benchmark test to evaluate the overhead of podMatchesScopeFunc

pkg/quota/v1/evaluator/core/pods.go

@@ -328,8 +328,9 @@ func podMatchesScopeFunc(selector corev1.ScopedResourceSelectorRequirement, obje
 	case corev1.ResourceQuotaScopeNotBestEffort:
 		return !isBestEffort(pod), nil
 	case corev1.ResourceQuotaScopePriorityClass:
-		if len(selector.Operator) == 0 && selector.Values == nil {
-			// this is just checking for existence of a priorityClass on the pod
+		if selector.Operator == corev1.ScopeSelectorOpExists {
+			// This is just checking for existence of a priorityClass on the pod,
+			// no need to take the overhead of selector parsing/evaluation.
 			return len(pod.Spec.PriorityClassName) != 0, nil
 		}
 		return podMatchesSelector(pod, selector)

pkg/quota/v1/evaluator/core/pods_test.go

@@ -1105,6 +1105,51 @@ func TestPodEvaluatorUsageResourceResize(t *testing.T) {
 	}
 }
 
+func BenchmarkPodMatchesScopeFunc(b *testing.B) {
+	pod, _ := toExternalPodOrError(makePod("p1", "high-priority",
+		api.ResourceList{api.ResourceCPU: resource.MustParse("1")}, api.PodRunning))
+
+	tests := []struct {
+		name     string
+		selector corev1.ScopedResourceSelectorRequirement
+	}{
+		{
+			name: "PriorityClass selector w/o operator",
+			selector: corev1.ScopedResourceSelectorRequirement{
+				ScopeName: corev1.ResourceQuotaScopePriorityClass,
+			},
+		},
+		{
+			name: "PriorityClass selector w/ 'Exists' operator",
+			selector: corev1.ScopedResourceSelectorRequirement{
+				ScopeName: corev1.ResourceQuotaScopePriorityClass,
+				Operator:  corev1.ScopeSelectorOpExists,
+			},
+		},
+		{
+			name: "BestEfforts selector w/o operator",
+			selector: corev1.ScopedResourceSelectorRequirement{
+				ScopeName: corev1.ResourceQuotaScopeBestEffort,
+			},
+		},
+		{
+			name: "BestEfforts selector w/ 'Exists' operator",
+			selector: corev1.ScopedResourceSelectorRequirement{
+				ScopeName: corev1.ResourceQuotaScopeBestEffort,
+				Operator:  corev1.ScopeSelectorOpExists,
+			},
+		},
+	}
+
+	for _, tt := range tests {
+		b.Run(tt.name, func(b *testing.B) {
+			for n := 0; n < b.N; n++ {
+				_, _ = podMatchesScopeFunc(tt.selector, pod)
+			}
+		})
+	}
+}
+
 func mockListerForResourceFunc(listerForResource map[schema.GroupVersionResource]cache.GenericLister) quota.ListerForResourceFunc {
 	return func(gvr schema.GroupVersionResource) (cache.GenericLister, error) {
 		lister, found := listerForResource[gvr]

staging/src/k8s.io/apiserver/pkg/quota/v1/generic/evaluator.go

@@ -199,7 +199,7 @@ func CalculateUsageStats(options quota.UsageStatsOptions,
 		// need to verify that the item matches the set of scopes
 		matchesScopes := true
 		for _, scope := range options.Scopes {
-			innerMatch, err := scopeFunc(corev1.ScopedResourceSelectorRequirement{ScopeName: scope}, item)
+			innerMatch, err := scopeFunc(corev1.ScopedResourceSelectorRequirement{ScopeName: scope, Operator: corev1.ScopeSelectorOpExists}, item)
 			if err != nil {
 				return result, nil
 			}