1 files changed, 126 insertions, 0 deletions
diff --git a/include/linux/migrate.h b/include/linux/migrate.h
new file mode 100644
index 000000000..a405d3dc0
--- /dev/null
+++ b/include/linux/migrate.h
@@ -0,0 +1,126 @@
+#ifndef _LINUX_MIGRATE_H
+#define _LINUX_MIGRATE_H
+
+#include <linux/mm.h>
+#include <linux/mempolicy.h>
+#include <linux/migrate_mode.h>
+
+typedef struct page *new_page_t(struct page *, unsigned long private, int **);
+
+/*
+ * Return values from addresss_space_operations.migratepage():
+ * - negative errno on page migration failure;
+ * - zero on page migration success;
+ *
+ * The balloon page migration introduces this special case where a 'distinct'
+ * return code is used to flag a successful page migration to unmap_and_move().
+ * This approach is necessary because page migration can race against balloon
+ * deflation procedure, and for such case we could introduce a nasty page leak
+ * if a successfully migrated balloon page gets released concurrently with
+ * migration's unmap_and_move() wrap-up steps.
+ */
+#define MIGRATEPAGE_SUCCESS		0
+#define MIGRATEPAGE_BALLOON_SUCCESS	1 /* special ret code for balloon page
+					   * sucessful migration case.
+					   */
+enum migrate_reason {
+	MR_COMPACTION,
+	MR_MEMORY_FAILURE,
+	MR_MEMORY_HOTPLUG,
+	MR_SYSCALL,		/* also applies to cpusets */
+	MR_MEMPOLICY_MBIND,
+	MR_NUMA_MISPLACED,
+	MR_CMA
+};
+
+#ifdef CONFIG_MIGRATION
+
+extern void putback_lru_pages(struct list_head *l);
+extern void putback_movable_pages(struct list_head *l);
+extern int migrate_page(struct address_space *,
+			struct page *, struct page *, enum migrate_mode);
+extern int migrate_pages(struct list_head *l, new_page_t x,
+		unsigned long private, enum migrate_mode mode, int reason);
+extern int migrate_huge_page(struct page *, new_page_t x,
+		unsigned long private, enum migrate_mode mode);
+
+extern int fail_migrate_page(struct address_space *,
+			struct page *, struct page *);
+
+extern int migrate_prep(void);
+extern int migrate_prep_local(void);
+extern int migrate_vmas(struct mm_struct *mm,
+		const nodemask_t *from, const nodemask_t *to,
+		unsigned long flags);
+extern void migrate_page_copy(struct page *newpage, struct page *page);
+extern int migrate_huge_page_move_mapping(struct address_space *mapping,
+				  struct page *newpage, struct page *page);
+#else
+
+static inline void putback_lru_pages(struct list_head *l) {}
+static inline void putback_movable_pages(struct list_head *l) {}
+static inline int migrate_pages(struct list_head *l, new_page_t x,
+		unsigned long private, enum migrate_mode mode, int reason)
+	{ return -ENOSYS; }
+static inline int migrate_huge_page(struct page *page, new_page_t x,
+		unsigned long private, enum migrate_mode mode)
+	{ return -ENOSYS; }
+
+static inline int migrate_prep(void) { return -ENOSYS; }
+static inline int migrate_prep_local(void) { return -ENOSYS; }
+
+static inline int migrate_vmas(struct mm_struct *mm,
+		const nodemask_t *from, const nodemask_t *to,
+		unsigned long flags)
+{
+	return -ENOSYS;
+}
+
+static inline void migrate_page_copy(struct page *newpage,
+				     struct page *page) {}
+
+static inline int migrate_huge_page_move_mapping(struct address_space *mapping,
+				  struct page *newpage, struct page *page)
+{
+	return -ENOSYS;
+}
+
+/* Possible settings for the migrate_page() method in address_operations */
+#define migrate_page NULL
+#define fail_migrate_page NULL
+
+#endif /* CONFIG_MIGRATION */
+
+#ifdef CONFIG_NUMA_BALANCING
+extern int migrate_misplaced_page(struct page *page, int node);
+extern int migrate_misplaced_page(struct page *page, int node);
+extern bool migrate_ratelimited(int node);
+#else
+static inline int migrate_misplaced_page(struct page *page, int node)
+{
+	return -EAGAIN; /* can't migrate now */
+}
+static inline bool migrate_ratelimited(int node)
+{
+	return false;
+}
+#endif /* CONFIG_NUMA_BALANCING */
+
+#if defined(CONFIG_NUMA_BALANCING) && defined(CONFIG_TRANSPARENT_HUGEPAGE)
+extern int migrate_misplaced_transhuge_page(struct mm_struct *mm,
+			struct vm_area_struct *vma,
+			pmd_t *pmd, pmd_t entry,
+			unsigned long address,
+			struct page *page, int node);
+#else
+static inline int migrate_misplaced_transhuge_page(struct mm_struct *mm,
+			struct vm_area_struct *vma,
+			pmd_t *pmd, pmd_t entry,
+			unsigned long address,
+			struct page *page, int node)
+{
+	return -EAGAIN;
+}
+#endif /* CONFIG_NUMA_BALANCING && CONFIG_TRANSPARENT_HUGEPAGE*/
+
+#endif /* _LINUX_MIGRATE_H */