[PATCH -mmotm 1/4] memcg: don't trigger oom at page migration

[Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>]

I think triggering OOM at mem_cgroup_prepare_migration would be just a bit
overkill.
Returning -ENOMEM would be enough for mem_cgroup_prepare_migration.
The caller would handle the case anyway.

Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com>
---
 mm/memcontrol.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index a4854a7..0683459 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -1331,7 +1331,7 @@ int mem_cgroup_prepare_migration(struct page *page, struct mem_cgroup **ptr)
 	unlock_page_cgroup(pc);
 
 	if (mem) {
-		ret = mem_cgroup_try_charge(NULL, GFP_KERNEL, &mem);
+		ret = __mem_cgroup_try_charge(NULL, GFP_KERNEL, &mem, false);
 		css_put(&mem->css);
 	}
 	*ptr = mem;