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authorLinus Torvalds <torvalds@linux-foundation.org>2022-03-23 03:03:12 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2022-03-23 03:03:12 +0300
commit9030fb0bb9d607908d51f9ee02efdbe01da355ee (patch)
tree9ee1d9d47fbb4b30c7f5cbc291432e666e58967a /mm/util.c
parent3bf03b9a0839c9fb06927ae53ebd0f960b19d408 (diff)
parent2a3c4bce3edb0d54983384aa8a88c0da330638f4 (diff)
downloadlinux-9030fb0bb9d607908d51f9ee02efdbe01da355ee.tar.xz
Merge tag 'folio-5.18c' of git://git.infradead.org/users/willy/pagecache
Pull folio updates from Matthew Wilcox: - Rewrite how munlock works to massively reduce the contention on i_mmap_rwsem (Hugh Dickins): https://lore.kernel.org/linux-mm/8e4356d-9622-a7f0-b2c-f116b5f2efea@google.com/ - Sort out the page refcount mess for ZONE_DEVICE pages (Christoph Hellwig): https://lore.kernel.org/linux-mm/20220210072828.2930359-1-hch@lst.de/ - Convert GUP to use folios and make pincount available for order-1 pages. (Matthew Wilcox) - Convert a few more truncation functions to use folios (Matthew Wilcox) - Convert page_vma_mapped_walk to use PFNs instead of pages (Matthew Wilcox) - Convert rmap_walk to use folios (Matthew Wilcox) - Convert most of shrink_page_list() to use a folio (Matthew Wilcox) - Add support for creating large folios in readahead (Matthew Wilcox) * tag 'folio-5.18c' of git://git.infradead.org/users/willy/pagecache: (114 commits) mm/damon: minor cleanup for damon_pa_young selftests/vm/transhuge-stress: Support file-backed PMD folios mm/filemap: Support VM_HUGEPAGE for file mappings mm/readahead: Switch to page_cache_ra_order mm/readahead: Align file mappings for non-DAX mm/readahead: Add large folio readahead mm: Support arbitrary THP sizes mm: Make large folios depend on THP mm: Fix READ_ONLY_THP warning mm/filemap: Allow large folios to be added to the page cache mm: Turn can_split_huge_page() into can_split_folio() mm/vmscan: Convert pageout() to take a folio mm/vmscan: Turn page_check_references() into folio_check_references() mm/vmscan: Account large folios correctly mm/vmscan: Optimise shrink_page_list for non-PMD-sized folios mm/vmscan: Free non-shmem folios without splitting them mm/rmap: Constify the rmap_walk_control argument mm/rmap: Convert rmap_walk() to take a folio mm: Turn page_anon_vma() into folio_anon_vma() mm/rmap: Turn page_lock_anon_vma_read() into folio_lock_anon_vma_read() ...
Diffstat (limited to 'mm/util.c')
-rw-r--r--mm/util.c36
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.