1 files changed, 17 insertions, 0 deletions

diff --git a/mm/slab.h b/mm/slab.h
index 53a623f85931..0a56d76ac0e9 100644
--- a/mm/slab.h
+++ b/mm/slab.h
@@ -163,6 +163,18 @@ ssize_t slabinfo_write(struct file *file, const char __user *buffer,
                        size_t count, loff_t *ppos);
 
 #ifdef CONFIG_MEMCG_KMEM
+/*
+ * Iterate over all memcg caches of the given root cache. The caller must hold
+ * slab_mutex.
+ */
+#define for_each_memcg_cache(iter, root) \
+        list_for_each_entry(iter, &(root)->memcg_params.list, \
+                            memcg_params.list)
+
+#define for_each_memcg_cache_safe(iter, tmp, root) \
+        list_for_each_entry_safe(iter, tmp, &(root)->memcg_params.list, \
+                                 memcg_params.list)
+
 static inline bool is_root_cache(struct kmem_cache *s)
 {
         return s->memcg_params.is_root_cache;
@@ -241,6 +253,11 @@ extern void slab_init_memcg_params(struct kmem_cache *);
 
 #else /* !CONFIG_MEMCG_KMEM */
 
+#define for_each_memcg_cache(iter, root) \
+        for ((void)(iter), (void)(root); 0; )
+#define for_each_memcg_cache_safe(iter, tmp, root) \
+        for ((void)(iter), (void)(tmp), (void)(root); 0; )
+
 static inline bool is_root_cache(struct kmem_cache *s)
 {
         return true;