Re: [PATCH v1 06/10] mm: Allow deferred splitting of arbitrary large anon folios

Yin Fengwei
2023-06-28T02:43:43Z

On 6/27/23 01:14, Ryan Roberts wrote:
> With the introduction of large folios for anonymous memory, we would
> like to be able to split them when they have unmapped subpages, in order
> to free those unused pages under memory pressure. So remove the
> artificial requirement that the large folio needed to be at least
> PMD-sized.
>
> Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
Reviewed-by: Yin Fengwei <fengwei.yin@intel.com>

Regards
Yin, Fengwei

> ---
> mm/rmap.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/mm/rmap.c b/mm/rmap.c
> index ac1d93d43f2b..3d11c5fb6090 100644
> --- a/mm/rmap.c
> +++ b/mm/rmap.c
> @@ -1567,7 +1567,7 @@ void page_remove_rmap(struct page *page, struct vm_area_struct *vma,
> * page of the folio is unmapped and at least one page
> * is still mapped.
> */
> - if (folio_test_pmd_mappable(folio) && folio_test_anon(folio))
> + if (folio_test_large(folio) && folio_test_anon(folio))
> if (!compound || nr < nr_pmdmapped)
> deferred_split_folio(folio);
> }