Re: [PATCH v2] mm/madvise: avoid skipping pages after splitting large folios

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

> 
> Let's at least split out the folio check into a helper to make things
> clearer:
> 
> static bool poison_splits_folio(const struct folio *folio)
> {
> 	/* Hugetlb is, as always, a world unto itself. */
> 	if (folio_test_hugetlb(folio))
> 		return false;
> 	/* Soft-offline errors out, hwpoison traverse DAX intact. */
> 	if (folio_is_zone_device(folio))
> 		return false;
> 	return true;
> }
> 
> Then for your patch:
> 
> -		size = PAGE_SIZE;
> -		if (folio_test_hugetlb(folio) || folio_is_zone_device(folio))
> -			size = folio_size(folio);
> +		size = poison_splits_folio(folio) ? PAGE_SIZE : folio_size(folio);
> 
> I tried writing something that was neater and nicer but AI kept pointing
> out how it was totally broken and I really really hate this code (not your
> fault :).

No, I don't think any such special casing on folios is the right way to handle it.

-- 
Cheers,

David