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>
diff --git a/mm/slab_common.c b/mm/slab_common.c
index 8c262e6..b50aef0 100644
--- a/mm/slab_common.c
+++ b/mm/slab_common.c
@@ -128,7 +128,7 @@
 	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 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 @@
 	}
 }
 
-#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 @@
 {
 	return 0;
 }
-#endif /* CONFIG_MEMCG_KMEM */
+#endif /* CONFIG_MEMCG && !CONFIG_SLOB */
 
 void slab_kmem_cache_release(struct kmem_cache *s)
 {
@@ -1123,7 +1123,7 @@
 	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);