On Wed, Aug 7, 2024 at 7:31 PM Baolin Wang
<baolin.wang@xxxxxxxxxxxxxxxxx> wrote:
>
> To support shmem large folio swap operations, add a new parameter to
> swap_shmem_alloc() that allows batch SWAP_MAP_SHMEM flag setting for
> shmem swap entries.
>
> While we are at it, using folio_nr_pages() to get the number of pages
> of the folio as a preparation.
>
> Signed-off-by: Baolin Wang <baolin.wang@xxxxxxxxxxxxxxxxx>
Reviewed-by: Barry Song <baohua@xxxxxxxxxx>
> ---
> include/linux/swap.h | 4 ++--
> mm/shmem.c | 6 ++++--
> mm/swapfile.c | 4 ++--
> 3 files changed, 8 insertions(+), 6 deletions(-)
>
> diff --git a/include/linux/swap.h b/include/linux/swap.h
> index 1c8f844a9f0f..248db1dd7812 100644
> --- a/include/linux/swap.h
> +++ b/include/linux/swap.h
> @@ -481,7 +481,7 @@ void put_swap_folio(struct folio *folio, swp_entry_t entry);
> extern swp_entry_t get_swap_page_of_type(int);
> extern int get_swap_pages(int n, swp_entry_t swp_entries[], int order);
> extern int add_swap_count_continuation(swp_entry_t, gfp_t);
> -extern void swap_shmem_alloc(swp_entry_t);
> +extern void swap_shmem_alloc(swp_entry_t, int);
> extern int swap_duplicate(swp_entry_t);
> extern int swapcache_prepare(swp_entry_t entry, int nr);
> extern void swap_free_nr(swp_entry_t entry, int nr_pages);
> @@ -548,7 +548,7 @@ static inline int add_swap_count_continuation(swp_entry_t swp, gfp_t gfp_mask)
> return 0;
> }
>
> -static inline void swap_shmem_alloc(swp_entry_t swp)
> +static inline void swap_shmem_alloc(swp_entry_t swp, int nr)
> {
> }
>
> diff --git a/mm/shmem.c b/mm/shmem.c
> index 4a5254bfd610..22cdc10f27ea 100644
> --- a/mm/shmem.c
> +++ b/mm/shmem.c
> @@ -1452,6 +1452,7 @@ static int shmem_writepage(struct page *page, struct writeback_control *wbc)
> struct shmem_sb_info *sbinfo = SHMEM_SB(inode->i_sb);
> swp_entry_t swap;
> pgoff_t index;
> + int nr_pages;
>
> /*
> * Our capabilities prevent regular writeback or sync from ever calling
> @@ -1484,6 +1485,7 @@ static int shmem_writepage(struct page *page, struct writeback_control *wbc)
> }
>
> index = folio->index;
> + nr_pages = folio_nr_pages(folio);
>
> /*
> * This is somewhat ridiculous, but without plumbing a SWAP_MAP_FALLOC
> @@ -1536,8 +1538,8 @@ static int shmem_writepage(struct page *page, struct writeback_control *wbc)
> if (add_to_swap_cache(folio, swap,
> __GFP_HIGH | __GFP_NOMEMALLOC | __GFP_NOWARN,
> NULL) == 0) {
> - shmem_recalc_inode(inode, 0, 1);
> - swap_shmem_alloc(swap);
> + shmem_recalc_inode(inode, 0, nr_pages);
> + swap_shmem_alloc(swap, nr_pages);
> shmem_delete_from_page_cache(folio, swp_to_radix_entry(swap));
>
> mutex_unlock(&shmem_swaplist_mutex);
> diff --git a/mm/swapfile.c b/mm/swapfile.c
> index ea023fc25d08..88d73880aada 100644
> --- a/mm/swapfile.c
> +++ b/mm/swapfile.c
> @@ -3604,9 +3604,9 @@ static int __swap_duplicate(swp_entry_t entry, unsigned char usage, int nr)
> * Help swapoff by noting that swap entry belongs to shmem/tmpfs
> * (in which case its reference count is never incremented).
> */
> -void swap_shmem_alloc(swp_entry_t entry)
> +void swap_shmem_alloc(swp_entry_t entry, int nr)
> {
> - __swap_duplicate(entry, SWAP_MAP_SHMEM, 1);
> + __swap_duplicate(entry, SWAP_MAP_SHMEM, nr);
> }
>
> /*
> --
> 2.39.3
>
