On 8.12.20 г. 21:46 ч., Matthew Wilcox (Oracle) wrote:
> Pages being added to the page cache should already be folios, so
> turn add_to_page_cache_lru() into a wrapper. Saves hundreds of
> bytes of text.
>
> Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
> ---
> include/linux/pagemap.h | 13 +++++++--
> mm/filemap.c | 62 ++++++++++++++++++++---------------------
> 2 files changed, 41 insertions(+), 34 deletions(-)
>
> diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h
> index 060faeb8d701..3bc56b3aa384 100644
> --- a/include/linux/pagemap.h
> +++ b/include/linux/pagemap.h
> @@ -778,9 +778,9 @@ static inline int fault_in_pages_readable(const char __user *uaddr, int size)
> }
>
> int add_to_page_cache_locked(struct page *page, struct address_space *mapping,
> - pgoff_t index, gfp_t gfp_mask);
> -int add_to_page_cache_lru(struct page *page, struct address_space *mapping,
> - pgoff_t index, gfp_t gfp_mask);
> + pgoff_t index, gfp_t gfp);
> +int folio_add_to_page_cache(struct folio *folio, struct address_space *mapping,
> + pgoff_t index, gfp_t gfp);
> extern void delete_from_page_cache(struct page *page);
> extern void __delete_from_page_cache(struct page *page, void *shadow);
> int replace_page_cache_page(struct page *old, struct page *new, gfp_t gfp_mask);
> @@ -805,6 +805,13 @@ static inline int add_to_page_cache(struct page *page,
> return error;
> }
>
> +static inline int add_to_page_cache_lru(struct page *page,
> + struct address_space *mapping, pgoff_t index, gfp_t gfp)
> +{
> + return folio_add_to_page_cache((struct folio *)page, mapping,
> + index, gfp);
> +}
> +
> /**
> * struct readahead_control - Describes a readahead request.
> *
> diff --git a/mm/filemap.c b/mm/filemap.c
> index 56ff6aa24265..297144524f58 100644
> --- a/mm/filemap.c
> +++ b/mm/filemap.c
> @@ -828,25 +828,25 @@ int replace_page_cache_page(struct page *old, struct page *new, gfp_t gfp_mask)
> }
> EXPORT_SYMBOL_GPL(replace_page_cache_page);
>
> -static noinline int __add_to_page_cache_locked(struct page *page,
> +static noinline int __add_to_page_cache_locked(struct folio *folio,
> struct address_space *mapping,
> - pgoff_t offset, gfp_t gfp,
> + pgoff_t index, gfp_t gfp,
> void **shadowp)
> {
> - XA_STATE(xas, &mapping->i_pages, offset);
> - int huge = PageHuge(page);
> + XA_STATE(xas, &mapping->i_pages, index);
> + int huge = PageHuge(&folio->page);
PageHuge also does page_compound, since you know this is either the head
page or not you could use PageHeadHuge which simply checks if it's a
head page and then goes directly to perform the hugepage check via the
dtor.
<snip>
