[PATCH] mm: migration page refcounting fix
Migration code currently does not take a reference to target page
properly, so between unlocking the pte and trying to take a new
reference to the page with isolate_lru_page, anything could happen to
it.
Fix this by holding the pte lock until we get a chance to elevate the
refcount.
Other small cleanups while we're here.
Signed-off-by: Nick Piggin <npiggin@suse.de>
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 e92054d..d01f7ef 100644
--- a/include/linux/swap.h
+++ b/include/linux/swap.h
@@ -167,6 +167,7 @@
extern void FASTCALL(activate_page(struct page *));
extern void FASTCALL(mark_page_accessed(struct page *));
extern void lru_add_drain(void);
+extern int lru_add_drain_all(void);
extern int rotate_reclaimable_page(struct page *page);
extern void swap_setup(void);