.. _libdoc_cuda_dnn: ================================ :mod:`sandbox.cuda.dnn` -- cuDNN ================================ .. moduleauthor:: LISA `cuDNN `_ is an NVIDIA library with functionality used by deep neural network. It provides optimized versions of some operations like the convolution. cuDNN is not currently installed with CUDA 6.5. You must download and install it yourself. To install it, decompress the downloaded file and make the ``*.h`` and ``*.so*`` files available to the compilation environment. There are at least three possible ways of doing so: - The easiest is to include them in your CUDA installation. Copy the ``*.h`` files to ``CUDA_ROOT/include`` and the ``*.so*`` files to ``CUDA_ROOT/lib64`` (by default, ``CUDA_ROOT`` is ``/usr/local/cuda`` on Linux). - Alternatively, on Linux, you can set the environment variables ``LD_LIBRARY_PATH``, ``LIBRARY_PATH`` and ``CPATH`` to the directory extracted from the download. If needed, separate multiple directories with ``:`` as in the ``PATH`` environment variable. example:: export LD_LIBRARY_PATH=/home/user/path_to_CUDNN_folder/lib64:$LD_LIBRARY_PATH export CPATH=/home/user/path_to_CUDNN_folder/include:$CPATH export LIBRARY_PATH=/home/user/path_to_CUDNN_folder/lib64:$LD_LIBRARY_PATH - And as a third way, also on Linux, you can copy the ``*.h`` files to ``/usr/include`` and the ``*.so*`` files to ``/lib64``. By default, Theano will detect if it can use cuDNN. If so, it will use it. If not, Theano optimizations will not introduce cuDNN ops. So Theano will still work if the user did not introduce them manually. To get an error if Theano can not use cuDNN, use this Theano flag: ``optimizer_including=cudnn``. .. note:: CuDNN v3 has now been released. CuDNN v2 remains supported but CuDNN v3 is faster and offers many more options. We recommend that everybody update to v3. .. note:: Starting in CuDNN v3, multiple convolution implementations are offered and it is possible to use heuristics to automatically choose a convolution implementation well suited to the parameters of the convolution. The Theano flag ``dnn.conv.algo_fwd`` allows to specify the CuDNN convolution implementation that Theano should use for forward convolutions. Possible values include : * ``small`` (default) : use a convolution implementation with small memory usage * ``none`` : use a slower implementation with minimal memory usage * ``large`` : use a sometimes faster implementation with large memory usage * ``fft`` : use the Fast Fourrier Transform implementation of convolution (very high memory usage) * ``guess_once`` : the first time a convolution is executed, the implementation to use is chosen according to CuDNN's heuristics and reused for every subsequent execution of the convolution. * ``guess_on_shape_change`` : like ``guess_once`` but a new convolution implementation selected every time the shapes of the inputs and kernels don't match the shapes from the last execution. * ``time_once`` : the first time a convolution is executed, every convolution implementation offered by CuDNN is executed and timed. The fastest is reused for every subsequent execution of the convolution. * ``time_on_shape_change`` : like ``time_once`` but a new convolution implementation selected every time the shapes of the inputs and kernels don't match the shapes from the last execution. The Theano flag ``dnn.conv.algo_bwd`` allows to specify the CuDNN convolution implementation that Theano should use for gradient convolutions. Possible values include : * ``none`` (default) : use the default non-deterministic convolution implementation * ``deterministic`` : use a slower but deterministic implementation * ``fft`` : use the Fast Fourrier Transform implementation of convolution (very high memory usage) * ``guess_once`` : the first time a convolution is executed, the implementation to use is chosen according to CuDNN's heuristics and reused for every subsequent execution of the convolution. * ``guess_on_shape_change`` : like ``guess_once`` but a new convolution implementation selected every time the shapes of the inputs and kernels don't match the shapes from the last execution. * ``time_once`` : the first time a convolution is executed, every convolution implementation offered by CuDNN is executed and timed. The fastest is reused for every subsequent execution of the convolution. * ``time_on_shape_change`` : like ``time_once`` but a new convolution implementation selected every time the shapes of the inputs and kernels don't match the shapes from the last execution. ``guess_*`` and ``time_*`` flag values take into account the amount of available memory when selecting an implementation. This means that slower implementations might be selected if not enough memory is available for the faster implementations. .. note:: Normally you should not call GPU Ops directly, but the CPU interface currently does not allow all options supported by cuDNN ops. So it is possible that you will need to call them manually. .. note:: The documentation of CUDNN tells that, for the 2 following operations, the reproducibility is not guaranteed with the default implementation: `cudnnConvolutionBackwardFilter` and `cudnnConvolutionBackwardData`. Those correspond to the gradient wrt the weights and the gradient wrt the input of the convolution. They are also used sometimes in the forward pass, when they give a speed up. The Theano flag ``dnn.conv.algo_bwd`` can be use to force the use of a slower but deterministic convolution implementation. .. note:: There is a problem we do not understand yet when cudnn paths are used with symbolic links. So avoid using that. .. note:: cudnn.so* must be readable and executable by everybody. cudnn.h must be readable by everybody. Functions ========= .. automodule:: theano.sandbox.cuda.dnn :noindex: :members: dnn_conv, dnn_pool Convolution Ops =============== .. automodule:: theano.sandbox.cuda.dnn :noindex: :members: GpuDnnConvDesc, GpuDnnConv, GpuDnnConv3d, GpuDnnConvGradW, GpuDnnConv3dGradW, GpuDnnConvGradI, GpuDnnConv3dGradI Pooling Ops =========== .. automodule:: theano.sandbox.cuda.dnn :noindex: :members: GpuDnnPoolDesc, GpuDnnPool, GpuDnnPoolGrad Softmax Ops =========== .. automodule:: theano.sandbox.cuda.dnn :noindex: :members: GpuDnnSoftmax, GpuDnnSoftmaxGrad