Merge pull request #117194 from sanposhiho/revert-preenqueue

Revert "Optimization on running prePreEnqueuePlugins before adding pods into activeQ"

CHANGELOG/CHANGELOG-1.27.md

@@ -8,6 +8,8 @@
     - [Node Binaries](#node-binaries)
     - [Container Images](#container-images)
   - [Changelog since v1.26.0](#changelog-since-v1260)
+  - [Known Issues](#known-issues)
+    - [The PreEnqueue extension point doesn't work in backoffQ](#the-preEnqueue-extension-point-doesnt-work-for-pods-going-to-activeq-through-backoffq)
   - [Urgent Upgrade Notes](#urgent-upgrade-notes)
     - [(No, really, you MUST read this before you upgrade)](#no-really-you-must-read-this-before-you-upgrade)
   - [Changes by Kind](#changes-by-kind)
@@ -198,6 +200,15 @@ name | architectures
 
 ## Changelog since v1.26.0
 
+## Known Issues
+
+### The PreEnqueue extension point doesn't work for Pods going to activeQ through backoffQ
+
+In v1.26.0, we've found the bug that the PreEnqueue extension point doesn't work for Pods going to activeQ through backoffQ. 
+It doesn't affect any of the vanilla Kubernetes behavior, but, may break custom PreEnqueue plugins.
+
+The cause PR is [reverted](https://github.com/kubernetes/kubernetes/pull/117194) by v1.26.1.
+
 ## Urgent Upgrade Notes 
 
 ### (No, really, you MUST read this before you upgrade)

pkg/scheduler/internal/queue/scheduling_queue.go

@@ -553,9 +553,7 @@ func (p *PriorityQueue) flushBackoffQCompleted() {
 			klog.ErrorS(err, "Unable to pop pod from backoff queue despite backoff completion", "pod", klog.KObj(pod))
 			break
 		}
-		if err := p.activeQ.Add(pInfo); err != nil {
-			klog.ErrorS(err, "Error adding pod to the active queue", "pod", klog.KObj(pInfo.Pod))
-		} else {
+		if added, _ := p.addToActiveQ(pInfo); added {
 			klog.V(5).InfoS("Pod moved to an internal scheduling queue", "pod", klog.KObj(pod), "event", BackoffComplete, "queue", activeQName)
 			metrics.SchedulerQueueIncomingPods.WithLabelValues("active", BackoffComplete).Inc()
 			activated = true

pkg/scheduler/internal/queue/scheduling_queue_test.go

@@ -452,8 +452,6 @@ func TestPriorityQueue_Activate(t *testing.T) {
 }
 
 type preEnqueuePlugin struct {
-	// called counts the number of calling PreEnqueue()
-	called     int
 	allowlists []string
 }
 
@@ -462,7 +460,6 @@ func (pl *preEnqueuePlugin) Name() string {
 }
 
 func (pl *preEnqueuePlugin) PreEnqueue(ctx context.Context, p *v1.Pod) *framework.Status {
-	pl.called++
 	for _, allowed := range pl.allowlists {
 		for label := range p.Labels {
 			if label == allowed {
@@ -544,47 +541,6 @@ func TestPriorityQueue_addToActiveQ(t *testing.T) {
 	}
 }
 
-func TestPriorityQueue_flushBackoffQCompleted(t *testing.T) {
-	tests := []struct {
-		name                       string
-		plugin                     framework.PreEnqueuePlugin
-		pod                        *v1.Pod
-		operations                 []operation
-		wantPreEnqueuePluginCalled int
-	}{
-		{
-			name:   "preEnqueue plugin registered, not running preEnqueue plugin when backoff completed",
-			plugin: &preEnqueuePlugin{},
-			pod:    st.MakePod().Name("foo").Label("foo", "").Obj(),
-			operations: []operation{
-				addPodBackoffQ,
-				flushBackoffQ,
-			},
-			wantPreEnqueuePluginCalled: 0,
-		},
-	}
-
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			ctx, cancel := context.WithCancel(context.Background())
-			defer cancel()
-
-			m := map[string][]framework.PreEnqueuePlugin{"": {tt.plugin}}
-			c := testingclock.NewFakeClock(time.Now())
-			q := NewTestQueueWithObjects(ctx, newDefaultQueueSort(), []runtime.Object{tt.pod}, WithPreEnqueuePluginMap(m),
-				WithPodInitialBackoffDuration(time.Second*1), WithPodMaxBackoffDuration(time.Second*60), WithClock(c))
-			pInfo := newQueuedPodInfoForLookup(tt.pod)
-			pInfo.Gated = true
-			for _, op := range tt.operations {
-				op(q, pInfo)
-			}
-			if tt.wantPreEnqueuePluginCalled != tt.plugin.(*preEnqueuePlugin).called {
-				t.Errorf("Unexpected number of calling preEnqueue: want %v, but got %v", tt.wantPreEnqueuePluginCalled, tt.plugin.(*preEnqueuePlugin).called)
-			}
-		})
-	}
-}
-
 func BenchmarkMoveAllToActiveOrBackoffQueue(b *testing.B) {
 	tests := []struct {
 		name      string