[LTP] [PATCH v2] controllers: skip test when cgroup v2 is loaded

[Jin Guojie]

Hi Li Wang,

This patch fixes the judgment of controllers in the cgroup v2 system
and improves the error message.
This is the second version I've made.
Would you please review it?

Regards,
Jin

On Thu, Dec 19, 2024 at 2:36 PM Jin Guojie <guojie.jin@gmail.com> wrote:
>
> V2:
> * Correction of comments
>
> V1:
> * Initial check for cgroup v2
>
> When running "controllers" case on some newer Linux distributions, there
> will be 10 ERROR messages during the setup phase, and several TFAIL
> results at the end.
>
> Current "controllers" cases only implement tests for cgroup v1 file interface.
> It's better to skip the test after checking that v2 hierarchy has
> already been loaded.
>
> [1] https://lists.linux.it/pipermail/ltp/2024-December/041082.html
>
> Signed-off-by: Jin Guojie <guojie.jin@gmail.com>
> ---
>  testcases/kernel/controllers/test_controllers.sh | 9 +++++++++
>  1 file changed, 9 insertions(+)
>
> diff --git a/testcases/kernel/controllers/test_controllers.sh
> b/testcases/kernel/controllers/test_controllers.sh
> index 7aa974ff2..0b67387ec 100755
> --- a/testcases/kernel/controllers/test_controllers.sh
> +++ b/testcases/kernel/controllers/test_controllers.sh
> @@ -37,6 +37,15 @@
>  #
>            #
>  ##################################################################################
>
> +# Currently only cgroup v1 interface can be tested.
> +# When the v2 hierarchy is already loaded in the system, skip the test.
> +mount | grep  " type cgroup2 " &>/dev/null
> +if [ $? == 0 ]
> +then
> +       tst_brkm TCONF "" "test_controllers.sh: V1 controller
> required, but mounted on V2"
> +       exit 32
> +fi
> +
>  if [ -f /proc/cgroups ]
>  then
>         CPU_CONTROLLER=`grep -w cpu /proc/cgroups | cut -f1`;
> --
> 2.34.1