add print_active_device flag

theano/configdefaults.py

@@ -75,6 +75,11 @@ AddConfigVar('force_device',
         BoolParam(False, allow_override=False),
         in_c_key=False)
 
+AddConfigVar('print_active_device',
+        "Print active device at startup",
+        BoolParam(True, allow_override=False),
+        in_c_key=False)
+
 # Do not add FAST_RUN_NOGC to this list (nor any other ALL CAPS shortcut).
 # The way to get FAST_RUN_NOGC is with the flag 'linker=c|py_nogc'.
 # The old all capital letter way of working is deprecated as it is not

theano/sandbox/cuda/__init__.py

@@ -379,8 +379,10 @@ def use(device,
 
             if enable_cuda:
                 cuda_enabled = True
-            print >> sys.stderr, "Using gpu device %d: %s" % (
-                use.device_number, active_device_name())
+
+            if config.print_active_device:
+                print >> sys.stderr, "Using gpu device %d: %s" %(
+                        active_device_number(), active_device_name())
             if device_properties(use.device_number)['regsPerBlock'] < 16384:
                 # We will try to use too much register per bloc at many places
                 # when there is only 8k register per multi-processor.