Re: [PATCH v2 4/7] mm: rename mm_struct::map_count to vma_count

[David Hildenbrand]

On 15.09.25 18:36, Kalesh Singh wrote:
> A mechanical rename of the mm_struct->map_count field to
> vma_count; no functional change is intended.
>
> The name "map_count" is ambiguous within the memory management subsystem,
> as it can be confused with the folio/page->_mapcount field, which tracks
> PTE references.
>
> The new name, vma_count, is more precise as this field has always
> counted the number of vm_area_structs associated with an mm_struct.
>
> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
> Cc: David Hildenbrand <david@xxxxxxxxxx>
> Cc: "Liam R. Howlett" <Liam.Howlett@xxxxxxxxxx>
> Cc: Lorenzo Stoakes <lorenzo.stoakes@xxxxxxxxxx>
> Cc: Mike Rapoport <rppt@xxxxxxxxxx>
> Cc: Minchan Kim <minchan@xxxxxxxxxx>
> Cc: Pedro Falcato <pfalcato@xxxxxxx>
> Signed-off-by: Kalesh Singh <kaleshsingh@xxxxxxxxxx>
> ---


[...]

> +++ b/mm/mmap.c
> @@ -1308,7 +1308,7 @@ void exit_mmap(struct mm_struct *mm)
>   		vma = vma_next(&vmi);
>   	} while (vma && likely(!xa_is_zero(vma)));
>   
> -	BUG_ON(count != mm->map_count);
> +	BUG_ON(count != mm->vma_count);
>   

While at it, best to change that to a WARN_ON_ONCE() or even a 
VM_WARN_ON_ONCE().

[ or remove it -- have we ever seen that firing? ]

Acked-by: David Hildenbrand <david@xxxxxxxxxx>

--
Cheers

David / dhildenb