Merge pull request kubernetes#86230 from hex108/skip_schedule

Scheduler handles pod annotation updates during scheduling more gracefully

Author: k8s-ci-robot

pkg/scheduler/scheduler.go

@@ -599,9 +599,7 @@ func (sched *Scheduler) scheduleOne(ctx context.Context) {
 		return
 	}
 	pod := podInfo.Pod
-	if pod.DeletionTimestamp != nil {
-		sched.Recorder.Eventf(pod, nil, v1.EventTypeWarning, "FailedScheduling", "Scheduling", "skip schedule deleting pod: %v/%v", pod.Namespace, pod.Name)
-		klog.V(3).Infof("Skip schedule deleting pod: %v/%v", pod.Namespace, pod.Name)
+	if sched.skipPodSchedule(pod) {
 		return
 	}
 
@@ -764,6 +762,25 @@ func (sched *Scheduler) scheduleOne(ctx context.Context) {
 	}()
 }
 
+// skipPodSchedule returns true if we could skip scheduling the pod for specified cases.
+func (sched *Scheduler) skipPodSchedule(pod *v1.Pod) bool {
+	// Case 1: pod is being deleted.
+	if pod.DeletionTimestamp != nil {
+		sched.Recorder.Eventf(pod, nil, v1.EventTypeWarning, "FailedScheduling", "Scheduling", "skip schedule deleting pod: %v/%v", pod.Namespace, pod.Name)
+		klog.V(3).Infof("Skip schedule deleting pod: %v/%v", pod.Namespace, pod.Name)
+		return true
+	}
+
+	// Case 2: pod has been assumed and pod updates could be skipped.
+	// An assumed pod can be added again to the scheduling queue if it got an update event
+	// during its previous scheduling cycle but before getting assumed.
+	if sched.skipPodUpdate(pod) {
+		return true
+	}
+
+	return false
+}
+
 type podConditionUpdaterImpl struct {
 	Client clientset.Interface
 }

pkg/scheduler/scheduler_test.go

@@ -291,6 +291,12 @@ func TestScheduler(t *testing.T) {
 				AssumeFunc: func(pod *v1.Pod) {
 					gotAssumedPod = pod
 				},
+				IsAssumedPodFunc: func(pod *v1.Pod) bool {
+					if pod == nil || gotAssumedPod == nil {
+						return false
+					}
+					return pod.UID == gotAssumedPod.UID
+				},
 			}
 
 			s := &Scheduler{