From b84fd2835c70e0149e2522fd746d3fb7049a1e19 Mon Sep 17 00:00:00 2001 From: "Matthew Wilcox (Oracle)" Date: Tue, 26 Mar 2024 17:10:28 +0000 Subject: [PATCH] mm: make page_mapped() take a const argument None of the functions called by page_mapped() modify the page or folio, so mark them all as const. Link: https://lkml.kernel.org/r/20240326171045.410737-7-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) Reviewed-by: David Hildenbrand Signed-off-by: Andrew Morton --- include/linux/mm.h | 12 ++++++------ mm/internal.h | 7 ++++--- mm/rmap.c | 2 +- 3 files changed, 11 insertions(+), 10 deletions(-) diff --git a/include/linux/mm.h b/include/linux/mm.h index 5dc65618e386..9c0e441664d4 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -1200,7 +1200,7 @@ static inline int is_vmalloc_or_module_addr(const void *x) * debugging purposes - it does not include PTE-mapped sub-pages; look * at folio_mapcount() or page_mapcount() instead. */ -static inline int folio_entire_mapcount(struct folio *folio) +static inline int folio_entire_mapcount(const struct folio *folio) { VM_BUG_ON_FOLIO(!folio_test_large(folio), folio); return atomic_read(&folio->_entire_mapcount) + 1; @@ -1240,7 +1240,7 @@ static inline int page_mapcount(struct page *page) return mapcount; } -int folio_total_mapcount(struct folio *folio); +int folio_total_mapcount(const struct folio *folio); /** * folio_mapcount() - Calculate the number of mappings of this folio. @@ -1253,14 +1253,14 @@ int folio_total_mapcount(struct folio *folio); * * Return: The number of times this folio is mapped. */ -static inline int folio_mapcount(struct folio *folio) +static inline int folio_mapcount(const struct folio *folio) { if (likely(!folio_test_large(folio))) return atomic_read(&folio->_mapcount) + 1; return folio_total_mapcount(folio); } -static inline bool folio_large_is_mapped(struct folio *folio) +static inline bool folio_large_is_mapped(const struct folio *folio) { /* * Reading _entire_mapcount below could be omitted if hugetlb @@ -1288,7 +1288,7 @@ static inline bool folio_mapped(struct folio *folio) * For compound page it returns true if any sub-page of compound page is mapped, * even if this particular sub-page is not itself mapped by any PTE or PMD. */ -static inline bool page_mapped(struct page *page) +static inline bool page_mapped(const struct page *page) { if (likely(!PageCompound(page))) return atomic_read(&page->_mapcount) >= 0; @@ -2070,7 +2070,7 @@ static inline void set_page_links(struct page *page, enum zone_type zone, * * Return: A positive power of two. */ -static inline long folio_nr_pages(struct folio *folio) +static inline long folio_nr_pages(const struct folio *folio) { if (!folio_test_large(folio)) return 1; diff --git a/mm/internal.h b/mm/internal.h index 5dbfa1c12e89..8e11f7b2da21 100644 --- a/mm/internal.h +++ b/mm/internal.h @@ -71,7 +71,7 @@ void page_writeback_init(void); * How many individual pages have an elevated _mapcount. Excludes * the folio's entire_mapcount. */ -static inline int folio_nr_pages_mapped(struct folio *folio) +static inline int folio_nr_pages_mapped(const struct folio *folio) { return atomic_read(&folio->_nr_pages_mapped) & FOLIO_PAGES_MAPPED; } @@ -81,7 +81,8 @@ static inline int folio_nr_pages_mapped(struct folio *folio) * folio. We cannot rely on folio->swap as there is no guarantee that it has * been initialized. Used for calling arch_swap_restore() */ -static inline swp_entry_t folio_swap(swp_entry_t entry, struct folio *folio) +static inline swp_entry_t folio_swap(swp_entry_t entry, + const struct folio *folio) { swp_entry_t swap = { .val = ALIGN_DOWN(entry.val, folio_nr_pages(folio)), @@ -90,7 +91,7 @@ static inline swp_entry_t folio_swap(swp_entry_t entry, struct folio *folio) return swap; } -static inline void *folio_raw_mapping(struct folio *folio) +static inline void *folio_raw_mapping(const struct folio *folio) { unsigned long mapping = (unsigned long)folio->mapping; diff --git a/mm/rmap.c b/mm/rmap.c index 3746a5531018..d52759aa3ff7 100644 --- a/mm/rmap.c +++ b/mm/rmap.c @@ -1134,7 +1134,7 @@ int pfn_mkclean_range(unsigned long pfn, unsigned long nr_pages, pgoff_t pgoff, return page_vma_mkclean_one(&pvmw); } -int folio_total_mapcount(struct folio *folio) +int folio_total_mapcount(const struct folio *folio) { int mapcount = folio_entire_mapcount(folio); int nr_pages;