1 files changed, 20 insertions, 4 deletions

diff --git a/include/linux/compaction.h b/include/linux/compaction.h
index ba98cfe0ae15..eed40ec4280b 100644
--- a/include/linux/compaction.h
+++ b/include/linux/compaction.h
@@ -1,15 +1,31 @@
 #ifndef _LINUX_COMPACTION_H
 #define _LINUX_COMPACTION_H
 
-/* Return values for compact_zone() */
-#define COMPACT_CONTINUE        0
-#define COMPACT_PARTIAL         1
-#define COMPACT_COMPLETE        2
+/* Return values for compact_zone() and try_to_compact_pages() */
+/* compaction didn't start as it was not possible or direct reclaim was more suitable */
+#define COMPACT_SKIPPED         0
+/* compaction should continue to another pageblock */
+#define COMPACT_CONTINUE        1
+/* direct compaction partially compacted a zone and there are suitable pages */
+#define COMPACT_PARTIAL         2
+/* The full zone was compacted */
+#define COMPACT_COMPLETE        3
 
 #ifdef CONFIG_COMPACTION
 extern int sysctl_compact_memory;
 extern int sysctl_compaction_handler(struct ctl_table *table, int write,
                         void __user *buffer, size_t *length, loff_t *ppos);
+
+extern int fragmentation_index(struct zone *zone, unsigned int order);
+extern unsigned long try_to_compact_pages(struct zonelist *zonelist,
+                        int order, gfp_t gfp_mask, nodemask_t *mask);
+#else
+static inline unsigned long try_to_compact_pages(struct zonelist *zonelist,
+                        int order, gfp_t gfp_mask, nodemask_t *nodemask)
+{
+        return COMPACT_CONTINUE;
+}
+
 #endif /* CONFIG_COMPACTION */
 
 #if defined(CONFIG_COMPACTION) && defined(CONFIG_SYSFS) && defined(CONFIG_NUMA)