From:   Muchun Song <songmuchun@bytedance.com>
To:     willy@infradead.org, akpm@linux-foundation.org, hannes@cmpxchg.org,
        mhocko@kernel.org, vdavydov.dev@gmail.com, shakeelb@google.com,
        guro@fb.com, shy828301@gmail.com, alexs@kernel.org,
        richard.weiyang@gmail.com, david@fromorbit.com,
        trond.myklebust@hammerspace.com, anna.schumaker@netapp.com,
        jaegeuk@kernel.org, chao@kernel.org, kari.argillander@gmail.com
Cc:     linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-mm@kvack.org, linux-nfs@vger.kernel.org,
        zhengqi.arch@bytedance.com, duanxiongchun@bytedance.com,
        fam.zheng@bytedance.com, smuchun@gmail.com,
        Muchun Song <songmuchun@bytedance.com>
Subject: [PATCH v5 11/16] mm: list_lru: rename memcg_drain_all_list_lrus to memcg_reparent_list_lrus
Date:   Mon, 20 Dec 2021 16:56:44 +0800
Message-Id: <20211220085649.8196-12-songmuchun@bytedance.com>
In-Reply-To: <20211220085649.8196-1-songmuchun@bytedance.com>
References: <20211220085649.8196-1-songmuchun@bytedance.com>
MIME-Version: 1.0
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Precedence: bulk

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@bytedance.com>
---
 include/linux/list_lru.h |  2 +-
 mm/list_lru.c            | 24 ++++++++++++------------
 mm/memcontrol.c          |  6 +++---
 3 files changed, 16 insertions(+), 16 deletions(-)

diff --git a/include/linux/list_lru.h b/include/linux/list_lru.h
index c36db6dc2a65..4b00fd8cb373 100644
--- a/include/linux/list_lru.h
+++ b/include/linux/list_lru.h
@@ -78,7 +78,7 @@ int __list_lru_init(struct list_lru *lru, bool memcg_aware,
 int memcg_list_lru_alloc(struct mem_cgroup *memcg, struct list_lru *lru,
 			 gfp_t gfp);
 int memcg_update_all_list_lrus(int num_memcgs);
-void memcg_drain_all_list_lrus(struct mem_cgroup *src, struct mem_cgroup *dst);
+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 fc938d8ff48f..488dacd1f8ff 100644
--- a/mm/list_lru.c
+++ b/mm/list_lru.c
@@ -457,8 +457,8 @@ 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;
@@ -486,22 +486,22 @@ 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, struct mem_cgroup *dst)
+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->kmemcg_id;
+	int src_idx = memcg->kmemcg_id;
 
 	/*
 	 * Change kmemcg_id of this cgroup and all its descendants to the
@@ -517,17 +517,17 @@ void memcg_drain_all_list_lrus(struct mem_cgroup *src, struct mem_cgroup *dst)
 	 * call.
 	 */
 	rcu_read_lock();
-	css_for_each_descendant_pre(css, &src->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->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, &memcg_list_lrus, list)
-		memcg_drain_list_lru(lru, src_idx, dst);
+		memcg_reparent_list_lru(lru, src_idx, parent);
 	mutex_unlock(&list_lrus_mutex);
 }
 
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 94d8f742c32e..a19b1a1c8ea9 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -3644,7 +3644,7 @@ 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 local @kmemcg_id.
 	 */
 	kmemcg_id = memcg->kmemcg_id;
@@ -3653,9 +3653,9 @@ static void memcg_offline_kmem(struct mem_cgroup *memcg)
 	 * After we have finished memcg_reparent_objcgs(), all list_lrus
 	 * corresponding to this cgroup are guaranteed to remain empty.
 	 * The ordering is imposed by list_lru_node->lock taken by
-	 * memcg_drain_all_list_lrus().
+	 * memcg_reparent_list_lrus().
 	 */
-	memcg_drain_all_list_lrus(memcg, parent);
+	memcg_reparent_list_lrus(memcg, parent);
 
 	memcg_free_cache_id(kmemcg_id);
 }
-- 
2.11.0