Training issue on Multiple Gpu

[DerrickXuNu]

Dear authors,

First of all, thanks for your great work and the efforts to opensource this project! I met some issues while training the model. I am able to train on single GPU, but when I give --num_gpus 2 to train.py, it throws me this error:

RuntimeError: Input type (torch.FloatTensor) and weight type (torch.cuda.FloatTensor) should be the same or input should be a MKLDNN tensor and weight is a dense tensor

Do you have any idea how to fix this? Thanks!