Hello. (I know this is heading for 6.7. Still I wanted to have a look at this after it stabilized somehow to understand the new concept better but I still have some questions below.) On Tue, Sep 05, 2023 at 09:32:36AM -0400, Waiman Long <longman@xxxxxxxxxx> wrote: > Both scheduling and isolated partitions can be formed as 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. > > > 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. I take the example with a nested cgroup `cont` to which I want to dedicate two CPUs (0 and 1). IIUC, I can do this both with a chain of local root partitions or as a single remote partion. [chain] root | \ mid1a mid1b cpuset.cpus=0-1 cpuset.cpus=2-15 cpuset.cpus.partition=root | mid2 cpuset.cpus=0-1 cpuset.cpus.partition=root | cont cpuset.cpus=0-1 cpuset.cpus.partition=root [remote] root | \ mid1a mid1b cpuset.cpus.exclusive=0-1 cpuset.cpus=2-15 | mid2 cpuset.cpus.exclusive=0-1 | cont cpuset.cpus.exclusive=0-1 cpuset.cpus.partition=root In the former case I must configure cpuset.cpus and cpuset.cpus.partition along the whole path and in the second case cpuset.cpus.exclusive still along the whole path and root at the bottom only. What is the difference between the two configs above? (Or can you please give an example where the remote partitions are better illustrated?) <snip> > 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. Such tools ready aren't ready to manage cpuset.cpus.exclusive, are they? IOW tools need to distinguish exclusive and "shared" CPUs which is equal to distinguishing root and member partitions. Thanks, Michal
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