diff -r e895db06e69f -r d0db3e1dab40 src/cpu/ozone/cpu_impl.hh
--- a/src/cpu/ozone/cpu_impl.hh	Mon Jul 15 18:08:57 2013 -0400
+++ b/src/cpu/ozone/cpu_impl.hh	Wed Aug 07 15:48:03 2013 -0500
@@ -282,7 +282,7 @@
     assert(thread_num == 0);
 
     assert(_status == Idle);
-    notIdleFraction++;
+    notIdleFraction = 1;
     scheduleTickEvent(delay);
     _status = Running;
     if (thread.quiesceEvent && thread.quiesceEvent->scheduled())
@@ -300,7 +300,7 @@
     // @todo: Figure out how to initially set the status properly so
     // this is running.
 //    assert(_status == Running);
-    notIdleFraction--;
+    notIdleFraction = 0;
     unscheduleTickEvent();
     _status = Idle;
 }
diff -r e895db06e69f -r d0db3e1dab40 src/cpu/simple/atomic.cc
--- a/src/cpu/simple/atomic.cc	Mon Jul 15 18:08:57 2013 -0400
+++ b/src/cpu/simple/atomic.cc	Wed Aug 07 15:48:03 2013 -0500
@@ -175,8 +175,10 @@
     if (thread->status() == ThreadContext::Active) {
         schedule(tickEvent, nextCycle());
         _status = BaseSimpleCPU::Running;
+        notIdleFraction = 1;
     } else {
         _status = BaseSimpleCPU::Idle;
+        notIdleFraction = 0;
     }
 
     system->totalNumInsts = 0;
@@ -244,7 +246,7 @@
     assert(_status == Idle);
     assert(!tickEvent.scheduled());
 
-    notIdleFraction++;
+    notIdleFraction = 1;
     numCycles += ticksToCycles(thread->lastActivate - thread->lastSuspend);
 
     //Make sure ticks are still on multiples of cycles
@@ -271,7 +273,7 @@
     if (tickEvent.scheduled())
         deschedule(tickEvent);
 
-    notIdleFraction--;
+    notIdleFraction = 0;
     _status = Idle;
 }
 
diff -r e895db06e69f -r d0db3e1dab40 src/cpu/simple/timing.cc
--- a/src/cpu/simple/timing.cc	Mon Jul 15 18:08:57 2013 -0400
+++ b/src/cpu/simple/timing.cc	Wed Aug 07 15:48:03 2013 -0500
@@ -144,8 +144,10 @@
     if (thread->status() == ThreadContext::Active) {
         schedule(fetchEvent, nextCycle());
         _status = BaseSimpleCPU::Running;
+        notIdleFraction = 1;
     } else {
         _status = BaseSimpleCPU::Idle;
+        notIdleFraction = 0;
     }
 }
 
@@ -207,7 +209,7 @@
 
     assert(_status == Idle);
 
-    notIdleFraction++;
+    notIdleFraction = 1;
     _status = BaseSimpleCPU::Running;
 
     // kick things off by initiating the fetch of the next instruction
@@ -231,7 +233,7 @@
     // just change status to Idle... if status != Running,
     // completeInst() will not initiate fetch of next instruction.
 
-    notIdleFraction--;
+    notIdleFraction = 0;
     _status = Idle;
 }