critical pods can preempt other pods to be admitted

plugin/pkg/scheduler/algorithm/predicates/error.go

@@ -70,6 +70,10 @@ func (e *InsufficientResourceError) GetReason() string {
 	return fmt.Sprintf("Insufficient %v", e.ResourceName)
 }
 
+func (e *InsufficientResourceError) GetInsufficientAmount() int64 {
+	return e.requested - (e.capacity - e.used)
+}
+
 type PredicateFailureError struct {
 	PredicateName string
 }