cgset --copy-from failed with error

Issue

• cgset --copy-from failed with the following message.

  1. Create new cgroup named test_cgroup1, test_cgroup2
      [root@host]#  cgcreate -g memory:/test_cgroup1
      [root@host]#  cgcreate -g memory:/test_cgroup2

  2. Set some parameters for test_cgroup1
      [root@host]#  cgset -r memory.limit_in_bytes=2G test_cgroup1
      [root@host]#  cgset -r memory.memsw.limit_in_bytes=2G test_cgroup1
      [root@host]#  cgset -r memory.swappiness=0 test_cgroup1

  3. Set parameters for test_cgroup2 using test_cgroup1
      [root@host]#  cgset --copy-from test_cgroup1/ test_cgroup2/
      cgset: the group can't be modified