diff --git a/configs/common/Options.py b/configs/common/Options.py
--- a/configs/common/Options.py
+++ b/configs/common/Options.py
@@ -104,6 +104,11 @@
     # CPU Switching - default switch model goes from a checkpoint
     # to a timing simple CPU with caches to warm up, then to detailed CPU for
     # data measurement
+    parser.add_option("--repeat-switch", action="store_true",
+        help="switch back and forth between CPUs periodically.")
+    parser.add_option("--switch-freq", action="store", type="int",
+        help="if --repeat-switch, the switch period. else, it's ignored",
+        default=5000000000)
     parser.add_option("-s", "--standard-switch", action="store_true",
         help="switch from timing CPU to Detailed CPU")
     parser.add_option("-w", "--warmup", action="store", type="int",
diff --git a/configs/common/Simulation.py b/configs/common/Simulation.py
--- a/configs/common/Simulation.py
+++ b/configs/common/Simulation.py
@@ -119,9 +119,16 @@
     if options.standard_switch and not options.caches:
         fatal("Must specify --caches when using --standard-switch")
 
+    if options.standard_switch and options.repeat_switch:
+        fatal("Can't specify both --standard-switch and --repeat-switch")
+
+    if options.repeat_switch and options.take_checkpoints != None:
+        fatal("Can't specify both --repeat-switch and --take-checkpoints")
+
     np = options.num_cpus
     max_checkpoints = options.max_checkpoints
     switch_cpus = None
+    repeat_switch_cpus = None
 
     if options.prog_interval:
         for i in xrange(np):
@@ -151,12 +158,42 @@
         testsys.switch_cpus = switch_cpus
         switch_cpu_list = [(testsys.cpu[i], switch_cpus[i]) for i in xrange(np)]
 
+    if options.repeat_switch:
+        if options.cpu_type == "arm_detailed":
+            if not options.caches:
+                print "O3 CPU must be used with caches"
+                sys.exit(1)
+            repeat_switch_cpus = [O3_ARM_v7a_3(defer_registration=True, \
+                                  cpu_id=(np+i)) for i in xrange(np)]
+        elif options.cpu_type == "detailed":
+            if not options.caches:
+                print "O3 CPU must be used with caches"
+                sys.exit(1)
+            repeat_switch_cpus = [DerivO3CPU(defer_registration=True, \
+                                  cpu_id=(np+i)) for i in xrange(np)]
+        elif options.cpu_type == "inorder":
+            print "inorder CPU switching not supported"
+            sys.exit(1)
+        elif options.cpu_type == "timing":
+            repeat_switch_cpus = [TimingSimpleCPU(defer_registration=True, \
+                                  cpu_id=(np+i)) for i in xrange(np)]
+        else:
+            repeat_switch_cpus = [AtomicSimpleCPU(defer_registration=True, \
+                                  cpu_id=(np+i)) for i in xrange(np)]
+
+        for i in xrange(np):
+            repeat_switch_cpus[i].system = testsys
+            repeat_switch_cpus[i].workload = testsys.cpu[i].workload
+            repeat_switch_cpus[i].clock = testsys.cpu[i].clock
+
+            if options.maxinsts:
+                repeat_switch_cpus[i].max_insts_any_thread = options.maxinsts
+
+        testsys.repeat_switch_cpus = repeat_switch_cpus
+        repeat_switch_cpu_list = [(testsys.cpu[i], repeat_switch_cpus[i])
+                                  for i in xrange(np)]
+
     if options.standard_switch:
-        if not options.caches:
-            # O3 CPU must have a cache to work.
-            print "O3 CPU must be used with caches"
-            sys.exit(1)
-
         switch_cpus = [TimingSimpleCPU(defer_registration=True, cpu_id=(np+i))
                        for i in xrange(np)]
         switch_cpus_1 = [DerivO3CPU(defer_registration=True, cpu_id=(2*np+i))
@@ -348,7 +385,7 @@
                 num_checkpoints += 1
 
             if exit_event.getCause() == "user interrupt received":
-                exit_cause = exit_event.getCause();
+                exit_cause = exit_event.getCause()
         else:
             when, period = options.take_checkpoints.split(",", 1)
             when = int(when)
@@ -380,23 +417,46 @@
                         num_checkpoints += 1
 
             if exit_event.getCause() != "simulate() limit reached":
-                exit_cause = exit_event.getCause();
+                exit_cause = exit_event.getCause()
 
     else: # no checkpoints being taken via this script
         if options.fast_forward:
             m5.stats.reset()
         print "**** REAL SIMULATION ****"
-        exit_event = m5.simulate(maxtick)
+        if options.repeat_switch and maxtick > options.switch_freq:
+            print 'starting switch loop'
+            while True:
+                exit_event = m5.simulate(options.switch_freq)
+                exit_cause = exit_event.getCause()
 
-        while exit_event.getCause() == "checkpoint":
-            m5.checkpoint(joinpath(cptdir, "cpt.%d"))
-            num_checkpoints += 1
-            if num_checkpoints == max_checkpoints:
-                exit_cause = "maximum %d checkpoints dropped" % max_checkpoints
-                break
+                if exit_cause != "simulate() limit reached":
+                    break
 
-            exit_event = m5.simulate(maxtick - m5.curTick())
-            exit_cause = exit_event.getCause()
+                print 'draining the system'
+                m5.doDrain(testsys)
+                m5.switchCpus(repeat_switch_cpu_list)
+                m5.resume(testsys)
+
+                tmp_cpu_list = []
+                for old_cpu, new_cpu in repeat_switch_cpu_list:
+                    tmp_cpu_list.append((new_cpu, old_cpu))
+                repeat_switch_cpu_list = tmp_cpu_list
+
+                if (maxtick - m5.curTick()) <= options.switch_freq:
+                    exit_event = m5.simulate(maxtick - m5.curTick())
+                    break
+        else:
+            exit_event = m5.simulate(maxtick)
+
+            while exit_event.getCause() == "checkpoint":
+                m5.checkpoint(joinpath(cptdir, "cpt.%d"))
+                num_checkpoints += 1
+                if num_checkpoints == max_checkpoints:
+                    exit_cause = "maximum %d checkpoints dropped" % max_checkpoints
+                    break
+
+                exit_event = m5.simulate(maxtick - m5.curTick())
+                exit_cause = exit_event.getCause()
 
     if exit_cause == '':
         exit_cause = exit_event.getCause()
@@ -404,4 +464,3 @@
 
     if options.checkpoint_at_end:
         m5.checkpoint(joinpath(cptdir, "cpt.%d"))
-