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

[David Hildenbrand]

> > > +             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.

--
Cheers,

David / dhildenb