Re: [PATCH] secretmem: Conert page_is_secretmem() to folio_is_secretmem()

[Mike Rapoport <rppt@kernel.org>]

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@infradead.org>

Reviewed-by: Mike Rapoport (IBM) <rppt@kernel.org>

> ---
>  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.