Make ShuffledRDD.prev transient

core/src/main/scala/spark/rdd/CoGroupedRDD.scala

@@ -29,7 +29,7 @@ private[spark] case class NarrowCoGroupSplitDep(
 private[spark] case class ShuffleCoGroupSplitDep(shuffleId: Int) extends CoGroupSplitDep
 
 private[spark]
-class CoGroupPartition(idx: Int, val deps: Seq[CoGroupSplitDep])
+class CoGroupPartition(idx: Int, val deps: Array[CoGroupSplitDep])
   extends Partition with Serializable {
   override val index: Int = idx
   override def hashCode(): Int = idx
@@ -88,7 +88,7 @@ class CoGroupedRDD[K](
           case _ =>
             new NarrowCoGroupSplitDep(rdd, i, rdd.partitions(i))
         }
-      }.toList)
+      }.toArray)
     }
     array
   }

core/src/main/scala/spark/rdd/ShuffledRDD.scala

@@ -16,7 +16,7 @@ private[spark] class ShuffledRDDPartition(val idx: Int) extends Partition {
  * @tparam V the value class.
  */
 class ShuffledRDD[K, V](
-    prev: RDD[(K, V)],
+    @transient prev: RDD[(K, V)],
     part: Partitioner)
   extends RDD[(K, V)](prev.context, List(new ShuffleDependency(prev, part))) {
 

core/src/main/scala/spark/rdd/SubtractedRDD.scala

@@ -56,7 +56,7 @@ private[spark] class SubtractedRDD[K: ClassManifest, V: ClassManifest, W: ClassM
           case _ =>
             new NarrowCoGroupSplitDep(rdd, i, rdd.partitions(i))
         }
-      }.toList)
+      }.toArray)
     }
     array
   }