bpftool: document cgroup tree command

Describe cgroup tree command in the corresponding bpftool man page.

Signed-off-by: Roman Gushchin <guro@fb.com>
Acked-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Cc: Quentin Monnet <quentin.monnet@netronome.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

diff --git a/tools/bpf/bpftool/Documentation/bpftool-cgroup.rst b/tools/bpf/bpftool/Documentation/bpftool-cgroup.rst
index 7b0e6d453e922f4db9f4536c217a76acd6b10d4b..edbe81534c6d2941b955cd0ab15cf845110fb130 100644 (file)
--- a/tools/bpf/bpftool/Documentation/bpftool-cgroup.rst
+++ b/tools/bpf/bpftool/Documentation/bpftool-cgroup.rst
@@ -15,12 +15,13 @@ SYNOPSIS
        *OPTIONS* := { { **-j** | **--json** } [{ **-p** | **--pretty** }] | { **-f** | **--bpffs** } }
 
        *COMMANDS* :=
-       { **show** | **list** | **attach** | **detach** | **help** }
+       { **show** | **list** | **tree** | **attach** | **detach** | **help** }
 
 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*.