diff --git a/Documentation/cgroup-v2.txt b/Documentation/cgroup-v2.txt
index 65b3eac8856cf7..e8d25e78421454 100644
--- a/Documentation/cgroup-v2.txt
+++ b/Documentation/cgroup-v2.txt
@@ -843,6 +843,10 @@ PAGE_SIZE multiple when read back.
 		Amount of memory used to cache filesystem data,
 		including tmpfs and shared memory.
 
+	  sock
+
+		Amount of memory used in network transmission buffers
+
 	  file_mapped
 
 		Amount of cached filesystem data mapped with mmap()