From: Matthew Wilcox <willy@infradead.org>
To: linux-mm@kvack.org
Cc: akpm@linuxfoundation.org, Matthew Wilcox <mawilcox@microsoft.com>
Subject: [PATCH v2 4/8] mm: Improve comment on page->mapping
Date: Wed, 20 Dec 2017 07:55:48 -0800 [thread overview]
Message-ID: <20171220155552.15884-5-willy@infradead.org> (raw)
In-Reply-To: <20171220155552.15884-1-willy@infradead.org>
From: Matthew Wilcox <mawilcox@microsoft.com>
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mapping is terse, and out of date (it does not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.
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>
---
include/linux/mm_types.h | 12 +++---------
1 file 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 */
--
2.15.1
--
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next prev parent reply other threads:[~2017-12-20 15:56 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-12-20 15:55 [PATCH v2 0/8] Restructure struct page Matthew Wilcox
2017-12-20 15:55 ` [PATCH v2 1/8] mm: Align struct page more aesthetically Matthew Wilcox
2017-12-20 15:55 ` [PATCH v2 2/8] mm: De-indent struct page Matthew Wilcox
2017-12-20 15:55 ` [PATCH v2 3/8] mm: Remove misleading alignment claims Matthew Wilcox
2017-12-20 15:55 ` Matthew Wilcox [this message]
2017-12-20 15:55 ` [PATCH v2 5/8] mm: Introduce _slub_counter_t Matthew Wilcox
2017-12-20 15:55 ` [PATCH v2 6/8] mm: Store compound_dtor / compound_order as bytes Matthew Wilcox
2017-12-20 23:39 ` Andrew Morton
2017-12-21 0:01 ` Matthew Wilcox
2017-12-20 15:55 ` [PATCH v2 7/8] mm: Document how to use struct page Matthew Wilcox
2017-12-20 15:55 ` [PATCH v2 8/8] mm: Remove reference to PG_buddy Matthew Wilcox
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