Explain how to determine hierarchy type from shell

This makes it easier for people than just recommending the syscall.

diff --git a/docs/CGROUP_DELEGATION.md b/docs/CGROUP_DELEGATION.md
index d05503bc97786e0f196b47b8d746f5ae44834977..4011f093228149afa9f184861f5b1c731dce759b 100644 (file)
--- a/docs/CGROUP_DELEGATION.md
+++ b/docs/CGROUP_DELEGATION.md
@@ -131,6 +131,8 @@ If you wonder how to detect which of these three modes is currently used, use
 you are either in legacy or hybrid mode. To distinguish these two cases, run
 `statfs()` again on `/sys/fs/cgroup/unified/`. If that succeeds and reports
 `CGROUP2_SUPER_MAGIC` you are in hybrid mode, otherwise not.
+From a shell, you can use check the `Type` in `stat -f /sys/fs/cgroup` and
+`stat -f /sys/fs/cgroup/unified`.
 
 ## systemd's Unit Types