mm: fix build warnings in <linux/compaction.h>

Randy reported below build error.

> In file included from ../include/linux/balloon_compaction.h:48:0,
>                  from ../mm/balloon_compaction.c:11:
> ../include/linux/compaction.h:237:51: warning: 'struct node' declared inside parameter list [enabled by default]
>  static inline int compaction_register_node(struct node *node)
> ../include/linux/compaction.h:237:51: warning: its scope is only this definition or declaration, which is probably not what you want [enabled by default]
> ../include/linux/compaction.h:242:54: warning: 'struct node' declared inside parameter list [enabled by default]
>  static inline void compaction_unregister_node(struct node *node)
>

It was caused by non-lru page migration which needs compaction.h but
compaction.h doesn't include any header to be standalone.

I think proper header for non-lru page migration is migrate.h rather
than compaction.h because migrate.h has already headers needed to work
non-lru page migration indirectly like isolate_mode_t, migrate_mode
MIGRATEPAGE_SUCCESS.

[akpm@linux-foundation.org: revert mm-balloon-use-general-non-lru-movable-page-feature-fix.patch temp fix]
Link: http://lkml.kernel.org/r/20160610003304.GE29779@bbox
Signed-off-by: Minchan Kim <minchan@kernel.org>
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Gioh Kim <gi-oh.kim@profitbricks.com>
Cc: Rafael Aquini <aquini@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Git-commit: dd4123f324bbaec7618b677b7bce2b11aee9594e
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
Change-Id: If9a33a471f69bf008f4c2d40f21ff30abce200bb
Signed-off-by: Vinayak Menon <vinmenon@codeaurora.org>

3 files changed, 16 insertions, 18 deletions

diff --git a/include/linux/balloon_compaction.h b/include/linux/balloon_compaction.h
index 504bd724e6ab..79542b2698ec 100644
--- a/include/linux/balloon_compaction.h
+++ b/include/linux/balloon_compaction.h
@@ -45,8 +45,7 @@
 #define _LINUX_BALLOON_COMPACTION_H
 #include <linux/pagemap.h>
 #include <linux/page-flags.h>
-#include <linux/node.h>
-#include <linux/compaction.h>
+#include <linux/migrate.h>
 #include <linux/gfp.h>
 #include <linux/err.h>
 #include <linux/fs.h>
diff --git a/include/linux/compaction.h b/include/linux/compaction.h
index c81e4e061801..e864751d870a 100644
--- a/include/linux/compaction.h
+++ b/include/linux/compaction.h
@@ -29,9 +29,6 @@
 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);
@@ -60,19 +57,6 @@ 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,
diff --git a/include/linux/migrate.h b/include/linux/migrate.h
index f10fd92860ac..5219df44cfec 100644
--- a/include/linux/migrate.h
+++ b/include/linux/migrate.h
@@ -67,6 +67,21 @@ static inline int migrate_huge_page_move_mapping(struct address_space *mapping,
 
 #endif /* CONFIG_MIGRATION */
 
+#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);
+#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)
+{
+}
+#endif
+
 #ifdef CONFIG_NUMA_BALANCING
 extern bool pmd_trans_migrating(pmd_t pmd);
 extern int migrate_misplaced_page(struct page *page,