ColossalAI/colossalai/shardformer/policies/opt.py

289 lines
13 KiB
Python

import warnings
from functools import partial
from typing import Callable, Dict, List
import torch.nn as nn
from torch import Tensor, nn
from colossalai.shardformer.layer import FusedLayerNorm, Linear1D_Col, Linear1D_Row, VocabParallelEmbedding1D
from .._utils import getattr_
from ..modeling.jit import get_jit_fused_dropout_add_func
from ..modeling.opt import OPTPipelineForwards, get_jit_fused_opt_decoder_layer_forward, get_opt_flash_attention_forward
from .base_policy import ModulePolicyDescription, Policy, SubModuleReplacementDescription
__all__ = [
'OPTPolicy', 'OPTModelPolicy', 'OPTForCausalLMPolicy', 'OPTForSequenceClassificationPolicy',
'OPTForQuestionAnsweringPolicy'
]
class OPTPolicy(Policy):
def config_sanity_check(self):
pass
def preprocess(self):
# reshape the embedding layer
r"""
Reshape the Embedding layer to make the embedding dimension divisible by world_size
"""
if self.shard_config.enable_tensor_parallelism:
vocab_size = self.model.config.vocab_size
world_size = self.shard_config.tensor_parallel_size
if vocab_size % world_size != 0:
new_vocab_size = vocab_size + world_size - vocab_size % world_size
self.model.resize_token_embeddings(new_vocab_size)
return self.model
def module_policy(self):
from transformers.models.opt.modeling_opt import OPTAttention, OPTDecoder, OPTDecoderLayer
policy = {}
if self.shard_config.enable_sequence_parallelism:
self.shard_config.enable_sequence_parallelism = False
warnings.warn("OPT dosen't support sequence parallelism now, will ignore the sequence parallelism flag.")
if self.shard_config.enable_tensor_parallelism:
policy[OPTDecoder] = ModulePolicyDescription(sub_module_replacement=[
SubModuleReplacementDescription(
suffix="embed_tokens",
target_module=VocabParallelEmbedding1D,
)
])
policy[OPTDecoderLayer] = ModulePolicyDescription(sub_module_replacement=[
SubModuleReplacementDescription(
suffix="fc1",
target_module=Linear1D_Col,
),
SubModuleReplacementDescription(
suffix="fc2",
target_module=Linear1D_Row,
)
])
policy[OPTAttention] = ModulePolicyDescription(attribute_replacement={
"embed_dim": self.model.config.hidden_size // self.shard_config.tensor_parallel_size,
"num_heads": self.model.config.num_attention_heads // self.shard_config.tensor_parallel_size
},
sub_module_replacement=[
SubModuleReplacementDescription(
suffix="q_proj",
target_module=Linear1D_Col,
),
SubModuleReplacementDescription(
suffix="k_proj",
target_module=Linear1D_Col,
),
SubModuleReplacementDescription(
suffix="v_proj",
target_module=Linear1D_Col,
),
SubModuleReplacementDescription(
suffix="out_proj",
target_module=Linear1D_Row,
),
])
# optimization configuration
if self.shard_config.enable_fused_normalization:
self.append_or_create_submodule_replacement(description=SubModuleReplacementDescription(
suffix="final_layer_norm", target_module=FusedLayerNorm, ignore_if_not_exist=True),
policy=policy,
target_key=OPTDecoder)
self.append_or_create_submodule_replacement(description=[
SubModuleReplacementDescription(suffix="self_attn_layer_norm",
target_module=FusedLayerNorm,
ignore_if_not_exist=True),
SubModuleReplacementDescription(suffix="final_layer_norm",
target_module=FusedLayerNorm,
ignore_if_not_exist=True)
],
policy=policy,
target_key=OPTDecoderLayer)
# use flash attention
# if self.shard_config.enable_flash_attention:
# self.append_or_create_method_replacement(description={
# 'forward': get_opt_flash_attention_forward(),
# },
# policy=policy,
# target_key=OPTAttention)
# use jit fused operator
# if self.shard_config.enable_jit_fused:
# self.append_or_create_method_replacement(description={
# 'forward': get_jit_fused_opt_decoder_layer_forward(),
# 'dropout_add': get_jit_fused_dropout_add_func(),
# },
# policy=policy,
# target_key=OPTDecoderLayer)
return policy
def postprocess(self):
return self.model
def get_held_layers(self) -> List[nn.Module]:
"""Get pipeline layers for current stage."""
assert self.pipeline_stage_manager is not None
if self.model.__class__.__name__ == 'OPTModel':
module = self.model.decoder
else:
module = self.model.model.decoder
stage_manager = self.pipeline_stage_manager
held_layers = []
layers_per_stage = self.distribute_layers(len(module.layers), stage_manager.num_stages)
if stage_manager.is_first_stage():
held_layers.append(module.embed_tokens)
held_layers.append(module.embed_positions)
held_layers.append(module.project_in)
start_idx, end_idx = self.get_stage_index(layers_per_stage, stage_manager.stage)
held_layers.extend(module.layers[start_idx:end_idx])
if stage_manager.is_last_stage():
held_layers.append(module.final_layer_norm)
held_layers.append(module.project_out)
return held_layers
def set_pipeline_forward(self, model_cls: nn.Module, new_forward: Callable, policy: Dict) -> None:
"""If under pipeline parallel setting, replacing the original forward method of huggingface
to customized forward method, and add this changing to policy."""
if self.pipeline_stage_manager:
stage_manager = self.pipeline_stage_manager
if self.model.__class__.__name__ == 'OPTModel':
module = self.model.decoder
else:
module = self.model.model.decoder
layers_per_stage = Policy.distribute_layers(len(module.layers), stage_manager.num_stages)
stage_index = Policy.get_stage_index(layers_per_stage, stage_manager.stage)
method_replacement = {'forward': partial(new_forward, stage_manager=stage_manager, stage_index=stage_index)}
self.append_or_create_method_replacement(description=method_replacement,
policy=policy,
target_key=model_cls)
class OPTModelPolicy(OPTPolicy):
def __init__(self) -> None:
super().__init__()
def module_policy(self):
from transformers.models.opt.modeling_opt import OPTModel
policy = super().module_policy()
if self.pipeline_stage_manager:
self.set_pipeline_forward(model_cls=OPTModel,
new_forward=OPTPipelineForwards.opt_model_forward,
policy=policy)
return policy
def get_held_layers(self) -> List[nn.Module]:
return super().get_held_layers()
def get_shared_params(self) -> List[Dict[int, Tensor]]:
"""No shared params in OPTModel."""
return []
class OPTForCausalLMPolicy(OPTPolicy):
def module_policy(self):
from transformers.models.opt.modeling_opt import OPTForCausalLM
policy = super().module_policy()
if self.shard_config.enable_tensor_parallelism:
self.append_or_create_submodule_replacement(description=SubModuleReplacementDescription(
suffix="lm_head", target_module=Linear1D_Col, kwargs=dict(gather_output=True)),
policy=policy,
target_key=OPTForCausalLM)
if self.pipeline_stage_manager:
self.set_pipeline_forward(model_cls=OPTForCausalLM,
new_forward=OPTPipelineForwards.opt_for_causal_lm_forward,
policy=policy)
return 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.lm_head)
return held_layers
def get_shared_params(self) -> List[Dict[int, Tensor]]:
opt_model = self.model
if self.pipeline_stage_manager and self.pipeline_stage_manager.num_stages > 1:
num_stages = self.pipeline_stage_manager.num_stages
if id(opt_model.model.decoder.embed_tokens.weight) == id(opt_model.lm_head.weight):
return [{0: opt_model.model.decoder.embed_tokens.weight, num_stages - 1: opt_model.lm_head.weight}]
return []
def postprocess(self):
if self.shard_config.enable_tensor_parallelism and self.pipeline_stage_manager is None:
binding_map = {
'model.decoder.embed_tokens': 'lm_head',
}
for k, v in binding_map.items():
src_mod = getattr_(self.model, k)
dst_mod = getattr_(self.model, v)
dst_mod.weight = src_mod.weight
return self.model
class OPTForSequenceClassificationPolicy(OPTPolicy):
def __init__(self) -> None:
super().__init__()
def module_policy(self):
from transformers.models.opt.modeling_opt import OPTForSequenceClassification
policy = super().module_policy()
if self.pipeline_stage_manager:
self.set_pipeline_forward(model_cls=OPTForSequenceClassification,
new_forward=OPTPipelineForwards.opt_for_sequence_classification_forward,
policy=policy)
return 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.score)
return held_layers
def get_shared_params(self) -> List[Dict[int, Tensor]]:
"no shared params in OPTForSequenceClassification"
return []
class OPTForQuestionAnsweringPolicy(OPTPolicy):
def __init__(self) -> None:
super().__init__()
def module_policy(self):
from transformers.models.opt.modeling_opt import OPTForQuestionAnswering
policy = super().module_policy()
if self.pipeline_stage_manager:
self.set_pipeline_forward(model_cls=OPTForQuestionAnswering,
new_forward=OPTPipelineForwards.opt_for_question_answering_forward,
policy=policy)
return 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 OPTForSequenceClassification"
return []