jetson显卡没有加速，而是在用cpu推理？

jetson的库，特别是使用显卡的库，大多需要单独安装

大概率是重装了pytorch，可以使用jetson官网的pytorch！

下面是官网的链接

PyTorch for Jetson - Announcements - NVIDIA Developer Forums

安装完成之后先使用命令查看是否安装成功

import torch
print(torch.__version__)
print(torch.cuda.is_available())

torchvision 也需要安装 

Select the version of torchvision to download depending on the version of PyTorch that you have installed:

PyTorch v1.0 - torchvision v0.2.2
PyTorch v1.1 - torchvision v0.3.0
PyTorch v1.2 - torchvision v0.4.0
PyTorch v1.3 - torchvision v0.4.2
PyTorch v1.4 - torchvision v0.5.0
PyTorch v1.5 - torchvision v0.6.0
PyTorch v1.6 - torchvision v0.7.0
PyTorch v1.7 - torchvision v0.8.1
PyTorch v1.8 - torchvision v0.9.0
PyTorch v1.9 - torchvision v0.10.0
PyTorch v1.10 - torchvision v0.11.1
PyTorch v1.11 - torchvision v0.12.0
PyTorch v1.12 - torchvision v0.13.0
PyTorch v1.13 - torchvision v0.13.0
PyTorch v1.14 - torchvision v0.14.1
PyTorch v2.0 - torchvision v0.15.1
PyTorch v2.1 - torchvision v0.16.1
PyTorch v2.2 - torchvision v0.17.1
PyTorch v2.3 - torchvision v0.18.0

从github下载源码：https://github.com/pytorch/vision/releases 

下载，解压，进入目录，安装

$ sudo apt-get install libjpeg-dev zlib1g-dev libpython3-dev libopenblas-dev libavcodec-dev libavformat-dev libswscale-dev
$ git clone --branch <version> https://github.com/pytorch/vision torchvision   # see below for version of torchvision to download
$ cd torchvision
$ export BUILD_VERSION=0.x.0  # where 0.x.0 is the torchvision version  
$ python3 setup.py install --user
$ cd ../  # attempting to load torchvision from build dir will result in import error
$ pip install 'pillow<7' # always needed for Python 2.7, not needed torchvision v0.5.0+ with Python 3.6