Page Migration: Provide fallback function for vma_migratable

There is no point in checking for migratable vma is CONFIG_MIGRATION
is not set. So move it into the #ifdef and provide a fallback function.

Signed-off-by: Christoph Lameter <clameter@sgi.com>


---
 include/linux/migrate.h |    4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

Index: linux-2.6.21-rc7-mm2/include/linux/migrate.h
===================================================================
--- linux-2.6.21-rc7-mm2.orig/include/linux/migrate.h	2007-05-02 14:28:23.000000000 -0700
+++ linux-2.6.21-rc7-mm2/include/linux/migrate.h	2007-05-02 14:29:32.000000000 -0700
@@ -7,6 +7,7 @@
 
 typedef struct page *new_page_t(struct page *, unsigned long private, int **);
 
+#ifdef CONFIG_MIGRATION
 /* Check if a vma is migratable */
 static inline int vma_migratable(struct vm_area_struct *vma)
 {
@@ -24,7 +25,6 @@ static inline int vma_migratable(struct 
 	return 1;
 }
 
-#ifdef CONFIG_MIGRATION
 extern int isolate_lru_page(struct page *p, struct list_head *pagelist);
 extern int putback_lru_pages(struct list_head *l);
 extern int migrate_page(struct address_space *,
@@ -39,6 +39,8 @@ extern int migrate_vmas(struct mm_struct
 		const nodemask_t *from, const nodemask_t *to,
 		unsigned long flags);
 #else
+static inline int vma_migratable(struct vm_area_struct *vma)
+					{ return 0; }
 
 static inline int isolate_lru_page(struct page *p, struct list_head *list)
 					{ return -ENOSYS; }