Re: [PATCH v2 1/5] mm,hugetlb: Change mechanism to detect a COW on private mapping

David Hildenbrand
2025-06-23T14:10:02Z

>
> - /*
> - * hugetlb_wp() requires page locks of pte_page(vmf.orig_pte) and
> - * pagecache_folio, so here we need take the former one
> - * when folio != pagecache_folio or !pagecache_folio.
> - */
> + /* hugetlb_wp() requires page locks of pte_page(vmf.orig_pte) */
> folio = page_folio(pte_page(vmf.orig_pte));
> - if (folio != pagecache_folio)
> - if (!folio_trylock(folio)) {
> - need_wait_lock = 1;
> - goto out_ptl;
> - }
> -
> + folio_lock(folio);
> folio_get(folio);

Just realized that this won't work for this patch here, as we are
holding the PTL.

In patch #2 you do the right thing.

--
Cheers,

David / dhildenb