[PATCH 1/2] Check PageUnevictable in lru_deactivate_fn

Minchan Kim
2011-05-01T15:04:19Z

The lru_deactivate_fn should not move page which in on unevictable lru
into inactive list. Otherwise, we can meet BUG when we use isolate_lru_pages
as __isolate_lru_page could return -EINVAL.
It's really BUG and let's fix it.

Reported-by: Ying Han <yinghan@google.com>
Tested-by: Ying Han <yinghan@google.com>
Signed-off-by: Minchan Kim <minchan.kim@gmail.com>
---
mm/swap.c | 3 +++
1 files changed, 3 insertions(+), 0 deletions(-)

diff --git a/mm/swap.c b/mm/swap.c
index a83ec5a..2e9656d 100644
--- a/mm/swap.c
+++ b/mm/swap.c
@@ -429,6 +429,9 @@ static void lru_deactivate_fn(struct page *page, void *arg)
if (!PageLRU(page))
return;

+ if (PageUnevictable(page))
+ return;
+
/* Some processes are using the page */
if (page_mapped(page))
return;
--
1.7.1