[CARMEL-7542][CARMEL-4965] maxNumConcurrentTasks should be defined to lazy (apache#513)

Co-authored-by: mingmwang <[email protected]>
Co-authored-by: Wang <[email protected]>

Author: 3 people

core/src/main/scala/org/apache/spark/scheduler/DAGScheduler.scala

@@ -719,7 +719,7 @@ private[spark] class DAGScheduler(
   private def checkBarrierStageWithNumSlots(rdd: RDD[_], rp: ResourceProfile): Unit = {
     if (rdd.isBarrier()) {
       val numPartitions = rdd.getNumPartitions
-      val maxNumConcurrentTasks = sc.maxNumConcurrentTasks(rp)
+      lazy val maxNumConcurrentTasks = sc.maxNumConcurrentTasks(rp)
       if (numPartitions > maxNumConcurrentTasks) {
         throw SparkCoreErrors.numPartitionsGreaterThanMaxNumConcurrentTasksError(numPartitions,
           maxNumConcurrentTasks)