From 02d65d6fb1aae151570c8bfd1bd77a8153d2e607 Mon Sep 17 00:00:00 2001 From: Sidhartha Kumar Date: Fri, 6 Jan 2023 15:52:51 -0600 Subject: mm: introduce folio_is_pfmemalloc Add a folio equivalent for page_is_pfmemalloc. This removes two instances of page_is_pfmemalloc(folio_page(folio, 0)) so the folio can be used directly. Link: https://lkml.kernel.org/r/20230106215251.599222-1-sidhartha.kumar@oracle.com Suggested-by: Matthew Wilcox Signed-off-by: Sidhartha Kumar Reviewed-by: Matthew Wilcox (Oracle) Reviewed-by: SeongJae Park Acked-by: Vlastimil Babka Signed-off-by: Andrew Morton --- include/linux/mm.h | 15 +++++++++++++++ 1 file changed, 15 insertions(+) (limited to 'include/linux') diff --git a/include/linux/mm.h b/include/linux/mm.h index 8a8563359946..76c97cb8ee9a 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -1926,6 +1926,21 @@ static inline bool page_is_pfmemalloc(const struct page *page) return (uintptr_t)page->lru.next & BIT(1); } +/* + * Return true only if the folio has been allocated with + * ALLOC_NO_WATERMARKS and the low watermark was not + * met implying that the system is under some pressure. + */ +static inline bool folio_is_pfmemalloc(const struct folio *folio) +{ + /* + * lru.next has bit 1 set if the page is allocated from the + * pfmemalloc reserves. Callers may simply overwrite it if + * they do not need to preserve that information. + */ + return (uintptr_t)folio->lru.next & BIT(1); +} + /* * Only to be called by the page allocator on a freshly allocated * page. -- cgit v1.2.3