From 18d8ebf3d04cd71d13ca95b432024f4d1f8c0718 Mon Sep 17 00:00:00 2001 From: Sandeep Date: Fri, 9 May 2014 08:44:05 +0530 Subject: [PATCH] SPARK-1775: Unneeded lock in ShuffleMapTask.deserializeInfo This was used in the past to have a cache of deserialized ShuffleMapTasks, but that's been removed, so there's no need for a lock. It slows down Spark when task descriptions are large, e.g. due to large lineage graphs or local variables. --- .../apache/spark/scheduler/ShuffleMapTask.scala | 16 +++++++--------- 1 file changed, 7 insertions(+), 9 deletions(-) diff --git a/core/src/main/scala/org/apache/spark/scheduler/ShuffleMapTask.scala b/core/src/main/scala/org/apache/spark/scheduler/ShuffleMapTask.scala index 2259df0b56bad..723bbd0dd3660 100644 --- a/core/src/main/scala/org/apache/spark/scheduler/ShuffleMapTask.scala +++ b/core/src/main/scala/org/apache/spark/scheduler/ShuffleMapTask.scala @@ -58,15 +58,13 @@ private[spark] object ShuffleMapTask { } def deserializeInfo(stageId: Int, bytes: Array[Byte]): (RDD[_], ShuffleDependency[_,_]) = { - synchronized { - val loader = Thread.currentThread.getContextClassLoader - val in = new GZIPInputStream(new ByteArrayInputStream(bytes)) - val ser = SparkEnv.get.closureSerializer.newInstance() - val objIn = ser.deserializeStream(in) - val rdd = objIn.readObject().asInstanceOf[RDD[_]] - val dep = objIn.readObject().asInstanceOf[ShuffleDependency[_,_]] - (rdd, dep) - } + val loader = Thread.currentThread.getContextClassLoader + val in = new GZIPInputStream(new ByteArrayInputStream(bytes)) + val ser = SparkEnv.get.closureSerializer.newInstance() + val objIn = ser.deserializeStream(in) + val rdd = objIn.readObject().asInstanceOf[RDD[_]] + val dep = objIn.readObject().asInstanceOf[ShuffleDependency[_,_]] + (rdd, dep) } // Since both the JarSet and FileSet have the same format this is used for both.