Avoid computing super-expensive DeepEqual on every pod update

pkg/controller/replication/replication_controller.go

@@ -367,12 +367,13 @@ func (rm *ReplicationManager) addPod(obj interface{}) {
 // up. If the labels of the pod have changed we need to awaken both the old
 // and new controller. old and cur must be *api.Pod types.
 func (rm *ReplicationManager) updatePod(old, cur interface{}) {
-	if api.Semantic.DeepEqual(old, cur) {
-		// A periodic relist will send update events for all known pods.
-		return
-	}
 	curPod := cur.(*api.Pod)
 	oldPod := old.(*api.Pod)
+	if curPod.ResourceVersion == oldPod.ResourceVersion {
+		// Periodic resync will send update events for all known pods.
+		// Two different versions of the same pod will always have different RVs.
+		return
+	}
 	glog.V(4).Infof("Pod %s updated, objectMeta %+v -> %+v.", curPod.Name, oldPod.ObjectMeta, curPod.ObjectMeta)
 	labelChanged := !reflect.DeepEqual(curPod.Labels, oldPod.Labels)
 	if curPod.DeletionTimestamp != nil {

pkg/controller/replication/replication_controller_test.go

@@ -547,8 +547,10 @@ func TestUpdatePods(t *testing.T) {
 	// testControllerSpec1, then update its labels to match testControllerSpec2.
 	// We expect to receive a sync request for both controllers.
 	pod1 := newPodList(manager.podStore.Indexer, 1, api.PodRunning, testControllerSpec1, "pod").Items[0]
+	pod1.ResourceVersion = "1"
 	pod2 := pod1
 	pod2.Labels = testControllerSpec2.Spec.Selector
+	pod2.ResourceVersion = "2"
 	manager.updatePod(&pod1, &pod2)
 	expected := sets.NewString(testControllerSpec1.Name, testControllerSpec2.Name)
 	for _, name := range expected.List() {
@@ -567,6 +569,7 @@ func TestUpdatePods(t *testing.T) {
 	// We update its labels to match no replication controller.  We expect to
 	// receive a sync request for testControllerSpec1.
 	pod2.Labels = make(map[string]string)
+	pod2.ResourceVersion = "2"
 	manager.updatePod(&pod1, &pod2)
 	expected = sets.NewString(testControllerSpec1.Name)
 	for _, name := range expected.List() {
@@ -969,6 +972,7 @@ func TestDeletionTimestamp(t *testing.T) {
 	}
 	pod := newPodList(nil, 1, api.PodPending, controllerSpec, "pod").Items[0]
 	pod.DeletionTimestamp = &unversioned.Time{Time: time.Now()}
+	pod.ResourceVersion = "1"
 	manager.expectations.ExpectDeletions(rcKey, []string{controller.PodKey(&pod)})
 
 	// A pod added with a deletion timestamp should decrement deletions, not creations.
@@ -988,6 +992,7 @@ func TestDeletionTimestamp(t *testing.T) {
 	// An update from no deletion timestamp to having one should be treated
 	// as a deletion.
 	oldPod := newPodList(nil, 1, api.PodPending, controllerSpec, "pod").Items[0]
+	oldPod.ResourceVersion = "2"
 	manager.expectations.ExpectDeletions(rcKey, []string{controller.PodKey(&pod)})
 	manager.updatePod(&oldPod, &pod)
 
@@ -1013,6 +1018,7 @@ func TestDeletionTimestamp(t *testing.T) {
 	}
 	manager.expectations.ExpectDeletions(rcKey, []string{controller.PodKey(secondPod)})
 	oldPod.DeletionTimestamp = &unversioned.Time{Time: time.Now()}
+	oldPod.ResourceVersion = "2"
 	manager.updatePod(&oldPod, &pod)
 
 	podExp, exists, err = manager.expectations.GetExpectations(rcKey)
@@ -1239,12 +1245,14 @@ func TestUpdateLabelsRemoveControllerRef(t *testing.T) {
 	manager.rcStore.Indexer.Add(rc)
 	// put one pod in the podStore
 	pod := newPod("pod", rc, api.PodRunning)
+	pod.ResourceVersion = "1"
 	var trueVar = true
 	rcOwnerReference := api.OwnerReference{UID: rc.UID, APIVersion: "v1", Kind: "ReplicationController", Name: rc.Name, Controller: &trueVar}
 	pod.OwnerReferences = []api.OwnerReference{rcOwnerReference}
 	updatedPod := *pod
 	// reset the labels
 	updatedPod.Labels = make(map[string]string)
+	updatedPod.ResourceVersion = "2"
 	// add the updatedPod to the store. This is consistent with the behavior of
 	// the Informer: Informer updates the store before call the handler
 	// (updatePod() in this case).