On 07/19/2018 09:52 AM, Peter Zijlstra wrote: > On Tue, Jul 03, 2018 at 08:58:23AM -0700, Tejun Heo wrote: >> Hello, Waiman. >> >> On Tue, Jul 03, 2018 at 08:41:31AM +0800, Waiman Long wrote: >>>> So, effective changing when enabling partition on a child feels wrong >>>> to me. It's supposed to contain what's actually allowed to the cgroup >>>> from its parent and that shouldn't change regardless of how those >>>> resources are used. It's still given to the cgroup from its parent. >>> Another way to work around this issue is to expose the reserved_cpus in >>> the parent for holding CPUs that can taken by a chid partition. That >>> will require adding one more cpuset file for those cgroups that are >>> partition roots. >> Yeah, that should work. >> >>> I don't mind restricting that to the first level children for now. That >>> does restrict where we can put the container root if we want a separate >>> partition for a container. Let's hear if others have any objection about >>> that. >> As currently implemented, partioning locks away the cpus which should >> be a system level decision, not container level, so it makes sense to >> me that it is only available to system root. > I'm terribly confused, what?! > > Why would a container not be allowed to create partitions for its > various RT workloads? As far as I understand, Tejun has some concern about the way that partitioning works is inconsistent with how other resources are being managed by cgroup v2 controllers. I adds an incremental patch to temporarily disable the creation of partition below the first level children to buy us time so that we can reach a compromise later on what to do. We can always add features, but taking away features after they are made available will be hard. I am fine either way. It is up to you and Tejun to figure out what should be made available to the users. Cheers, Longman -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
