Re: [PATCH RFC 3/6] mm: swap: make should_try_to_free_swap() support large-folio

[Chris Li]

Acked-by: Chris Li <chrisl@xxxxxxxxxx>

Chris

On Thu, Jan 18, 2024 at 3:11 AM Barry Song <21cnbao@xxxxxxxxx> wrote:
>
> From: Chuanhua Han <hanchuanhua@xxxxxxxx>
>
> should_try_to_free_swap() works with an assumption that swap-in is always done
> at normal page granularity, aka, folio_nr_pages = 1. To support large folio
> swap-in, this patch removes the assumption.
>
> Signed-off-by: Chuanhua Han <hanchuanhua@xxxxxxxx>
> Co-developed-by: Barry Song <v-songbaohua@xxxxxxxx>
> Signed-off-by: Barry Song <v-songbaohua@xxxxxxxx>
> ---
>  mm/memory.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/mm/memory.c b/mm/memory.c
> index 7e1f4849463a..f61a48929ba7 100644
> --- a/mm/memory.c
> +++ b/mm/memory.c
> @@ -3714,7 +3714,7 @@ static inline bool should_try_to_free_swap(struct folio *folio,
>          * reference only in case it's likely that we'll be the exlusive user.
>          */
>         return (fault_flags & FAULT_FLAG_WRITE) && !folio_test_ksm(folio) &&
> -               folio_ref_count(folio) == 2;
> +               folio_ref_count(folio) == (1 + folio_nr_pages(folio));
>  }
>
>  static vm_fault_t pte_marker_clear(struct vm_fault *vmf)
> --
> 2.34.1
>
>