Re: [PATCH] mm/sparse: Fix sparse_vmemmap_init_nid_early definition without CONFIG_SPARSEMEM

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

On 11/27/25 10:25, Jinhui Guo wrote:
> When CONFIG_SPARSEMEM is disabled, the macro
> sparse_vmemmap_init_nid_early(_nid, _use) passes
> two arguments, while the actual function accepts
> only nid. Drop the extra argument _use.
> 
> Fixes: d65917c42373 ("mm/sparse: allow for alternate vmemmap section init at boot")
> Signed-off-by: Jinhui Guo <guojinhui.liam@bytedance.com>
> ---
>   include/linux/mmzone.h | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
> index 7fb7331c5725..f6dd181a4821 100644
> --- a/include/linux/mmzone.h
> +++ b/include/linux/mmzone.h
> @@ -2293,7 +2293,7 @@ void sparse_init(void);
>   #else
>   #define sparse_init()	do {} while (0)
>   #define sparse_index_init(_sec, _nid)  do {} while (0)
> -#define sparse_vmemmap_init_nid_early(_nid, _use) do {} while (0)
> +#define sparse_vmemmap_init_nid_early(_nid) do {} while (0)
>   #define sparse_vmemmap_init_nid_late(_nid) do {} while (0)
>   #define pfn_in_present_section pfn_valid
>   #define subsection_map_init(_pfn, _nr_pages) do {} while (0)

That commit is from early 2025.

So what are the symptoms we are fixing? I would have assumed a 
compile-time problem, but no built bot caught that?

-- 
Cheers

David