diff options
Diffstat (limited to 'mm/util.c')
| -rw-r--r-- | mm/util.c | 36 |
1 files changed, 34 insertions, 2 deletions
diff --git a/mm/util.c b/mm/util.c index d3102081add0..1e2728736398 100644 --- a/mm/util.c +++ b/mm/util.c @@ -681,9 +681,8 @@ bool folio_mapped(struct folio *folio) } EXPORT_SYMBOL(folio_mapped); -struct anon_vma *page_anon_vma(struct page *page) +struct anon_vma *folio_anon_vma(struct folio *folio) { - struct folio *folio = page_folio(page); unsigned long mapping = (unsigned long)folio->mapping; if ((mapping & PAGE_MAPPING_FLAGS) != PAGE_MAPPING_ANON) @@ -743,6 +742,39 @@ int __page_mapcount(struct page *page) EXPORT_SYMBOL_GPL(__page_mapcount); /** + * folio_mapcount() - Calculate the number of mappings of this folio. + * @folio: The folio. + * + * A large folio tracks both how many times the entire folio is mapped, + * and how many times each individual page in the folio is mapped. + * This function calculates the total number of times the folio is + * mapped. + * + * Return: The number of times this folio is mapped. + */ +int folio_mapcount(struct folio *folio) +{ + int i, compound, nr, ret; + + if (likely(!folio_test_large(folio))) + return atomic_read(&folio->_mapcount) + 1; + + compound = folio_entire_mapcount(folio); + nr = folio_nr_pages(folio); + if (folio_test_hugetlb(folio)) + return compound; + ret = compound; + for (i = 0; i < nr; i++) + ret += atomic_read(&folio_page(folio, i)->_mapcount) + 1; + /* File pages has compound_mapcount included in _mapcount */ + if (!folio_test_anon(folio)) + return ret - compound * nr; + if (folio_test_double_map(folio)) + ret -= nr; + return ret; +} + +/** * folio_copy - Copy the contents of one folio to another. * @dst: Folio to copy to. * @src: Folio to copy from. |