[PATCH bpf-next 2/2] bpftool: document cgroup tree command

[Roman Gushchin]

Describe cgroup tree command in the corresponding bpftool man page.

Signed-off-by: Roman Gushchin <guro@xxxxxx>
Cc: Jakub Kicinski <jakub.kicinski@xxxxxxxxxxxxx>
Cc: Quentin Monnet <quentin.monnet@xxxxxxxxxxxxx>
Cc: Daniel Borkmann <daniel@xxxxxxxxxxxxx>
Cc: Alexei Starovoitov <ast@xxxxxxxxxx>
---
 tools/bpf/bpftool/Documentation/bpftool-cgroup.rst | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/tools/bpf/bpftool/Documentation/bpftool-cgroup.rst b/tools/bpf/bpftool/Documentation/bpftool-cgroup.rst
index 7b0e6d453e92..3b3d6c534317 100644
--- a/tools/bpf/bpftool/Documentation/bpftool-cgroup.rst
+++ b/tools/bpf/bpftool/Documentation/bpftool-cgroup.rst
@@ -21,6 +21,7 @@ MAP COMMANDS
 =============
 
 |	**bpftool** **cgroup { show | list }** *CGROUP*
+|	**bpftool** **cgroup tree** [*CGROUP_ROOT*]
 |	**bpftool** **cgroup attach** *CGROUP* *ATTACH_TYPE* *PROG* [*ATTACH_FLAGS*]
 |	**bpftool** **cgroup detach** *CGROUP* *ATTACH_TYPE* *PROG*
 |	**bpftool** **cgroup help**
@@ -39,6 +40,15 @@ DESCRIPTION
 		  Output will start with program ID followed by attach type,
 		  attach flags and program name.
 
+	**bpftool cgroup tree** [*CGROUP_ROOT*]
+		  Iterate over all cgroups in *CGROUP_ROOT* and list all
+		  attached programs. If *CGROUP_ROOT* is not specified,
+		  bpftool uses cgroup v2 mountpoint.
+
+		  The output is similar to the output of cgroup show/list
+		  commands: it starts with absolute cgroup path, followed by
+		  program ID, attach type, attach flags and program name.
+
 	**bpftool cgroup attach** *CGROUP* *ATTACH_TYPE* *PROG* [*ATTACH_FLAGS*]
 		  Attach program *PROG* to the cgroup *CGROUP* with attach type
 		  *ATTACH_TYPE* and optional *ATTACH_FLAGS*.
-- 
2.14.4