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-rw-r--r--include/linux/compaction.h19
1 files changed, 19 insertions, 0 deletions
diff --git a/include/linux/compaction.h b/include/linux/compaction.h
index 51a90b7f2d6..e988037abd2 100644
--- a/include/linux/compaction.h
+++ b/include/linux/compaction.h
@@ -1,6 +1,8 @@
#ifndef _LINUX_COMPACTION_H
#define _LINUX_COMPACTION_H
+#include <linux/node.h>
+
/* 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
@@ -11,6 +13,23 @@
/* The full zone was compacted */
#define COMPACT_COMPLETE 3
+/*
+ * compaction supports three modes
+ *
+ * COMPACT_ASYNC_MOVABLE uses asynchronous migration and only scans
+ * MIGRATE_MOVABLE pageblocks as migration sources and targets.
+ * COMPACT_ASYNC_UNMOVABLE uses asynchronous migration and only scans
+ * MIGRATE_MOVABLE pageblocks as migration sources.
+ * MIGRATE_UNMOVABLE pageblocks are scanned as potential migration
+ * targets and convers them to MIGRATE_MOVABLE if possible
+ * COMPACT_SYNC uses synchronous migration and scans all pageblocks
+ */
+enum compact_mode {
+ COMPACT_ASYNC_MOVABLE,
+ COMPACT_ASYNC_UNMOVABLE,
+ COMPACT_SYNC,
+};
+
#ifdef CONFIG_COMPACTION
extern int sysctl_compact_memory;
extern int sysctl_compaction_handler(struct ctl_table *table, int write,