From 3972f6bb1c6ae1d32dcf2e4ff635d24b77f26dcb Mon Sep 17 00:00:00 2001
From: Vlastimil Babka
Date: Thu, 11 Jul 2019 20:55:13 -0700
Subject: mm, debug_pagealloc: use a page type instead of page_ext flag

When debug_pagealloc is enabled, we currently allocate the page_ext
array to mark guard pages with the PAGE_EXT_DEBUG_GUARD flag.  Now that
we have the page_type field in struct page, we can use that instead, as
guard pages are neither PageSlab nor mapped to userspace.  This reduces
memory overhead when debug_pagealloc is enabled and there are no other
features requiring the page_ext array.

Link: http://lkml.kernel.org/r/20190603143451.27353-4-vbabka@suse.cz
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
 mm/page_ext.c | 3 ---
 1 file changed, 3 deletions(-)

(limited to 'mm/page_ext.c')

diff --git a/mm/page_ext.c b/mm/page_ext.c
index d8f1aca4ad43..5f5769c7db3b 100644
--- a/mm/page_ext.c
+++ b/mm/page_ext.c
@@ -59,9 +59,6 @@
  */
 
 static struct page_ext_operations *page_ext_ops[] = {
-#ifdef CONFIG_DEBUG_PAGEALLOC
-	&debug_guardpage_ops,
-#endif
 #ifdef CONFIG_PAGE_OWNER
 	&page_owner_ops,
 #endif
-- 
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