On 07/19/2018 11:30 AM, Tejun Heo wrote: > Hello, > > On Thu, Jul 19, 2018 at 10:04:54AM -0400, Waiman Long wrote: >>> 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. > So, the main thing is that putting a cpu into a partition locks away > the cpu from its ancestors. That's a system level operation which > isn't delegatable. If we want to allow partitioning in subtrees, the > parent still be able to take away partitioned cpus too even if that > means ignoring descendants' configurations, which btw is exactly what > cpuset does for non-partition configs. > > I don't think this would be technically too challenging to implement, > but unless there are immediate use cases for it, we can start simpler > & restricted. > > Thanks. > BTW, the way the partition is currently implemented right now is that a child cannot be a partition root unless its parent is a partition root itself. That is to avoid turning on partition to affect ancestors further up the hierarchy than just the parent. So in the case of a container, it cannot allocate sub-partitions underneath it unless it is a partition itself. Will that solve your concern? Thanks, Longman -- To unsubscribe from this list: send the line "unsubscribe cgroups" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
