Re: [PATCH mm-unstable v1 3/4] mm/swap: inline folio_set_swap_entry() and folio_swap_entry()

[Chris Li <chrisl@kernel.org>]

Reviewed-by: Chris Li <chrisl@kernel.org>

Chris

On Mon, Aug 21, 2023 at 9:09 AM David Hildenbrand <david@redhat.com> wrote:
>
> Let's simply work on the folio directly and remove the helpers.
>
> Suggested-by: Matthew Wilcox <willy@infradead.org>
> Signed-off-by: David Hildenbrand <david@redhat.com>
> ---
>  include/linux/swap.h | 12 +-----------
>  mm/memory.c          |  2 +-
>  mm/shmem.c           |  6 +++---
>  mm/swap_state.c      |  7 +++----
>  mm/swapfile.c        |  2 +-
>  mm/util.c            |  2 +-
>  mm/vmscan.c          |  2 +-
>  mm/zswap.c           |  4 ++--
>  8 files changed, 13 insertions(+), 24 deletions(-)
>
> diff --git a/include/linux/swap.h b/include/linux/swap.h
> index 82859a1944f5..603acf813873 100644
> --- a/include/linux/swap.h
> +++ b/include/linux/swap.h
> @@ -333,25 +333,15 @@ struct swap_info_struct {
>                                            */
>  };
>
> -static inline swp_entry_t folio_swap_entry(struct folio *folio)
> -{
> -       return folio->swap;
> -}
> -
>  static inline swp_entry_t page_swap_entry(struct page *page)
>  {
>         struct folio *folio = page_folio(page);
> -       swp_entry_t entry = folio_swap_entry(folio);
> +       swp_entry_t entry = folio->swap;
>
>         entry.val += page - &folio->page;
>         return entry;
>  }
>
> -static inline void folio_set_swap_entry(struct folio *folio, swp_entry_t entry)
> -{
> -       folio->swap = entry;
> -}
> -
>  /* linux/mm/workingset.c */
>  bool workingset_test_recent(void *shadow, bool file, bool *workingset);
>  void workingset_age_nonresident(struct lruvec *lruvec, unsigned long nr_pages);
> diff --git a/mm/memory.c b/mm/memory.c
> index ff13242c1589..c51800dbfa9b 100644
> --- a/mm/memory.c
> +++ b/mm/memory.c
> @@ -3831,7 +3831,7 @@ vm_fault_t do_swap_page(struct vm_fault *vmf)
>                                 folio_add_lru(folio);
>
>                                 /* To provide entry to swap_readpage() */
> -                               folio_set_swap_entry(folio, entry);
> +                               folio->swap = entry;
>                                 swap_readpage(page, true, NULL);
>                                 folio->private = NULL;
>                         }
> diff --git a/mm/shmem.c b/mm/shmem.c
> index 7a0c1e19d9f8..fc1afe9dfcfe 100644
> --- a/mm/shmem.c
> +++ b/mm/shmem.c
> @@ -1657,7 +1657,7 @@ static int shmem_replace_folio(struct folio **foliop, gfp_t gfp,
>         int error;
>
>         old = *foliop;
> -       entry = folio_swap_entry(old);
> +       entry = old->swap;
>         swap_index = swp_offset(entry);
>         swap_mapping = swap_address_space(entry);
>
> @@ -1678,7 +1678,7 @@ static int shmem_replace_folio(struct folio **foliop, gfp_t gfp,
>         __folio_set_locked(new);
>         __folio_set_swapbacked(new);
>         folio_mark_uptodate(new);
> -       folio_set_swap_entry(new, entry);
> +       new->swap = entry;
>         folio_set_swapcache(new);
>
>         /*
> @@ -1800,7 +1800,7 @@ static int shmem_swapin_folio(struct inode *inode, pgoff_t index,
>         /* We have to do this with folio locked to prevent races */
>         folio_lock(folio);
>         if (!folio_test_swapcache(folio) ||
> -           folio_swap_entry(folio).val != swap.val ||
> +           folio->swap.val != swap.val ||
>             !shmem_confirm_swap(mapping, index, swap)) {
>                 error = -EEXIST;
>                 goto unlock;
> diff --git a/mm/swap_state.c b/mm/swap_state.c
> index 2f2417810052..b3b14bd0dd64 100644
> --- a/mm/swap_state.c
> +++ b/mm/swap_state.c
> @@ -100,7 +100,7 @@ int add_to_swap_cache(struct folio *folio, swp_entry_t entry,
>
>         folio_ref_add(folio, nr);
>         folio_set_swapcache(folio);
> -       folio_set_swap_entry(folio, entry);
> +       folio->swap = entry;
>
>         do {
>                 xas_lock_irq(&xas);
> @@ -156,8 +156,7 @@ void __delete_from_swap_cache(struct folio *folio,
>                 VM_BUG_ON_PAGE(entry != folio, entry);
>                 xas_next(&xas);
>         }
> -       entry.val = 0;
> -       folio_set_swap_entry(folio, entry);
> +       folio->swap.val = 0;
>         folio_clear_swapcache(folio);
>         address_space->nrpages -= nr;
>         __node_stat_mod_folio(folio, NR_FILE_PAGES, -nr);
> @@ -233,7 +232,7 @@ bool add_to_swap(struct folio *folio)
>   */
>  void delete_from_swap_cache(struct folio *folio)
>  {
> -       swp_entry_t entry = folio_swap_entry(folio);
> +       swp_entry_t entry = folio->swap;
>         struct address_space *address_space = swap_address_space(entry);
>
>         xa_lock_irq(&address_space->i_pages);
> diff --git a/mm/swapfile.c b/mm/swapfile.c
> index bd9d904671b9..e52f486834eb 100644
> --- a/mm/swapfile.c
> +++ b/mm/swapfile.c
> @@ -1536,7 +1536,7 @@ static bool swap_page_trans_huge_swapped(struct swap_info_struct *si,
>
>  static bool folio_swapped(struct folio *folio)
>  {
> -       swp_entry_t entry = folio_swap_entry(folio);
> +       swp_entry_t entry = folio->swap;
>         struct swap_info_struct *si = _swap_info_get(entry);
>
>         if (!si)
> diff --git a/mm/util.c b/mm/util.c
> index cde229b05eb3..f31e2ca62cfa 100644
> --- a/mm/util.c
> +++ b/mm/util.c
> @@ -764,7 +764,7 @@ struct address_space *folio_mapping(struct folio *folio)
>                 return NULL;
>
>         if (unlikely(folio_test_swapcache(folio)))
> -               return swap_address_space(folio_swap_entry(folio));
> +               return swap_address_space(folio->swap);
>
>         mapping = folio->mapping;
>         if ((unsigned long)mapping & PAGE_MAPPING_FLAGS)
> diff --git a/mm/vmscan.c b/mm/vmscan.c
> index c7c149cb8d66..6f13394b112e 100644
> --- a/mm/vmscan.c
> +++ b/mm/vmscan.c
> @@ -1423,7 +1423,7 @@ static int __remove_mapping(struct address_space *mapping, struct folio *folio,
>         }
>
>         if (folio_test_swapcache(folio)) {
> -               swp_entry_t swap = folio_swap_entry(folio);
> +               swp_entry_t swap = folio->swap;
>
>                 if (reclaimed && !mapping_exiting(mapping))
>                         shadow = workingset_eviction(folio, target_memcg);
> diff --git a/mm/zswap.c b/mm/zswap.c
> index 7300b98d4a03..412b1409a0d7 100644
> --- a/mm/zswap.c
> +++ b/mm/zswap.c
> @@ -1190,7 +1190,7 @@ static void zswap_fill_page(void *ptr, unsigned long value)
>
>  bool zswap_store(struct folio *folio)
>  {
> -       swp_entry_t swp = folio_swap_entry(folio);
> +       swp_entry_t swp = folio->swap;
>         int type = swp_type(swp);
>         pgoff_t offset = swp_offset(swp);
>         struct page *page = &folio->page;
> @@ -1370,7 +1370,7 @@ bool zswap_store(struct folio *folio)
>
>  bool zswap_load(struct folio *folio)
>  {
> -       swp_entry_t swp = folio_swap_entry(folio);
> +       swp_entry_t swp = folio->swap;
>         int type = swp_type(swp);
>         pgoff_t offset = swp_offset(swp);
>         struct page *page = &folio->page;
> --
> 2.41.0
>
>