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> >>       newfolio->mapping = folio->mapping; > >> -    if (folio_test_anon(folio) && folio_test_large(folio)) > >> +    if (folio_test_anon(folio) && folio_test_large(folio) && > >> +        !folio_test_hugetlb(folio)) > > > > If the hugetlb folio has a non-NULL mapping (i.e., it's a shared mapping), we > > should migrate it via hugetlbfs_migrate_folio()- > >>migrate_huge_page_move_mapping(). In other words, shared hugetlb mappings > > should not reach this path, so this hugetlb check can be dropped. Or am I > > missing something? > > Good point: we should only reach here with anonymous folios that are in the > swapcache. That doesn't apply to hugetlb. > > -- > Cheers, > > David > I think this is right. THe second site requires folio_test_anon() with a non-NULL mapping, i. e. an anon folio in the swap cache, and hugetlb folios never enter the swap cache. Shared hugetlb goes through migrate_huge_page_move_mapping() as you say, and the only other callers of folio_migrate_mapping() never pass hugetlb folios either. So the check in the second hunk can't fire. --Richard