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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,
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        alexander.h.duyck@linux.intel.com, richard.weiyang@gmail.com
Cc:     linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-mm@kvack.org, Muchun Song <songmuchun@bytedance.com>
Subject: [PATCH 9/9] mm: memcontrol: rename memcg_{get,put}_cache_ids to memcg_list_lru_resize_{lock,unlock}
Date:   Wed, 28 Apr 2021 17:49:49 +0800
Message-Id: <20210428094949.43579-10-songmuchun@bytedance.com>
In-Reply-To: <20210428094949.43579-1-songmuchun@bytedance.com>
References: <20210428094949.43579-1-songmuchun@bytedance.com>
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The rwsem is held for writing during list lru arrays relocation and
memcg_nr_cache_ids updates. Therefore memcg_get_cache_ids implies
memcg_nr_cache_ids cannot be updated. It acts as a lock primitive.
So rename it to a more suitable name.

Signed-off-by: Muchun Song <songmuchun@bytedance.com>
---
 include/linux/memcontrol.h | 8 ++++----
 mm/list_lru.c              | 8 ++++----
 mm/memcontrol.c            | 4 ++--
 3 files changed, 10 insertions(+), 10 deletions(-)

diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index 6350c563c7b8..e8ba6ee1b369 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -1635,8 +1635,8 @@ void obj_cgroup_uncharge(struct obj_cgroup *objcg, size_t size);
 extern struct static_key_false memcg_kmem_enabled_key;
 
 extern int memcg_nr_cache_ids;
-void memcg_get_cache_ids(void);
-void memcg_put_cache_ids(void);
+void memcg_list_lru_resize_lock(void);
+void memcg_list_lru_resize_unlock(void);
 
 /*
  * Helper macro to loop through all memcg-specific caches. Callers must still
@@ -1711,11 +1711,11 @@ static inline int memcg_cache_id(struct mem_cgroup *memcg)
 	return -1;
 }
 
-static inline void memcg_get_cache_ids(void)
+static inline void memcg_list_lru_resize_lock(void)
 {
 }
 
-static inline void memcg_put_cache_ids(void)
+static inline void memcg_list_lru_resize_unlock(void)
 {
 }
 
diff --git a/mm/list_lru.c b/mm/list_lru.c
index 3ee5239922c9..e0ba0641b4e1 100644
--- a/mm/list_lru.c
+++ b/mm/list_lru.c
@@ -640,7 +640,7 @@ int __list_lru_init(struct list_lru *lru, bool memcg_aware,
 	else
 		lru->shrinker_id = -1;
 #endif
-	memcg_get_cache_ids();
+	memcg_list_lru_resize_lock();
 
 	lru->node = kcalloc(nr_node_ids, sizeof(*lru->node), GFP_KERNEL);
 	if (!lru->node)
@@ -663,7 +663,7 @@ int __list_lru_init(struct list_lru *lru, bool memcg_aware,
 
 	list_lru_register(lru);
 out:
-	memcg_put_cache_ids();
+	memcg_list_lru_resize_unlock();
 	return err;
 }
 EXPORT_SYMBOL_GPL(__list_lru_init);
@@ -674,7 +674,7 @@ void list_lru_destroy(struct list_lru *lru)
 	if (!lru->node)
 		return;
 
-	memcg_get_cache_ids();
+	memcg_list_lru_resize_lock();
 
 	list_lru_unregister(lru);
 
@@ -685,6 +685,6 @@ void list_lru_destroy(struct list_lru *lru)
 #ifdef CONFIG_MEMCG_KMEM
 	lru->shrinker_id = -1;
 #endif
-	memcg_put_cache_ids();
+	memcg_list_lru_resize_unlock();
 }
 EXPORT_SYMBOL_GPL(list_lru_destroy);
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index f8cdd87cf693..437465611845 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -367,12 +367,12 @@ static int kmemcg_max_id;
 /* Protects memcg_nr_cache_ids */
 static DECLARE_RWSEM(memcg_cache_ids_sem);
 
-void memcg_get_cache_ids(void)
+void memcg_list_lru_resize_lock(void)
 {
 	down_read(&memcg_cache_ids_sem);
 }
 
-void memcg_put_cache_ids(void)
+void memcg_list_lru_resize_unlock(void)
 {
 	up_read(&memcg_cache_ids_sem);
 }
-- 
2.11.0