Hello, Vivek. On Fri, Sep 14, 2012 at 03:28:40PM -0400, Vivek Goyal wrote: > Hmm.., In that case how libvirt will make use of blkio in the proposed > scheme. We can't disable blkio nesting at "system" level. So We will > have to disable it at each service level except "libvirtd" so that > libvirt can use blkio for its virtual machines. > > That means blkio will see each service in a cgroup of its own and if > that does not make sense by default, its a problem. In the existing Yeap, if libvirtd wants use blkcg, blkcg will be enabled upto libvirtd's root. It might not be optimal but I think it makes sense. If you want to excercise hierarchical control on a resource, the only sane way is sticking to the hierarchy until it reaches root. > scheme, atleast every service does not show up in its cgroup from > blkio point of view. Everthig is in root and libvirt can create its > own cgroups, keeping number of cgroups small. Even a broken clock is right twice a day. I don't think this is a behavior we can keep for the sake of "but if we do this ass-weird thing, we can bypass the overhead for XYZ" when it breaks so many fundamental things. I think there currently is too much (broken) flexibility and intent to remove it. That doesn't mean that removeing all flexibility is the right direction. It inherently is a balancing act and I think the proposed solution is a reasonable tradeoff. There's important difference between causing full overhead by default for all users and requiring some overhead when the use case at hand calls for the functionality. Thanks. -- tejun -- 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
