NACK: [PATCH 1/1] UBUNTU: SAUCE: Enable upstream config option "CONFIG_CPUSETS_V1"

[Massimiliano Pellizzer]

On Fri, 19 Dec 2025 at 09:59, Mehmet Basaran
<mehmet.basaran at canonical.com> wrote:
>
> BugLink: https://bugs.launchpad.net/bugs/2128722
>
> For noble, some of the applied upstream commits are using "CONFIG_CPUSETS_V1"
> to enable/disable some code paths. This changes the behaviour of cpusets and
> currently noble is neither V1 nor V2. Because of this, "cpuset_inherit" and
> "cpuset_hotplug" test cases are failing in ubuntu_ltp_controllers test suite.
>
> cpuset_inherit 37 TFAIL: memory_migrate: Test result - 1 Expected string - "0"
> cpuset_inherit 39 TFAIL: memory_migrate: Test result - 1 Expected string - "0"
> cpuset_inherit 49 TFAIL: sched_load_balance: Test result - 0 Expected string - "1"
>
> cpuset_hotplug 1 TINFO: CPUs are numbered continuously starting at 0 (0-1)
> cpuset_hotplug 1 TINFO: Nodes are numbered continuously starting at 0 (0)
> cpuset_hotplug 1 TFAIL: root group's cpus isn't expected(Result: 0-1, Expect: 0).
> cpuset_hotplug 5 TFAIL: general group's cpus isn't expected(Result: 0-1, Expect: 0).
> cpuset_hotplug 7 TFAIL: test task was still in general group, but its cpus is NULL
> cpuset_hotplug 11 TFAIL: task's cpu present list isn't expected(Result: 0-1, Expect: 0).
>
> For noble, we have to use v1 because there is no support for v2. Added
> "CONFIG_CPUSETS_V1" kernel config option. This was added to upstream via
> the following commit:
>
>     [ Upstream commit 1abab1ba0775036bb67c6c57945c637be644c04f ]
>     cgroup/cpuset: guard cpuset-v1 code under CONFIG_CPUSETS_V1
>
> I have chosen to go with a SAUCE patch since, the commit above depends on
> other commits. And in the future, we can revert this one and apply the
> dependent commits if we want to follow cpusets follow from 6.12 versions so
> that there are less conflicts between upstream stable and noble sources.
>
> The other solution is to remove the use of "CONFIG_CPUSETS_V1" macro from
> sources. However this will also cause noble and upstream stable sources to
> diverge and make it difficult to backport patches.
>
> Signed-off-by: Mehmet Basaran <mehmet.basaran at canonical.com>
> ---
>  debian.master/config/annotations |  1 +
>  init/Kconfig                     | 13 +++++++++++++
>  2 files changed, 14 insertions(+)
>
> diff --git a/debian.master/config/annotations b/debian.master/config/annotations
> index 9ebb2a92ba55..3f3150b3aa99 100644
> --- a/debian.master/config/annotations
> +++ b/debian.master/config/annotations
> @@ -3293,6 +3293,7 @@ CONFIG_CPU5_WDT                                 policy<{'amd64': 'm'}>
>  CONFIG_CPUFREQ_DT_PLATDEV                       policy<{'arm64': 'y', 'armhf': 'y', 'ppc64el': 'y', 'riscv64': 'y'}>
>  CONFIG_CPUMASK_OFFSTACK                         policy<{'amd64': 'y'}>
>  CONFIG_CPUSETS                                  policy<{'amd64': 'y', 'arm64': 'y', 'armhf': 'y', 'ppc64el': 'y', 'riscv64': 'y', 's390x': 'y'}>
> +CONFIG_CPUSETS_V1                               policy<{'amd64': 'y', 'arm64': 'y', 'armhf': 'y', 'ppc64el': 'y', 'riscv64': 'y', 's390x': 'y'}>
>  CONFIG_CPU_32v6K                                policy<{'armhf': 'y'}>
>  CONFIG_CPU_32v7                                 policy<{'armhf': 'y'}>
>  CONFIG_CPU_ABRT_EV7                             policy<{'armhf': 'y'}>
> diff --git a/init/Kconfig b/init/Kconfig
> index 426c2464f653..3b728ed594cc 100644
> --- a/init/Kconfig
> +++ b/init/Kconfig
> @@ -1143,6 +1143,19 @@ config CPUSETS
>
>           Say N if unsure.
>
> +config CPUSETS_V1
> +       bool "Legacy cgroup v1 cpusets controller"
> +       depends on CPUSETS
> +       default n
> +       help
> +         Legacy cgroup v1 cpusets controller which has been deprecated by
> +         cgroup v2 implementation. The v1 is there for legacy applications
> +         which haven't migrated to the new cgroup v2 interface yet. If you
> +         do not have any such application then you are completely fine leaving
> +         this option disabled.
> +
> +         Say N if unsure.
> +
>  config PROC_PID_CPUSET
>         bool "Include legacy /proc/<pid>/cpuset file"
>         depends on CPUSETS
> --
> 2.43.0
>
>
> --
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SRU and series tags missing in the subject.

-- 
Massimiliano Pellizzer