v7: - Simplify the documentation patch (patch 5) as suggested by Tejun. - Fix a typo in patch 2 and improper commit log in patch 3.
v6: - Remove duplicated tmpmask from update_prstate() which should fix the frame size too large problem reported by kernel test robot.
v5: - Rebased to the latest for-5.15 branch of cgroup git tree and drop the 1st v4 patch as it has been merged. - Update patch 1 to always allow changing partition root back to member even if it invalidates child partitions undeneath it. - Adjust the empty effective cpu partition patch to not allow 0 effective cpu for terminal partition which will make it invalid). - Add a new patch to enable reading of cpuset.cpus.partition to display the reason that causes invalid partition. - Adjust the documentation and testing patch accordingly.
This patchset makes four enhancements to the cpuset v2 code.
Patch 1: Properly handle partition root tree and make partition invalid in case changes to cpuset.cpus violate any of the partition root constraints.
Patch 2: Enable the "cpuset.cpus.partition" file to show the reason that causes invalid partition like "root invalid (No cpu available due to hotplug)".
Patch 3: Add a new partition state "isolated" to create a partition root without load balancing. This is for handling intermitten workloads that have a strict low latency requirement.
Patch 4: Allow partition roots that are not the top cpuset to distribute all its cpus to child partitions as long as there is no task associated with that partition root. This allows more flexibility for middleware to manage multiple partitions.
Patch 5 updates the cgroup-v2.rst file accordingly. Patch 6 adds a new cpuset test to test the new cpuset partition code.
Waiman Long (6): cgroup/cpuset: Properly transition to invalid partition cgroup/cpuset: Show invalid partition reason string cgroup/cpuset: Add a new isolated cpus.partition type cgroup/cpuset: Allow non-top parent partition to distribute out all CPUs 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 | 112 +-- kernel/cgroup/cpuset.c | 337 ++++++--- tools/testing/selftests/cgroup/Makefile | 5 +- .../selftests/cgroup/test_cpuset_prs.sh | 663 ++++++++++++++++++ tools/testing/selftests/cgroup/wait_inotify.c | 86 +++ 5 files changed, 1050 insertions(+), 153 deletions(-) create mode 100755 tools/testing/selftests/cgroup/test_cpuset_prs.sh create mode 100644 tools/testing/selftests/cgroup/wait_inotify.c