From dd10ab049beb479dc83bb14a7b5cd68c363983ce Mon Sep 17 00:00:00 2001 From: "Matthew Wilcox (Oracle)" Date: Mon, 12 Apr 2021 16:45:17 -0400 Subject: mm: Add folio_mapped() This function is the equivalent of page_mapped(). It is slightly shorter as we do not need to handle the PageTail() case. Reimplement page_mapped() as a wrapper around folio_mapped(). folio_mapped() is 13 bytes smaller than page_mapped(), but the page_mapped() wrapper is 30 bytes, for a net increase of 17 bytes of text. Signed-off-by: Matthew Wilcox (Oracle) Acked-by: Vlastimil Babka Reviewed-by: William Kucharski Reviewed-by: Christoph Hellwig Reviewed-by: David Howells Acked-by: Kirill A. Shutemov Acked-by: Mike Rapoport --- mm/folio-compat.c | 6 ++++++ mm/util.c | 29 ++++++++++++++++------------- 2 files changed, 22 insertions(+), 13 deletions(-) (limited to 'mm') diff --git a/mm/folio-compat.c b/mm/folio-compat.c index 3c83f03b80d7..7044fcc8a8aa 100644 --- a/mm/folio-compat.c +++ b/mm/folio-compat.c @@ -35,3 +35,9 @@ void wait_for_stable_page(struct page *page) return folio_wait_stable(page_folio(page)); } EXPORT_SYMBOL_GPL(wait_for_stable_page); + +bool page_mapped(struct page *page) +{ + return folio_mapped(page_folio(page)); +} +EXPORT_SYMBOL(page_mapped); diff --git a/mm/util.c b/mm/util.c index 6c1fe9bee30a..e322a42090e5 100644 --- a/mm/util.c +++ b/mm/util.c @@ -671,28 +671,31 @@ void *page_rmapping(struct page *page) return __page_rmapping(page); } -/* - * Return true if this page is mapped into pagetables. - * For compound page it returns true if any subpage of compound page is mapped. +/** + * folio_mapped - Is this folio mapped into userspace? + * @folio: The folio. + * + * Return: True if any page in this folio is referenced by user page tables. */ -bool page_mapped(struct page *page) +bool folio_mapped(struct folio *folio) { - int i; + long i, nr; - if (likely(!PageCompound(page))) - return atomic_read(&page->_mapcount) >= 0; - page = compound_head(page); - if (atomic_read(compound_mapcount_ptr(page)) >= 0) + if (folio_test_single(folio)) + return atomic_read(&folio->_mapcount) >= 0; + if (atomic_read(folio_mapcount_ptr(folio)) >= 0) return true; - if (PageHuge(page)) + if (folio_test_hugetlb(folio)) return false; - for (i = 0; i < compound_nr(page); i++) { - if (atomic_read(&page[i]._mapcount) >= 0) + + nr = folio_nr_pages(folio); + for (i = 0; i < nr; i++) { + if (atomic_read(&folio_page(folio, i)->_mapcount) >= 0) return true; } return false; } -EXPORT_SYMBOL(page_mapped); +EXPORT_SYMBOL(folio_mapped); struct anon_vma *page_anon_vma(struct page *page) { -- cgit