[PATCH v1 4/9] mm: memcg: gather memcg1-specific fields initialization in memcg1_memcg_init()

[Roman Gushchin]

Gather all memcg1-specific struct mem_cgroup's members initialization
in a new memcg1_memcg_init() function, defined in mm/memcontrol-v1.c.
Obviously, if CONFIG_MEMCG_V1 is not set, there is no need to
initialize these fields, so the function becomes trivial.

Signed-off-by: Roman Gushchin <roman.gushchin@xxxxxxxxx>
---
 mm/memcontrol-v1.c | 9 +++++++++
 mm/memcontrol-v1.h | 2 ++
 mm/memcontrol.c    | 6 +-----
 3 files changed, 12 insertions(+), 5 deletions(-)

diff --git a/mm/memcontrol-v1.c b/mm/memcontrol-v1.c
index c9b4c3e4797d..5fa48a45e34b 100644
--- a/mm/memcontrol-v1.c
+++ b/mm/memcontrol-v1.c
@@ -1961,6 +1961,15 @@ static ssize_t memcg_write_event_control(struct kernfs_open_file *of,
 	return ret;
 }
 
+void memcg1_memcg_init(struct mem_cgroup *memcg)
+{
+	INIT_LIST_HEAD(&memcg->oom_notify);
+	mutex_init(&memcg->thresholds_lock);
+	spin_lock_init(&memcg->move_lock);
+	INIT_LIST_HEAD(&memcg->event_list);
+	spin_lock_init(&memcg->event_list_lock);
+}
+
 void memcg1_css_offline(struct mem_cgroup *memcg)
 {
 	struct mem_cgroup_event *event, *tmp;
diff --git a/mm/memcontrol-v1.h b/mm/memcontrol-v1.h
index c8e5119223bb..6545fa1b7d09 100644
--- a/mm/memcontrol-v1.h
+++ b/mm/memcontrol-v1.h
@@ -76,6 +76,7 @@ int memory_stat_show(struct seq_file *m, void *v);
 
 /* Cgroup v1-specific declarations */
 #ifdef CONFIG_MEMCG_V1
+void memcg1_memcg_init(struct mem_cgroup *memcg);
 void memcg1_remove_from_trees(struct mem_cgroup *memcg);
 
 static inline void memcg1_soft_limit_reset(struct mem_cgroup *memcg)
@@ -124,6 +125,7 @@ extern struct cftype mem_cgroup_legacy_files[];
 
 #else	/* CONFIG_MEMCG_V1 */
 
+static inline void memcg1_memcg_init(struct mem_cgroup *memcg) {}
 static inline void memcg1_remove_from_trees(struct mem_cgroup *memcg) {}
 static inline void memcg1_soft_limit_reset(struct mem_cgroup *memcg) {}
 static inline bool memcg1_wait_acct_move(struct mem_cgroup *memcg) { return false; }
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index b69abd327549..e78ed54d46d2 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -3624,13 +3624,9 @@ static struct mem_cgroup *mem_cgroup_alloc(struct mem_cgroup *parent)
 		goto fail;
 
 	INIT_WORK(&memcg->high_work, high_work_func);
-	INIT_LIST_HEAD(&memcg->oom_notify);
-	mutex_init(&memcg->thresholds_lock);
-	spin_lock_init(&memcg->move_lock);
 	vmpressure_init(&memcg->vmpressure);
-	INIT_LIST_HEAD(&memcg->event_list);
-	spin_lock_init(&memcg->event_list_lock);
 	memcg->socket_pressure = jiffies;
+	memcg1_memcg_init(memcg);
 #ifdef CONFIG_MEMCG_KMEM
 	memcg->kmemcg_id = -1;
 	INIT_LIST_HEAD(&memcg->objcg_list);
-- 
2.45.2.803.g4e1b14247a-goog