diff --git a/Documentation/cgroup-v1/memory.txt b/Documentation/cgroup-v1/memory.txt
index 7017b44f0bde218db6cedb2b120409c48dd87e9d..d31b7cd5a81c83dcf6a27edabb0d2221f5713eec 100644
--- a/Documentation/cgroup-v1/memory.txt
+++ b/Documentation/cgroup-v1/memory.txt
@@ -79,6 +79,9 @@ Brief summary of control files.
  memory.numa_stat		 # show the number of memory usage per numa node
 
  memory.kmem.limit_in_bytes      # set/show hard limit for kernel memory
+                                   This knob is deprecated and shouldn't be
+                                   used. It is planned that this be removed in
+                                   the foreseeable future.
  memory.kmem.usage_in_bytes      # show current kernel memory allocation
  memory.kmem.failcnt             # show the number of kernel memory usage hits limits
  memory.kmem.max_usage_in_bytes  # show max kernel memory usage recorded
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 99767b540b16fa03547007bf1a3242aa304e3218..4e9c5f2387030d29d9f696d2061c414e52ccce4d 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -3279,6 +3279,9 @@ static ssize_t mem_cgroup_write(struct kernfs_open_file *of,
 			ret = mem_cgroup_resize_max(memcg, nr_pages, true);
 			break;
 		case _KMEM:
+			pr_warn_once("kmem.limit_in_bytes is deprecated and will be removed. "
+				     "Please report your usecase to linux-mm@kvack.org if you "
+				     "depend on this functionality.\n");
 			ret = memcg_update_kmem_max(memcg, nr_pages);
 			break;
 		case _TCP: