before cleaning the comments

megatron/data/biencoder_dataset_utils.py

@@ -20,12 +20,6 @@ def make_attention_mask(source_block, target_block):
     # (source_length, target_length)
     return mask
 
-def make_history_mask(block):
-    length = block.shape[0]
-    arange = np.arange(length)
-    history_mask = (arange[None, ] <= arange[:, None])
-    history_mask = history_mask.astype(np.int64)
-    return history_mask
 
 def get_one_epoch_dataloader(dataset, micro_batch_size=None):
     """Specifically one epoch to be used in an indexing job."""

tasks/orqa/supervised/data.py

@@ -25,8 +25,6 @@ from torch.utils.data import Dataset
 
 from megatron import print_rank_0, get_args
 from megatron.data.biencoder_dataset_utils import make_attention_mask
-from megatron.data.biencoder_dataset_utils import make_history_mask
-
 
 def build_token_types_from_context_list(ctx_list, tokenizer, max_seq_length):
     ctx_id_list, ctx_types_list = [], []