[PATCH] page migration: use allocator function for migrate_pages()

Instead of passing a list of new pages, pass a function to allocate a new
page.  This allows the correct placement of MPOL_INTERLEAVE pages during page
migration.  It also further simplifies the callers of migrate pages.
migrate_pages() becomes similar to migrate_pages_to() so drop
migrate_pages_to().  The batching of new page allocations becomes unnecessary.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: Jes Sorensen <jes@trained-monkey.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Andi Kleen <ak@muc.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 6 insertions, 5 deletions

diff --git a/include/linux/migrate.h b/include/linux/migrate.h
index 83af25949fa9..5b95d6568dc4 100644
--- a/include/linux/migrate.h
+++ b/include/linux/migrate.h
@@ -3,14 +3,15 @@
 
 #include <linux/mm.h>
 
+typedef struct page *new_page_t(struct page *, unsigned long private);
+
 #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 *,
                         struct page *, struct page *);
-extern int migrate_pages(struct list_head *l, struct list_head *t);
-extern int migrate_pages_to(struct list_head *pagelist,
-                        struct vm_area_struct *vma, int dest);
+extern int migrate_pages(struct list_head *l, new_page_t x, unsigned long);
+
 extern int fail_migrate_page(struct address_space *,
                         struct page *, struct page *);
 
@@ -21,8 +22,8 @@ extern int migrate_prep(void);
 static inline int isolate_lru_page(struct page *p, struct list_head *list)
                                         { return -ENOSYS; }
 static inline int putback_lru_pages(struct list_head *l) { return 0; }
-static inline int migrate_pages(struct list_head *l, struct list_head *t)
-                                        { return -ENOSYS; }
+static inline int migrate_pages(struct list_head *l, new_page_t x,
+                unsigned long private) { return -ENOSYS; }
 
 static inline int migrate_pages_to(struct list_head *pagelist,
                         struct vm_area_struct *vma, int dest) { return 0; }