perf: Cache taints for existing nodes (#1827)

pkg/controllers/provisioning/scheduling/existingnode.go

@@ -31,14 +31,15 @@ import (
 type ExistingNode struct {
 	*state.StateNode
 	cachedAvailable v1.ResourceList // Cache so we don't have to re-subtract resources on the StateNode every time
+	cachedTaints    []v1.Taint      // Cache so we don't hae to re-construct the taints each time we attempt to schedule a pod
 
 	Pods         []*v1.Pod
 	topology     *Topology
 	requests     v1.ResourceList
 	requirements scheduling.Requirements
 }
 
-func NewExistingNode(n *state.StateNode, topology *Topology, daemonResources v1.ResourceList) *ExistingNode {
+func NewExistingNode(n *state.StateNode, topology *Topology, taints []v1.Taint, daemonResources v1.ResourceList) *ExistingNode {
 	// The state node passed in here must be a deep copy from cluster state as we modify it
 	// the remaining daemonResources to schedule are the total daemonResources minus what has already scheduled
 	remainingDaemonResources := resources.Subtract(daemonResources, n.DaemonSetRequests())
@@ -54,6 +55,7 @@ func NewExistingNode(n *state.StateNode, topology *Topology, daemonResources v1.
 	node := &ExistingNode{
 		StateNode:       n,
 		cachedAvailable: n.Available(),
+		cachedTaints:    taints,
 		topology:        topology,
 		requests:        remainingDaemonResources,
 		requirements:    scheduling.NewLabelRequirements(n.Labels()),
@@ -65,7 +67,7 @@ func NewExistingNode(n *state.StateNode, topology *Topology, daemonResources v1.
 
 func (n *ExistingNode) Add(ctx context.Context, kubeClient client.Client, pod *v1.Pod, podRequests v1.ResourceList) error {
 	// Check Taints
-	if err := scheduling.Taints(n.Taints()).Tolerates(pod); err != nil {
+	if err := scheduling.Taints(n.cachedTaints).Tolerates(pod); err != nil {
 		return err
 	}
 	// determine the volumes that will be mounted if the pod schedules

pkg/controllers/provisioning/scheduling/scheduler.go

@@ -318,17 +318,18 @@ func (s *Scheduler) calculateExistingNodeClaims(stateNodes []*state.StateNode, d
 	// create our existing nodes
 	for _, node := range stateNodes {
 		// Calculate any daemonsets that should schedule to the inflight node
+		taints := node.Taints()
 		var daemons []*corev1.Pod
 		for _, p := range daemonSetPods {
-			if err := scheduling.Taints(node.Taints()).Tolerates(p); err != nil {
+			if err := scheduling.Taints(taints).Tolerates(p); err != nil {
 				continue
 			}
 			if err := scheduling.NewLabelRequirements(node.Labels()).Compatible(scheduling.NewPodRequirements(p)); err != nil {
 				continue
 			}
 			daemons = append(daemons, p)
 		}
-		s.existingNodes = append(s.existingNodes, NewExistingNode(node, s.topology, resources.RequestsForPods(daemons...)))
+		s.existingNodes = append(s.existingNodes, NewExistingNode(node, s.topology, taints, resources.RequestsForPods(daemons...)))
 
 		// We don't use the status field and instead recompute the remaining resources to ensure we have a consistent view
 		// of the cluster during scheduling.  Depending on how node creation falls out, this will also work for cases where