mm: memcontrol: move kmem accounting code to CONFIG_MEMCG

The cgroup2 memory controller will account important in-kernel memory
consumers per default.  Move all necessary components to CONFIG_MEMCG.

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Vladimir Davydov <vdavydov@virtuozzo.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

5 files changed, 60 insertions, 47 deletions

diff --git a/mm/list_lru.c b/mm/list_lru.c
index afc71ea9a381..1d05cb9d363d 100644
--- a/mm/list_lru.c
+++ b/mm/list_lru.c
@@ -12,7 +12,7 @@
 #include <linux/mutex.h>
 #include <linux/memcontrol.h>
 
-#ifdef CONFIG_MEMCG_KMEM
+#if defined(CONFIG_MEMCG) && !defined(CONFIG_SLOB)
 static LIST_HEAD(list_lrus);
 static DEFINE_MUTEX(list_lrus_mutex);
 
@@ -37,9 +37,9 @@ static void list_lru_register(struct list_lru *lru)
 static void list_lru_unregister(struct list_lru *lru)
 {
 }
-#endif /* CONFIG_MEMCG_KMEM */
+#endif /* CONFIG_MEMCG && !CONFIG_SLOB */
 
-#ifdef CONFIG_MEMCG_KMEM
+#if defined(CONFIG_MEMCG) && !defined(CONFIG_SLOB)
 static inline bool list_lru_memcg_aware(struct list_lru *lru)
 {
 	/*
@@ -104,7 +104,7 @@ list_lru_from_kmem(struct list_lru_node *nlru, void *ptr)
 {
 	return &nlru->lru;
 }
-#endif /* CONFIG_MEMCG_KMEM */
+#endif /* CONFIG_MEMCG && !CONFIG_SLOB */
 
 bool list_lru_add(struct list_lru *lru, struct list_head *item)
 {
@@ -292,7 +292,7 @@ static void init_one_lru(struct list_lru_one *l)
 	l->nr_items = 0;
 }
 
-#ifdef CONFIG_MEMCG_KMEM
+#if defined(CONFIG_MEMCG) && !defined(CONFIG_SLOB)
 static void __memcg_destroy_list_lru_node(struct list_lru_memcg *memcg_lrus,
 					  int begin, int end)
 {
@@ -529,7 +529,7 @@ static int memcg_init_list_lru(struct list_lru *lru, bool memcg_aware)
 static void memcg_destroy_list_lru(struct list_lru *lru)
 {
 }
-#endif /* CONFIG_MEMCG_KMEM */
+#endif /* CONFIG_MEMCG && !CONFIG_SLOB */
 
 int __list_lru_init(struct list_lru *lru, bool memcg_aware,
 		    struct lock_class_key *key)
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 7f8219b58e0c..fe51d5e61389 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -297,7 +297,7 @@ static inline struct mem_cgroup *mem_cgroup_from_id(unsigned short id)
 	return mem_cgroup_from_css(css);
 }
 
-#ifdef CONFIG_MEMCG_KMEM
+#ifndef CONFIG_SLOB
 /*
  * This will be the memcg's index in each cache's ->memcg_params.memcg_caches.
  * The main reason for not using cgroup id for this:
@@ -349,7 +349,7 @@ void memcg_put_cache_ids(void)
 DEFINE_STATIC_KEY_FALSE(memcg_kmem_enabled_key);
 EXPORT_SYMBOL(memcg_kmem_enabled_key);
 
-#endif /* CONFIG_MEMCG_KMEM */
+#endif /* !CONFIG_SLOB */
 
 static struct mem_cgroup_per_zone *
 mem_cgroup_zone_zoneinfo(struct mem_cgroup *memcg, struct zone *zone)
@@ -2203,7 +2203,7 @@ static void commit_charge(struct page *page, struct mem_cgroup *memcg,
 		unlock_page_lru(page, isolated);
 }
 
-#ifdef CONFIG_MEMCG_KMEM
+#ifndef CONFIG_SLOB
 static int memcg_alloc_cache_id(void)
 {
 	int id, size;
@@ -2424,7 +2424,7 @@ void __memcg_kmem_uncharge(struct page *page, int order)
 	page->mem_cgroup = NULL;
 	css_put_many(&memcg->css, nr_pages);
 }
-#endif /* CONFIG_MEMCG_KMEM */
+#endif /* !CONFIG_SLOB */
 
 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 
@@ -2860,7 +2860,7 @@ static u64 mem_cgroup_read_u64(struct cgroup_subsys_state *css,
 	}
 }
 
-#ifdef CONFIG_MEMCG_KMEM
+#ifndef CONFIG_SLOB
 static int memcg_online_kmem(struct mem_cgroup *memcg)
 {
 	int err = 0;
@@ -2908,24 +2908,6 @@ out:
 	return err;
 }
 
-static int memcg_update_kmem_limit(struct mem_cgroup *memcg,
-				   unsigned long limit)
-{
-	int ret;
-
-	mutex_lock(&memcg_limit_mutex);
-	/* Top-level cgroup doesn't propagate from root */
-	if (!memcg_kmem_online(memcg)) {
-		ret = memcg_online_kmem(memcg);
-		if (ret)
-			goto out;
-	}
-	ret = page_counter_limit(&memcg->kmem, limit);
-out:
-	mutex_unlock(&memcg_limit_mutex);
-	return ret;
-}
-
 static int memcg_propagate_kmem(struct mem_cgroup *memcg)
 {
 	int ret = 0;
@@ -3000,16 +2982,45 @@ static void memcg_free_kmem(struct mem_cgroup *memcg)
 	}
 }
 #else
+static int memcg_propagate_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_SLOB */
+
+#ifdef CONFIG_MEMCG_KMEM
 static int memcg_update_kmem_limit(struct mem_cgroup *memcg,
 				   unsigned long limit)
 {
-	return -EINVAL;
+	int ret;
+
+	mutex_lock(&memcg_limit_mutex);
+	/* Top-level cgroup doesn't propagate from root */
+	if (!memcg_kmem_online(memcg)) {
+		ret = memcg_online_kmem(memcg);
+		if (ret)
+			goto out;
+	}
+	ret = page_counter_limit(&memcg->kmem, limit);
+out:
+	mutex_unlock(&memcg_limit_mutex);
+	return ret;
 }
-static void memcg_offline_kmem(struct mem_cgroup *memcg)
+#else
+static int memcg_update_kmem_limit(struct mem_cgroup *memcg,
+				   unsigned long limit)
 {
+	return -EINVAL;
 }
 #endif /* CONFIG_MEMCG_KMEM */
 
+
 /*
  * The user of this function is...
  * RES_LIMIT.
@@ -4182,7 +4193,7 @@ mem_cgroup_css_alloc(struct cgroup_subsys_state *parent_css)
 	vmpressure_init(&memcg->vmpressure);
 	INIT_LIST_HEAD(&memcg->event_list);
 	spin_lock_init(&memcg->event_list_lock);
-#ifdef CONFIG_MEMCG_KMEM
+#ifndef CONFIG_SLOB
 	memcg->kmemcg_id = -1;
 #endif
 #ifdef CONFIG_CGROUP_WRITEBACK
@@ -4244,10 +4255,11 @@ mem_cgroup_css_online(struct cgroup_subsys_state *css)
 	}
 	mutex_unlock(&memcg_create_mutex);
 
-#ifdef CONFIG_MEMCG_KMEM
 	ret = memcg_propagate_kmem(memcg);
 	if (ret)
 		return ret;
+
+#ifdef CONFIG_MEMCG_KMEM
 	ret = tcp_init_cgroup(memcg);
 	if (ret)
 		return ret;
@@ -4308,8 +4320,9 @@ static void mem_cgroup_css_free(struct cgroup_subsys_state *css)
 		static_branch_dec(&memcg_sockets_enabled_key);
 #endif
 
-#ifdef CONFIG_MEMCG_KMEM
 	memcg_free_kmem(memcg);
+
+#ifdef CONFIG_MEMCG_KMEM
 	tcp_destroy_cgroup(memcg);
 #endif
 
diff --git a/mm/slab.h b/mm/slab.h
index c63b8699cfa3..834ad240c0bb 100644
--- a/mm/slab.h
+++ b/mm/slab.h
@@ -173,7 +173,7 @@ ssize_t slabinfo_write(struct file *file, const char __user *buffer,
 void __kmem_cache_free_bulk(struct kmem_cache *, size_t, void **);
 int __kmem_cache_alloc_bulk(struct kmem_cache *, gfp_t, size_t, void **);
 
-#ifdef CONFIG_MEMCG_KMEM
+#if defined(CONFIG_MEMCG) && !defined(CONFIG_SLOB)
 /*
  * Iterate over all memcg caches of the given root cache. The caller must hold
  * slab_mutex.
@@ -251,7 +251,7 @@ static __always_inline int memcg_charge_slab(struct page *page,
 
 extern void slab_init_memcg_params(struct kmem_cache *);
 
-#else /* !CONFIG_MEMCG_KMEM */
+#else /* CONFIG_MEMCG && !CONFIG_SLOB */
 
 #define for_each_memcg_cache(iter, root) \
 	for ((void)(iter), (void)(root); 0; )
@@ -292,7 +292,7 @@ static inline int memcg_charge_slab(struct page *page, gfp_t gfp, int order,
 static inline void slab_init_memcg_params(struct kmem_cache *s)
 {
 }
-#endif /* CONFIG_MEMCG_KMEM */
+#endif /* CONFIG_MEMCG && !CONFIG_SLOB */
 
 static inline struct kmem_cache *cache_from_obj(struct kmem_cache *s, void *x)
 {
diff --git a/mm/slab_common.c b/mm/slab_common.c
index 8c262e6dc33e..b50aef01ccf7 100644
--- a/mm/slab_common.c
+++ b/mm/slab_common.c
@@ -128,7 +128,7 @@ int __kmem_cache_alloc_bulk(struct kmem_cache *s, gfp_t flags, size_t nr,
 	return i;
 }
 
-#ifdef CONFIG_MEMCG_KMEM
+#if defined(CONFIG_MEMCG) && !defined(CONFIG_SLOB)
 void slab_init_memcg_params(struct kmem_cache *s)
 {
 	s->memcg_params.is_root_cache = true;
@@ -221,7 +221,7 @@ static inline int init_memcg_params(struct kmem_cache *s,
 static inline void destroy_memcg_params(struct kmem_cache *s)
 {
 }
-#endif /* CONFIG_MEMCG_KMEM */
+#endif /* CONFIG_MEMCG && !CONFIG_SLOB */
 
 /*
  * Find a mergeable slab cache
@@ -477,7 +477,7 @@ static void release_caches(struct list_head *release, bool need_rcu_barrier)
 	}
 }
 
-#ifdef CONFIG_MEMCG_KMEM
+#if defined(CONFIG_MEMCG) && !defined(CONFIG_SLOB)
 /*
  * memcg_create_kmem_cache - Create a cache for a memory cgroup.
  * @memcg: The memory cgroup the new cache is for.
@@ -689,7 +689,7 @@ static inline int shutdown_memcg_caches(struct kmem_cache *s,
 {
 	return 0;
 }
-#endif /* CONFIG_MEMCG_KMEM */
+#endif /* CONFIG_MEMCG && !CONFIG_SLOB */
 
 void slab_kmem_cache_release(struct kmem_cache *s)
 {
@@ -1123,7 +1123,7 @@ static int slab_show(struct seq_file *m, void *p)
 	return 0;
 }
 
-#ifdef CONFIG_MEMCG_KMEM
+#if defined(CONFIG_MEMCG) && !defined(CONFIG_SLOB)
 int memcg_slab_show(struct seq_file *m, void *p)
 {
 	struct kmem_cache *s = list_entry(p, struct kmem_cache, list);
diff --git a/mm/slub.c b/mm/slub.c
index b21fd24b08b1..2e1355ac056b 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -5207,7 +5207,7 @@ static ssize_t slab_attr_store(struct kobject *kobj,
 		return -EIO;
 
 	err = attribute->store(s, buf, len);
-#ifdef CONFIG_MEMCG_KMEM
+#ifdef CONFIG_MEMCG
 	if (slab_state >= FULL && err >= 0 && is_root_cache(s)) {
 		struct kmem_cache *c;
 
@@ -5242,7 +5242,7 @@ static ssize_t slab_attr_store(struct kobject *kobj,
 
 static void memcg_propagate_slab_attrs(struct kmem_cache *s)
 {
-#ifdef CONFIG_MEMCG_KMEM
+#ifdef CONFIG_MEMCG
 	int i;
 	char *buffer = NULL;
 	struct kmem_cache *root_cache;
@@ -5328,7 +5328,7 @@ static struct kset *slab_kset;
 
 static inline struct kset *cache_kset(struct kmem_cache *s)
 {
-#ifdef CONFIG_MEMCG_KMEM
+#ifdef CONFIG_MEMCG
 	if (!is_root_cache(s))
 		return s->memcg_params.root_cache->memcg_kset;
 #endif
@@ -5405,7 +5405,7 @@ static int sysfs_slab_add(struct kmem_cache *s)
 	if (err)
 		goto out_del_kobj;
 
-#ifdef CONFIG_MEMCG_KMEM
+#ifdef CONFIG_MEMCG
 	if (is_root_cache(s)) {
 		s->memcg_kset = kset_create_and_add("cgroup", NULL, &s->kobj);
 		if (!s->memcg_kset) {
@@ -5438,7 +5438,7 @@ void sysfs_slab_remove(struct kmem_cache *s)
 		 */
 		return;
 
-#ifdef CONFIG_MEMCG_KMEM
+#ifdef CONFIG_MEMCG
 	kset_unregister(s->memcg_kset);
 #endif
 	kobject_uevent(&s->kobj, KOBJ_REMOVE);