[PATCH v5 3/5] memcg: fail to create cgroup if the cgroup id is too big
From: Li Zefan <hidden>
Date: 2013-08-08 02:34:59
Also in:
linux-mm, lkml
Subsystem:
control group - memory resource controller (memcg), memory management, the rest · Maintainers:
Johannes Weiner, Michal Hocko, Roman Gushchin, Shakeel Butt, Andrew Morton, Linus Torvalds
memcg requires the cgroup id to be smaller than 65536. This is a preparation to kill css id. Signed-off-by: Li Zefan <redacted> Acked-by: Michal Hocko <redacted> --- mm/memcontrol.c | 9 +++++++++ 1 file changed, 9 insertions(+)
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 3189f70..c0bb83c 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c@@ -503,6 +503,12 @@ static inline bool mem_cgroup_is_root(struct mem_cgroup *memcg) return (memcg == root_mem_cgroup); } +/* + * We restrict the id in the range of [1, 65535], so it can fit into + * an unsigned short. + */ +#define MEM_CGROUP_ID_MAX USHRT_MAX + static inline unsigned short mem_cgroup_id(struct mem_cgroup *memcg) { /*
@@ -6056,6 +6062,9 @@ mem_cgroup_css_alloc(struct cgroup *cont) long error = -ENOMEM; int node; + if (cont->id > MEM_CGROUP_ID_MAX) + return ERR_PTR(-ENOSPC); + memcg = mem_cgroup_alloc(); if (!memcg) return ERR_PTR(error);
--
1.8.0.2