configs: add option for repeatedly switching back-and-forth between cpu types.

This patch adds a --repeat-switch option that will enable repeat core
switching at a user defined period (set with --switch-freq option).
currently, a switch can only occur between like CPU types. inorder CPU
switching is not supported.

*note*
this patch simply allows a config that will perform repeat switching, it
does not fix drain/switchout functionality. if you run with repeat switching
you will hit assertion failures and/or your workload with hang or die.

2 files changed, 92 insertions, 18 deletions

diff --git a/configs/common/Options.py b/configs/common/Options.py
index c625ab179..6f7059f26 100644
--- a/configs/common/Options.py
+++ b/configs/common/Options.py
@@ -104,11 +104,12 @@ def addCommonOptions(parser):
     # 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 timing CPU to Detailed CPU")
-    parser.add_option("-w", "--warmup", action="store", type="int",
-        help="if -s, then this is the warmup period.  else, this is ignored",
-        default=5000000000)
+    parser.add_option("--repeat-switch", action="store", type="int",
+        default=None,
+        help="switch back and forth between CPUs with period <N>")
+    parser.add_option("-s", "--standard-switch", action="store", type="int",
+        default=None,
+        help="switch from timing to Detailed CPU after warmup period of <N>")
     parser.add_option("-p", "--prog-interval", type="int",
         help="CPU Progress Interval")
 
diff --git a/configs/common/Simulation.py b/configs/common/Simulation.py
index 72c99c20c..0c399e9b7 100644
--- a/configs/common/Simulation.py
+++ b/configs/common/Simulation.py
@@ -214,10 +214,6 @@ def scriptCheckpoints(options):
     return exit_cause
 
 def benchCheckpoints(options, maxtick, cptdir):
-    if options.fast_forward:
-        m5.stats.reset()
-
-    print "**** REAL SIMULATION ****"
     exit_event = m5.simulate(maxtick)
     exit_cause = exit_event.getCause()
 
@@ -236,6 +232,29 @@ def benchCheckpoints(options, maxtick, cptdir):
 
     return exit_cause
 
+def repeatSwitch(testsys, repeat_switch_cpu_list, maxtick, switch_freq):
+    print "starting switch loop"
+    while True:
+        exit_event = m5.simulate(switch_freq)
+        exit_cause = exit_event.getCause()
+
+        if exit_cause != "simulate() limit reached":
+            return exit_cause
+
+        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()) <= switch_freq:
+            exit_event = m5.simulate(maxtick - m5.curTick())
+            return exit_event.getCause()
+
 def run(options, root, testsys, cpu_class):
     if options.maxtick:
         maxtick = options.maxtick
@@ -259,6 +278,12 @@ def run(options, root, testsys, cpu_class):
     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:
+        fatal("Can't specify both --repeat-switch and --take-checkpoints")
+
     np = options.num_cpus
     switch_cpus = None
 
@@ -271,7 +296,7 @@ def run(options, root, testsys, cpu_class):
             testsys.cpu[i].max_insts_any_thread = options.maxinsts
 
     if cpu_class:
-        switch_cpus = [cpu_class(defer_registration=True, cpu_id=(np+i))
+        switch_cpus = [cpu_class(defer_registration=True, cpu_id=(i))
                        for i in xrange(np)]
 
         for i in xrange(np):
@@ -290,15 +315,55 @@ def run(options, root, testsys, cpu_class):
         testsys.switch_cpus = switch_cpus
         switch_cpu_list = [(testsys.cpu[i], 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"
+    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=(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=(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=(i)) for i in xrange(np)]
+        else:
+            repeat_switch_cpus = [AtomicSimpleCPU(defer_registration=True, \
+                                  cpu_id=(i)) for i in xrange(np)]
 
-        switch_cpus = [TimingSimpleCPU(defer_registration=True, cpu_id=(np+i))
+        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
+
+            if options.checker:
+                repeat_switch_cpus[i].addCheckerCpu()
+
+        testsys.repeat_switch_cpus = repeat_switch_cpus
+
+        if cpu_class:
+            repeat_switch_cpu_list = [(switch_cpus[i], repeat_switch_cpus[i])
+                                      for i in xrange(np)]
+        else:
+            repeat_switch_cpu_list = [(testsys.cpu[i], repeat_switch_cpus[i])
+                                      for i in xrange(np)]
+
+    if options.standard_switch:
+        switch_cpus = [TimingSimpleCPU(defer_registration=True, cpu_id=(i))
                        for i in xrange(np)]
-        switch_cpus_1 = [DerivO3CPU(defer_registration=True, cpu_id=(2*np+i))
+        switch_cpus_1 = [DerivO3CPU(defer_registration=True, cpu_id=(i))
                         for i in xrange(np)]
 
         for i in xrange(np):
@@ -400,7 +465,7 @@ def run(options, root, testsys, cpu_class):
             if options.warmup_insts:
                 exit_event = m5.simulate()
             else:
-                exit_event = m5.simulate(options.warmup)
+                exit_event = m5.simulate(options.standard_switch)
             print "Switching CPUS @ tick %s" % (m5.curTick())
             print "Simulation ends instruction count:%d" % \
                     (testsys.switch_cpus_1[0].max_insts_any_thread)
@@ -425,9 +490,17 @@ def run(options, root, testsys, cpu_class):
         # favor of command line checkpoint instructions.
         exit_cause = scriptCheckpoints(options)
     else:
+        if options.fast_forward:
+            m5.stats.reset()
+        print "**** REAL SIMULATION ****"
+
         # If checkpoints are being taken, then the checkpoint instruction
         # will occur in the benchmark code it self.
-        exit_cause = benchCheckpoints(options, maxtick, cptdir)
+        if options.repeat_switch and maxtick > options.repeat_switch:
+            exit_cause = repeatSwitch(testsys, repeat_switch_cpu_list,
+                                      maxtick, options.repeat_switch)
+        else:
+            exit_cause = benchCheckpoints(options, maxtick, cptdir)
 
     print 'Exiting @ tick %i because %s' % (m5.curTick(), exit_cause)
     if options.checkpoint_at_end: