memcg: clean up force_empty_list() return value check

After bf544fdc241da8 "memcg: move charges to root cgroup if
use_hierarchy=0 in mem_cgroup_move_hugetlb_parent()"
mem_cgroup_move_parent() returns only -EBUSY or -EINVAL.  So we can remove
the -ENOMEM and -EINTR checks.

Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Michal Hocko <mhocko@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 8062d45ee7f4e5988e4c760a12a01e9b026bd1e1..a1f00f0a66cdce69a363d80abf5542f8b48c3acc 100644 (file)
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -3653,8 +3653,6 @@ static int mem_cgroup_force_empty_list(struct mem_cgroup *memcg,
                pc = lookup_page_cgroup(page);
 
                ret = mem_cgroup_move_parent(page, pc, memcg, GFP_KERNEL);
-               if (ret == -ENOMEM || ret == -EINTR)
-                       break;
 
                if (ret == -EBUSY || ret == -EINVAL) {
                        /* found lock contention or "pc" is obsolete. */
@@ -3711,9 +3709,6 @@ move_account:
                }
                mem_cgroup_end_move(memcg);
                memcg_oom_recover(memcg);
-               /* it seems parent cgroup doesn't have enough mem */
-               if (ret == -ENOMEM)
-                       goto try_to_free;
                cond_resched();
        /* "ret" should also be checked to ensure all lists are empty. */
        } while (res_counter_read_u64(&memcg->res, RES_USAGE) > 0 || ret);