diff -r dc26d1d5e4a5 -r 889cd4396022 configs/common/Simulation.py
--- a/configs/common/Simulation.py	Wed Oct 24 17:36:45 2012 -0400
+++ b/configs/common/Simulation.py	Wed Oct 24 17:55:04 2012 -0400
@@ -242,7 +242,7 @@
             return exit_cause
 
         print "draining the system"
-        m5.doDrain(testsys)
+        m5.drain(testsys)
         m5.switchCpus(repeat_switch_cpu_list)
         m5.resume(testsys)
 
@@ -469,7 +469,7 @@
             print "Switching CPUS @ tick %s" % (m5.curTick())
             print "Simulation ends instruction count:%d" % \
                     (testsys.switch_cpus_1[0].max_insts_any_thread)
-            m5.doDrain(testsys)
+            m5.drain(testsys)
             m5.switchCpus(switch_cpu_list1)
             m5.resume(testsys)
 
diff -r dc26d1d5e4a5 -r 889cd4396022 src/python/m5/simulate.py
--- a/src/python/m5/simulate.py	Wed Oct 24 17:36:45 2012 -0400
+++ b/src/python/m5/simulate.py	Wed Oct 24 17:55:04 2012 -0400
@@ -157,28 +157,29 @@
 # register our C++ exit callback function with Python
 atexit.register(internal.core.doExitCleanup)
 
-# This loops until all objects have been fully drained.
-def doDrain(root):
-    all_drained = drain(root)
+# Drain the system in preparation of a checkpoint or memory mode
+# switch.
+def drain(root):
+    # Try to drain all objects. Draining might not be completed unless
+    # all objects return that they are drained on the first call. This
+    # is because as objects drain they may cause other objects to no
+    # longer be drained.
+    def _drain():
+        all_drained = False
+        dm = internal.drain.createDrainManager()
+        unready_objs = sum(obj.drain(dm) for obj in root.descendants())
+        # If we've got some objects that can't drain immediately, then simulate
+        if unready_objs > 0:
+            dm.setCount(unready_objs)
+            simulate()
+        else:
+            all_drained = True
+        internal.drain.cleanupDrainManager(dm)
+        return all_drained
+
+    all_drained = _drain()
     while (not all_drained):
-        all_drained = drain(root)
-
-# Tries to drain all objects.  Draining might not be completed unless
-# all objects return that they are drained on the first call.  This is
-# because as objects drain they may cause other objects to no longer
-# be drained.
-def drain(root):
-    all_drained = False
-    dm = internal.drain.createDrainManager()
-    unready_objs = sum(obj.drain(dm) for obj in root.descendants())
-    # If we've got some objects that can't drain immediately, then simulate
-    if unready_objs > 0:
-        dm.setCount(unready_objs)
-        simulate()
-    else:
-        all_drained = True
-    internal.drain.cleanupDrainManager(dm)
-    return all_drained
+        all_drained = _drain()
 
 def resume(root):
     for obj in root.descendants(): obj.drainResume()
@@ -187,7 +188,7 @@
     root = objects.Root.getInstance()
     if not isinstance(root, objects.Root):
         raise TypeError, "Checkpoint must be called on a root object."
-    doDrain(root)
+    drain(root)
     print "Writing checkpoint"
     internal.core.serializeAll(dir)
     resume(root)
@@ -197,7 +198,7 @@
         raise TypeError, "Parameter of type '%s'.  Must be type %s or %s." % \
               (type(system), objects.Root, objects.System)
     if system.getMemoryMode() != mode:
-        doDrain(system)
+        drain(system)
         system.setMemoryMode(mode)
     else:
         print "System already in target mode. Memory mode unchanged."