Re: [PATCH v2 2/2] cgroup/cpuset: Add test cases for sibling CPU exclusion on partition update

[Waiman Long <longman@redhat.com>]

On 5/27/26 3:05 AM, Sun Shaojie wrote:
> When sibling CPU exclusion occurs, a partition's effective_xcpus may be
> a subset of its user_xcpus. The partcmd_update path must use
> effective_xcpus instead of user_xcpus when calculating CPUs to return
> to or request from the parent.
>
> Add two test cases to verify this behavior:
>
>    1) Narrowing cpuset.cpus to only the sibling-excluded CPUs should not
>       return CPUs to parent that the partition never actually owned.
>
>    2) Expanding cpuset.cpus after a sibling becomes a member should
>       correctly request the additional CPUs from parent.
>
> Co-developed-by: Zhang Guopeng <zhangguopeng@kylinos.cn>
> Signed-off-by: Zhang Guopeng <zhangguopeng@kylinos.cn>
> Signed-off-by: Sun Shaojie <sunshaojie@kylinos.cn>
> ---
>   tools/testing/selftests/cgroup/test_cpuset_prs.sh | 10 ++++++++++
>   1 file changed, 10 insertions(+)
>
> diff --git a/tools/testing/selftests/cgroup/test_cpuset_prs.sh b/tools/testing/selftests/cgroup/test_cpuset_prs.sh
> index a56f4153c64d..683b05062810 100755
> --- a/tools/testing/selftests/cgroup/test_cpuset_prs.sh
> +++ b/tools/testing/selftests/cgroup/test_cpuset_prs.sh
> @@ -492,6 +492,16 @@ REMOTE_TEST_MATRIX=(
>   	"  C1-5:P1   .  C1-4:P1   C2-3     .       .  \
>   	      .      .     .       P1      .       .     p1:5|c11:1-4|c12:5 \
>   							 p1:P1|c11:P1|c12:P-1"
> +	# Narrowing cpuset.cpus to previously sibling-excluded CPUs should
> +	# not return CPUs that were never actually owned.
> +	"  C1-4:P1   .   C1-2:P1  C1-3:P2  .       .  \
> +	      .      .     .         C3    .       .     p1:4|c11:1-2|c12:3 \
> +							 p1:P1|c11:P1|c12:P2 3"
> +	# Expanding cpuset.cpus to include a previously sibling-excluded CPU
> +	# after the sibling has become a member should correctly request it.
> +	"  C1-4:P1   .   C1-2:P1  C1-3:P2  .       .  \
> +	      .      .      P0     C2-3    .       .     p1:1,4|c11:1|c12:2-3 \
> +							 p1:P1|c11:P0|c12:P2 2-3"
>   )
>   
>   #
Reviewed-by: Waiman Long <longman@redhat.com>