Re: [PATCH v3 3/4] mm: Support batched unmap for lazyfree large folios during reclamation

David Hildenbrand
2025-02-04T11:40:10Z

Hi,

> unsigned long hsz = 0;
>
> @@ -1780,6 +1800,16 @@ static bool try_to_unmap_one(struct folio *folio, struct vm_area_struct *vma,
> hugetlb_vma_unlock_write(vma);
> }
> pteval = huge_ptep_clear_flush(vma, address, pvmw.pte);
> + } else if (folio_test_large(folio) && !(flags & TTU_HWPOISON) &&
> + can_batch_unmap_folio_ptes(address, folio, pvmw.pte)) {
> + nr_pages = folio_nr_pages(folio);
> + flush_cache_range(vma, range.start, range.end);
> + pteval = get_and_clear_full_ptes(mm, address, pvmw.pte, nr_pages, 0);
> + if (should_defer_flush(mm, flags))
> + set_tlb_ubc_flush_pending(mm, pteval, address,
> + address + folio_size(folio));
> + else
> + flush_tlb_range(vma, range.start, range.end);
> } else {

I have some fixes [1] that will collide with this series. I'm currently
preparing a v2, and am not 100% sure when the fixes will get queued+merged.

I'll base them against mm-stable for now, and send them out based on
that, to avoid the conflicts here (should all be fairly easy to resolve
from a quick glimpse).

So we might have to refresh this series here if the fixes go in first.

[1] https://lkml.kernel.org/r/20250129115411.2077152-1-david@redhat.com

--
Cheers,

David / dhildenb