Test the nvidia driver on reduction when loading the gpu backend.

theano/__init__.py

@@ -99,6 +99,11 @@ import gof
 
 if config.device.startswith('gpu') or config.init_gpu_device.startswith('gpu'):
     import theano.sandbox.cuda
+# We can't test the driver during import of theano.sandbox.cuda as
+# this cause circular import dependency. So we also test it manually
+# after the import
+    import theano.sandbox.cuda.tests.test_driver
+    theano.sandbox.cuda.tests.test_driver.test_nvidia_driver1()
 
 # Use config.numpy to call numpy.seterr
 import numpy

theano/sandbox/cuda/__init__.py

 import atexit, logging, os, shutil, stat, sys
+
+import numpy
+
+import theano
 from theano.compile import optdb
 from theano.gof.cmodule import get_lib_extension
 from theano.configparser import config, AddConfigVar, StrParam
@@ -133,6 +137,9 @@ if cuda_available:
             os.symlink(cuda_ndarray_so, libcuda_ndarray_so)
 
     try:
+        # This only test if the cuda driver is available and if there
+        # is at least one GPU that support cuda. This do not select a
+        # device.
         gpu_init()
         cuda_available = True
         cuda_initialization_error_message = ""
@@ -184,7 +191,8 @@ def use(device,
         force=False,
         default_to_move_computation_to_gpu=True,
         move_shared_float32_to_gpu=True,
-        enable_cuda=True):
+        enable_cuda=True,
+        test_driver=True):
     """
     Error and warning about CUDA should be displayed only when this
     function is called.  We need to be able to load this module only
@@ -246,10 +254,13 @@ def use(device,
         try:
             if device != 'gpu':
                 gpu_init(device)
+            use.device_number = device
+            if test_driver:
+                import theano.sandbox.cuda.tests.test_driver
+                theano.sandbox.cuda.tests.test_driver.test_nvidia_driver1()
 
             if move_shared_float32_to_gpu:
                 handle_shared_float32(True)
-            use.device_number = device
 
             if enable_cuda:
                 cuda_enabled = True
@@ -302,8 +313,10 @@ def handle_shared_float32(tf):
     else:
         raise NotImplementedError('removing our handler')
 
+# We can't test the driver during import here as this cause circular
+# import dependency. So we also test it in the file theano/__init__.py
 if config.device.startswith('gpu'):
-    use(device=config.device, force=config.force_device)
+    use(device=config.device, force=config.force_device, test_driver=False)
 elif config.init_gpu_device:
     assert config.device == "cpu", (
         "We can use the Theano flag init_gpu_device"
@@ -318,4 +331,4 @@ elif config.init_gpu_device:
         force=config.force_device,
         default_to_move_computation_to_gpu=False,
         move_shared_float32_to_gpu=False,
-        enable_cuda=False)
+        enable_cuda=False, test_driver=False)

theano/sandbox/cuda/tests/test_driver.py

+import numpy
+import theano
+
+# Skip test if cuda_ndarray is not available.
+from nose.plugins.skip import SkipTest
+import theano.sandbox.cuda as cuda_ndarray
+if cuda_ndarray.cuda_available == False:
+    raise SkipTest('Optional package cuda disabled')
+
+import theano.sandbox.cuda as cuda
+import theano.sandbox.cuda.basic_ops as B
+
+
+if theano.config.mode == 'FAST_COMPILE':
+    mode_with_gpu = theano.compile.mode.get_mode('FAST_RUN').including('gpu')
+else:
+    mode_with_gpu = theano.compile.mode.get_default_mode().including('gpu')
+
+
+def test_nvidia_driver1():
+    """ Some nvidia driver give bad result for reduction
+        This execute some reduction test to ensure it run correctly
+    """
+    a = numpy.random.rand(10000).astype("float32")
+    A = cuda.shared_constructor(a)
+    f = theano.function(inputs=[], outputs=A.sum(), mode=mode_with_gpu)
+    topo = f.maker.env.toposort()
+    assert len(topo) == 2
+    assert sum(isinstance(node.op, B.GpuSum) for node in topo) == 1
+    if not numpy.allclose(f(), a.sum()):
+        raise Exception("The nvidia driver version installed with the OS "
+                        "don't give good result for reduction."
+                        "Installing the nvidia driver available on the same "
+                        "download page as the cuda package will fix the "
+                        "problem: http://developer.nvidia.com/cuda-downloads")
+
+
+def test_nvidia_driver2():
+    """ Test that the gpu device is initialized by theano when
+        we manually make a shared variable on the gpu.
+
+        The driver should always be tested during theano initialization
+        of the gpu device
+    """
+    a = numpy.random.rand(10000).astype("float32")
+    cuda.shared_constructor(a)
+    assert theano.sandbox.cuda.use.device_number is not None
+
+
+def test_nvidia_driver3():
+    """ Test that the gpu device is initialized by theano when
+        we build a function with gpu op.
+
+        The driver should always be tested during theano initialization
+        of the gpu device
+    """
+    var = cuda.fvector()
+    f = theano.function([var], var + 1, mode=mode_with_gpu)
+    topo = f.maker.env.toposort()
+    assert any([isinstance(node.op, cuda.GpuElemwise) for node in topo])
+    assert theano.sandbox.cuda.use.device_number is not None
+
+# TODO make sure the test_nvidia_driver test are executed when we make manually
+# a CudaNdarray like this: cuda.CudaNdarray.zeros((5,4))