PyTorch使用tensorboard的SummaryWriter报错

PyTorch使用tensorboard可以显示网络运行情况，但偶尔使用SummaryWriter时遇到Segmentation fault错误。

利用python3的faulthandler，可定位到出错的代码行，具体操作有两种方式如下：

(1) 在代码中写入faulthandler

bash 复制代码

import faulthandler
# 在import之后直接添加以下启用代码即可
faulthandler.enable()
# 后边正常写你的代码

(2)直接通过命令行来启用，运行时添加-X faulthandler参数即可：

bash 复制代码

python -X faulthandler your_script.py

错误代码：

bash 复制代码

import xxx
from torch.utils.tensorboard import SummaryWriter
import yyy

log_dir = './run_logs'
self.writer = SummaryWriter(log_dir)

报错如下：

bash 复制代码

 File "/opt/conda/lib/python3.7/site-packages/tensorboard/compat/__init__.py", line 45 in tf
  File "/opt/conda/lib/python3.7/site-packages/tensorboard/lazy.py", line 50 in load_once
  File "/opt/conda/lib/python3.7/site-packages/tensorboard/lazy.py", line 97 in wrapper
  File "/opt/conda/lib/python3.7/site-packages/tensorboard/lazy.py", line 65 in __getattr__
  File "/opt/conda/lib/python3.7/site-packages/tensorboard/summary/writer/event_file_writer.py", line 72 in __init__
  File "/opt/conda/lib/python3.7/site-packages/torch/utils/tensorboard/writer.py",line 66 in __init__
  File "/opt/conda/lib/python3.7/site-packages/torch/utils/tensorboard/writer.py",line 256 in _get_file_writer
  File "/opt/conda/lib/python3.7/site-packages/torch/utils/tensorboard/writer.py", line 225 in __init__

经过查询，发现极有可能是导包(from torch.utils.tensorboard import SummaryWriter)顺序导致的问题。参考链接：[TensorBoard] The different order of import SummaryWriter may cause Segmentation fault

将from torch.utils.tensorboard import SummaryWriter顺序调前，可以顺利导包和实例化了。

bash 复制代码

import xxx
from torch.utils.tensorboard import SummaryWriter
import yyy

改为

bash 复制代码

from torch.utils.tensorboard import SummaryWriter
import xxx
import yyy