[PATCH 4/8] mm: memcontrol: group kmem init and exit functions together

Johannes Weiner
2015-12-08T18:36:47Z

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>
---
mm/memcontrol.c | 157 +++++++++++++++++++++++++++-----------------------------
1 file changed, 76 insertions(+), 81 deletions(-)

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 22b8c4f..5118618 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -2924,12 +2924,88 @@ 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 */

/*
@@ -3555,87 +3631,6 @@ 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)
--
2.6.3