diff options
authorGlauber Costa <glommer@parallels.com>2013-02-12 13:46:22 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2013-02-12 14:34:00 -0800
commit4ba902b5741859a04fdb90d675b9a87721a3fd59 (patch)
parent9977f0f164d46613288e0b5778eae500dfe06f31 (diff)
memcg: fix kmemcg registration for late caches
The designed workflow for the caches in kmemcg is: register it with memcg_register_cache() if kmemcg is already available or later on when a new kmemcg appears at memcg_update_cache_sizes() which will handle all caches in the system. The caches created at boot time will be handled by the later, and the memcg-caches as well as any system caches that are registered later on by the former. There is a bug, however, in memcg_register_cache: we correctly set up the array size, but do not mark the cache as a root cache. This means that allocations for any cache appearing late in the game will see memcg->memcg_params->is_root_cache == false, and in particular, trigger VM_BUG_ON(!cachep->memcg_params->is_root_cache) in __memcg_kmem_cache_get. The obvious fix is to include the missing assignment. Signed-off-by: Glauber Costa <glommer@parallels.com> Cc: Michal Hocko <mhocko@suse.cz> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1 files changed, 3 insertions, 1 deletions
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 09255ec8159..fbb60b103e6 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -3030,7 +3030,9 @@ int memcg_register_cache(struct mem_cgroup *memcg, struct kmem_cache *s,
if (memcg) {
s->memcg_params->memcg = memcg;
s->memcg_params->root_cache = root_cache;
- }
+ } else
+ s->memcg_params->is_root_cache = true;
return 0;