[PATCH v10 0/8] cgroup/cpuset: Major cpu partition code restructuring

Waiman Long
2022-05-03T16:21:41Z

v10:
- Relax constraints for changes made to "cpuset.cpus"
and "cpuset.cpus.partition" as suggested. Now almost all changes
are allowed.

v9:
- Add a new patch 1 to remove the child cpuset restriction on parent's
"cpuset.cpus".
- Relax initial root partition entry limitation to allow cpuset.cpus to
overlap that of parent's.
- An "isolated invalid" displayed type is added to
cpuset.cpus.partition.
- Resetting partition root to "member" will leave child partition root
as invalid.
- Update documentation and test accordingly.

v8:
- Reorganize the patch series and rationalize the features and
constraints of a partition.
- Update patch descriptions and documentation accordingly.

This patchset include the following enhancements to the cpuset v2
partition code.
1) Allow partitions that have no task to have empty effective cpus.
2) Relax the constraints on what changes are allowed in cpuset.cpus
and cpuset.cpus.partition. However, the partition remain invalid
until the constraints of a valid partition root is satisfied.
3) Add a new "isolated" partition type for partitions with no load
balancing which is available in v1 but not yet in v2.
4) Allow the reading of cpuset.cpus.partition to include a reason
string as to why the partition remain invalid.

In addition, the cgroup-v2.rst documentation file is updated and
a self test is added to verify the correctness the partition code.

Waiman Long (8):
cgroup/cpuset: Add top_cpuset check in update_tasks_cpumask()
cgroup/cpuset: Miscellaneous cleanups & add helper functions
cgroup/cpuset: Allow no-task partition to have empty
cpuset.cpus.effective
cgroup/cpuset: Relax constraints to partition & cpus changes
cgroup/cpuset: Add a new isolated cpus.partition type
cgroup/cpuset: Show invalid partition reason string
cgroup/cpuset: Update description of cpuset.cpus.partition in
cgroup-v2.rst
kselftest/cgroup: Add cpuset v2 partition root state test

Documentation/admin-guide/cgroup-v2.rst | 145 ++--
kernel/cgroup/cpuset.c | 712 +++++++++++-------
tools/testing/selftests/cgroup/Makefile | 5 +-
.../selftests/cgroup/test_cpuset_prs.sh | 674 +++++++++++++++++
tools/testing/selftests/cgroup/wait_inotify.c | 87 +++
5 files changed, 1295 insertions(+), 328 deletions(-)
create mode 100755 tools/testing/selftests/cgroup/test_cpuset_prs.sh
create mode 100644 tools/testing/selftests/cgroup/wait_inotify.c

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2.27.0