[PATCH] page migration reorg
Centralize the page migration functions in anticipation of additional
tinkering. Creates a new file mm/migrate.c
1. Extract buffer_migrate_page() from fs/buffer.c
2. Extract central migration code from vmscan.c
3. Extract some components from mempolicy.c
4. Export pageout() and remove_from_swap() from vmscan.c
5. Make it possible to configure NUMA systems without page migration
and non-NUMA systems with page migration.
I had to so some #ifdeffing in mempolicy.c that may need a cleanup.
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/include/linux/swap.h b/include/linux/swap.h
index 3dc6c89..12415dd 100644
--- a/include/linux/swap.h
+++ b/include/linux/swap.h
@@ -175,6 +175,21 @@
extern unsigned long try_to_free_pages(struct zone **, gfp_t);
extern unsigned long shrink_all_memory(unsigned long nr_pages);
extern int vm_swappiness;
+extern int remove_mapping(struct address_space *mapping, struct page *page);
+
+/* possible outcome of pageout() */
+typedef enum {
+ /* failed to write page out, page is locked */
+ PAGE_KEEP,
+ /* move page to the active list, page is locked */
+ PAGE_ACTIVATE,
+ /* page has been sent to the disk successfully, page is unlocked */
+ PAGE_SUCCESS,
+ /* page is clean and locked */
+ PAGE_CLEAN,
+} pageout_t;
+
+extern pageout_t pageout(struct page *page, struct address_space *mapping);
#ifdef CONFIG_NUMA
extern int zone_reclaim_mode;
@@ -188,25 +203,6 @@
}
#endif
-#ifdef CONFIG_MIGRATION
-extern int isolate_lru_page(struct page *p);
-extern unsigned long putback_lru_pages(struct list_head *l);
-extern int migrate_page(struct page *, struct page *);
-extern void migrate_page_copy(struct page *, struct page *);
-extern int migrate_page_remove_references(struct page *, struct page *, int);
-extern unsigned long migrate_pages(struct list_head *l, struct list_head *t,
- struct list_head *moved, struct list_head *failed);
-extern int fail_migrate_page(struct page *, struct page *);
-#else
-static inline int isolate_lru_page(struct page *p) { 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,
- struct list_head *moved, struct list_head *failed) { return -ENOSYS; }
-/* Possible settings for the migrate_page() method in address_operations */
-#define migrate_page NULL
-#define fail_migrate_page NULL
-#endif
-
#ifdef CONFIG_MMU
/* linux/mm/shmem.c */
extern int shmem_unuse(swp_entry_t entry, struct page *page);