Eclass Task 1: clean up old equiv class code

Co-authored-by: Harry Zhang <resouer@gmail.com>
Co-authored-by: Wang Qingcan <wangqingcan@baidu.com>

pkg/scheduler/algorithmprovider/defaults/compatibility_test.go

@@ -36,8 +36,6 @@ import (
 	"k8s.io/kubernetes/pkg/scheduler/factory"
 )
 
-const enableEquivalenceCache = true
-
 func TestCompatibility_v1_Scheduler(t *testing.T) {
 	// Add serialized versions of scheduler config that exercise available options to ensure compatibility between releases
 	schedulerFiles := map[string]struct {
@@ -987,7 +985,6 @@ func TestCompatibility_v1_Scheduler(t *testing.T) {
 			PdbInformer:                    informerFactory.Policy().V1beta1().PodDisruptionBudgets(),
 			StorageClassInformer:           informerFactory.Storage().V1().StorageClasses(),
 			HardPodAffinitySymmetricWeight: v1.DefaultHardPodAffinitySymmetricWeight,
-			EnableEquivalenceClassCache:    enableEquivalenceCache,
 			DisablePreemption:              false,
 			PercentageOfNodesToScore:       schedulerapi.DefaultPercentageOfNodesToScore,
 		}).CreateFromConfig(policy); err != nil {

pkg/scheduler/algorithmprovider/defaults/defaults.go

@@ -49,13 +49,6 @@ func init() {
 	registerAlgorithmProvider(defaultPredicates(), defaultPriorities())
 
 	// IMPORTANT NOTES for predicate developers:
-	// We are using cached predicate result for pods belonging to the same equivalence class.
-	// So when implementing a new predicate, you are expected to check whether the result
-	// of your predicate function can be affected by related API object change (ADD/DELETE/UPDATE).
-	// If yes, you are expected to invalidate the cached predicate result for related API object change.
-	// For example:
-	// https://github.com/kubernetes/kubernetes/blob/36a218e/plugin/pkg/scheduler/factory/factory.go#L422
-
 	// Registers predicates and priorities that are not enabled by default, but user can pick when creating their
 	// own set of priorities/predicates.