I use pytorch0.4 version, Sometimes an error occurs when I call torch.save to save model.  but most of the time it is OK。
Traceback (most recent call last):
  File "train.py", line 263, in <module>
    test()
  File "train.py", line 254, in test
    }, is_best, checkpoint=args.checkpoint)
  File "train.py", line 38, in save_checkpoint
    torch.save(state, filepath)
  File "/usr/local/python3/lib/python3.6/site-packages/torch/serialization.py", line 161, in save
    return _with_file_like(f, "wb", lambda f: _save(obj, f, pickle_module, pickle_protocol))
  File "/usr/local/python3/lib/python3.6/site-packages/torch/serialization.py", line 118, in _with_file_like
    return body(f)
  File "/usr/local/python3/lib/python3.6/site-packages/torch/serialization.py", line 161, in <lambda>
    return _with_file_like(f, "wb", lambda f: _save(obj, f, pickle_module, pickle_protocol))
  File "/usr/local/python3/lib/python3.6/site-packages/torch/serialization.py", line 238, in _save
    serialized_storages[key]._write_file(f, _is_real_file(f))
RuntimeError: cuda runtime error (63) : OS call failed or operation not supported on this OS at /pytorch/torch/csrc/generic/serialization.cpp:17