Re: [PATCH 2/2] mm/migrate: exclude hugetlb folios from MTHP_STAT_NR_ANON accounting

[David Hildenbrand (Arm)]

>>       newfolio->index = folio->index;
>>       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