Hello! Thanks for sharing the excellent work !!!

When I run the codes using multiple GPUs with nn.parallel.DistributedDataParallel, it'll always raise an error as follows :
RuntimeError: one of the variables needed for gradient computation has been modified by an inplace operation: [torch.cuda.FloatTensor [2]] is at version 3; expected version 2 instead. Hint: enable anomaly detection to find the operation that failed to compute its gradient, with torch.autograd.set_detect_anomaly(True).

However, when I run using a single GPU, no errors raise, I am confused...