[PATCH 2/8] memcg: get rid of mem_cgroup_root_css for !CONFIG_MEMCG

Michal Hocko
2015-07-08T12:28:23Z

The only user is cgwb_bdi_init and that one depends on
CONFIG_CGROUP_WRITEBACK which in turn depends on CONFIG_MEMCG
so it doesn't make much sense to definte an empty stub for
!CONFIG_MEMCG. Moreover ERR_PTR(-EINVAL) is ugly and would lead
to runtime crashes if used in unguarded code paths. Better fail
during compilation.

Signed-off-by: Michal Hocko <mhocko@kernel.org>
---
include/linux/memcontrol.h | 2 --
1 file changed, 2 deletions(-)

diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index f5a8d0bbef8d..680cefec8c2a 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -496,8 +496,6 @@ void mem_cgroup_split_huge_fixup(struct page *head);
#else /* CONFIG_MEMCG */
struct mem_cgroup;

-#define mem_cgroup_root_css ((struct cgroup_subsys_state *)ERR_PTR(-EINVAL))
-
static inline void mem_cgroup_events(struct mem_cgroup *memcg,
enum mem_cgroup_events_index idx,
unsigned int nr)
--
2.1.4