From b92a6edd4b77a8794adb497280beea5df5e59a14 Mon Sep 17 00:00:00 2001
From: Mel Gorman <mel@csn.ul.ie>
Date: Tue, 16 Oct 2007 01:25:50 -0700
Subject: Add a configure option to group pages by mobility

The grouping mechanism has some memory overhead and a more complex allocation
path.  This patch allows the strategy to be disabled for small memory systems
or if it is known the workload is suffering because of the strategy.  It also
acts to show where the page groupings strategy interacts with the standard
buddy allocator.

Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Joel Schopp <jschopp@austin.ibm.com>
Cc: Andy Whitcroft <apw@shadowen.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
 include/linux/mmzone.h | 6 ++++++
 1 file changed, 6 insertions(+)

(limited to 'include')

diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index 57700038e6..7d7e4fe0fd 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -33,9 +33,15 @@
  */
 #define PAGE_ALLOC_COSTLY_ORDER 3
 
+#ifdef CONFIG_PAGE_GROUP_BY_MOBILITY
 #define MIGRATE_UNMOVABLE     0
 #define MIGRATE_MOVABLE       1
 #define MIGRATE_TYPES         2
+#else
+#define MIGRATE_UNMOVABLE     0
+#define MIGRATE_MOVABLE       0
+#define MIGRATE_TYPES         1
+#endif
 
 #define for_each_migratetype_order(order, type) \
 	for (order = 0; order < MAX_ORDER; order++) \
-- 
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