Re: [PATCH v4 2/3] mm/rmap: integrate PMD-mapped folio splitting into pagewalk loop

[Lance Yang <ioworker0@gmail.com>]

Hey David,

Thanks for reaching out!

On Tue, May 7, 2024 at 4:17 PM David Hildenbrand <david@redhat.com> wrote:
>
> >>>
> >>> +             if (!pvmw.pte && (flags & TTU_SPLIT_HUGE_PMD)) {
> >>> +                     /*
> >>> +                      * We temporarily have to drop the PTL and start once
> >>> +                      * again from that now-PTE-mapped page table.
> >>> +                      */
> >>> +                     split_huge_pmd_locked(vma, range.start, pvmw.pmd, false,
> >>> +                                           folio);
> >>> +                     pvmw.pmd = NULL;
> >>> +                     spin_unlock(pvmw.ptl);
> >>
> >> IMO, you should also make the 'pvmw.ptl = NULL;' after unlocking as
> >> page_vma_mapped_walk() did, in case some corner case met.
> >
> > Yep, I'll also set pvmw.ptl to NULL here if any corner cases arise.
> >
>
> This series already resides in mm-stable. I asked Andrew to remove it
> for now. If that doesn't work, we'll need fixup patches to address any
> review feedback.

I'll patiently wait Andrew's response, and then submit the next version or
fixup patches accordingly.

Thanks,
Lance

>
> --
> Cheers,
>
> David / dhildenb
>