Merge "mm: migrate: support non-lru movable page migration"

6 files changed, 48 insertions, 9 deletions

diff --git a/include/linux/compaction.h b/include/linux/compaction.h
index d7c8de583a23..c81e4e061801 100644
--- a/include/linux/compaction.h
+++ b/include/linux/compaction.h
@@ -29,6 +29,9 @@
 struct alloc_context; /* in mm/internal.h */
 
 #ifdef CONFIG_COMPACTION
+extern int PageMovable(struct page *page);
+extern void __SetPageMovable(struct page *page, struct address_space *mapping);
+extern void __ClearPageMovable(struct page *page);
 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);
@@ -57,6 +60,19 @@ extern void kcompactd_stop(int nid);
 extern void wakeup_kcompactd(pg_data_t *pgdat, int order, int classzone_idx);
 
 #else
+static inline int PageMovable(struct page *page)
+{
+	return 0;
+}
+static inline void __SetPageMovable(struct page *page,
+			struct address_space *mapping)
+{
+}
+
+static inline void __ClearPageMovable(struct page *page)
+{
+}
+
 static inline unsigned long try_to_compact_pages(gfp_t gfp_mask,
 			unsigned int order, int alloc_flags,
 			const struct alloc_context *ac,
@@ -103,6 +119,7 @@ static inline void wakeup_kcompactd(pg_data_t *pgdat, int order, int classzone_i
 #endif /* CONFIG_COMPACTION */
 
 #if defined(CONFIG_COMPACTION) && defined(CONFIG_SYSFS) && defined(CONFIG_NUMA)
+struct node;
 extern int compaction_register_node(struct node *node);
 extern void compaction_unregister_node(struct node *node);
 
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 94edbb64f1c6..db16b3fd48c0 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -404,6 +404,8 @@ struct address_space_operations {
 	 */
 	int (*migratepage) (struct address_space *,
 			struct page *, struct page *, enum migrate_mode);
+	bool (*isolate_page)(struct page *, isolate_mode_t);
+	void (*putback_page)(struct page *);
 	int (*launder_page) (struct page *);
 	int (*is_partially_uptodate) (struct page *, unsigned long,
 					unsigned long);
diff --git a/include/linux/ksm.h b/include/linux/ksm.h
index 7ae216a39c9e..481c8c4627ca 100644
--- a/include/linux/ksm.h
+++ b/include/linux/ksm.h
@@ -43,8 +43,7 @@ static inline struct stable_node *page_stable_node(struct page *page)
 static inline void set_page_stable_node(struct page *page,
 					struct stable_node *stable_node)
 {
-	page->mapping = (void *)stable_node +
-				(PAGE_MAPPING_ANON | PAGE_MAPPING_KSM);
+	page->mapping = (void *)((unsigned long)stable_node | PAGE_MAPPING_KSM);
 }
 
 /*
diff --git a/include/linux/migrate.h b/include/linux/migrate.h
index cac1c0904d5f..f10fd92860ac 100644
--- a/include/linux/migrate.h
+++ b/include/linux/migrate.h
@@ -33,6 +33,8 @@ 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 new, free_page_t free,
 		unsigned long private, enum migrate_mode mode, int reason);
+extern bool isolate_movable_page(struct page *page, isolate_mode_t mode);
+extern void putback_movable_page(struct page *page);
 
 extern int migrate_prep(void);
 extern int migrate_prep_local(void);
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 97b11c9fd48a..87a4bb8ed512 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -995,6 +995,7 @@ static inline int page_mapped(struct page *page)
 {
 	return atomic_read(&(page)->_mapcount) >= 0;
 }
+struct address_space *page_mapping(struct page *page);
 
 /*
  * Return true only if the page has been allocated with
diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h
index 4b115168607f..86c233be1cfc 100644
--- a/include/linux/page-flags.h
+++ b/include/linux/page-flags.h
@@ -132,6 +132,9 @@ enum pageflags {
 
 	/* SLOB */
 	PG_slob_free = PG_private,
+
+	/* non-lru isolated movable page */
+	PG_isolated = PG_reclaim,
 };
 
 #ifndef __GENERATING_BOUNDS_H
@@ -309,25 +312,38 @@ PAGEFLAG(Idle, idle)
  * with the PAGE_MAPPING_ANON bit set to distinguish it.  See rmap.h.
  *
  * On an anonymous page in a VM_MERGEABLE area, if CONFIG_KSM is enabled,
- * the PAGE_MAPPING_KSM bit may be set along with the PAGE_MAPPING_ANON bit;
- * and then page->mapping points, not to an anon_vma, but to a private
+ * the PAGE_MAPPING_MOVABLE bit may be set along with the PAGE_MAPPING_ANON
+ * bit; and then page->mapping points, not to an anon_vma, but to a private
  * structure which KSM associates with that merged page.  See ksm.h.
  *
- * PAGE_MAPPING_KSM without PAGE_MAPPING_ANON is currently never used.
+ * PAGE_MAPPING_KSM without PAGE_MAPPING_ANON is used for non-lru movable
+ * page and then page->mapping points a struct address_space.
  *
  * Please note that, confusingly, "page_mapping" refers to the inode
  * address_space which maps the page from disk; whereas "page_mapped"
  * refers to user virtual address space into which the page is mapped.
  */
-#define PAGE_MAPPING_ANON	1
-#define PAGE_MAPPING_KSM	2
-#define PAGE_MAPPING_FLAGS	(PAGE_MAPPING_ANON | PAGE_MAPPING_KSM)
+#define PAGE_MAPPING_ANON	0x1
+#define PAGE_MAPPING_MOVABLE	0x2
+#define PAGE_MAPPING_KSM	(PAGE_MAPPING_ANON | PAGE_MAPPING_MOVABLE)
+#define PAGE_MAPPING_FLAGS	(PAGE_MAPPING_ANON | PAGE_MAPPING_MOVABLE)
+
+static __always_inline int PageMappingFlags(struct page *page)
+{
+	return ((unsigned long)page->mapping & PAGE_MAPPING_FLAGS) != 0;
+}
 
 static inline int PageAnon(struct page *page)
 {
 	return ((unsigned long)page->mapping & PAGE_MAPPING_ANON) != 0;
 }
 
+static __always_inline int __PageMovable(struct page *page)
+{
+	return ((unsigned long)page->mapping & PAGE_MAPPING_FLAGS) ==
+				PAGE_MAPPING_MOVABLE;
+}
+
 #ifdef CONFIG_KSM
 /*
  * A KSM page is one of those write-protected "shared pages" or "merged pages"
@@ -338,7 +354,7 @@ static inline int PageAnon(struct page *page)
 static inline int PageKsm(struct page *page)
 {
 	return ((unsigned long)page->mapping & PAGE_MAPPING_FLAGS) ==
-				(PAGE_MAPPING_ANON | PAGE_MAPPING_KSM);
+				PAGE_MAPPING_KSM;
 }
 #else
 TESTPAGEFLAG_FALSE(Ksm)
@@ -557,6 +573,8 @@ static inline void __ClearPageBalloon(struct page *page)
 	atomic_set(&page->_mapcount, -1);
 }
 
+__PAGEFLAG(Isolated, isolated);
+
 /*
  * If network-based swap is enabled, sl*b must keep track of whether pages
  * were allocated from pfmemalloc reserves.