On Tue, Sep 11, 2012 at 10:51:06AM -0400, Vivek Goyal wrote: > On Mon, Sep 10, 2012 at 03:31:25PM -0700, Tejun Heo wrote: > > Currently, cgroup hierarchy support is a mess. cpu related subsystems > > behave correctly - configuration, accounting and control on a parent > > properly cover its children. blkio and freezer completely ignore > > hierarchy and treat all cgroups as if they're directly under the root > > cgroup. Others show yet different behaviors. > > > > These differing interpretations of cgroup hierarchy make using cgroup > > confusing and it impossible to co-mount controllers into the same > > hierarchy and obtain sane behavior. > > > > Eventually, we want full hierarchy support from all subsystems and > > probably a unified hierarchy. Users using separate hierarchies > > expecting completely different behaviors depending on the mounted > > subsystem is deterimental to making any progress on this front. > > > > This patch adds cgroup_subsys.broken_hierarchy and sets it to %true > > for controllers which are lacking in hierarchy support. The goal of > > this patch is two-fold. > > > > * Move users away from using hierarchy on currently non-hierarchical > > subsystems, so that implementing proper hierarchy support on those > > doesn't surprise them. > > I know two current/potential users. systemd and libvirt. They are > anyway going to create hierarchy irrespective of the fact whether > controller supports it or not.
Just to be little precise here. AFAIK, systemd only mounts blkio controller on a separate hiearchy but does not create child cgroups under it. So all the services should still run in root cgroup. For libvirt, I think by default they had enabled using blkio controller and they were creating hiearchies under that for each virtual machine/container. Thanks Vivek -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
