perf-monitor: print load avg

utils/gr-perf-to-csv

@@ -20,6 +20,7 @@
 import sys, time
 
 from gnuradio import gr, ctrlport
+from subprocess import Popen, PIPE
 
 class MyApp(object):
     def __init__(self, args):
@@ -63,7 +64,7 @@ class MyApp(object):
         client.setKnobs(knobs)
 
         # let the flow graph run for some time
-        time.sleep(30)
+        time.sleep(60)
 
         ## get work time for all blocks
         kl = map(lambda x: "%s::total work time" % x, blocks)
@@ -75,4 +76,7 @@ class MyApp(object):
 
         print(",".join(map(lambda x: str(x[1]), sorted(work_times.items()))))
 
+        p = Popen("uptime", stdout=PIPE, close_fds=True, shell=True)
+        print(p.stdout.read())
+
 MyApp(sys.argv)