On Mon, Aug 21, 2023 at 03:17:28PM +0100, Matthew Wilcox (Oracle) wrote:
> The only caller already has a folio, so use it to save calling
> compound_head() in PageLRU() and remove a use of page->mapping.
>
> Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Reviewed-by: Mike Rapoport (IBM) <rppt@xxxxxxxxxx>
> ---
> include/linux/secretmem.h | 15 +++++++--------
> mm/gup.c | 2 +-
> 2 files changed, 8 insertions(+), 9 deletions(-)
>
> diff --git a/include/linux/secretmem.h b/include/linux/secretmem.h
> index 988528b5da43..6996f1f53f14 100644
> --- a/include/linux/secretmem.h
> +++ b/include/linux/secretmem.h
> @@ -6,24 +6,23 @@
>
> extern const struct address_space_operations secretmem_aops;
>
> -static inline bool page_is_secretmem(struct page *page)
> +static inline bool folio_is_secretmem(struct folio *folio)
> {
> struct address_space *mapping;
>
> /*
> - * Using page_mapping() is quite slow because of the actual call
> - * instruction and repeated compound_head(page) inside the
> - * page_mapping() function.
> + * Using folio_mapping() is quite slow because of the actual call
> + * instruction.
> * We know that secretmem pages are not compound and LRU so we can
> * save a couple of cycles here.
> */
> - if (PageCompound(page) || !PageLRU(page))
> + if (folio_test_large(folio) || folio_test_lru(folio))
> return false;
>
> mapping = (struct address_space *)
> - ((unsigned long)page->mapping & ~PAGE_MAPPING_FLAGS);
> + ((unsigned long)folio->mapping & ~PAGE_MAPPING_FLAGS);
>
> - if (!mapping || mapping != page->mapping)
> + if (!mapping || mapping != folio->mapping)
> return false;
>
> return mapping->a_ops == &secretmem_aops;
> @@ -39,7 +38,7 @@ static inline bool vma_is_secretmem(struct vm_area_struct *vma)
> return false;
> }
>
> -static inline bool page_is_secretmem(struct page *page)
> +static inline bool folio_is_secretmem(struct folio *folio)
> {
> return false;
> }
> diff --git a/mm/gup.c b/mm/gup.c
> index 6d0c24e93425..2f8a2d89fde1 100644
> --- a/mm/gup.c
> +++ b/mm/gup.c
> @@ -2600,7 +2600,7 @@ static int gup_pte_range(pmd_t pmd, pmd_t *pmdp, unsigned long addr,
> if (!folio)
> goto pte_unmap;
>
> - if (unlikely(page_is_secretmem(page))) {
> + if (unlikely(folio_is_secretmem(folio))) {
> gup_put_folio(folio, 1, flags);
> goto pte_unmap;
> }
> --
> 2.40.1
>
>
--
Sincerely yours,
Mike.
