Re: [PATCH v1 0/2] mm/huge_memory: don't mark refcounted pages special in vmf_insert_folio_*()

[David Hildenbrand]

On 03.06.25 23:16, David Hildenbrand wrote:
> Based on Linus' master.
>
> While working on improving vm_normal_page() and friends, I stumbled
> over this issues: refcounted "normal" pages must not be marked
> using pmd_special() / pud_special().
>
> Fortunately, so far there doesn't seem to be serious damage.
>
> This is only compile-tested so far. Still looking for an easy way to test
> PMD/PUD mappings with DAX. Any tests I can easily run?

... aaaand I should have waited for the cross compiles.

s390x and loongarch are not happy about pud_mkhuge() and pfn_pud().

Need to fence folio_mk_pud() by CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD.

--
Cheers,

David / dhildenb