Batch Size Issue in Maissi Generative Model Configuration

Dear Dong Yang (@dongyang0122),

I hope this message finds you well. Thank you in advance for your time and support.

I am currently working with the Maissi generative model and planning to accelerate the training process by increasing the batch size. However, I encountered an issue where, despite modifying the batch size in the configuration file, the DataLoader batch size remains set to 1.

Could you kindly advise on how to resolve this issue?

The log file is as bellow:

wherein the log is recorded base on the code:

if local_rank == 0:
            logger.info(
                "[{0}] epoch {1}, iter {2}/{3}, loss: {4:.4f}, lr: {5:.12f}.".format(
                    str(datetime.now())[:19], epoch + 1, _iter, len(train_loader), loss.item(), current_lr
                )
            )

Note that the number of itereation is equal to the length of train_loader and the number of training set is 1000. In my understanding, the enlarged batch size should decrease the length of train_loader. However, the length of train_loader is still equal to 1000 (the number of training set), which seems that the batch size is 1.

Additionaly, the corresponding code for data loader is in the scripts.diff_model_train.py:

  def prepare_data(
      train_files: list, device: torch.device, cache_rate: float, num_workers: int = 2, batch_size: int = 1
  ) -> ThreadDataLoader:
      """
      Prepare training data.
  
      Args:
          train_files (list): List of training files.
          device (torch.device): Device to use for training.
          cache_rate (float): Cache rate for dataset.
          num_workers (int): Number of workers for data loading.
          batch_size (int): Mini-batch size.
  
      Returns:
          ThreadDataLoader: Data loader for training.
      """
      train_transforms = Compose(
          [
              monai.transforms.LoadImaged(keys=["image"]),
              monai.transforms.EnsureChannelFirstd(keys=["image"]),
              monai.transforms.Lambdad(
                  keys="top_region_index", func=lambda x: torch.FloatTensor(json.load(open(x))["top_region_index"])
              ),
              monai.transforms.Lambdad(
                  keys="bottom_region_index", func=lambda x: torch.FloatTensor(json.load(open(x))["bottom_region_index"])
              ),
              monai.transforms.Lambdad(keys="spacing", func=lambda x: torch.FloatTensor(json.load(open(x))["spacing"])),
              monai.transforms.Lambdad(keys="top_region_index", func=lambda x: x * 1e2),
              monai.transforms.Lambdad(keys="bottom_region_index", func=lambda x: x * 1e2),
              monai.transforms.Lambdad(keys="spacing", func=lambda x: x * 1e2),
          ]
      )
  
      train_ds = monai.data.CacheDataset(
          data=train_files, transform=train_transforms, cache_rate=cache_rate, num_workers=num_workers
      )
      return ThreadDataLoader(train_ds, num_workers=6, batch_size=batch_size, shuffle=True) 

Start in scripts/diff_model_train.py at prepare_data and inspect how the configured batch size reaches the ThreadDataLoader call. Compare the logged len(train_loader) with the number of training files and verify the effective loader configuration; the issue is done when the configured batch size is actually reflected in the loader behavior or the discrepancy is explained.