[PATCH v2 16/21] mm: list_lru: rename memcg_drain_all_list_lrus to memcg_reparent_list_lrus

[Muchun Song]

The purpose of the memcg_drain_all_list_lrus() is list_lrus reparenting.
It is very similar to memcg_reparent_objcgs(). Rename it to
memcg_reparent_list_lrus() so that the name can more consistent with
memcg_reparent_objcgs().

Signed-off-by: Muchun Song <songmuchun@xxxxxxxxxxxxx>
---
 include/linux/list_lru.h |  3 +--
 mm/list_lru.c            | 25 ++++++++++++-------------
 mm/memcontrol.c          |  4 ++--
 3 files changed, 15 insertions(+), 17 deletions(-)

diff --git a/include/linux/list_lru.h b/include/linux/list_lru.h
index 00c15dc1ede3..60970ea48c29 100644
--- a/include/linux/list_lru.h
+++ b/include/linux/list_lru.h
@@ -76,8 +76,7 @@ int __list_lru_init(struct list_lru *lru, bool memcg_aware,
 	__list_lru_init((lru), true, NULL, shrinker)
 
 int memcg_update_all_list_lrus(int num_memcgs);
-void memcg_drain_all_list_lrus(struct mem_cgroup *src_memcg,
-			       struct mem_cgroup *dst_memcg);
+void memcg_reparent_list_lrus(struct mem_cgroup *memcg, struct mem_cgroup *parent);
 
 /**
  * list_lru_add: add an element to the lru list's tail
diff --git a/mm/list_lru.c b/mm/list_lru.c
index 43eadb0834e1..dec116a12629 100644
--- a/mm/list_lru.c
+++ b/mm/list_lru.c
@@ -462,8 +462,8 @@ int memcg_update_all_list_lrus(int new_size)
 	return ret;
 }
 
-static void memcg_drain_list_lru_node(struct list_lru *lru, int nid,
-				      int src_idx, struct mem_cgroup *dst_memcg)
+static void memcg_reparent_list_lru_node(struct list_lru *lru, int nid,
+					 int src_idx, struct mem_cgroup *dst_memcg)
 {
 	struct list_lru_node *nlru = &lru->node[nid];
 	int dst_idx = dst_memcg->kmemcg_id;
@@ -491,23 +491,22 @@ static void memcg_drain_list_lru_node(struct list_lru *lru, int nid,
 	spin_unlock_irq(&nlru->lock);
 }
 
-static void memcg_drain_list_lru(struct list_lru *lru,
-				 int src_idx, struct mem_cgroup *dst_memcg)
+static void memcg_reparent_list_lru(struct list_lru *lru,
+				    int src_idx, struct mem_cgroup *dst_memcg)
 {
 	int i;
 
 	for_each_node(i)
-		memcg_drain_list_lru_node(lru, i, src_idx, dst_memcg);
+		memcg_reparent_list_lru_node(lru, i, src_idx, dst_memcg);
 
 	memcg_list_lru_free(lru, src_idx);
 }
 
-void memcg_drain_all_list_lrus(struct mem_cgroup *src_memcg,
-			       struct mem_cgroup *dst_memcg)
+void memcg_reparent_list_lrus(struct mem_cgroup *memcg, struct mem_cgroup *parent)
 {
 	struct cgroup_subsys_state *css;
 	struct list_lru *lru;
-	int src_idx = src_memcg->kmemcg_id;
+	int src_idx = memcg->kmemcg_id;
 
 	/*
 	 * Change kmemcg_id of this cgroup and all its descendants to the
@@ -522,17 +521,17 @@ void memcg_drain_all_list_lrus(struct mem_cgroup *src_memcg,
 	 * memcg_list_lru_free().
 	 */
 	rcu_read_lock();
-	css_for_each_descendant_pre(css, &src_memcg->css) {
-		struct mem_cgroup *memcg;
+	css_for_each_descendant_pre(css, &memcg->css) {
+		struct mem_cgroup *child;
 
-		memcg = mem_cgroup_from_css(css);
-		memcg->kmemcg_id = dst_memcg->kmemcg_id;
+		child = mem_cgroup_from_css(css);
+		child->kmemcg_id = parent->kmemcg_id;
 	}
 	rcu_read_unlock();
 
 	mutex_lock(&list_lrus_mutex);
 	list_for_each_entry(lru, &list_lrus, list)
-		memcg_drain_list_lru(lru, src_idx, dst_memcg);
+		memcg_reparent_list_lru(lru, src_idx, parent);
 	mutex_unlock(&list_lrus_mutex);
 }
 
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 1994513a33d4..205bf710486c 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -3655,12 +3655,12 @@ static void memcg_offline_kmem(struct mem_cgroup *memcg)
 	memcg_reparent_objcgs(memcg, parent);
 
 	/*
-	 * memcg_drain_all_list_lrus() can change memcg->kmemcg_id.
+	 * memcg_reparent_list_lrus() can change memcg->kmemcg_id.
 	 * Cache it to @kmemcg_id.
 	 */
 	kmemcg_id = memcg->kmemcg_id;
 
-	memcg_drain_all_list_lrus(memcg, parent);
+	memcg_reparent_list_lrus(memcg, parent);
 
 	memcg_free_cache_id(kmemcg_id);
 }
-- 
2.11.0