On Thu, Dec 5, 2024 at 4:54 PM Baolin Wang
<baolin.wang@xxxxxxxxxxxxxxxxx> wrote:
>
> Commit 5d65c8d758f2 ("mm: count the number of anonymous THPs per size") adds
> a new anonymous counter per THP size, however, when folio_mapping() is not NULL
> during folio migration, it means this is not an anonymous folio, so remove the
> redundant anonymous statistics in this case.
why? Are you sure anon folios won't call __folio_migrate_mapping()?
folio->mapping is PAGE_MAPPING_ANON for anon folios.
static __always_inline bool folio_test_anon(const struct folio *folio)
{
return ((unsigned long)folio->mapping & PAGE_MAPPING_ANON) != 0;
}
>
> Signed-off-by: Baolin Wang <baolin.wang@xxxxxxxxxxxxxxxxx>
> ---
> mm/migrate.c | 2 --
> 1 file changed, 2 deletions(-)
>
> diff --git a/mm/migrate.c b/mm/migrate.c
> index e9e00d1d1d19..d7fdfdd23fd0 100644
> --- a/mm/migrate.c
> +++ b/mm/migrate.c
> @@ -523,8 +523,6 @@ static int __folio_migrate_mapping(struct address_space *mapping,
> */
> newfolio->index = folio->index;
> newfolio->mapping = folio->mapping;
> - if (folio_test_anon(folio) && folio_test_large(folio))
> - mod_mthp_stat(folio_order(folio), MTHP_STAT_NR_ANON, 1);
> folio_ref_add(newfolio, nr); /* add cache reference */
> if (folio_test_swapbacked(folio)) {
> __folio_set_swapbacked(newfolio);
> --
> 2.39.3
>
Thanks
Barry
