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| author | Matthew Wilcox (Oracle) <willy@infradead.org> | 2021-04-12 23:45:17 +0300 |
|---|---|---|
| committer | Matthew Wilcox (Oracle) <willy@infradead.org> | 2021-09-27 16:27:31 +0300 |
| commit | dd10ab049beb479dc83bb14a7b5cd68c363983ce (patch) | |
| tree | 954b257996e8d30144667ee4a15f97d1c0a34dad /mm/util.c | |
| parent | 6abbaa5b01730a1f0883d199cf5a90ae5c5dccea (diff) | |
| download | linux-dd10ab049beb479dc83bb14a7b5cd68c363983ce.tar.xz | |
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) <willy@infradead.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Howells <dhowells@redhat.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Mike Rapoport <rppt@linux.ibm.com>
Diffstat (limited to 'mm/util.c')
| -rw-r--r-- | mm/util.c | 29 |
1 files changed, 16 insertions, 13 deletions
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) { |