bing:

AssertionError: DistributedDataParallel device_ids and output_device arguments only work with single-device CUDA modules, but got device_ids [device(type='cuda', index=0)], output_device None, and module parameters {device(type='cuda', index=0), device(type='cpu')}.



The error message means the model you passed to DDP ctor lives on both CPU and GPU. Is this intentional?

module parameters {device(type=‘cuda’, index=0), device(type=‘cpu’)}