[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>

1 files changed, 0 insertions, 21 deletions

diff --git a/include/linux/mm_inline.h b/include/linux/mm_inline.h
index 49cc68a..8ac854f 100644
--- a/include/linux/mm_inline.h
+++ b/include/linux/mm_inline.h
@@ -39,24 +39,3 @@ del_page_from_lru(struct zone *zone, struct page *page)
 	}
 }
 
-/*
- * Isolate one page from the LRU lists.
- *
- * - zone->lru_lock must be held
- */
-static inline int __isolate_lru_page(struct page *page)
-{
-	if (unlikely(!TestClearPageLRU(page)))
-		return 0;
-
-	if (get_page_testone(page)) {
-		/*
-		 * It is being freed elsewhere
-		 */
-		__put_page(page);
-		SetPageLRU(page);
-		return -ENOENT;
-	}
-
-	return 1;
-}