Files
peft/src/pet/pet_model.py
T

402 lines
17 KiB
Python

import inspect
import warnings
import torch
from torch.nn import BCEWithLogitsLoss, CrossEntropyLoss, MSELoss
from transformers import PreTrainedModel
from transformers.modeling_outputs import SequenceClassifierOutput
from .tuners import LoRAModel, PrefixEncoder, PromptEmbedding, PromptEncoder
from .utils import PETConfig, PETType, TaskType, shift_tokens_right
class PETModel(torch.nn.Module):
def __init__(self, model, pet_config: PETConfig):
super().__init__()
self.pet_config = pet_config
self.base_model = model
if pet_config.pet_type != PETType.LORA:
self._setup_prompt_encoder()
else:
self.base_model = LoRAModel(pet_config, model)
def _setup_prompt_encoder(self):
num_transformer_submodules = 0
transformer_backbone = None
for name, module in self.base_model.named_children():
if isinstance(module, PreTrainedModel):
# Make sure to freeze Tranformers model
for param in module.parameters():
param.requires_grad = False
if transformer_backbone is None:
transformer_backbone = module
self.transformer_backbone_name = name
num_transformer_submodules += 1
self.pet_config.num_transformer_submodules = 2 if self.pet_config.task_type == TaskType.SEQ_2_SEQ_LM else 1
for named_param, value in list(transformer_backbone.named_parameters()):
if value.shape[0] == self.base_model.config.vocab_size:
self.word_embeddings = transformer_backbone.get_submodule(named_param.replace(".weight", ""))
break
if self.pet_config.pet_type == PETType.PROMPT_TUNING:
prompt_encoder = PromptEmbedding(self.pet_config, self.word_embeddings)
elif self.pet_config.pet_type == PETType.P_TUNING:
prompt_encoder = PromptEncoder(self.pet_config)
elif self.pet_config.pet_type == PETType.PREFIX_TUNING:
prompt_encoder = PrefixEncoder(self.pet_config)
else:
raise ValueError("Not supported")
self.prompt_encoder = prompt_encoder
self.prompt_tokens = torch.arange(
self.pet_config.num_virtual_tokens * self.pet_config.num_transformer_submodules
).long()
def get_prompt(self, batch_size):
prompt_tokens = self.prompt_tokens.unsqueeze(0).expand(batch_size, -1).to(self.base_model.device)
if self.pet_config.pet_type == PETType.PREFIX_TUNING:
prompt_tokens = prompt_tokens[:, : self.pet_config.num_virtual_tokens]
if self.pet_config.inference_mode:
past_key_values = self.prompt_encoder.embedding.weight.repeat(batch_size, 1, 1)
else:
past_key_values = self.prompt_encoder(prompt_tokens)
past_key_values = past_key_values.view(
batch_size,
self.pet_config.num_virtual_tokens,
self.pet_config.num_layers * 2,
self.pet_config.num_attention_heads,
self.pet_config.token_dim // self.pet_config.num_attention_heads,
)
if self.pet_config.num_transformer_submodules == 2:
past_key_values = torch.cat([past_key_values, past_key_values], dim=2)
past_key_values = past_key_values.permute([2, 0, 3, 1, 4]).split(
self.pet_config.num_transformer_submodules * 2
)
if self.pet_config.postprocess_past_key_value_function is not None:
post_process_fn = self.pet_config.postprocess_past_key_value_function
past_key_values = post_process_fn(past_key_values)
return past_key_values
else:
if self.pet_config.inference_mode:
prompts = self.prompt_encoder.embedding.weight.repeat(batch_size, 1, 1)
else:
prompts = self.prompt_encoder(prompt_tokens)
return prompts
def print_trainable_parameters(self):
trainable_params = 0
all_param = 0
for _, param in self.named_parameters():
all_param += param.numel()
if param.requires_grad:
trainable_params += param.numel()
print(
f"trainable params: {trainable_params} || all params: {all_param} || trainable%: {100 * trainable_params / all_param}"
)
class PETModelForSequenceClassification(PETModel):
def __init__(self, model, pet_config: PETConfig):
super().__init__(model, pet_config)
self.config = self.base_model.config
for name, module in self.base_model.named_children():
if isinstance(module, torch.nn.Linear):
self.cls_layer_name = name
break
def forward(
self,
input_ids=None,
attention_mask=None,
inputs_embeds=None,
labels=None,
output_attentions=None,
output_hidden_states=None,
return_dict=None,
**kwargs,
):
return_dict = return_dict if return_dict is not None else self.config.use_return_dict
if self.pet_config.pet_type == PETType.LORA:
return self.base_model(
input_ids=input_ids,
attention_mask=attention_mask,
inputs_embeds=inputs_embeds,
labels=labels,
output_attentions=output_attentions,
output_hidden_states=output_hidden_states,
return_dict=return_dict,
**kwargs,
)
batch_size = input_ids.shape[0]
if attention_mask is not None:
# concat prompt attention mask
prefix_attention_mask = torch.ones(batch_size, self.pet_config.num_virtual_tokens).to(
self.base_model.device
)
attention_mask = torch.cat((prefix_attention_mask, attention_mask), dim=1)
if kwargs.get("position_ids", None) is not None:
warnings.warn("Position ids are not supported for parameter efficient tuning. Ignoring position ids.")
kwargs["position_ids"] = None
kwargs.update(
{
"attention_mask": attention_mask,
"labels": labels,
"output_attentions": output_attentions,
"output_hidden_states": output_hidden_states,
"return_dict": return_dict,
}
)
if self.pet_config.pet_type == PETType.PREFIX_TUNING:
return self.prefix_tuning_forward(input_ids=input_ids, **kwargs)
else:
if kwargs.get("token_type_ids", None) is not None:
kwargs["token_type_ids"] = torch.cat(
(
torch.zeros(batch_size, self.pet_config.num_virtual_tokens).to(self.base_model.device),
kwargs["token_type_ids"],
),
dim=1,
).long()
if inputs_embeds is None:
inputs_embeds = self.word_embeddings(input_ids)
prompts = self.get_prompt(batch_size=batch_size)
inputs_embeds = torch.cat((prompts, inputs_embeds), dim=1)
return self.base_model(inputs_embeds=inputs_embeds, **kwargs)
def prefix_tuning_forward(
self,
input_ids=None,
attention_mask=None,
inputs_embeds=None,
labels=None,
output_attentions=None,
output_hidden_states=None,
return_dict=None,
**kwargs,
):
batch_size = input_ids.shape[0]
past_key_values = self.get_prompt(batch_size)
fwd_params = list(inspect.signature(self.base_model.forward).parameters.keys())
kwargs.update(
{
"input_ids": input_ids,
"attention_mask": attention_mask,
"inputs_embeds": inputs_embeds,
"output_attentions": output_attentions,
"output_hidden_states": output_hidden_states,
"return_dict": return_dict,
"past_key_values": past_key_values,
}
)
if "past_key_values" in fwd_params:
return self.base_model(labels=labels, **kwargs)
else:
transformer_backbone_name = self.base_model.get_submodule(self.transformer_backbone_name)
fwd_params = list(inspect.signature(transformer_backbone_name.forward).parameters.keys())
if "past_key_values" not in fwd_params:
raise ValueError("Model does not support past key values which are required for prefix tuning.")
outputs = transformer_backbone_name(**kwargs)
pooled_output = outputs[1] if len(outputs) > 1 else outputs[0]
if "dropout" in [name for name, _ in list(self.base_model.named_children())]:
pooled_output = self.base_model.dropout(pooled_output)
logits = self.base_model.get_submodule(self.cls_layer_name)(pooled_output)
loss = None
if labels is not None:
if self.config.problem_type is None:
if self.base_model.num_labels == 1:
self.config.problem_type = "regression"
elif self.base_model.num_labels > 1 and (labels.dtype == torch.long or labels.dtype == torch.int):
self.config.problem_type = "single_label_classification"
else:
self.config.problem_type = "multi_label_classification"
if self.config.problem_type == "regression":
loss_fct = MSELoss()
if self.base_model.num_labels == 1:
loss = loss_fct(logits.squeeze(), labels.squeeze())
else:
loss = loss_fct(logits, labels)
elif self.config.problem_type == "single_label_classification":
loss_fct = CrossEntropyLoss()
loss = loss_fct(logits.view(-1, self.base_model.num_labels), labels.view(-1))
elif self.config.problem_type == "multi_label_classification":
loss_fct = BCEWithLogitsLoss()
loss = loss_fct(logits, labels)
if not return_dict:
output = (logits,) + outputs[2:]
return ((loss,) + output) if loss is not None else output
return SequenceClassifierOutput(
loss=loss,
logits=logits,
hidden_states=outputs.hidden_states,
attentions=outputs.attentions,
)
class PETModelForCausalLM(PETModel):
def __init__(self, model, pet_config: PETConfig):
super().__init__(model, pet_config)
self.config = self.base_model.config
def forward(
self,
input_ids=None,
attention_mask=None,
inputs_embeds=None,
labels=None,
output_attentions=None,
output_hidden_states=None,
return_dict=None,
**kwargs,
):
if self.pet_config.pet_type == PETType.LORA:
return self.base_model(
input_ids=input_ids,
attention_mask=attention_mask,
inputs_embeds=inputs_embeds,
labels=labels,
output_attentions=output_attentions,
output_hidden_states=output_hidden_states,
return_dict=return_dict,
**kwargs,
)
batch_size = input_ids.shape[0]
if attention_mask is not None:
# concat prompt attention mask
prefix_attention_mask = torch.ones(batch_size, self.pet_config.num_virtual_tokens).to(
self.base_model.device
)
attention_mask = torch.cat((prefix_attention_mask, attention_mask), dim=1)
if kwargs.get("position_ids", None) is not None:
warnings.warn("Position ids are not supported for parameter efficient tuning. Ignoring position ids.")
kwargs["position_ids"] = None
if kwargs.get("token_type_ids", None) is not None:
warnings.warn("Token type ids are not supported for parameter efficient tuning. Ignoring token type ids")
kwargs["token_type_ids"] = None
kwargs.update(
{
"attention_mask": attention_mask,
"labels": labels,
"output_attentions": output_attentions,
"output_hidden_states": output_hidden_states,
"return_dict": return_dict,
}
)
if self.pet_config.pet_type == PETType.PREFIX_TUNING:
past_key_values = self.get_prompt(batch_size)
return self.base_model(input_ids=input_ids, past_key_values=past_key_values, **kwargs)
else:
if inputs_embeds is None:
inputs_embeds = self.word_embeddings(input_ids)
# concat prompt labels
if labels is not None:
prefix_labels = torch.full((batch_size, self.pet_config.num_virtual_tokens), -100).to(
self.base_model.device
)
kwargs["labels"] = torch.cat((prefix_labels, labels), dim=1)
prompts = self.get_prompt(batch_size=batch_size)
inputs_embeds = torch.cat((prompts, inputs_embeds), dim=1)
return self.base_model(inputs_embeds=inputs_embeds, **kwargs)
class PETModelForSeq2SeqLM(PETModel):
def __init__(self, model, pet_config: PETConfig):
super().__init__(model, pet_config)
self.config = self.base_model.config
def forward(
self,
input_ids=None,
attention_mask=None,
inputs_embeds=None,
decoder_input_ids=None,
decoder_attention_mask=None,
decoder_inputs_embeds=None,
labels=None,
output_attentions=None,
output_hidden_states=None,
return_dict=None,
**kwargs,
):
if self.pet_config.pet_type == PETType.LORA:
return self.base_model(
input_ids=input_ids,
attention_mask=attention_mask,
inputs_embeds=inputs_embeds,
decoder_input_ids=decoder_input_ids,
decoder_attention_mask=decoder_attention_mask,
decoder_inputs_embeds=decoder_inputs_embeds,
labels=labels,
output_attentions=output_attentions,
output_hidden_states=output_hidden_states,
return_dict=return_dict,
**kwargs,
)
batch_size = input_ids.shape[0]
if decoder_attention_mask is not None:
# concat prompt attention mask
prefix_attention_mask = torch.ones(batch_size, self.pet_config.num_virtual_tokens).to(
self.base_model.device
)
decoder_attention_mask = torch.cat((prefix_attention_mask, decoder_attention_mask), dim=1)
if kwargs.get("position_ids", None) is not None:
warnings.warn("Position ids are not supported for parameter efficient tuning. Ignoring position ids.")
kwargs["position_ids"] = None
if kwargs.get("token_type_ids", None) is not None:
warnings.warn("Token type ids are not supported for parameter efficient tuning. Ignoring token type ids")
kwargs["token_type_ids"] = None
kwargs.update(
{
"attention_mask": attention_mask,
"decoder_attention_mask": decoder_attention_mask,
"labels": labels,
"output_attentions": output_attentions,
"output_hidden_states": output_hidden_states,
"return_dict": return_dict,
}
)
if self.pet_config.pet_type == PETType.PREFIX_TUNING:
past_key_values = self.get_prompt(batch_size)
return self.base_model(
input_ids=input_ids, decoder_input_ids=decoder_input_ids, past_key_values=past_key_values, **kwargs
)
else:
if inputs_embeds is None:
inputs_embeds = self.word_embeddings(input_ids)
if decoder_inputs_embeds is None and decoder_input_ids is None:
decoder_input_ids = shift_tokens_right(
labels, self.config.pad_token_id, self.config.decoder_start_token_id
)
decoder_inputs_embeds = self.word_embeddings(decoder_input_ids)
if attention_mask is not None:
# concat prompt attention mask
prefix_attention_mask = torch.ones(batch_size, self.pet_config.num_virtual_tokens).to(
self.base_model.device
)
kwargs["attention_mask"] = torch.cat((prefix_attention_mask, attention_mask), dim=1)
# concat prompt labels
if labels is not None:
prefix_labels = torch.full((batch_size, self.pet_config.num_virtual_tokens), -100).to(
self.base_model.device
)
kwargs["labels"] = torch.cat((prefix_labels, labels), dim=1)
prompts = self.get_prompt(batch_size=batch_size)
inputs_embeds = torch.cat((prompts[:, : self.pet_config.num_virtual_tokens], inputs_embeds), dim=1)
decoder_inputs_embeds = torch.cat(
(prompts[:, self.pet_config.num_virtual_tokens :], decoder_inputs_embeds), dim=1
)
return self.base_model(inputs_embeds=inputs_embeds, decoder_inputs_embeds=decoder_inputs_embeds, **kwargs)