[ctrl/workload] Preserve the preemption AC status

pkg/controller/core/workload_controller.go

@@ -39,6 +39,7 @@ import (
 
 	kueue "sigs.k8s.io/kueue/apis/kueue/v1beta1"
 	"sigs.k8s.io/kueue/pkg/cache"
+	"sigs.k8s.io/kueue/pkg/constants"
 	"sigs.k8s.io/kueue/pkg/controller/core/indexer"
 	"sigs.k8s.io/kueue/pkg/queue"
 	"sigs.k8s.io/kueue/pkg/util/limitrange"
@@ -194,11 +195,16 @@ func (r *WorkloadReconciler) reconcileSyncAdmissionChecks(ctx context.Context, w
 		return false, err
 	}
 
-	queueAdmissionChecks := queue.Spec.AdmissionChecks
-	newChecks, shouldUpdate := syncAdmissionCheckConditions(wl.Status.AdmissionChecks, queueAdmissionChecks)
+	targetChecks := queue.Spec.AdmissionChecks
+	// preserve the preemption check if necessary
+	if pc := apimeta.FindStatusCondition(wl.Status.AdmissionChecks, constants.PreemptionAdmissionCheckName); pc != nil && apimeta.IsStatusConditionTrue(wl.Status.Conditions, kueue.WorkloadQuotaReserved) {
+		targetChecks = append(targetChecks, constants.PreemptionAdmissionCheckName)
+	}
+
+	newChecks, shouldUpdate := syncAdmissionCheckConditions(wl.Status.AdmissionChecks, targetChecks)
 	if shouldUpdate {
 		log := ctrl.LoggerFrom(ctx)
-		log.V(3).Info("The workload needs admission checks updates", "clusterQueue", klog.KRef("", cqName), "admissionChecks", queueAdmissionChecks)
+		log.V(3).Info("The workload needs admission checks updates", "clusterQueue", klog.KRef("", cqName), "admissionChecks", targetChecks)
 		wl.Status.AdmissionChecks = newChecks
 		err := r.client.Status().Update(ctx, wl)
 		return true, client.IgnoreNotFound(err)