From 4da1984edbbed0ffc961006d265d78a7b0095ea4 Mon Sep 17 00:00:00 2001
From: Matthew Wilcox <mawilcox@microsoft.com>
Date: Thu, 7 Jun 2018 17:08:50 -0700
Subject: mm: combine LRU and main union in struct page
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This gives us five words of space in a single union in struct page.  The
compound_mapcount moves position (from offset 24 to offset 20) on 64-bit
systems, but that does not seem likely to cause any trouble.

Link: http://lkml.kernel.org/r/20180518194519.3820-11-willy@infradead.org
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
 mm/page_alloc.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

(limited to 'mm/page_alloc.c')

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 628fd3e24731..ef1811531999 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -943,7 +943,7 @@ static int free_tail_pages_check(struct page *head_page, struct page *page)
 	}
 	switch (page - head_page) {
 	case 1:
-		/* the first tail page: ->mapping is compound_mapcount() */
+		/* the first tail page: ->mapping may be compound_mapcount() */
 		if (unlikely(compound_mapcount(page))) {
 			bad_page(page, "nonzero compound_mapcount", 0);
 			goto out;
-- 
cgit