[pipeline] support shardformer for GPT2ForQuestionAnswering & complete pipeline support for GPT2 (#4245)

* change for transformers loggers

* add forward for GPT2ForQuestionAnswering

* fix assert

* fix torchrec test

colossalai/shardformer/policies/auto_policy.py

@@ -68,6 +68,8 @@ _POLICY_LIST = {
         PolicyLocation(file_name="gpt2", class_name="GPT2LMHeadModelPolicy"),
     "transformers.models.gpt2.modeling_gpt2.GPT2DoubleHeadsModel":
         PolicyLocation(file_name="gpt2", class_name="GPT2DoubleHeadsModelPolicy"),
+    "transformers.models.gpt2.modeling_gpt2.GPT2ForQuestionAnswering":
+        PolicyLocation(file_name="gpt2", class_name="GPT2ForQuestionAnsweringPolicy"),
     "transformers.models.gpt2.modeling_gpt2.GPT2ForTokenClassification":
         PolicyLocation(file_name="gpt2", class_name="GPT2ForTokenClassificationPolicy"),
     "transformers.models.gpt2.modeling_gpt2.GPT2ForSequenceClassification":

colossalai/shardformer/policies/gpt2.py

@@ -1,6 +1,4 @@
-import logging
 from functools import partial
-from types import MethodType
 from typing import Callable, Dict, List, Optional, Tuple, Union
 
 import torch
@@ -298,6 +296,33 @@ class GPT2DoubleHeadsModelPolicy(GPT2Policy):
         return self.model
 
 
+# GPT2ForQuestionAnswering
+class GPT2ForQuestionAnsweringPolicy(GPT2Policy):
+
+    def __init__(self) -> None:
+        super().__init__()
+
+    def module_policy(self):
+        from transformers.models.gpt2.modeling_gpt2 import GPT2ForQuestionAnswering
+
+        module_policy = super().module_policy()
+        self.set_pipeline_forward(model_cls=GPT2ForQuestionAnswering,
+                                  new_forward=GPT2PipelineForwards.gpt2_for_question_answering_forward,
+                                  policy=module_policy)
+
+        return module_policy
+
+    def get_held_layers(self) -> List[nn.Module]:
+        held_layers = super().get_held_layers()
+        if self.pipeline_stage_manager.is_last_stage():
+            held_layers.append(self.model.qa_outputs)
+        return held_layers
+
+    def get_shared_params(self) -> List[Dict[int, Tensor]]:
+        '''No shared_params in gpt2 for QA.'''
+        return []
+
+
 # GPT2ForTokenClassification
 class GPT2ForTokenClassificationPolicy(GPT2Policy):
 
@@ -391,6 +416,8 @@ class GPT2PipelineForwards:
         # Please refer to original code of transformers for more details.
 
         from transformers.modeling_outputs import BaseModelOutputWithPastAndCrossAttentions
+        from transformers.utils import logging
+        logger = logging.get_logger(__name__)
 
         # Preprocess passed in arguments
         output_attentions = output_attentions if output_attentions is not None else self.config.output_attentions
@@ -416,7 +443,8 @@ class GPT2PipelineForwards:
             if token_type_ids is not None:
                 token_type_ids = token_type_ids.view(-1, seq_length)
         else:
-            assert hidden_states is not None
+            if hidden_states is None:
+                raise ValueError("hidden_states shouldn't be None for stages other than the first stage.")
             input_shape = hidden_states.size()[:-1]
             batch_size, seq_length = input_shape[0], input_shape[1]
             device = hidden_states.device
@@ -478,21 +506,21 @@ class GPT2PipelineForwards:
 
         # TODO: left the recording kv-value tensors as () or None type, this feature may be added in the future.
         if past_key_values:
-            logging.warning('Non-empty past_key_values is not supported for pipeline models at the moment.')
+            logger.warning_once('Non-empty past_key_values is not supported for pipeline models at the moment.')
             past_key_values = None
         if output_attentions:
-            logging.warning('output_attentions=True is not supported for pipeline models at the moment.')
+            logger.warning_once('output_attentions=True is not supported for pipeline models at the moment.')
             output_attentions = False
         if output_hidden_states:
-            logging.warning('output_hidden_states=True is not supported for pipeline models at the moment.')
+            logger.warning_once('output_hidden_states=True is not supported for pipeline models at the moment.')
             output_hidden_states = False
         if use_cache:
-            logging.warning('use_cache=True is not supported for pipeline models at the moment.')
+            logger.warning_once('use_cache=True is not supported for pipeline models at the moment.')
             use_cache = False
 
         if self.gradient_checkpointing and self.training:
             if use_cache:
-                logging.warning(
+                logger.warning_once(
                     "`use_cache=True` is incompatible with gradient checkpointing. Setting `use_cache=False`...")
                 use_cache = False
         presents = () if use_cache else None
@@ -751,6 +779,94 @@ class GPT2PipelineForwards:
             attentions=outputs.attentions,
         )
 
+    @staticmethod
+    def gpt2_for_question_answering_forward(
+            self: 'GPT2ForQuestionAnswering',
+            input_ids: Optional[torch.LongTensor] = None,
+            attention_mask: Optional[torch.FloatTensor] = None,
+            token_type_ids: Optional[torch.LongTensor] = None,
+            position_ids: Optional[torch.LongTensor] = None,
+            head_mask: Optional[torch.FloatTensor] = None,
+            inputs_embeds: Optional[torch.FloatTensor] = None,
+            start_positions: Optional[torch.LongTensor] = None,
+            end_positions: Optional[torch.LongTensor] = None,
+            output_attentions: Optional[bool] = None,
+            output_hidden_states: Optional[bool] = None,
+            return_dict: Optional[bool] = None,
+            stage_manager: Optional[PipelineStageManager] = None,
+            hidden_states: Optional[torch.FloatTensor] = None,
+            stage_index: Optional[List[int]] = None) -> Union[Tuple, 'QuestionAnsweringModelOutput']:
+        r"""
+        start_positions (`torch.LongTensor` of shape `(batch_size,)`, *optional*):
+            Labels for position (index) of the start of the labelled span for computing the token classification loss.
+            Positions are clamped to the length of the sequence (`sequence_length`). Position outside of the sequence
+            are not taken into account for computing the loss.
+        end_positions (`torch.LongTensor` of shape `(batch_size,)`, *optional*):
+            Labels for position (index) of the end of the labelled span for computing the token classification loss.
+            Positions are clamped to the length of the sequence (`sequence_length`). Position outside of the sequence
+            are not taken into account for computing the loss.
+
+        # This function is modified on the basis of transformers.models.gpt2.modeling_gpt2.GPT2ForQuestionAnswering.forward.
+        # Please refer to original code of transformers for more details.
+        """
+        from transformers.modeling_outputs import QuestionAnsweringModelOutput
+
+        return_dict = return_dict if return_dict is not None else self.config.use_return_dict
+
+        outputs = GPT2PipelineForwards.gpt2_model_forward(self.transformer,
+                                                          input_ids,
+                                                          attention_mask=attention_mask,
+                                                          token_type_ids=token_type_ids,
+                                                          position_ids=position_ids,
+                                                          head_mask=head_mask,
+                                                          inputs_embeds=inputs_embeds,
+                                                          output_attentions=output_attentions,
+                                                          output_hidden_states=output_hidden_states,
+                                                          return_dict=return_dict,
+                                                          stage_manager=stage_manager,
+                                                          hidden_states=hidden_states,
+                                                          stage_index=stage_index)
+
+        # If not at the last stage, return hidden_states as in GPT2Model
+        if not stage_manager.is_last_stage():
+            return {'hidden_states': outputs['hidden_states']}
+
+        sequence_output = outputs[0]
+
+        logits = self.qa_outputs(sequence_output)
+        start_logits, end_logits = logits.split(1, dim=-1)
+        start_logits = start_logits.squeeze(-1).contiguous()
+        end_logits = end_logits.squeeze(-1).contiguous()
+
+        total_loss = None
+        if start_positions is not None and end_positions is not None:
+            # If we are on multi-GPU, split add a dimension
+            if len(start_positions.size()) > 1:
+                start_positions = start_positions.squeeze(-1).to(start_logits.device)
+            if len(end_positions.size()) > 1:
+                end_positions = end_positions.squeeze(-1).to(end_logits.device)
+            # sometimes the start/end positions are outside our model inputs, we ignore these terms
+            ignored_index = start_logits.size(1)
+            start_positions = start_positions.clamp(0, ignored_index)
+            end_positions = end_positions.clamp(0, ignored_index)
+
+            loss_fct = CrossEntropyLoss(ignore_index=ignored_index)
+            start_loss = loss_fct(start_logits, start_positions)
+            end_loss = loss_fct(end_logits, end_positions)
+            total_loss = (start_loss + end_loss) / 2
+
+        if not return_dict:
+            output = (start_logits, end_logits) + outputs[2:]
+            return ((total_loss,) + output) if total_loss is not None else output
+
+        return QuestionAnsweringModelOutput(
+            loss=total_loss,
+            start_logits=start_logits,
+            end_logits=end_logits,
+            hidden_states=outputs.hidden_states,
+            attentions=outputs.attentions,
+        )
+
     @staticmethod
     def gpt2_for_token_classification_forward(
             self: 'GPT2ForTokenClassification',
@@ -852,6 +968,8 @@ class GPT2PipelineForwards:
         # Please refer to original code of transformers for more details.
        """
         from transformers.modeling_outputs import SequenceClassifierOutputWithPast
+        from transformers.utils import logging
+        logger = logging.get_logger(__name__)
 
         if input_ids is not None:
             batch_size, _ = input_ids.shape[:2]
@@ -892,7 +1010,7 @@ class GPT2PipelineForwards:
                 sequence_lengths = (torch.ne(input_ids, self.config.pad_token_id).sum(-1) - 1).to(logits.device)
             else:
                 sequence_lengths = -1
-                logging.warning(
+                logger.warning_once(
                     f"{self.__class__.__name__} will not detect padding tokens in `inputs_embeds`. Results may be "
                     "unexpected if using padding tokens in conjunction with `inputs_embeds.`")
 

tests/kit/model_zoo/torchrec/__init__.py

@@ -1 +1 @@
-#from .torchrec import *
+from .torchrec import *

tests/kit/model_zoo/transformers/gpt.py

@@ -29,6 +29,17 @@ def data_gen_for_lm():
     return data
 
 
+def data_gen_for_question_answering():
+    # question answering data gen
+    # `labels` is the type not the token id for token classification, 0 or 1
+    data = data_gen()
+    start_positions = torch.tensor([0], dtype=torch.int64)
+    data['start_positions'] = start_positions
+    end_positions = torch.tensor([1], dtype=torch.int64)
+    data['end_positions'] = end_positions
+    return data
+
+
 def data_gen_for_token_classification():
     # token classification data gen
     # `labels` is the type not the token id for token classification, 0 or 1
@@ -82,6 +93,12 @@ model_zoo.register(name='transformers_gpt_double_heads',
                    output_transform_fn=output_transform_fn,
                    loss_fn=loss_fn,
                    model_attribute=ModelAttribute(has_control_flow=True))
+model_zoo.register(name='transformers_gpt_for_question_answering',
+                   model_fn=lambda: transformers.GPT2ForQuestionAnswering(config),
+                   data_gen_fn=data_gen_for_question_answering,
+                   output_transform_fn=output_transform_fn,
+                   loss_fn=loss_fn,
+                   model_attribute=ModelAttribute(has_control_flow=True))
 model_zoo.register(name='transformers_gpt_for_token_classification',
                    model_fn=lambda: transformers.GPT2ForTokenClassification(config),
                    data_gen_fn=data_gen_for_token_classification,

tests/test_shardformer/test_model/test_shard_gpt2_pipeline.py

@@ -27,7 +27,6 @@ def run_gpt2_test(enable_fused_normalization, enable_tensor_parallelism, use_laz
 
     sub_model_zoo = model_zoo.get_sub_registry('transformers_gpt')
     for name, (model_fn, data_gen_fn, _, _, _) in sub_model_zoo.items():
-
         inputs = data_gen_fn()
         inputs = {k: v.cuda() for k, v in inputs.items()}
         input_ids, _ = inputs['input_ids'], inputs['attention_mask']