code: func (kl *Kubelet) fastStatusUpdateOnce() {
  	for {
  		time.Sleep(100 * time.Millisecond)
  		node, err := kl.GetNode()
  		if err != nil {
  			klog.Errorf(err.Error())
  			continue
  		}
  		if node.Spec.PodCIDR != "" {
  			if _, err := kl.updatePodCIDR(node.Spec.PodCIDR); err != nil {
  				klog.Errorf("Pod CIDR update failed %v", err)
  				continue
  			}
  			kl.updateRuntimeUp()
  			kl.syncNodeStatus()
  			return
  		}
  	}
  }
docs: // fastStatusUpdateOnce starts a loop that checks the internal node indexer cache for when a CIDR
  // is applied  and tries to update pod CIDR immediately. After pod CIDR is updated it fires off
  // a runtime update and a node status update. Function returns after one successful node status update.
  // Function is executed only during Kubelet start which improves latency to ready node by updating
  // pod CIDR, runtime status and node statuses ASAP.