Re: [PATCH v4 -next 00/12] cgroup:cpuset:separate legacy cgroup v1 code and put under config option

[Waiman Long <longman@redhat.com>]

On 8/30/24 06:02, Chen Ridong wrote:
> Cgroups v2 have been around for a while and many users have fully adopted
> them, so they never use cgroups v1 features and functionality. Yet they
> have to "pay" for the cgroup v1 support anyway:
> 1) the kernel binary contains an unused cgroup v1 code,
> 2) some code paths have additional checks which are not needed,
> 3) some common structures like task_struct and mem_cgroup contain unused
>     cgroup v1-specific members.
>
> Cgroup memory controller has already separated legacy code to
> memory-v1.c. So it is time to do the same thing for cpuset controller.
>
> This patchset aims to do:
> 1) moving cgroup v1-specific cpuset code to the new cpuset-v1.c file,
> 2) putting definitions shared by cpuset.c and cpuset-v1.c into the
>     cpuset-internal.h header,
> 3) introducing the CONFIG_CPUSETS_V1 config option, turned off by default,
> 4) making cpuset-v1.c to compile only if CONFIG_CPUSETS_V1 is set.
>
> ---
> V4:
> - Rename legacy_files to cpuset1_files.
> - Revert rebuild_sched_domain and fmeter_init rename.
>
> V3:
> - Delete blank line at the end of file.
> - Rename some generic functions name with cpuset_/cpuset1_ prefix.
>
> V2:
> - Update to base on the latest cgroup/for-6.12.
> - Add CONFIG_CPUSETS_V1 for cpuset_memory_pressure_bump.
>
> Chen Ridong (12):
>    cgroup/cpuset: introduce cpuset-v1.c
>    cgroup/cpuset: move common code to cpuset-internal.h
>    cgroup/cpuset: move memory_pressure to cpuset-v1.c
>    cgroup/cpuset: move relax_domain_level to cpuset-v1.c
>    cgroup/cpuset: move memory_spread to cpuset-v1.c
>    cgroup/cpuset: add callback_lock helper
>    cgroup/cpuset: move legacy hotplug update to cpuset-v1.c
>    cgroup/cpuset: move validate_change_legacy to cpuset-v1.c
>    cgroup/cpuset: move v1 interfaces to cpuset-v1.c
>    cgroup/cpuset: rename functions shared between v1 and v2
>    cgroup/cpuset: guard cpuset-v1 code under CONFIG_CPUSETS_V1
>    cgroup/cpuset: add sefltest for cpuset v1
>
>   MAINTAINERS                                   |   3 +
>   include/linux/cpuset.h                        |   4 +
>   init/Kconfig                                  |  13 +
>   kernel/cgroup/Makefile                        |   1 +
>   kernel/cgroup/cpuset-internal.h               | 304 ++++++
>   kernel/cgroup/cpuset-v1.c                     | 562 +++++++++++
>   kernel/cgroup/cpuset.c                        | 892 +-----------------
>   .../selftests/cgroup/test_cpuset_v1_base.sh   |  77 ++
>   8 files changed, 1005 insertions(+), 851 deletions(-)
>   create mode 100644 kernel/cgroup/cpuset-internal.h
>   create mode 100644 kernel/cgroup/cpuset-v1.c
>   create mode 100755 tools/testing/selftests/cgroup/test_cpuset_v1_base.sh
>
For the series,

Acked-by: Waiman Long <longman@redhat.com>