| # This file contains the changes to implement DDP training with the train.yaml config. | |
| is_dist: '$dist.is_initialized()' | |
| rank: '$dist.get_rank() if @is_dist else 0' | |
| device: '$torch.device(f"cuda:{@rank}" if torch.cuda.is_available() else "cpu")' # assumes GPU # matches rank # | |
| # wrap the network in a DistributedDataParallel instance, moving it to the chosen device for this process | |
| network: | |
| _target_: torch.nn.parallel.DistributedDataParallel | |
| module: $@network_def.to(@device) | |
| device_ids: ['@device'] | |
| find_unused_parameters: true | |
| train_sampler: | |
| _target_: DistributedSampler | |
| dataset: '@train_dataset' | |
| even_divisible: true | |
| shuffle: true | |
| train_dataloader#sampler: '@train_sampler' | |
| train_dataloader#shuffle: false | |
| val_sampler: | |
| _target_: DistributedSampler | |
| dataset: '@val_dataset' | |
| even_divisible: false | |
| shuffle: false | |
| val_dataloader#sampler: '@val_sampler' | |
| run: | |
| - $import torch.distributed as dist | |
| - $dist.init_process_group(backend='nccl') | |
| - $torch.cuda.set_device(@device) | |
| - $monai.utils.set_determinism(seed=123) # may want to choose a different seed or not do this here | |
| - $@trainer.run() | |
| - $dist.destroy_process_group() | |