diff --git a/core/src/main/scala/spark/scheduler/cluster/TaskSetManager.scala b/core/src/main/scala/spark/scheduler/cluster/TaskSetManager.scala
index cf4aae03a70767be7cd0e2ecd6d6c344cd222088..a842afcdeb2ed0ee2ef61e5d4ea96370e6c58a1e 100644
--- a/core/src/main/scala/spark/scheduler/cluster/TaskSetManager.scala
+++ b/core/src/main/scala/spark/scheduler/cluster/TaskSetManager.scala
@@ -201,7 +201,8 @@ private[spark] class TaskSetManager(
           val taskId = sched.newTaskId()
           // Figure out whether this should count as a preferred launch
           val preferred = isPreferredLocation(task, host)
-          val prefStr = if (preferred) "preferred" else "non-preferred"
+          val prefStr = if (preferred) "preferred"
+                        else "non-preferred, not one of " + task.preferredLocations.mkString(", ")
           logInfo("Starting task %s:%d as TID %s on slave %s: %s (%s)".format(
             taskSet.id, index, taskId, slaveId, host, prefStr))
           // Do various bookkeeping