUMBER(SECTION_SIZE_BITS);
> + VMCOREINFO_NUMBER(SECTION_HAS_MEM_MAP);
> VMCOREINFO_NUMBER(MAX_PHYSMEM_BITS);
> #endif
> VMCOREINFO_STRUCT_SIZE(page);
>
> ---
>
> base-commit: 57e4ac91fc62d75d84b5a03827a19ceb4094ecd9
>
> change-id: 20260928-section_has_mem_map-6205dc90a09f
>
> --
>
> Cheers,
>
> David
>