Commit b84fd283 authored by Matthew Wilcox (Oracle)'s avatar Matthew Wilcox (Oracle) Committed by Andrew Morton
Browse files

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: default avatarMatthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: default avatarDavid Hildenbrand <david@redhat.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 2ace5a67

include/linux/mm.h

+6 −6
Original line number Diff line number Diff line
@@ -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;

mm/internal.h

+4 −3
Original line number Diff line number Diff line
@@ -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;

mm/rmap.c

+1 −1
Original line number Diff line number Diff line
@@ -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;