memcg: fix lru rotation in isolate_pages

Try to fix memcg's lru rotation sanity: make memcg use the same logic as
the global LRU does.

Now, at __isolate_lru_page() retruns -EBUSY, the page is rotated to the
tail of LRU in global LRU's isolate LRU pages.  But in memcg, it's not
handled.  This makes memcg do the same behavior as global LRU and rotate
LRU in the page is busy.

Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Acked-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Minchan Kim <minchan.kim@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 12 insertions, 1 deletions

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 6ceb6f2dbac2..e2fa20dadf40 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -649,6 +649,7 @@ unsigned long mem_cgroup_isolate_pages(unsigned long nr_to_scan,
         int zid = zone_idx(z);
         struct mem_cgroup_per_zone *mz;
         int lru = LRU_FILE * !!file + !!active;
+        int ret;
 
         BUG_ON(!mem_cont);
         mz = mem_cgroup_zoneinfo(mem_cont, nid, zid);
@@ -666,9 +667,19 @@ unsigned long mem_cgroup_isolate_pages(unsigned long nr_to_scan,
                         continue;
 
                 scan++;
-                if (__isolate_lru_page(page, mode, file) == 0) {
+                ret = __isolate_lru_page(page, mode, file);
+                switch (ret) {
+                case 0:
                         list_move(&page->lru, dst);
+                        mem_cgroup_del_lru(page);
                         nr_taken++;
+                        break;
+                case -EBUSY:
+                        /* we don't affect global LRU but rotate in our LRU */
+                        mem_cgroup_rotate_lru_list(page, page_lru(page));
+                        break;
+                default:
+                        break;
                 }
         }