mm: memcontrol: group kmem init and exit functions together

Put all the related code to setup and teardown the kmem accounting state
into the same location.  No functional change intended.

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Tejun Heo <tj@kernel.org>
Acked-by: Vladimir Davydov <vdavydov@virtuozzo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 76 insertions, 81 deletions

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 24b6bded13f8..3dd9fe35fe62 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -2945,12 +2945,88 @@ static int memcg_propagate_kmem(struct mem_cgroup *memcg)
         mutex_unlock(&memcg_limit_mutex);
         return ret;
 }
+
+static int memcg_init_kmem(struct mem_cgroup *memcg)
+{
+        int ret;
+
+        ret = memcg_propagate_kmem(memcg);
+        if (ret)
+                return ret;
+
+        return tcp_init_cgroup(memcg);
+}
+
+static void memcg_offline_kmem(struct mem_cgroup *memcg)
+{
+        struct cgroup_subsys_state *css;
+        struct mem_cgroup *parent, *child;
+        int kmemcg_id;
+
+        if (memcg->kmem_state != KMEM_ONLINE)
+                return;
+        /*
+         * Clear the online state before clearing memcg_caches array
+         * entries. The slab_mutex in memcg_deactivate_kmem_caches()
+         * guarantees that no cache will be created for this cgroup
+         * after we are done (see memcg_create_kmem_cache()).
+         */
+        memcg->kmem_state = KMEM_ALLOCATED;
+
+        memcg_deactivate_kmem_caches(memcg);
+
+        kmemcg_id = memcg->kmemcg_id;
+        BUG_ON(kmemcg_id < 0);
+
+        parent = parent_mem_cgroup(memcg);
+        if (!parent)
+                parent = root_mem_cgroup;
+
+        /*
+         * Change kmemcg_id of this cgroup and all its descendants to the
+         * parent's id, and then move all entries from this cgroup's list_lrus
+         * to ones of the parent. After we have finished, 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().
+         */
+        css_for_each_descendant_pre(css, &memcg->css) {
+                child = mem_cgroup_from_css(css);
+                BUG_ON(child->kmemcg_id != kmemcg_id);
+                child->kmemcg_id = parent->kmemcg_id;
+                if (!memcg->use_hierarchy)
+                        break;
+        }
+        memcg_drain_all_list_lrus(kmemcg_id, parent->kmemcg_id);
+
+        memcg_free_cache_id(kmemcg_id);
+}
+
+static void memcg_free_kmem(struct mem_cgroup *memcg)
+{
+        if (memcg->kmem_state == KMEM_ALLOCATED) {
+                memcg_destroy_kmem_caches(memcg);
+                static_branch_dec(&memcg_kmem_enabled_key);
+                WARN_ON(page_counter_read(&memcg->kmem));
+        }
+        tcp_destroy_cgroup(memcg);
+}
 #else
 static int memcg_update_kmem_limit(struct mem_cgroup *memcg,
                                    unsigned long limit)
 {
         return -EINVAL;
 }
+static int memcg_init_kmem(struct mem_cgroup *memcg)
+{
+        return 0;
+}
+static void memcg_offline_kmem(struct mem_cgroup *memcg)
+{
+}
+static void memcg_free_kmem(struct mem_cgroup *memcg)
+{
+}
 #endif /* CONFIG_MEMCG_KMEM */
 
 /*
@@ -3577,87 +3653,6 @@ static int mem_cgroup_oom_control_write(struct cgroup_subsys_state *css,
         return 0;
 }
 
-#ifdef CONFIG_MEMCG_KMEM
-static int memcg_init_kmem(struct mem_cgroup *memcg)
-{
-        int ret;
-
-        ret = memcg_propagate_kmem(memcg);
-        if (ret)
-                return ret;
-
-        return tcp_init_cgroup(memcg);
-}
-
-static void memcg_offline_kmem(struct mem_cgroup *memcg)
-{
-        struct cgroup_subsys_state *css;
-        struct mem_cgroup *parent, *child;
-        int kmemcg_id;
-
-        if (memcg->kmem_state != KMEM_ONLINE)
-                return;
-        /*
-         * Clear the online state before clearing memcg_caches array
-         * entries. The slab_mutex in memcg_deactivate_kmem_caches()
-         * guarantees that no cache will be created for this cgroup
-         * after we are done (see memcg_create_kmem_cache()).
-         */
-        memcg->kmem_state = KMEM_ALLOCATED;
-
-        memcg_deactivate_kmem_caches(memcg);
-
-        kmemcg_id = memcg->kmemcg_id;
-        BUG_ON(kmemcg_id < 0);
-
-        parent = parent_mem_cgroup(memcg);
-        if (!parent)
-                parent = root_mem_cgroup;
-
-        /*
-         * Change kmemcg_id of this cgroup and all its descendants to the
-         * parent's id, and then move all entries from this cgroup's list_lrus
-         * to ones of the parent. After we have finished, 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().
-         */
-        css_for_each_descendant_pre(css, &memcg->css) {
-                child = mem_cgroup_from_css(css);
-                BUG_ON(child->kmemcg_id != kmemcg_id);
-                child->kmemcg_id = parent->kmemcg_id;
-                if (!memcg->use_hierarchy)
-                        break;
-        }
-        memcg_drain_all_list_lrus(kmemcg_id, parent->kmemcg_id);
-
-        memcg_free_cache_id(kmemcg_id);
-}
-
-static void memcg_free_kmem(struct mem_cgroup *memcg)
-{
-        if (memcg->kmem_state == KMEM_ALLOCATED) {
-                memcg_destroy_kmem_caches(memcg);
-                static_branch_dec(&memcg_kmem_enabled_key);
-                WARN_ON(page_counter_read(&memcg->kmem));
-        }
-        tcp_destroy_cgroup(memcg);
-}
-#else
-static int memcg_init_kmem(struct mem_cgroup *memcg, struct cgroup_subsys *ss)
-{
-        return 0;
-}
-
-static void memcg_offline_kmem(struct mem_cgroup *memcg)
-{
-}
-
-static void memcg_free_kmem(struct mem_cgroup *memcg)
-{
-}
-#endif
-
 #ifdef CONFIG_CGROUP_WRITEBACK
 
 struct list_head *mem_cgroup_cgwb_list(struct mem_cgroup *memcg)