[PATCH v2 02/20] mm: factor out large folio handling from folio_nr_pages() into folio_large_nr_pages()
From: David Hildenbrand <hidden>
Date: 2025-02-24 16:56:13
Also in:
cgroups, linux-doc, linux-fsdevel, linux-mm, lkml
Subsystem:
memory management - core, the rest · Maintainers:
Andrew Morton, David Hildenbrand, Linus Torvalds
Let's factor it out into a simple helper function. This helper will also come in handy when working with code where we know that our folio is large. While at it, let's consistently return a "long" value from all these similar functions. Note that we cannot use "unsigned int" (even though _folio_nr_pages is of that type), because it would break some callers that do stuff like "-folio_nr_pages()". Both "int" or "unsigned long" would work as well. Maybe in the future we'll have the nr_pages readily available for all large folios, maybe even for small folios, or maybe for none. Reviewed-by: Kirill A. Shutemov <redacted> Signed-off-by: David Hildenbrand <redacted> --- include/linux/mm.h | 28 ++++++++++++++++------------ 1 file changed, 16 insertions(+), 12 deletions(-)
diff --git a/include/linux/mm.h b/include/linux/mm.h
index d00214e22a174..7c5a8fd29cfcd 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h@@ -1199,6 +1199,18 @@ static inline unsigned int folio_large_order(const struct folio *folio) return folio->_flags_1 & 0xff; } +#ifdef CONFIG_64BIT +static inline long folio_large_nr_pages(const struct folio *folio) +{ + return folio->_folio_nr_pages; +} +#else +static inline long folio_large_nr_pages(const struct folio *folio) +{ + return 1L << folio_large_order(folio); +} +#endif + /* * compound_order() can be called without holding a reference, which means * that niceties like page_folio() don't work. These callers should be
@@ -2141,11 +2153,7 @@ static inline long folio_nr_pages(const struct folio *folio) { if (!folio_test_large(folio)) return 1; -#ifdef CONFIG_64BIT - return folio->_folio_nr_pages; -#else - return 1L << folio_large_order(folio); -#endif + return folio_large_nr_pages(folio); } /* Only hugetlbfs can allocate folios larger than MAX_ORDER */
@@ -2160,24 +2168,20 @@ static inline long folio_nr_pages(const struct folio *folio) * page. compound_nr() can be called on a tail page, and is defined to * return 1 in that case. */ -static inline unsigned long compound_nr(struct page *page) +static inline long compound_nr(struct page *page) { struct folio *folio = (struct folio *)page; if (!test_bit(PG_head, &folio->flags)) return 1; -#ifdef CONFIG_64BIT - return folio->_folio_nr_pages; -#else - return 1L << folio_large_order(folio); -#endif + return folio_large_nr_pages(folio); } /** * thp_nr_pages - The number of regular pages in this huge page. * @page: The head page of a huge page. */ -static inline int thp_nr_pages(struct page *page) +static inline long thp_nr_pages(struct page *page) { return folio_nr_pages((struct folio *)page); }
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2.48.1