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authorTejun Heo <tj@kernel.org>2015-05-22 17:13:20 -0400
committerJens Axboe <axboe@fb.com>2015-06-02 08:33:33 -0600
commit56161634e4824380a67243a4cf3fa52eb1e5d836 (patch)
treef270436ae91d6a472efc425c256f487460e9b108 /include/linux/memcontrol.h
parentec13b1d6f0a0457312e615335ce8ceb07da50a11 (diff)
downloadlwn-56161634e4824380a67243a4cf3fa52eb1e5d836.tar.gz
lwn-56161634e4824380a67243a4cf3fa52eb1e5d836.zip
memcg: add mem_cgroup_root_css
Add global mem_cgroup_root_css which points to the root memcg css. This will be used by cgroup writeback support. If memcg is disabled, it's defined as ERR_PTR(-EINVAL). Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Johannes Weiner <hannes@cmpxchg.org> aCc: Michal Hocko <mhocko@suse.cz> Signed-off-by: Jens Axboe <axboe@fb.com>
Diffstat (limited to 'include/linux/memcontrol.h')
-rw-r--r--include/linux/memcontrol.h4
1 files changed, 4 insertions, 0 deletions
diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index 5fe6411b5e54..294498f4f6fc 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -68,6 +68,8 @@ enum mem_cgroup_events_index {
};
#ifdef CONFIG_MEMCG
+extern struct cgroup_subsys_state *mem_cgroup_root_css;
+
void mem_cgroup_events(struct mem_cgroup *memcg,
enum mem_cgroup_events_index idx,
unsigned int nr);
@@ -196,6 +198,8 @@ 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)