【TensorRT】Video Swin-Transformer部署相关

1. TensorRT(.engine) python接口推理 代码

def allocate_buffers(engine):
    inputs = []
    outputs = []
    bindings = []
    stream = cuda.Stream()
    for binding in engine:
        size = trt.volume(engine.get_binding_shape(binding)) * engine.max_batch_size
        dtype = trt.nptype(engine.get_binding_dtype(binding))
        # Allocate host and device buffers
        host_mem = cuda.pagelocked_empty(size, dtype)
        device_mem = cuda.mem_alloc(host_mem.nbytes)
        # Append the device buffer to device bindings.
        bindings.append(int(device_mem))
        # Append to the appropriate list.
        if engine.binding_is_input(binding):
            inputs.append(HostDeviceMem(host_mem, device_mem))
        else:
            outputs.append(HostDeviceMem(host_mem, device_mem))
    return inputs, outputs, bindings, stream
    
def do_inference(context, bindings, inputs, outputs, stream, ctx, batch_size=1):
    # Transfer input data to the GPU.

    '''
    Initialize cuda to avoid error:
        [TensorRT] ERROR: ../rtSafe/cuda/reformat.cu (925) - Cuda Error in NCHWToNCHHW2: 400 
        (invalid resource handle)
    Solution ref.: https://blog.csdn.net/yiyayi1/article/details/111314520
        ```
            ctx.push()
            {your inference code}
            ctx.pop()
        ```
    '''
    ctx.push()
    [cuda.memcpy_htod_async(inp.device, inp.host, stream) for inp in inputs]
    # Run inference.
    context.execute_async(batch_size=batch_size, bindings=bindings, stream_handle=stream.handle)
    # Transfer predictions back from the GPU.
    [cuda.memcpy_dtoh_async(out.host, out.device, stream) for out in outputs]
    # Synchronize the stream
    stream.synchronize()
    ctx.pop()
    # Return only the host outputs.
    return [out.host for out in outputs]

def inf_trt(engine_path, data_loader):
	# Initialize cuda
	cuda.init()
    ctx = cuda.Device(0).make_context()
    
    # Load engine
    TRT_LOGGER = trt.Logger(trt.Logger.WARNING)
    trt.init_libnvinfer_plugins(TRT_LOGGER, '')
    runtime = trt.Runtime(TRT_LOGGER)
    engine = None
    with open(engine_path, mode='rb') as f:
        engine_bytes = f.read()
    engine = runtime.deserialize_cuda_engine(engine_bytes)
	
	# Allocate inputs/outputs/stream buffers
    inputs, outputs, bindings, stream = allocate_buffers(engine)
	
	# Fetch context 
    context = engine.create_execution_context()
    # get output tensor
    dataset = data_loader.dataset
    
    # TensorRT inference
    results = []
    for data_idx, data in enumerate(data_loader):
        # Inference
        result_buffer = do_inference(context, bindings, inputs, outputs, stream, ctx)
        result = copy.deepcopy(result_buffer)
        results.append(result_info)

    del engine
    ctx.pop()
    del context
    del stream
    del inputs
    del outputs
    return results

2. 常见问题 (坑不少)  [TensorRT] ERROR: …/rtSafe/cuda/reformat.cu (925) - Cuda Error in NCHWToNCHHW2: 400 (invalid resource handle) 解决方法

Reference: https://github.com/NVIDIA/TensorRT/issues/1107

# Initialize
cuda.init()
ctx = cuda.Device(0).make_context()
...

# Inference
ctx.push()
{your inference code}
ctx.pop()

 PyCUDA ERROR: The context stack was not empty upon module cleanup.

PyCUDA ERROR: The context stack was not empty upon module cleanup.
-------------------------------------------------------------------
A context was still active when the context stack was being
cleaned up. At this point in our execution, CUDA may already
have been deinitialized, so there is no way we can finish
cleanly. The program will be aborted now.
Use Context.pop() to avoid this problem.

解决方法

Reference: https://github.com/NVIDIA/TensorRT/issues/1107

在del engine 后，加上 ctx.pop()，否则会出现上述报错

del engine
ctx.pop()
del context
del stream
del inputs
del outputs

3. 叨叨

夸一下TRT 8.+, transformer模块的提速简直起飞 

其他待补充啦…