On Tue, Jul 07, 2026 at 09:36:17PM +0800, Wandun wrote:
<snip>
> > diff --git a/mm/mlock.c b/mm/mlock.c
> > index ac65de40b22b..f56c685533f5 100644
> > --- a/mm/mlock.c
> > +++ b/mm/mlock.c
<snip>
> > +static int mlock_collect_migratable_pte_range(pmd_t *pmd, unsigned long
> > addr,
> > + unsigned long end, struct mm_walk *walk)
> > +{
> > + struct vm_area_struct *vma = walk->vma;
> > + struct list_head *folio_list = walk->private;
> > + spinlock_t *ptl;
> > + pte_t *start_pte, *pte;
> > + pte_t ptent;
> > + struct folio *folio;
> > + unsigned int step = 1;
> > +
> > + if (!(vma->vm_flags & VM_LOCKED))
> > + return 0;
> > +
> > + ptl = pmd_trans_huge_lock(pmd, vma);
> > + if (ptl) {
> > + if (!pmd_present(*pmd)) {
> > + if
> > (unlikely(softleaf_is_migration(softleaf_from_pmd(*pmd)))) {
> > + spin_unlock(ptl);
> > + pmd_migration_entry_wait(vma->vm_mm, pmd);
> > + walk->action = ACTION_AGAIN;
> > + return 0;
> > + }
> > + goto out;
> > + }
> > + if (is_huge_zero_pmd(*pmd))
> > + goto out;
> > + folio = pmd_folio(*pmd);
> > + if (folio_is_zone_device(folio))
> > + goto out;
> > + if (is_migrate_cma_page(&folio->page))
> > + isolate_folio_to_list(folio, folio_list);
> > + goto out;
> > + }
> > +
> > + start_pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
> > + if (!start_pte) {
> > + walk->action = ACTION_AGAIN;
> > + return 0;
> > + }
> > +
> > + for (pte = start_pte; addr != end; pte += step, addr += step *
> > PAGE_SIZE) {
> > + step = 1;
> > + ptent = ptep_get(pte);
> > + if (!pte_present(ptent)) {
> > + if
> > (unlikely(softleaf_is_migration(softleaf_from_pte(ptent)))) {
> > + pte_unmap_unlock(start_pte, ptl);
> > + migration_entry_wait(vma->vm_mm, pmd, addr);
> > + walk->action = ACTION_AGAIN;
> > + return 0;
> > + }
> > + continue;
> > + }
> > + folio = vm_normal_folio(vma, addr, ptent);
> > + if (!folio || folio_is_zone_device(folio))
> > + continue;
> > + step = folio_mlock_step(folio, pte, addr, end);
> > + if (is_migrate_cma_page(&folio->page))
> Here should be, sorry about this.
> if (!is_migrate_cma_page(&folio->page))
> continue;
But above you do the:
if (is_migrate_cma_page(&folio->page))
isolate_folio_to_list(folio, folio_list);
Pattern :) so these should be consistent. But you're copy/pasting and need to
not do that so it's kind of by the by.
Anyway, yes I assumed you meant this. But see the main review, I am not really a
fan of the implementation, overall.
>
> Best regards
> Wandun
Thanks, Lorenzo
