下面是基本步骤:
import torch
from model import Model
model = Model()
model.load_state_dict(torch.load("path/to/weights"))
import torch
from torch.autograd import Function
class CustomOp(Function):
@staticmethod
def forward(ctx, input, weight):
# 这里实现自定义操作的前向传递
output = ...
ctx.save_for_backward(input, weight)
return output
@staticmethod
def backward(ctx, grad_output):
# 这里实现自定义操作的反向传递
input, weight = ctx.saved_tensors
grad_input = ...
grad_weight = ...
return grad_input, grad_weight
import torch.nn as nn
class Transformer(nn.Module):
def __init__(self):
super(Transformer, self).__init__()
self.self_attn = CustomOp() # 将自定义操作应用于transformer模块的网络层
def forward(self, x):
output = self.self_attn(x, weight)
return output
import onnx
from onnx import TensorProto, helper
# 将模型和权重参数转换为ONNX格式
input_shape = (1,3,224,224)
input_names = ['input']
output_names = ['output']
x = torch.randn(input_shape)
torch.onnx.export(model, x, 'model.onnx', input_names=input_names, output_names=output_names)
# 加载ONNX模型
model = onnx.load("model.onnx")
# 新增自定义操作,并将其插入ONNX模型
op_def = helper.make_node(
"CustomOp",
inputs=["input", "weight"],
outputs=["output"]
)
model.graph.node.append(op_def)
# 修改输入和输出张量的数据类型为float32
for i in range(len(model.graph.input)):
model.graph.input[i].type.tensor_type.elem_type = TensorProto.FLOAT
for i in range(len(model.graph.output)):
model.graph.output[i].type.tensor_type.elem_type = TensorProto.FLOAT
# 保存修改后的ONNX模型
onnx.save(model, "model_custom_op.onnx")
这样,我们就获得了带有自定义操作的ONNX模型。
首先,我们需要将原始PyTorch模型转换为ONNX格式,这可以通过以下代码完成:
import torch
import onnx
import onnxruntime
# Load the model
model = torch.load("model.pt")
# Set the model to evaluation mode
model.eval()
# Dummy input for the model
input_names = ["input"]
output_names = ["output"]
dummy_input = torch.randn(1, 3, 224, 224)
# Export the model to ONNX
onnx_path = "model.onnx"
torch.onnx.export(model, dummy_input, onnx_path, input_names=input_names, output_names=output_names, opset_version=12)
接下来,我们需要使用ONNX库加载模型,并替换转换器模块的网络层。我们可以使用ONNX的Graph和Model API来实现这个过程。
import onnx
from onnx import numpy_helper
from onnx import ModelProto
import onnx.tools
# Load the ONNX model
model_path = 'model.onnx'
onnx_model = onnx.load(model_path)
# Find the Transformer module in the ONNX graph
for node in onnx_model.graph.node:
if 'Transformer' in node.name:
transformer_node = node
# Find the weights of the Transformer module
for initializer in onnx_model.graph.initializer:
if transformer_node.name in initializer.name:
transformer_weights = numpy_helper.to_array(initializer)
# Replace the Transformer module with custom node
from onnx.helper import make_node
custom_node = make_node(op_type='CustomOp', inputs=transformer_node.input, outputs=transformer_node.output, name=transformer_node.name)
onnx_model.graph.node.remove(transformer_node)
onnx_model.graph.node.append(custom_node)
# Save the modified ONNX model
onnx.checker.check_model(onnx_model)
onnx.save(onnx_model, 'custom_model.onnx')
在代码中,我们首先加载了ONNX模型,然后遍历图寻找我们想要替换的Transformer模块。然后,我们在图中找到该层的权重,并使用其创建一个新的自定义节点,然后通过删除已有的Transformer节点,并将自定义节点添加到图中来替换它。最后,我们将修改后的模型保存为新的ONNX文件。
接下来,我们需要使用TensorRT来加载我们的自定义模型并运行推理。在TensorRT中使用自定义操作需要实现自定义插件。TensorRT提供了C++ API和Python API来实现自定义插件。这里我们将介绍如何使用Python API来实现自定义插件。
首先,我们需要实现我们的自定义操作。我们可以使用C ++编写自定义操作,然后使用Python API将其转换为TensorRT插件。这里,我们将为您提供一个示例代码,以了解如何将PyTorch中的自定义操作转换为TensorRT插件。
// Sample code for a custom operation to replace the Transformer module in PyTorch
#include "NvInfer.h"
#include "NvInferPlugin.h"
int main(int argc, char** argv) {
// Create a new logger for TensorRT
auto logger = nvinfer1::createLogger(nvinfer1::ILogger::Severity::kINFO);
// Create a TensorRT builder and network
auto builder = nvinfer1::createInferBuilder(logger);
auto network = builder->createNetwork();
// Define the input tensor shape
nvinfer1::Dims input_shape;
input_shape.nbDims = 4;
input_shape.d[0] = 1;
input_shape.d[1] = 3;
input_shape.d[2] = 224;
input_shape.d[3] = 224;
// Define the input tensor
auto input = network->addInput("input", nvinfer1::DataType::kFLOAT, input_shape);
// Define the output tensor shape
nvinfer1::Dims output_shape;
output_shape.nbDims = 4;
output_shape.d[0] = 1;
output_shape.d[1] = 3;
output_shape.d[2] = 224;
output_shape.d[3] = 224;
// Define the output tensor
auto output = network->addOutput("output", nvinfer1::DataType::kFLOAT, output_shape);
// Create a new plugin layer
auto plugin_factory = getPluginRegistry()->getPluginFactory("CustomOp");
std::vector<nvinfer1::PluginField> plugin_fields;
nvinfer1::PluginFieldCollection plugin_field_collection;
plugin_field_collection.nbFields = static_cast<int>(plugin_fields.size());
plugin_field_collection.fields = plugin_fields.data();
auto plugin_layer = plugin_factory->createPlugin("CustomOp", &plugin_field_collection);
// Add the plugin layer to the network
nvinfer1::IPluginV2Layer* plugin = network->addPluginV2(&input, 1, *plugin_layer);
// Build the TensorRT engine
auto engine = builder->buildCudaEngine(*network);
// Serialize the engine to a file
nvinfer1::IHostMemory* serialized_engine = engine->serialize();
std::ofstream engine_file("engine.trt", std::ios::binary);
engine_file.write(static_cast<char*>(serialized_engine->data()), serialized_engine->size());
// Destroy the objects
serialized_engine->destroy();
engine->destroy();
plugin_layer->destroy();
network->destroy();
builder->destroy();
logger->destroy();
return 0;
}
这里,我们定义了一个新的TensorRT Builder和Network,然后添加了我们的自定义OP。请注意,我们在创建自定义层时使用了PluginFactory,这需要从TensorRT插件注册表获取。PluginFactory需要插件类型名称来创建自定义插件。
接下来,我们使用以下代码将C ++插件转换为Python插件。
import tensorrt as trt
import numpy as np
# Define our custom plugin layer with an instance normalization operation
class CustomOpLayer(trt.PluginLayer):
def __init__(self, context, max_batch_size, *args, **kwargs):
super().__init__(context, max_batch_size)
def get_plugin_fields(self):
# Define the plugin fields
fields = [trt.PluginField("norm", np.array([1.0], dtype=np.float32), trt.PluginFieldType.FLOAT32)]
# Return the plugin fields
return fields
def get_output_type(self, idx, input_types):
# Return the output types of the plugin layer
return input_types[0]
def plugin_op(self):
# Implement the custom plugin operation
return input_tensor * self.norm
def create_plugin():
# Create the plugin layer
layer = CustomOpLayer()
# Return the plugin layer
return layer
# Register the plugin with TensorRT
trt.init_libnvinfer_plugins(logger, '')
plugin_registry = trt.get_plugin_registry()
plugin_creator = plugin_registry.get_plugin_creator("CustomOp", "1", "")
plugin = plugin_creator.create_plugin('CustomOp', trt.PluginFieldCollection())
在代码中,我们定义了一个自定义层,该层包含一个实例归一化操作,并重写了基类中的get_plugin_fields,get_output_type和plugin_op方法。然后,我们通过使用get_plugin_registry来注册自定义插件,并使用get_plugin_creator和create_plugin方法来创建TensorRT插件。
现在,我们已经成功地将PyTorch模型转换为带有自定义操作的ONNX模型,并使用TensorRT API将其转换为可用于推理的TensorRT引擎和插件。我们可以使用如下代码来加载TensorRT引擎并运行推理:
import tensorrt as trt
import pycuda.driver as cuda
import pycuda.autoinit
# Load the serialized engine
serialized_engine = open("engine.trt", "rb").read()
# Create a TensorRT runtime
runtime = trt.Runtime(trt.Logger(trt.Logger.WARNING))
# Deserialize the engine
engine = runtime.deserialize_cuda_engine(serialized_engine)
# Create a TensorRT execution context
context = engine.create_execution_context()
# Allocate device memory for inputs and outputs
input = cuda.mem_alloc(1 * 3 * 224 * 224 * 4)
output = cuda.mem_alloc(1 * 3 * 224 * 224 * 4)
# Load the input data to device memory
input_data = np.zeros((1, 3, 224, 224), dtype=np.float32)
cuda.memcpy_htod(input, input_data.ravel())
# Run inference on the device
context.execute(1, [int(input), int(output)])
# Copy the output data from device memory to host memory
output_data = np.empty((1, 3, 224, 224), dtype=np.float32)
cuda.memcpy_dtoh(output_data.ravel(), output)
# Print the output data
print(output_data)
在代码中,我们首先使用TensorRT运行时和序列化引擎初始化TensorRT引擎。然后,我们为输入和输出分配设备内存,并将输入数据加载到设备内存中。最后,我们在设备上运行推理,并将输出数据从设备内存复制到主机内存。
这样就可以实现PyTorch自定义操作的TensorRT部署了。
以下是一个示例代码,用于将transformer模块的网络层融合为一个自定义的ONNX节点,并使用TensorRT插件实现。
首先,需要安装必要的Python库和TensorRT。以下是安装TensorRT的步骤:
pip install tensorrt
pip install tensorrt-plugin
接下来,使用以下代码将transformer模块的网络层融合为一个自定义的ONNX节点:
import onnx
from onnx import helper, numpy_helper, shape_inference
# Load the trained model
model_file = 'model.pt'
model = torch.load(model_file)
# Get the weights of the transformer module
transformer_weights = model.transformer.state_dict()
# Create the inputs and outputs for the new custom node
inputs = [
helper.make_tensor_value_info('input', onnx.TensorProto.FLOAT, ['batch_size', 'seq_len', 'hidden_size']),
helper.make_tensor_value_info('weights', onnx.TensorProto.FLOAT, ['num_layers', '3', 'hidden_size', 'hidden_size']),
helper.make_tensor_value_info('bias', onnx.TensorProto.FLOAT, ['num_layers', '3', 'hidden_size']),
]
outputs = [
helper.make_tensor_value_info('output', onnx.TensorProto.FLOAT, ['batch_size', 'seq_len', 'hidden_size'])
]
# Create the new custom node
custom_node = helper.make_node(
'MyTransform',
inputs=['input', 'weights', 'bias'],
outputs=['output'],
)
# Create the new ONNX graph with the custom node
graph_def = onnx.GraphProto()
graph_def.node.extend([custom_node])
graph_def.input.extend(inputs)
graph_def.output.extend(outputs)
# Set the shape information for the inputs and outputs
graph_def = shape_inference.infer_shapes(graph_def)
# Add the weights to the graph
for name, weight in transformer_weights.items():
tensor = numpy_helper.from_array(weight.numpy(), name=name)
graph_def.initializer.append(tensor)
# Save the new ONNX graph
onnx_file = 'model.onnx'
onnx.save(graph_def, onnx_file)
注意,这里假设已经使用PyTorch训练好了一个transformer模型并保存为model.pt
文件,需要将其加载到内存中。此外,在新的ONNX图中,使用了自定义节点MyTransform
,需要在后续代码中实现这个节点。
接下来,使用TensorRT插件实现自定义节点。以下是示例代码:
import tensorrt as trt
import numpy as np
# Define the custom plugin and create a TensorRT plugin registry
class MyTransformPlugin(trt.IPluginV2DynamicExt):
def __init__(self, weights, bias):
self.weights = weights
self.bias = bias
def get_plugin_type(self):
return 'MyTransform'
def get_plugin_version(self):
return '1'
def get_output_dtype(self, idx, layer):
return trt.DataType.FLOAT
def get_output_dimensions(self, idx, inputs, outputs, network):
return inputs[0].shape
def configure_plugin(self, inputs, outputs, layers, max_batch_size):
self.batch_size = inputs[0].shape[0]
self.seq_len = inputs[0].shape[1]
self.hidden_size = inputs[0].shape[2]
self.num_layers = self.weights.shape[0]
self.stream = None
def enqueue(self, inputs, outputs, bindings, workspace, stream):
self.stream = stream
input_buf = inputs[0].as_gpu_tensor() # [batch_size, seq_len, hidden_size]
weights_buf = self.weights.as_gpu_tensor() # [num_layers, 3, hidden_size, hidden_size]
bias_buf = self.bias.as_gpu_tensor() # [num_layers, 3, hidden_size]
output_buf = outputs[0].as_gpu_tensor() # [batch_size, seq_len, hidden_size]
# Use CUDA kernel to perform the transformation
cuda_module = None # Load the CUDA module here
cuda_module.my_transform(
input_buf, weights_buf, bias_buf, output_buf,
self.batch_size, self.seq_len, self.hidden_size, self.num_layers,
stream.handle
)
def get_workspace_size(self, max_batch_size):
return 0
def destroy(self):
pass
def clone(self):
return MyTransformPlugin(self.weights, self.bias)
plugin_registry = trt.PluginRegistry()
# Register the plugin with the TensorRT plugin registry
def register_plugin():
plugin_creator = trt.PluginCreator(
name='MyTransform',
plugin_version='1',
plugin_creator=MyTransformPlugin
)
plugin_registry.register_creator(plugin_creator, 'MyTransform')
register_plugin()
# Load the ONNX model with the custom node
onnx_file = 'model.onnx'
model_stream = open(onnx_file, 'rb')
model_proto = onnx.load(model_stream)
# Create the TensorRT engine from the ONNX model
trt_logger = trt.Logger()
builder = trt.Builder(trt_logger)
builder.max_batch_size = 1
builder.fp16_mode = True
engine = builder.build_engine(model_proto, plugin_registry)
这个问题涉及到多个步骤,我尝试简单介绍一下:
使用PyTorch加载模型权重参数,尤其是transformer层的权重参数,可以使用以下代码:
import torch
model = MyModel() # 假设MyModel是你的模型
state_dict = torch.load("model_weights.pth")
model.load_state_dict(state_dict)
在PyTorch中定义自定义op的方式是通过继承torch.autograd.Function
类并实现forward
和backward
方法。例如,以下是一个简单的自定义op示例:
import torch
class MyCustomOp(torch.autograd.Function):
@staticmethod
def forward(ctx, input_tensor, weight_tensor):
# 前向传递的逻辑
output_tensor = input_tensor.mm(weight_tensor.t())
ctx.save_for_backward(input_tensor, weight_tensor)
return output_tensor
@staticmethod
def backward(ctx, grad_output):
# 反向传递的逻辑
input_tensor, weight_tensor = ctx.saved_tensors
grad_input = grad_output.mm(weight_tensor)
grad_weight = grad_output.t().mm(input_tensor)
return grad_input, grad_weight
在这个例子中,自定义op将输入张量input_tensor
与权重张量weight_tensor
相乘,并返回结果。在反向传递中,它计算输入张量和权重张量同时对梯度的贡献。
为了使用自定义op替换transformer层,你需要知道transformer层的具体实现。在PyTorch中,transformer层通常是一个torch.nn.TransformerEncoderLayer
对象,它包含了多个子层,如self-attention层和全连接层。你需要将这些子层替换为自定义op。
以下是一个示例代码,假设你要将transformer层的全连接层替换为自定义op:
import torch.nn as nn
class MyModel(nn.Module):
def __init__(self):
super(MyModel, self).__init__()
self.transformer = nn.TransformerEncoderLayer(d_model=512, nhead=8)
self.custom_op = MyCustomOp.apply
def forward(self, x):
# 获取transformer层的各个子层
self_attn = self.transformer.self_attn
linear1 = self.transformer.linear1
dropout = self.transformer.dropout
linear2 = self.transformer.linear2
norm1 = self.transformer.norm1
norm2 = self.transformer.norm2
# 使用自定义op替换linear2层
x = self_attn(x, x, x)[0]
x = linear1(x)
x = dropout(x)
x = self.custom_op(x, linear2.weight)
x = norm1(x)
x = x + linear2.bias
x = norm2(x)
# 返回输出
return x
在这个例子中,注意到我们使用了MyCustomOp.apply
而不是直接调用MyCustomOp
。这是因为PyTorch要求自定义op使用apply
方法来处理前向和反向传递逻辑。
使用PyTorch将模型导出为ONNX格式,可以使用以下代码:
import torch.onnx
model = MyModel() # 假设MyModel是你的模型
input_shape = (1, 512) # 假设输入张量的形状为(1, 512)
output_path = "my_model.onnx"
model.eval()
# 导出为ONNX模型
x = torch.randn(input_shape)
torch.onnx.export(model, x, output_path, input_names=["input"], output_names=["output"])
在这个例子中,我们使用torch.onnx.export
方法将PyTorch模型导出为ONNX模型。注意要将模型设置为eval模式并提供模型输入和输出的名称。
使用TensorRT加载ONNX模型需要使用TensorRT的C++ API。以下是一个简单的示例代码,假设你要使用TensorRT加载带有自定义op的ONNX模型:
#include "NvInfer.h"
#include "NvOnnxParser.h"
using namespace nvinfer1;
using namespace nvonnxparser;
void loadModelWithCustomOp(const std::string& model_path)
{
// 创建TensorRT builder、network和ONNX解析器
IBuilder* builder = createInferBuilder(gLogger);
INetworkDefinition* network = builder->createNetwork();
IParser* parser = createParser(*network, gLogger);
// 解析ONNX模型并检查是否成功
if (!parser->parseFromFile(model_path.c_str(), 1))
{
std::cerr << "Failed to parse ONNX model" << std::endl;
exit(EXIT_FAILURE);
}
// 注册自定义op
const char* op_name = "MyCustomOp";
const char* plugin_name = "MyCustomOpPlugin";
MyCustomOpPluginCreator plugin_creator;
plugin_creator.setPluginName(plugin_name);
bool registered = parser->registerPlugin(op_name, &plugin_creator);
if (!registered)
{
std::cerr << "Failed to register custom op" << std::endl;
exit(EXIT_FAILURE);
}
// 创建推理引擎
builder->setMaxBatchSize(1);
builder->setMaxWorkspaceSize(1 << 30);
ICudaEngine* engine = builder->buildCudaEngine(*network);
// 释放资源
parser->destroy();
network->destroy();
builder->destroy();
engine->destroy();
}
在这个例子中,我们使用createParser
方法创建ONNX解析器,并使用parseFromFile
方法从文件中解析ONNX模型。然后,我们使用MyCustomOpPluginCreator
类创建自定义op的插件,并使用registerPlugin
方法注册自定义op。最后,我们使用buildCudaEngine
方法创建推理引擎。
注意到我们需要为自定义op编写一个插件,并将其注册到ONNX解析器中。这是因为自定义op并不是TensorRT原生支持的操作。插件的编写和注册需要额外的代码,我在这里就不展开了。如果你想知道更多细节,可以参阅TensorRT的官方文档和代码示例。
希望这些代码能够帮助你解决问题!
对于这个问题,需要进行以下步骤:
首先需要安装一些必要的库和工具,包括PyTorch、ONNX、TensorRT等。可以通过以下命令安装:
pip install torch==1.6.0 onnx==1.7.0 tensorrt==7.2.2.3 pycuda==2020.1
使用PyTorch加载训练好的模型权重,并将其转换为ONNX格式。可以参考以下代码:
import torch
import onnx
# 加载PyTorch模型
model = torch.load('model.pth')
# 转换为ONNX格式
dummy_input = torch.randn(1, 3, 224, 224)
input_names = ['input']
output_names = ['output']
torch.onnx.export(model, dummy_input, 'model.onnx', input_names=input_names, output_names=output_names, opset_version=11)
定义一个自定义节点来融合Transformer的所有子层。可以参考以下代码:
import onnx
from onnx import helper, shape_inference, TensorProto
class TransformerFusion(helper.Node):
def __init__(self, transformer_inputs, transformer_outputs, name=None):
super().__init__('TransformerFusion', transformer_inputs, transformer_outputs, name=name)
def transformer_fusion(inputs, outputs, name=None):
node = TransformerFusion(inputs, outputs, name=name)
return node
使用ONNX API加载模型,并使用自定义节点替换Transformer的所有子层。可以参考以下代码:
# 加载ONNX模型
model = onnx.load('model.onnx')
# 替换Transformer的所有子层
for node in model.graph.node:
if node.op_type == 'MultiHeadAttention':
# 替换MultiHeadAttention子层
inputs = []
for i in range(len(node.input)):
if i == 0:
inputs.append(node.input[i])
else:
inputs.append('dummy')
outputs = node.output
transformer_fusion_node = transformer_fusion(inputs, outputs)
model.graph.node.remove(node)
model.graph.node.extend([transformer_fusion_node])
elif node.op_type == 'LayerNormalization':
# 替换LayerNormalization子层
inputs = []
for i in range(len(node.input)):
if i == 0:
inputs.append(node.input[i])
else:
inputs.append('dummy')
outputs = node.output
transformer_fusion_node = transformer_fusion(inputs, outputs)
model.graph.node.remove(node)
model.graph.node.extend([transformer_fusion_node])
# 推断模型形状
onnx.checker.check_model(model)
onnx.shape_inference.infer_shapes(model)
使用ONNX API导出带有自定义op的ONNX模型。可以参考以下代码:
# 导出有自定义op的ONNX模型
onnx.save(model, 'model_fused.onnx')
使用TensorRT进行推断。可以参考以下代码:
import pycuda.driver as cuda
import pycuda.autoinit
import numpy as np
import tensorrt as trt
# 定义TensorRT logger
TRT_LOGGER = trt.Logger(trt.Logger.WARNING)
# 加载TensorRT引擎
def load_engine():
with open('model.plan', 'rb') as f, trt.Runtime(TRT_LOGGER) as runtime:
engine = runtime.deserialize_cuda_engine(f.read())
return engine
# 创建TensorRT上下文
def create_context():
engine = load_engine()
context = engine.create_execution_context()
return engine, context
# 推断函数
def infer(context, inputs):
inputs = [inp.astype(np.float32) for inp in inputs]
outputs = [np.empty(output.shape, dtype=np.float32) for output in outputs]
stream = cuda.Stream()
bindings = []
for inp in inputs:
bindings.append(int(inp.gpudata))
for out in outputs:
bindings.append(int(out.gpudata))
context.execute_async_v2(bindings=bindings, stream_handle=stream.handle)
stream.synchronize()
return [out.get() for out in outputs]
import torch
import onnx
from onnx import helper, shape_inference, TensorProto
import pycuda.driver as cuda
import pycuda.autoinit
import numpy as np
import tensorrt as trt
# 定义自定义节点
class TransformerFusion(helper.Node):
def __init__(self, transformer_inputs, transformer_outputs, name=None):
super().__init__('TransformerFusion', transformer_inputs, transformer_outputs, name=name)
def transformer_fusion(inputs, outputs, name=None):
node = TransformerFusion(inputs, outputs, name=name)
return node
# 加载PyTorch模型
model = torch.load('model.pth')
# 转换为ONNX格式
dummy_input = torch.randn(1, 3, 224, 224)
input_names = ['input']
output_names = ['output']
torch.onnx.export(model, dummy_input, 'model.onnx', input_names=input_names, output_names=output_names, opset_version=11)
# 加载ONNX模型
model = onnx.load('model.onnx')
# 替换Transformer的所有子层
for node in model.graph.node:
if node.op_type == 'MultiHeadAttention':
# 替换MultiHeadAttention子层
inputs = []
for i in range(len(node.input)):
if i == 0:
inputs.append(node.input[i])
else:
inputs.append('dummy')
outputs = node.output
transformer_fusion_node = transformer_fusion(inputs, outputs)
model.graph.node.remove(node)
model.graph.node.extend([transformer_fusion_node])
elif node.op_type == 'LayerNormalization':
# 替换LayerNormalization子层
inputs = []
for i in range(len(node.input)):
if i == 0:
inputs.append(node.input[i])
else:
inputs.append('dummy')
outputs = node.output
transformer_fusion_node = transformer_fusion(inputs, outputs)
model.graph.node.remove(node)
model.graph.node.extend([transformer_fusion_node])
# 推断模型形状
onnx.checker.check_model(model)
onnx.shape_inference.infer_shapes(model)
# 导出有自定义op的ONNX模型
onnx.save(model, 'model_fused.onnx')
# 创建TensorRT上下文
def create_context():
with open('model.plan', 'rb') as f, trt.Runtime(TRT_LOGGER) as runtime:
engine = runtime.deserialize_cuda_engine(f.read())
context = engine.create_execution_context()
return engine, context
# 推断函数
def infer(context, inputs):
inputs = [inp.astype(np.float32) for inp in inputs]
outputs = [np.empty(output.shape, dtype=np.float32) for output in outputs]
stream = cuda.Stream()
bindings = []
for inp in inputs:
bindings.append(int(inp.gpudata))
for out in outputs:
bindings.append(int(out.gpudata))
context.execute_async_v2(bindings=bindings, stream_handle=stream.handle)
stream.synchronize()
return [out.get() for out in outputs]
# 加载TensorRT引擎
TRT_LOGGER = trt.Logger(trt.Logger.WARNING)
engine, context = create_context()
# 准备输入数据
input_data = np.random.randn(1, 3, 224, 224).astype(np.float32)
outputs = [np.empty(shape, dtype=np.float32) for shape in engine.get_binding_shape(1)]
# 进行推断
trt_outputs = infer(context, [input_data])
# 验证推断结果
for i, trt_output in enumerate(trt_outputs):
np.testing.assert_allclose(outputs[i], trt_output, atol=1e-3)
这是一个比较复杂的问题,需要详细的代码和步骤来回答。以下是一个大体的解决方案:
Step 1. 融合所有层并替换为自定义node
你需要先使用Python和ONNX Runtime执行以下步骤:
加载训练好的CNN Transformer网络权重参数,并将其转换为ONNX模型。
将ONNX模型中所有transformer层的节点融合成一个节点。
将融合后的节点替换为自定义node,并添加相应的属性和输入/输出。
导出新的ONNX模型。
这里给出一个简单的示例代码,假设模型的输入和输出都是固定的:
import onnx
from onnx import helper, shape_inference, TensorProto
from onnx import numpy_helper
# 加载模型
model_path = 'model.onnx'
model = onnx.load(model_path)
# 获取输入和输出张量的名称和形状
input_name = model.graph.input[0].name
input_shape = model.graph.input[0].type.tensor_type.shape.dim
output_name = model.graph.output[0].name
output_shape = model.graph.output[0].type.tensor_type.shape.dim
# 获取transformer层节点
transformer_node = []
for node in model.graph.node:
if node.op_type == 'Transformer':
transformer_node.append(node)
# 融合所有transformer层节点
inputs = [helper.make_tensor_value_info('input', TensorProto.FLOAT, input_shape)]
outputs = [helper.make_tensor_value_info('output', TensorProto.FLOAT, output_shape)]
for node in transformer_node:
inputs.append(node.input[0])
outputs.append(node.output[0])
merge_node = helper.make_node(
'CustomTransformerOp', inputs, outputs, name='Merged_Transformer'
)
# 替换所有transformer层节点为融合节点
new_nodes = []
for node in model.graph.node:
if node not in transformer_node:
new_nodes.append(node)
else:
new_nodes.append(merge_node)
# 更新输入和输出节点的张量名称和形状
model.graph.input[0].name = 'input'
model.graph.input[0].type.tensor_type.shape.dim[0].dim_param = 'batch_size'
model.graph.output[0].name = 'output'
model.graph.output[0].type.tensor_type.shape.dim[0].dim_param = 'batch_size'
# 更新ONNX模型
model.graph.node[:] = new_nodes
onnx.checker.check_model(model)
onnx.save(model, 'merged_model.onnx')
Step 2. 加载新的ONNX模型并使用TensorRT API生成plugin
我们需要使用C++代码加载新的ONNX模型,并使用TensorRT API生成plugin。这里需要TensorRT-7.0.0以上版本。
使用ONNX Parser加载新的ONNX模型。
声明自定义node的plugin。
实现自定义node的plugin,并注册到TensorRT。
构建一个TensorRT engine并运行推理。
以下是一个简单的示例代码,其中假设我们已经定义了CustomTransformerPlugin类和相应的实现:
#include
#include
#include
#include
#include
#include
#include
#include
using namespace std;
using namespace nvinfer1;
using namespace nvonnxparser;
using namespace plugin;
// 声明自定义transformer plugin
class CustomTransformerPlugin : public IPluginV2DynamicExt {
public:
// 构造函数
CustomTransformerPlugin(const int hidden_size);
// 使用weights加载模型参数
CustomTransformerPlugin(const void* data, size_t length);
// 返回plugin名称
const char* getPluginType() const override;
// 返回plugin版本
const char* getPluginVersion() const override;
// 返回plugin能力
const PluginFieldCollection* getFieldNames() override;
// 复制plugin
IPluginV2DynamicExt* clone() const override;
// 返回plugin输出大小
DimsExprs getOutputDimensions(
int outputIndex, const DimsExprs* inputs,
int nbInputs, IExprBuilder& exprBuilder) override;
// 设置plugin数据类型
void setDataType(DataType type) override;
// 返回plugin数据类型
DataType getDataType() const override;
// 返回plugin输出格式
bool supportsFormatCombination(
int pos, const PluginTensorDesc* inOut,
int nbInputs, int nbOutputs) override;
// 初始化plugin
void configurePlugin(
const DynamicPluginTensorDesc* in, int nbInputs,
const DynamicPluginTensorDesc* out, int nbOutputs) override;
// 返回plugin输出格式
size_t getWorkspaceSize(
const PluginTensorDesc* inputs, int nbInputs,
const PluginTensorDesc* outputs, int nbOutputs) const override;
// 运行推理
int enqueue(
const PluginTensorDesc* inputDesc, const PluginTensorDesc* outputDesc,
const void* const* inputs, void* const* outputs, void* workspace,
cudaStream_t stream) override;
// 返回plugin序列化数据大小
size_t getSerializationSize() const override;
// 序列化plugin
void serialize(void* buffer) const override;
// 清空plugin
void destroy() override;
private:
const int mHiddenSize; // transformer隐藏层大小
DataType mDataType; // plugin数据类型
};
// 实现plugin
CustomTransformerPlugin::CustomTransformerPlugin(const int hidden_size)
: mHiddenSize(hidden_size), mDataType(DataType::kFLOAT) {}
CustomTransformerPlugin::CustomTransformerPlugin(const void* data, size_t length)
: mDataType(DataType::kFLOAT) {
// 从weights中加载模型参数
}
const char* CustomTransformerPlugin::getPluginType() const {
return "CustomTransformerPlugin";
}
const char* CustomTransformerPlugin::getPluginVersion() const {
return "1";
}
const PluginFieldCollection* CustomTransformerPlugin::getFieldNames() {
static PluginFieldCollection fields;
return &fields;
}
IPluginV2DynamicExt* CustomTransformerPlugin::clone() const {
return new CustomTransformerPlugin(mHiddenSize);
}
DimsExprs CustomTransformerPlugin::getOutputDimensions(
int outputIndex, const DimsExprs* inputs, int nbInputs,
IExprBuilder& exprBuilder) {
DimsExprs output(inputs[0]);
output.d[2] = exprBuilder.operation(DimensionOperation::kPROD, *output.d[2], *exprBuilder.constant(mHiddenSize));
return output;
}
void CustomTransformerPlugin::setDataType(DataType type) {
mDataType = type;
}
DataType CustomTransformerPlugin::getDataType() const {
return mDataType;
}
bool CustomTransformerPlugin::supportsFormatCombination(
int pos, const PluginTensorDesc* inOut,
int nbInputs, int nbOutputs) {
if (inOut[pos].format != TensorFormat::kLINEAR) {
return false;
}
return true;
}
void CustomTransformerPlugin::configurePlugin(
const DynamicPluginTensorDesc* in, int nbInputs,
const DynamicPluginTensorDesc* out, int nbOutputs) {}
size_t CustomTransformerPlugin::getWorkspaceSize(
const PluginTensorDesc* inputs, int nbInputs,
const PluginTensorDesc* outputs, int nbOutputs) const {
return 0;
}
int CustomTransformerPlugin::enqueue(
const PluginTensorDesc* inputDesc, const PluginTensorDesc* outputDesc,
const void* const* inputs, void* const* outputs, void* workspace,
cudaStream_t stream) {
// 实现推理
return 0;
}
size_t CustomTransformerPlugin::getSerializationSize() const {
// 返回序列化数据大小
return 0;
}
void CustomTransformerPlugin::serialize(void* buffer) const {
// 序列化plugin
}
void CustomTransformerPlugin::destroy() {
// 清空plugin
}
然后是加载新的ONNX模型和生成plugin的完整示例代码:
int main() {
// 加载ONNX模型
const char* model_path = "merged_model.onnx";
size_t size;
char* buffer = readBuffer(model_path, size); // 读取ONNX模型数据
IRuntime* runtime = createInferRuntime(gLogger);
assert(runtime != nullptr);
IPluginFactory* plugin_factory = createPluginFactory(gLogger);
assert(plugin_factory != nullptr);
nvonnxparser::IParser* parser = nvonnxparser::createParser(*plugin_factory, gLogger);
assert(parser != nullptr);
parser->parse(buffer, size);
const int batch_size = 1;
const int hidden_size = 512;
const int seq_len = 128;
const std::string input_name = "input";
const std::string output_name = "output";
// 注册自定义transformer plugin
const std::string plugin_name = "CustomTransformerPlugin";
plugin_factory->registerCreator(
plugin_name.c_str(), new PluginCreatorImpl<CustomTransformerPlugin>, true);
// 创建engine
IBuilder* builder = createInferBuilder(gLogger);
assert(builder != nullptr);
builder->setMaxBatchSize(batch_size);
builder->setMaxWorkspaceSize(1 << 28);
builder->setFp16Mode(false);
builder->setInt8Mode(false);
builder->setStrictTypeConstraints(false);
INetworkDefinition* network = builder->createNetworkV2(
1U << static_cast<uint32_t>(NetworkDefinitionCreationFlag::kEXPLICIT_BATCH));
IOptimizationProfile* profile = builder->createOptimizationProfile();
ITensor* input_tensor = network->addInput(
input_name.c_str(), DataType::kFLOAT, Dims4(batch_size, seq_len, hidden_size));
ITensor* output_tensor = network->addOutput(
output_name.c_str(), DataType::kFLOAT, Dims4(batch_size, seq_len, hidden_size));
// 添加plugin
const auto plugin_creator = getPluginRegistry()->getPluginCreator(
plugin_name.c_str(), "1", "");
const PluginFieldCollection* plugin_fields = plugin_creator->getFieldNames();
std::vector<PluginField> plugin_params;
IPluginV2DynamicExt* plugin = plugin_creator->createPlugin(
"", plugin_fields, plugin_params);
ITensor* plugin_outputs[] = {
plugin->enqueue(1, &input_tensor, &output_tensor, nullptr, nullptr)
};
assert(plugin_outputs[0] != nullptr);
// 构建engine
profile->setDimensions(
input_name.c_str(), OptProfileSelector::kMIN, Dims4(1, 1, hidden_size));
profile->setDimensions(
input_name.c_str(), OptProfileSelector::kOPT, Dims4(batch_size, seq_len, hidden_size));
profile->setDimensions(
input_name.c_str(), OptProfileSelector::kMAX, Dims4(batch_size, seq_len, hidden_size));
profile->setDimensions(
output_name.c_str(), OptProfileSelector::kMIN, Dims4(1, 1, hidden_size));
profile->setDimensions(
output_name.c_str(), OptProfileSelector::kOPT, Dims4(batch_size, seq_len, hidden_size));
profile->setDimensions(
output_name.c_str(), OptProfileSelector::kMAX, Dims4(batch_size, seq_len, hidden_size));
IOptimizationProfile** profiles = new IOptimizationProfile* {profile};
ICudaEngine* engine = builder->buildEngineWithCustomizedOp(
*network, *parser, *plugin_factory, *plugin, profiles, 1);
assert(engine != nullptr);
// 释放资源
plugin->destroy();
input_tensor->destroy();
output_tensor->destroy();
network->destroy();
parser->destroy();
plugin_factory->destroy();
builder->destroy();
runtime->destroy();
free(buffer);
return 0;
}
这就是完整的解决方案,需要注意的是,由于自定义node和plugin的实现需要基本的TensorRT知识,这里只是提供了一个简单的示例,具体的实现还需要根据自己的模型和需求进行调整。
以下是一个用PyTorch实现的简单示例,用于将一个训练好的CNN Transformer模型导出为带有自定义OP的ONNX模型。由于没有提供模型和权重参数,您需要根据您自己的模型和权重参数进行调整。
import torch
import onnx
import onnxruntime as ort
from onnx import helper
from onnx import AttributeProto, TensorProto, GraphProto
import numpy as np
# Load trained model
model = torch.load('model.pt')
# Set up input and output names
input_names = ['input_ids', 'attention_mask']
output_names = ['output']
# Convert PyTorch model to ONNX
dummy_input = (torch.zeros(1, 512), torch.zeros(1, 512))
torch.onnx.export(model=model, args=dummy_input, f='model.onnx', input_names=input_names, output_names=output_names, opset_version=11)
# Load ONNX model
onnx_model = onnx.load('model.onnx')
# Create a custom ONNX node for the fused CNN Transformer model
custom_node = helper.make_node(
'CustomCNNTransformer',
inputs=['input_ids', 'attention_mask', 'encoder_layer_0_attention_self_query_weight', 'encoder_layer_0_attention_self_query_bias', ...], # Replace with all necessary input names
outputs=['output'],
name='fused_model'
)
# Remove original CNN Transformer nodes
graph = onnx_model.graph
for i in range(len(graph.node)):
if graph.node[i].op_type == 'EncoderLayer':
graph.node.pop(i)
# Add custom ONNX node
graph.node.append(custom_node)
# Create ONNX tensor for each weight parameter
encoder_layer_0_attention_self_query_weight_tensor = helper.make_tensor('encoder_layer_0_attention_self_query_weight', TensorProto.FLOAT, [512, 512], np.random.rand(512, 512).flatten().tolist())
encoder_layer_0_attention_self_query_bias_tensor = helper.make_tensor('encoder_layer_0_attention_self_query_bias', TensorProto.FLOAT, [512], np.random.rand(512).flatten().tolist())
...
# Add ONNX tensor to graph initializers
graph.initializer.extend([encoder_layer_0_attention_self_query_weight_tensor, encoder_layer_0_attention_self_query_bias_tensor, ...])
# Export final ONNX model with custom node and weight parameters
onnx.checker.check_model(onnx_model)
onnx.save(onnx_model, 'model_custom.onnx')
# Load ONNX model with custom node and weight parameters using ONNXRuntime
session = ort.InferenceSession('model_custom.onnx')
input_data = {'input_ids': np.zeros((1, 512)), 'attention_mask': np.zeros((1, 512))}
outputs = session.run(None, input_data)
# Implement custom plugin using TensorRT C++ API
# TODO: Implement custom plugin using TensorRT C++ API
此示例涉及以下步骤:
加载已训练好的CNN Transformer模型。
使用PyTorch将模型转换为ONNX格式。
创建自定义ONNX节点用于融合CNN Transformer模型的所有层,并将其添加到ONNX图中。
移除原始CNN Transformer节点。
创建ONNX张量以存储融合模型的权重参数,并将它们添加到ONNX图的初始值中。
导出包括自定义节点和权重参数的ONNX模型。
使用ONNXRuntime加载带有自定义节点和权重参数的ONNX模型。
用TensorRT C++ API实现自定义插件。
请注意,此示例仅包括用于将CNN Transformer模型融合为自定义ONNX节点的代码,不包括实现自定义插件的代码。你需要自己编写自定义插件的代码。