UPSTREAM: <carry>: Export cpu stats of ovs.slice via prometheus

When a PerformanceProfile configures a node for cpu partitioning,
it also lets OVS use all the cpus available to burstable pods.
To be able to do that, OVS was moved to its own slice and that
slice needs to be re-added to cAdvisor for monitoring purposes.

Author: MarSik

Diff for: cmd/kubelet/app/server.go

@@ -766,6 +766,12 @@ func run(ctx context.Context, s *options.KubeletServer, kubeDeps *kubelet.Depend
 		cgroupRoots = append(cgroupRoots, s.SystemCgroups)
 	}
 
+	// CARRY: Monitor extra cgroups that are specific to OpenShift deployments
+	//        Adding them here since there is no way to handle this via configuration atm
+	// - ovs.slice is configured on clusters that use the NTO's PerformanceProfile and only exists together
+	//   with system-cpu-reserved
+	cgroupRoots = append(cgroupRoots, "/ovs.slice")
+
 	if kubeDeps.CAdvisorInterface == nil {
 		imageFsInfoProvider := cadvisor.NewImageFsInfoProvider(s.ContainerRuntimeEndpoint)
 		kubeDeps.CAdvisorInterface, err = cadvisor.New(imageFsInfoProvider, s.RootDirectory, cgroupRoots, cadvisor.UsingLegacyCadvisorStats(s.ContainerRuntimeEndpoint), s.LocalStorageCapacityIsolation)