mm: fix incorrect page removal from LRU

The isolated page is "cursor_page" not "page".

This could cause LRU list corruption under memory pressure, caught by
CONFIG_DEBUG_LIST.

Reported-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reviewed-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Tested-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/mm/vmscan.c b/mm/vmscan.c
index e8fa2d9..5415526 100644 (file)
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -932,7 +932,7 @@ static unsigned long isolate_lru_pages(unsigned long nr_to_scan,
                                continue;
                        if (__isolate_lru_page(cursor_page, mode, file) == 0) {
                                list_move(&cursor_page->lru, dst);
-                               mem_cgroup_del_lru(page);
+                               mem_cgroup_del_lru(cursor_page);
                                nr_taken++;
                                scan++;
                        }