使用 torch.compile 后端编译 BERT

此交互式脚本旨在作为在 BERT 模型上使用 torch.compile 的 Torch-TensorRT 工作流程的示例。

导入和模型定义

import torch
import torch_tensorrt
from transformers import BertModel

# Initialize model with float precision and sample inputs
model = BertModel.from_pretrained("bert-base-uncased").eval().to("cuda")
inputs = [
    torch.randint(0, 2, (1, 14), dtype=torch.int32).to("cuda"),
    torch.randint(0, 2, (1, 14), dtype=torch.int32).to("cuda"),
]

torch_tensorrt.compile 的可选输入参数

# Enabled precision for TensorRT optimization
enabled_precisions = {torch.float}

# Whether to print verbose logs
debug = True

# Workspace size for TensorRT
workspace_size = 20 << 30

# Maximum number of TRT Engines
# (Lower value allows more graph segmentation)
min_block_size = 7

# Operations to Run in Torch, regardless of converter support
torch_executed_ops = {}

使用 torch.compile 编译

# Define backend compilation keyword arguments
compilation_kwargs = {
    "enabled_precisions": enabled_precisions,
    "debug": debug,
    "workspace_size": workspace_size,
    "min_block_size": min_block_size,
    "torch_executed_ops": torch_executed_ops,
}

# Build and compile the model with torch.compile, using Torch-TensorRT backend
optimized_model = torch.compile(
    model,
    backend="torch_tensorrt",
    dynamic=False,
    options=compilation_kwargs,
)
optimized_model(*inputs)

等效地，我们可以通过便利的前端运行上述操作，如下所示：torch_tensorrt.compile(model, ir=”torch_compile”, inputs=inputs, **compilation_kwargs)

推理

# Does not cause recompilation (same batch size as input)
new_inputs = [
    torch.randint(0, 2, (1, 14), dtype=torch.int32).to("cuda"),
    torch.randint(0, 2, (1, 14), dtype=torch.int32).to("cuda"),
]
new_outputs = optimized_model(*new_inputs)

# Does cause recompilation (new batch size)
new_inputs = [
    torch.randint(0, 2, (4, 14), dtype=torch.int32).to("cuda"),
    torch.randint(0, 2, (4, 14), dtype=torch.int32).to("cuda"),
]
new_outputs = optimized_model(*new_inputs)

清理

# Finally, we use Torch utilities to clean up the workspace
torch._dynamo.reset()

Cuda 驱动程序错误说明

有时，在使用 torch_tensorrt 进行 Dynamo 编译后退出 Python 运行时，可能会遇到 Cuda 驱动程序错误。此问题与 https://github.com/NVIDIA/TensorRT/issues/2052 相关，可以通过将编译/推理包装在函数中并使用作用域调用来解决，如

if __name__ == '__main__':
    compile_engine_and_infer()