Re: [PATCH 07/17] selftests/cgroup: Test type-change validation with child-owned CPUs

[Waiman Long <longman@redhat.com>]

On 8/20/26 8:41 AM, Guopeng Zhang wrote:
> From: Guopeng Zhang <zhangguopeng@kylinos.cn>
>
> Create an isolated child which owns a CPU isolated at boot, then change
> its parent from isolated to root. Check that the change succeeds without
> altering the child or its isolated CPU.
>
> Signed-off-by: Guopeng Zhang <zhangguopeng@kylinos.cn>
> ---
>   .../selftests/cgroup/test_cpuset_prs.sh       | 47 +++++++++++++++++++
>   1 file changed, 47 insertions(+)
>
> diff --git a/tools/testing/selftests/cgroup/test_cpuset_prs.sh b/tools/testing/selftests/cgroup/test_cpuset_prs.sh
> index 9a1cce4807b4..bc8dbb724d5c 100755
> --- a/tools/testing/selftests/cgroup/test_cpuset_prs.sh
> +++ b/tools/testing/selftests/cgroup/test_cpuset_prs.sh
> @@ -1214,6 +1214,52 @@ test_boot_isolated()
>   	echo "$TEST_NAME test PASSED."
>   }
>   
> +#
> +# A parent's type change must validate only CPUs owned directly by the parent,
> +# not a boot-isolated CPU owned by a valid isolated child partition.
> +#
> +test_owned_cpus_housekeeping()
> +{
> +	TEST_NAME="Child-owned CPU type change"
> +	get_boot_isolated_cpu "$TEST_NAME" || return 0
> +	echo "Running $TEST_NAME test ..."
> +
> +	cd $CGROUP2/test
> +	echo member > cpuset.cpus.partition
> +	echo +cpuset > cgroup.subtree_control
> +	echo 2,$BOOT_CPU > cpuset.cpus
> +	[[ $(cat cpuset.cpus.effective) = "2,$BOOT_CPU" ]] || {

You are using the same BOOT_CPU set up in get_boot_isolated_cpu() in 
patch 3. That creates an hidden dependency on the order of the tests. I 
will suggest that you set up BOOT_CPU and  BOOT_CPUS as part of the 
initialization so the data is available to all the tests that want to 
use it.

Cheers,
Longman