diff --git a/man7/cgroups.7 b/man7/cgroups.7
index 57e08b96c..6bd44942b 100644
--- a/man7/cgroups.7
+++ b/man7/cgroups.7
@@ -554,6 +554,24 @@ A cgroup v2 controller is available only if it is not currently in use
 via a mount against a cgroup v1 hierarchy.
 Or, to put things another way, it is not possible to employ
 the same controller against both a v1 hierarchy and the unified v2 hierarchy.
+This means that it may be necessary first to unmount a v1 controller
+(as described above) before that controller is available in v2.
+Since
+.BR systemd (1)
+makes heavy use of some v1 controllers by default,
+it can in some cases be simpler to boot the system with
+selected v1 controllers disabled.
+To do this, specify the
+.IR cgroup_no_v1=list
+option on the kernel boot command line;
+.I list
+is a comma-separated list of the names of the controllers to disable,
+or the word
+.I all
+to disable all v1 controllers.
+(This situation is correctly handled by
+.BR systemd (1),
+which falls back to operating without the specified controllers.)
 .PP
 Note that on many modern systems,
 .BR systemd (1)