fix(scheduler): fix a possible memory leak for QueueingHint

pkg/scheduler/backend/queue/scheduling_queue.go

@@ -120,6 +120,7 @@ type SchedulingQueue interface {
 	AssignedPodUpdated(logger klog.Logger, oldPod, newPod *v1.Pod, event framework.ClusterEvent)
 	PendingPods() ([]*v1.Pod, string)
 	PodsInActiveQ() []*v1.Pod
+	InFlightPods() []*v1.Pod
 	// Close closes the SchedulingQueue so that the goroutine which is
 	// waiting to pop items can exit gracefully.
 	Close()
@@ -837,6 +838,15 @@ func (p *PriorityQueue) Done(pod types.UID) {
 	p.activeQ.done(pod)
 }
 
+func (p *PriorityQueue) InFlightPods() []*v1.Pod {
+	if !p.isSchedulingQueueHintEnabled {
+		// do nothing if schedulingQueueHint is disabled.
+		// In that case, we don't have inFlightPods and inFlightEvents.
+		return nil
+	}
+	return p.activeQ.listInFlightPods()
+}
+
 // isPodUpdated checks if the pod is updated in a way that it may have become
 // schedulable. It drops status of the pod and compares it with old version,
 // except for pod.status.resourceClaimStatuses: changing that may have an

pkg/scheduler/schedule_one.go

@@ -87,9 +87,12 @@ func (sched *Scheduler) ScheduleOne(ctx context.Context) {
 		// This shouldn't happen, because we only accept for scheduling the pods
 		// which specify a scheduler name that matches one of the profiles.
 		logger.Error(err, "Error occurred")
+		sched.SchedulingQueue.Done(pod.UID)
 		return
 	}
 	if sched.skipPodSchedule(ctx, fwk, pod) {
+		// We don't put this Pod back to the queue, but we have to cleanup the in-flight pods/events.
+		sched.SchedulingQueue.Done(pod.UID)
 		return
 	}
 

pkg/scheduler/schedule_one_test.go

@@ -41,16 +41,19 @@ import (
 	"k8s.io/apimachinery/pkg/types"
 	"k8s.io/apimachinery/pkg/util/sets"
 	"k8s.io/apimachinery/pkg/util/wait"
+	utilfeature "k8s.io/apiserver/pkg/util/feature"
 	"k8s.io/client-go/informers"
 	clientsetfake "k8s.io/client-go/kubernetes/fake"
 	"k8s.io/client-go/kubernetes/scheme"
 	clienttesting "k8s.io/client-go/testing"
 	clientcache "k8s.io/client-go/tools/cache"
 	"k8s.io/client-go/tools/events"
+	featuregatetesting "k8s.io/component-base/featuregate/testing"
 	"k8s.io/component-helpers/storage/volume"
 	"k8s.io/klog/v2"
 	"k8s.io/klog/v2/ktesting"
 	extenderv1 "k8s.io/kube-scheduler/extender/v1"
+	"k8s.io/kubernetes/pkg/features"
 	schedulerapi "k8s.io/kubernetes/pkg/scheduler/apis/config"
 	internalcache "k8s.io/kubernetes/pkg/scheduler/backend/cache"
 	fakecache "k8s.io/kubernetes/pkg/scheduler/backend/cache/fake"
@@ -747,8 +750,10 @@ func TestSchedulerScheduleOne(t *testing.T) {
 		},
 	}
 
+	for _, qHintEnabled := range []bool{true, false} {
 		for _, item := range table {
-		t.Run(item.name, func(t *testing.T) {
+			t.Run(fmt.Sprintf("[QueueingHint: %v] %s", qHintEnabled, item.name), func(t *testing.T) {
+				featuregatetesting.SetFeatureGateDuringTest(t, utilfeature.DefaultFeatureGate, features.SchedulerQueueingHints, qHintEnabled)
 				var gotError error
 				var gotPod *v1.Pod
 				var gotForgetPod *v1.Pod
@@ -776,14 +781,13 @@ func TestSchedulerScheduleOne(t *testing.T) {
 					gotBinding = action.(clienttesting.CreateAction).GetObject().(*v1.Binding)
 					return true, gotBinding, item.injectBindError
 				})
-			registerPluginFuncs := append(item.registerPluginFuncs,
-				tf.RegisterQueueSortPlugin(queuesort.Name, queuesort.New),
-				tf.RegisterBindPlugin(defaultbinder.Name, defaultbinder.New),
-			)
 				ctx, cancel := context.WithCancel(context.Background())
 				defer cancel()
 				fwk, err := tf.NewFramework(ctx,
-				registerPluginFuncs,
+					append(item.registerPluginFuncs,
+						tf.RegisterQueueSortPlugin(queuesort.Name, queuesort.New),
+						tf.RegisterBindPlugin(defaultbinder.Name, defaultbinder.New),
+					),
 					testSchedulerName,
 					frameworkruntime.WithClientSet(client),
 					frameworkruntime.WithEventRecorder(eventBroadcaster.NewRecorder(scheme.Scheme, testSchedulerName)),
@@ -794,15 +798,15 @@ func TestSchedulerScheduleOne(t *testing.T) {
 				}
 
 				informerFactory := informers.NewSharedInformerFactory(client, 0)
+				queue := internalqueue.NewSchedulingQueue(nil, informerFactory)
 				sched := &Scheduler{
 					Cache:           cache,
 					client:          client,
-				NextPod: func(logger klog.Logger) (*framework.QueuedPodInfo, error) {
-					return &framework.QueuedPodInfo{PodInfo: mustNewPodInfo(t, item.sendPod)}, nil
-				},
-				SchedulingQueue: internalqueue.NewSchedulingQueue(nil, informerFactory),
+					NextPod:         queue.Pop,
+					SchedulingQueue: queue,
 					Profiles:        profile.Map{testSchedulerName: fwk},
 				}
+				queue.Add(klog.Logger{}, item.sendPod)
 
 				sched.SchedulePod = func(ctx context.Context, fwk framework.Framework, state *framework.CycleState, pod *v1.Pod) (ScheduleResult, error) {
 					return item.mockResult.result, item.mockResult.err
@@ -813,6 +817,7 @@ func TestSchedulerScheduleOne(t *testing.T) {
 
 					msg := truncateMessage(gotError.Error())
 					fwk.EventRecorder().Eventf(p.Pod, nil, v1.EventTypeWarning, "FailedScheduling", "Scheduling", msg)
+					queue.Done(p.Pod.UID)
 				}
 				called := make(chan struct{})
 				stopFunc, err := eventBroadcaster.StartEventWatcher(func(obj runtime.Object) {
@@ -842,10 +847,14 @@ func TestSchedulerScheduleOne(t *testing.T) {
 				if diff := cmp.Diff(item.expectBind, gotBinding); diff != "" {
 					t.Errorf("got binding diff (-want, +got): %s", diff)
 				}
+				if len(queue.InFlightPods()) != 0 {
+					t.Errorf("in-flight pods should be always empty after SchedulingOne. It has %v Pods", len(queue.InFlightPods()))
+				}
 				stopFunc()
 			})
 		}
 	}
+}
 
 func TestSchedulerNoPhantomPodAfterExpire(t *testing.T) {
 	logger, ctx := ktesting.NewTestContext(t)