The memcg_cache_params structure contains the common part and the union, which represents two different types of data: one for root cashes and another for child caches. The size of child data is fixed. The size of the memcg_caches array is calculated in runtime. Currently the size of memcg_cache_params for root caches is calculated incorrectly, because it includes the size of parameters for child caches. ssize_t size = memcg_caches_array_size(num_groups); size *= sizeof(void *); size += sizeof(struct memcg_cache_params); Cc: Glauber Costa <glommer@xxxxxxxxxx> Cc: Johannes Weiner <hannes@xxxxxxxxxxx> Cc: Michal Hocko <mhocko@xxxxxxx> Cc: Balbir Singh <bsingharora@xxxxxxxxx> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Signed-off-by: Andrey Vagin <avagin@xxxxxxxxxx> --- mm/memcontrol.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index c5792a5..d69a10b 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -3140,7 +3140,7 @@ int memcg_update_cache_size(struct kmem_cache *s, int num_groups) ssize_t size = memcg_caches_array_size(num_groups); size *= sizeof(void *); - size += sizeof(struct memcg_cache_params); + size += sizeof(offsetof(struct memcg_cache_params, memcg_caches)); s->memcg_params = kzalloc(size, GFP_KERNEL); if (!s->memcg_params) { @@ -3183,13 +3183,16 @@ int memcg_update_cache_size(struct kmem_cache *s, int num_groups) int memcg_register_cache(struct mem_cgroup *memcg, struct kmem_cache *s, struct kmem_cache *root_cache) { - size_t size = sizeof(struct memcg_cache_params); + size_t size; if (!memcg_kmem_enabled()) return 0; - if (!memcg) + if (!memcg) { + size = offsetof(struct memcg_cache_params, memcg_caches); size += memcg_limited_groups_array_size * sizeof(void *); + } else + size = sizeof(struct memcg_cache_params); s->memcg_params = kzalloc(size, GFP_KERNEL); if (!s->memcg_params) -- 1.8.3.1 -- To unsubscribe from this list: send the line "unsubscribe cgroups" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html