Use half_float16 instead of float32 if defined both CUDNN and CUDNN_HALF. Use Tensor Cores.

This commit is contained in:
AlexeyAB 2018-02-22 22:54:40 +03:00
parent 033e934ce8
commit dda993f3dd
3 changed files with 117 additions and 11 deletions

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@ -74,6 +74,38 @@ void binarize_weights_gpu(float *weights, int n, int size, float *binary)
check_error(cudaPeekAtLastError());
}
__global__ void cuda_f32_to_f16(float* input_f32, size_t size, half *output_f16)
{
int idx = blockIdx.x * blockDim.x + threadIdx.x;
if (idx < size) output_f16[idx] = input_f32[idx];
}
void cuda_convert_f32_to_f16(float* input_f32, size_t size, half *output_f16) {
cuda_f32_to_f16 <<< size / BLOCK + 1, BLOCK, 0, get_cuda_stream() >>> (input_f32, size, output_f16);
}
__global__ void cuda_f16_to_f32(half* input_f16, size_t size, float *output_f32)
{
int idx = blockIdx.x * blockDim.x + threadIdx.x;
if (idx < size) output_f32[idx] = input_f16[idx];
}
void cuda_convert_f16_to_f32(half* input_f16, size_t size, float *output_f32) {
cuda_f16_to_f32 <<< size / BLOCK + 1, BLOCK, 0, get_cuda_stream() >>> (input_f16, size, output_f32);
}
half *cuda_make_f16_from_f32_array(float *src, size_t n)
{
half *dst16;
size_t size = sizeof(half)*n;
check_error(cudaMalloc((void **)&dst16, size));
if (src) {
cuda_convert_f32_to_f16(src, n, dst16);
}
if (!dst16) error("Cuda malloc failed\n");
return dst16;
}
void forward_convolutional_layer_gpu(convolutional_layer l, network_state state)
{
fill_ongpu(l.outputs*l.batch, 0, l.output_gpu, 1);
@ -90,9 +122,57 @@ void forward_convolutional_layer_gpu(convolutional_layer l, network_state state)
}
#ifdef CUDNN
float one = 1;
//float one = 1; // alpha[0], beta[0] is float for HALF and FLOAT
float alpha = 1, beta = 0;
#ifdef CUDNN_HALF
// Note: For improved performance it is advised to use beta[0] = 0.0.
// For Tensor Core: cudnnSetConvolutionMathType() where cudnnMathType_t mathType = CUDNN_TENSOR_OP_MATH;
// 1. or CUDNN_CONVOLUTION_FWD_ALGO_IMPLICIT_PRECOMP_GEMM and use CUDNN_DATA_HALF
// 2. or CUDNN_CONVOLUTION_FWD_ALGO_WINOGRAD_NONFUSED
// More: http://docs.nvidia.com/deeplearning/sdk/cudnn-developer-guide/index.html#tensor_ops
const size_t input16_size = l.batch*l.c*l.w*l.h;
static size_t max_input16_size = input16_size;
static half* input16 = cuda_make_f16_from_f32_array(NULL, max_input16_size);
const size_t output16_size = l.batch*l.out_c*l.out_h*l.out_w;
static size_t max_output16_size = output16_size;
static half* output16 = cuda_make_f16_from_f32_array(NULL, max_output16_size);
if (max_input16_size < input16_size) {
max_input16_size = input16_size;
cuda_free((float *)input16);
input16 = cuda_make_f16_from_f32_array(state.input, max_input16_size);
}
if (max_output16_size < output16_size) {
max_output16_size = output16_size;
cuda_free((float *)output16);
output16 = cuda_make_f16_from_f32_array(NULL, max_output16_size);
}
cuda_convert_f32_to_f16(state.input, input16_size, input16);
cudnnConvolutionForward(cudnn_handle(),
&alpha,
l.srcTensorDesc,
input16,
l.weightDesc,
l.weights_gpu16,
l.convDesc,
l.fw_algo,
state.workspace,
l.workspace_size,
&beta,
l.dstTensorDesc,
output16);
cuda_convert_f16_to_f32(output16, output16_size, l.output_gpu);
#else
cudnnConvolutionForward(cudnn_handle(),
&one,
&alpha,
l.srcTensorDesc,
state.input,
l.weightDesc,
@ -101,9 +181,11 @@ void forward_convolutional_layer_gpu(convolutional_layer l, network_state state)
l.fw_algo,
state.workspace,
l.workspace_size,
&one,
&beta,
l.dstTensorDesc,
l.output_gpu);
#endif
#else
int i;
@ -232,6 +314,9 @@ void pull_convolutional_layer(convolutional_layer layer)
void push_convolutional_layer(convolutional_layer layer)
{
cuda_push_array(layer.weights_gpu, layer.weights, layer.c*layer.n*layer.size*layer.size);
#ifdef CUDNN_HALF
cuda_convert_f32_to_f16(layer.weights_gpu, layer.c*layer.n*layer.size*layer.size, (half *)layer.weights_gpu16);
#endif
cuda_push_array(layer.biases_gpu, layer.biases, layer.n);
cuda_push_array(layer.weight_updates_gpu, layer.weight_updates, layer.c*layer.n*layer.size*layer.size);
cuda_push_array(layer.bias_updates_gpu, layer.bias_updates, layer.n);

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@ -139,22 +139,38 @@ size_t get_workspace_size(layer l){
#ifdef CUDNN
void cudnn_convolutional_setup(layer *l, int cudnn_preference)
{
cudnnSetTensor4dDescriptor(l->dsrcTensorDesc, CUDNN_TENSOR_NCHW, CUDNN_DATA_FLOAT, l->batch, l->c, l->h, l->w);
cudnnSetTensor4dDescriptor(l->ddstTensorDesc, CUDNN_TENSOR_NCHW, CUDNN_DATA_FLOAT, l->batch, l->out_c, l->out_h, l->out_w);
cudnnSetFilter4dDescriptor(l->dweightDesc, CUDNN_DATA_FLOAT, CUDNN_TENSOR_NCHW, l->n, l->c, l->size, l->size);
cudnnSetTensor4dDescriptor(l->srcTensorDesc, CUDNN_TENSOR_NCHW, CUDNN_DATA_FLOAT, l->batch, l->c, l->h, l->w);
cudnnSetTensor4dDescriptor(l->dstTensorDesc, CUDNN_TENSOR_NCHW, CUDNN_DATA_FLOAT, l->batch, l->out_c, l->out_h, l->out_w);
cudnnSetFilter4dDescriptor(l->weightDesc, CUDNN_DATA_FLOAT, CUDNN_TENSOR_NCHW, l->n, l->c, l->size, l->size);
#ifdef CUDNN_HALF
// TRUE_HALF_CONFIG is only supported on architectures with true fp16 support (compute capability 5.3 and 6.0):
// Tegra X1, Jetson TX1, DRIVE CX, DRIVE PX, Quadro GP100, Tesla P100
const cudnnDataType_t data_type = CUDNN_DATA_HALF;
#else
cudnnDataType_t data_type = CUDNN_DATA_FLOAT;
#endif
// Tensor Core uses CUDNN_TENSOR_OP_MATH instead of CUDNN_DEFAULT_MATH
cudnnSetConvolutionMathType(l->convDesc, CUDNN_TENSOR_OP_MATH);
// INT8_CONFIG, INT8_EXT_CONFIG, INT8x4_CONFIG and INT8x4_EXT_CONFIG are only supported
// on architectures with DP4A support (compute capability 6.1 and later).
//cudnnDataType_t data_type = CUDNN_DATA_INT8;
cudnnSetTensor4dDescriptor(l->dsrcTensorDesc, CUDNN_TENSOR_NCHW, data_type, l->batch, l->c, l->h, l->w);
cudnnSetTensor4dDescriptor(l->ddstTensorDesc, CUDNN_TENSOR_NCHW, data_type, l->batch, l->out_c, l->out_h, l->out_w);
cudnnSetFilter4dDescriptor(l->dweightDesc, data_type, CUDNN_TENSOR_NCHW, l->n, l->c, l->size, l->size);
cudnnSetTensor4dDescriptor(l->srcTensorDesc, CUDNN_TENSOR_NCHW, data_type, l->batch, l->c, l->h, l->w);
cudnnSetTensor4dDescriptor(l->dstTensorDesc, CUDNN_TENSOR_NCHW, data_type, l->batch, l->out_c, l->out_h, l->out_w);
cudnnSetFilter4dDescriptor(l->weightDesc, data_type, CUDNN_TENSOR_NCHW, l->n, l->c, l->size, l->size);
#if(CUDNN_MAJOR >= 6)
cudnnSetConvolution2dDescriptor(l->convDesc, l->pad, l->pad, l->stride, l->stride, 1, 1, CUDNN_CROSS_CORRELATION, CUDNN_DATA_FLOAT); // cudnn 6.0
cudnnSetConvolution2dDescriptor(l->convDesc, l->pad, l->pad, l->stride, l->stride, 1, 1, CUDNN_CROSS_CORRELATION, data_type); // cudnn >= 6.0
#else
cudnnSetConvolution2dDescriptor(l->convDesc, l->pad, l->pad, l->stride, l->stride, 1, 1, CUDNN_CROSS_CORRELATION); // cudnn 5.1
#endif
int forward_algo = CUDNN_CONVOLUTION_FWD_PREFER_FASTEST;
int backward_algo = CUDNN_CONVOLUTION_BWD_DATA_PREFER_FASTEST;
int backward_filter = CUDNN_CONVOLUTION_BWD_FILTER_PREFER_FASTEST;
if (cudnn_preference == cudnn_smallest) {
if (cudnn_preference == cudnn_smallest)
{
forward_algo = CUDNN_CONVOLUTION_FWD_NO_WORKSPACE;
backward_algo = CUDNN_CONVOLUTION_BWD_DATA_NO_WORKSPACE;
backward_filter = CUDNN_CONVOLUTION_BWD_FILTER_NO_WORKSPACE;
@ -275,6 +291,9 @@ convolutional_layer make_convolutional_layer(int batch, int h, int w, int c, int
}
l.weights_gpu = cuda_make_array(l.weights, c*n*size*size);
#ifdef CUDNN_HALF
l.weights_gpu16 = cuda_make_array(l.weights, c*n*size*size/2);
#endif
l.weight_updates_gpu = cuda_make_array(l.weight_updates, c*n*size*size);
l.biases_gpu = cuda_make_array(l.biases, n);

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@ -242,6 +242,8 @@ struct layer{
float * weights_gpu;
float * weight_updates_gpu;
float * weights_gpu16;
float * biases_gpu;
float * bias_updates_gpu;