Suggestion for torch.backends.cudnn.benchmark = True in search process

[marsggbo]

First, thanks for your code! It is much clearer than original code and easy to read.

In your code, you set torch.backends.cudnn.benchmark = True in search.py, but the Pytorch document mentions that if the graph will not be modified, then torch.backends.cudnn.benchmark = True would speed up, otherwise it would reduce the performance. So is it better to set it False? Just a suggestion,hah. Thanks again!