Delay sorting of evictUnits slice in kuberuntime_gc

Signed-off-by: zyu <[email protected]>

Author: tedyu

pkg/kubelet/kuberuntime/kuberuntime_gc.go

@@ -125,6 +125,9 @@ func (cgc *containerGC) enforceMaxContainersPerEvictUnit(evictUnits containersBy
 func (cgc *containerGC) removeOldestN(containers []containerGCInfo, toRemove int) []containerGCInfo {
 	// Remove from oldest to newest (last to first).
 	numToKeep := len(containers) - toRemove
+	if numToKeep > 0 {
+		sort.Sort(byCreated(containers))
+	}
 	for i := len(containers) - 1; i >= numToKeep; i-- {
 		if containers[i].unknown {
 			// Containers in known state could be running, we should try
@@ -151,8 +154,11 @@ func (cgc *containerGC) removeOldestN(containers []containerGCInfo, toRemove int
 // removeOldestNSandboxes removes the oldest inactive toRemove sandboxes and
 // returns the resulting slice.
 func (cgc *containerGC) removeOldestNSandboxes(sandboxes []sandboxGCInfo, toRemove int) {
-	// Remove from oldest to newest (last to first).
 	numToKeep := len(sandboxes) - toRemove
+	if numToKeep > 0 {
+		sort.Sort(sandboxByCreated(sandboxes))
+	}
+	// Remove from oldest to newest (last to first).
 	for i := len(sandboxes) - 1; i >= numToKeep; i-- {
 		if !sandboxes[i].active {
 			cgc.removeSandbox(sandboxes[i].id)
@@ -210,11 +216,6 @@ func (cgc *containerGC) evictableContainers(minAge time.Duration) (containersByE
 		evictUnits[key] = append(evictUnits[key], containerInfo)
 	}
 
-	// Sort the containers by age.
-	for uid := range evictUnits {
-		sort.Sort(byCreated(evictUnits[uid]))
-	}
-
 	return evictUnits, nil
 }
 
@@ -309,11 +310,6 @@ func (cgc *containerGC) evictSandboxes(evictTerminatedPods bool) error {
 		sandboxesByPod[podUID] = append(sandboxesByPod[podUID], sandboxInfo)
 	}
 
-	// Sort the sandboxes by age.
-	for uid := range sandboxesByPod {
-		sort.Sort(sandboxByCreated(sandboxesByPod[uid]))
-	}
-
 	for podUID, sandboxes := range sandboxesByPod {
 		if cgc.podStateProvider.IsPodDeleted(podUID) || (cgc.podStateProvider.IsPodTerminated(podUID) && evictTerminatedPods) {
 			// Remove all evictable sandboxes if the pod has been removed.