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authorMatthew Wilcox <mawilcox@microsoft.com>2018-02-01 03:18:55 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2018-02-01 04:18:38 +0300
commitb26435a0115b245ea2dd705efcce877ec417bc74 (patch)
treea195dd21d5de4d8c47b1967cb866e19990fc0655
parent4cf7c8bfb36f4b4dbc333bf844ea801d089f44f8 (diff)
downloadlinux-b26435a0115b245ea2dd705efcce877ec417bc74.tar.xz
mm: improve comment on page->mapping
The comment on page->mapping is terse, and out of date (it does not mention the possibility of PAGE_MAPPING_MOVABLE). Instead, point the interested reader to page-flags.h where there is a much better comment. Link: http://lkml.kernel.org/r/20171220155552.15884-5-willy@infradead.org Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Christoph Lameter <cl@linux.com> Cc: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--include/linux/mm_types.h12
1 files changed, 3 insertions, 9 deletions
diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h
index c2294e6204e8..8c3b8cea22ee 100644
--- a/include/linux/mm_types.h
+++ b/include/linux/mm_types.h
@@ -50,15 +50,9 @@ struct page {
unsigned long flags; /* Atomic flags, some possibly
* updated asynchronously */
union {
- struct address_space *mapping; /* If low bit clear, points to
- * inode address_space, or NULL.
- * If page mapped as anonymous
- * memory, low bit is set, and
- * it points to anon_vma object
- * or KSM private structure. See
- * PAGE_MAPPING_ANON and
- * PAGE_MAPPING_KSM.
- */
+ /* See page-flags.h for the definition of PAGE_MAPPING_FLAGS */
+ struct address_space *mapping;
+
void *s_mem; /* slab first object */
atomic_t compound_mapcount; /* first tail page */
/* page_deferred_list().next -- second tail page */