fix: eliminate a possible double-record of UnscheduledPodUpdate event handling latency

Author: sanposhiho

pkg/scheduler/eventhandlers.go

@@ -133,7 +133,6 @@ func (sched *Scheduler) addPodToSchedulingQueue(obj interface{}) {
 
 func (sched *Scheduler) updatePodInSchedulingQueue(oldObj, newObj interface{}) {
 	start := time.Now()
-	defer metrics.EventHandlingLatency.WithLabelValues(framework.UnscheduledPodUpdate.Label).Observe(metrics.SinceInSeconds(start))
 
 	logger := sched.logger
 	oldPod, newPod := oldObj.(*v1.Pod), newObj.(*v1.Pod)
@@ -143,8 +142,16 @@ func (sched *Scheduler) updatePodInSchedulingQueue(oldObj, newObj interface{}) {
 		return
 	}
 
+	isUnschedPodUpdateIncluded := false
 	for _, evt := range framework.PodSchedulingPropertiesChange(newPod, oldPod) {
 		defer metrics.EventHandlingLatency.WithLabelValues(evt.Label).Observe(metrics.SinceInSeconds(start))
+		if evt.Label == framework.UnscheduledPodUpdate.Label {
+			isUnschedPodUpdateIncluded = true
+		}
+	}
+	if !isUnschedPodUpdateIncluded {
+		// make sure we always record the latency with UnscheduledPodUpdate label.
+		defer metrics.EventHandlingLatency.WithLabelValues(framework.UnscheduledPodUpdate.Label).Observe(metrics.SinceInSeconds(start))
 	}
 
 	isAssumed, err := sched.Cache.IsAssumedPod(newPod)