add some comments and make the warmup period in a switchover parameterizable.

configs/common/Options.py:
    make the warmup period in a standard switch part of the option.
configs/common/Simulation.py:
    add some comments and also make the warmup period an option.

--HG--
extra : convert_revision : 0fa587291b97ff87c3b3a617e7359ac6d9bed7a5

configs/common/Options.py

@@ -53,5 +53,6 @@ parser.add_option("-r", "--checkpoint_restore", action="store", type="int",
 # 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("-s", "--standard_switch", action="store_true",
-                  help="switch from one cpu mode to another")
+parser.add_option("-s", "--standard_switch", action="store", type="int",
+                  help="switch from timing CPU to Detailed CPU after a period of \
+                  <N> cycles warmup", default=5000000000)

configs/common/Simulation.py

@@ -116,12 +116,15 @@ def run(options, root, testsys):
         m5.switchCpus(switch_cpu_list)
         m5.resume(testsys)
 
-        exit_event = m5.simulate(3000000)
+        exit_event = m5.simulate(options.standard_switch)
         m5.switchCpus(switch_cpu_list1)
 
     num_checkpoints = 0
     exit_cause = ''
 
+    ## Checkpoints being taken via the command line at <when> and at subsequent
+    ## periods of <period>.  Checkpoint instructions received from the benchmark running
+    ## are ignored and skipped in favor of command line checkpoint instructions.
     if options.take_checkpoints:
         [when, period] = options.take_checkpoints.split(",", 1)
         when = int(when)