Re: [PATCH v3 20/20] mm: stop maintaining the per-page mapcount of large folios (CONFIG_NO_PAGE_MAPCOUNT)

David Hildenbrand
2025-10-14T14:38:44Z

On 14.10.25 16:32, Matthew Wilcox wrote:
> On Tue, Oct 14, 2025 at 02:59:30PM +0200, David Hildenbrand wrote:
>>> As commit 349994cf61e6 mentioned, we don't support partially mapped PUD-sized
>>> folio yet.
>>
>> We do support partially mapped PUD-sized folios I think, but not anonymous
>> PUD-sized folios.
>
> I don't think so? The only mechanism I know of to allocate PUD-sized
> chunks of memory is hugetlb, and that doesn't permit partial mappings.

Greetings from the latest DAX rework :)

--
Cheers

David / dhildenb