On Fri, Dec 09, 2022 at 02:02:09AM +0800, Kairui Song wrote:
> From: Kairui Song <kasong@xxxxxxxxxxx>
>
> __read_swap_cache_async should just call swap_cache_get_folio for trying
> to look up the swap cache. Because swap_cache_get_folio handles the
> readahead statistic, and clears the RA flag, looking up the cache
> directly will skip these parts.
>
> And the comment no longer applies after commit 442701e7058b
> ("mm/swap: remove swap_cache_info statistics"), just remove them.
But what about the readahead stats?
> Fixes: 442701e7058b ("mm/swap: remove swap_cache_info statistics")
> Signed-off-by: Kairui Song <kasong@xxxxxxxxxxx>
> ---
> mm/swap_state.c | 7 ++-----
> 1 file changed, 2 insertions(+), 5 deletions(-)
>
> diff --git a/mm/swap_state.c b/mm/swap_state.c
> index eba388f67741..f39cfb62551d 100644
> --- a/mm/swap_state.c
> +++ b/mm/swap_state.c
> @@ -418,15 +418,12 @@ struct page *__read_swap_cache_async(swp_entry_t entry, gfp_t gfp_mask,
> for (;;) {
> int err;
> /*
> - * First check the swap cache. Since this is normally
> - * called after swap_cache_get_folio() failed, re-calling
> - * that would confuse statistics.
> + * First check the swap cache in case of race.
> */
> si = get_swap_device(entry);
> if (!si)
> return NULL;
> - folio = filemap_get_folio(swap_address_space(entry),
> - swp_offset(entry));
> + folio = swap_cache_get_folio(entry, vma, addr);
> put_swap_device(si);
> if (folio)
> return folio_file_page(folio, swp_offset(entry));
> --
> 2.35.2
>
>
