Messages in this thread | | | Date | Tue, 25 Jul 2023 16:49:51 -0400 | Subject | Re: [PATCH-cgroup v5 0/5] cgroup/cpuset: Support remote partitions | From | Waiman Long <> |
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On 7/13/23 13:25, Waiman Long wrote: > v5: > - [v4] https://lore.kernel.org/lkml/20230627143508.1576882-1-longman@redhat.com/ > - Drop the first 4 patches as they had been merged. > - Make cpuset.cpus.exclusive invariant once it is manually set. This > also means the cpuset.cpus.exclusive may not show the effective value > that is actually being used. > - Update the documentation and test accordingly. > > v4: > - [v3] https://lore.kernel.org/lkml/20230627005529.1564984-1-longman@redhat.com/ > - Fix compilation problem reported by kernel test robot. > > This patch series introduces a new cpuset control file > "cpuset.cpus.exclusive" which must be a subset of "cpuset.cpus" > and the parent's "cpuset.cpus.exclusive". This control file lists > the exclusive CPUs to be distributed down the hierarchy. Any one > of the exclusive CPUs can only be distributed to at most one child > cpuset. Unlike "cpuset.cpus", invalid input to "cpuset.cpus.exclusive" > will be rejected with an error. This new control file has no effect on > the behavior of the cpuset until it turns into a partition root. At that > point, its effective CPUs will be set to its exclusive CPUs unless some > of them are offline. > > This patch series also introduces a new category of cpuset partition > called remote partitions. The existing partition category where the > partition roots have to be clustered around the root cgroup in a > hierarchical way is now referred to as local partitions. > > A remote partition can be formed far from the root cgroup > with no partition root parent. While local partitions can be > created without touching "cpuset.cpus.exclusive" as it can be set > automatically if a cpuset becomes a local partition root. Properly set > "cpuset.cpus.exclusive" values down the hierarchy are required to create > a remote partition. > > Both scheduling and isolated partitions can be formed in a remote > partition. A local partition can be created under a remote partition. > A remote partition, however, cannot be formed under a local partition > for now. > > Modern container orchestration tools like Kubernetes use the cgroup > hierarchy to manage different containers. And it is relying on other > middleware like systemd to help managing it. If a container needs to > use isolated CPUs, it is hard to get those with the local partitions > as it will require the administrative parent cgroup to be a partition > root too which tool like systemd may not be ready to manage. > > With this patch series, we allow the creation of remote partition > far from the root. The container management tool can manage the > "cpuset.cpus.exclusive" file without impacting the other cpuset > files that are managed by other middlewares. Of course, invalid > "cpuset.cpus.exclusive" values will be rejected. > > Waiman Long (5): > cgroup/cpuset: Add cpuset.cpus.exclusive for v2 > cgroup/cpuset: Introduce remote partition > cgroup/cpuset: Check partition conflict with housekeeping setup > cgroup/cpuset: Documentation update for partition > cgroup/cpuset: Extend test_cpuset_prs.sh to test remote partition > > Documentation/admin-guide/cgroup-v2.rst | 114 +- > kernel/cgroup/cpuset.c | 1242 ++++++++++++----- > .../selftests/cgroup/test_cpuset_prs.sh | 419 ++++-- > 3 files changed, 1291 insertions(+), 484 deletions(-) > Tejun,
Do you have any further suggested change that you would like to see?
Cheers, Longman
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