ColossalAI/colossalai/shardformer/policies/mistral.py

381 lines
15 KiB
Python

import warnings
from functools import partial
from typing import Callable, Dict, List, Union
import torch.nn as nn
from torch import Tensor
from torch.nn import Module
from colossalai.shardformer.layer import (
FusedRMSNorm,
Linear1D_Col,
Linear1D_Row,
PaddingEmbedding,
PaddingLMHead,
VocabParallelEmbedding1D,
VocabParallelLMHead1D,
)
from ..modeling.mistral import (
MistralForwards,
get_lm_forward_with_dist_cross_entropy,
get_mistral_flash_attention_forward,
get_mistral_model_forward_for_flash_attn,
)
from .base_policy import ModulePolicyDescription, Policy, SubModuleReplacementDescription
__all__ = ["MistralPolicy", "MistralModelPolicy", "MistralForCausalLMPolicy", "MistralForSequenceClassificationPolicy"]
class MistralPolicy(Policy):
def config_sanity_check(self):
pass
def preprocess(self):
self.tie_weight = self.tie_weight_check()
self.origin_attn_implement = self.model.config._attn_implementation
return self.model
def module_policy(self) -> Dict[Union[str, nn.Module], ModulePolicyDescription]:
from transformers.models.mistral.modeling_mistral import (
MistralAttention,
MistralDecoderLayer,
MistralFlashAttention2,
MistralModel,
MistralSdpaAttention,
)
ATTN_IMPLEMENTATION = {
"eager": MistralAttention,
"flash_attention_2": MistralFlashAttention2,
"sdpa": MistralSdpaAttention,
}
policy = {}
attn_cls = ATTN_IMPLEMENTATION[self.model.config._attn_implementation]
embedding_cls = None
if self.shard_config.enable_tensor_parallelism:
embedding_cls = VocabParallelEmbedding1D
else:
if self.tie_weight:
embedding_cls = PaddingEmbedding
if self.shard_config.enable_sequence_parallelism:
self.shard_config.enable_sequence_parallelism = False
warnings.warn(
"Mistral doesn't support sequence parallelism now, will ignore the sequence parallelism flag."
)
if self.shard_config.enable_tensor_parallelism:
assert (
self.model.config.num_attention_heads % self.shard_config.tensor_parallel_size == 0
), f"The number of attention heads must be divisible by tensor parallel size."
assert (
self.model.config.num_key_value_heads % self.shard_config.tensor_parallel_size == 0
), f"The number of key_value heads must be divisible by tensor parallel size."
decoder_attribute_replacement = {
"self_attn.hidden_size": self.model.config.hidden_size // self.shard_config.tensor_parallel_size,
"self_attn.num_heads": self.model.config.num_attention_heads // self.shard_config.tensor_parallel_size,
"self_attn.num_key_value_heads": self.model.config.num_key_value_heads
// self.shard_config.tensor_parallel_size,
}
policy[MistralDecoderLayer] = ModulePolicyDescription(
attribute_replacement=decoder_attribute_replacement,
sub_module_replacement=[
SubModuleReplacementDescription(
suffix="self_attn.q_proj",
target_module=Linear1D_Col,
),
SubModuleReplacementDescription(
suffix="self_attn.k_proj",
target_module=Linear1D_Col,
),
SubModuleReplacementDescription(
suffix="self_attn.v_proj",
target_module=Linear1D_Col,
),
SubModuleReplacementDescription(
suffix="self_attn.o_proj",
target_module=Linear1D_Row,
),
SubModuleReplacementDescription(
suffix="mlp.gate_proj",
target_module=Linear1D_Col,
),
SubModuleReplacementDescription(
suffix="mlp.up_proj",
target_module=Linear1D_Col,
),
SubModuleReplacementDescription(
suffix="mlp.down_proj",
target_module=Linear1D_Row,
),
],
)
if embedding_cls is not None:
self.append_or_create_submodule_replacement(
description=SubModuleReplacementDescription(
suffix="embed_tokens",
target_module=embedding_cls,
kwargs={"make_vocab_size_divisible_by": self.shard_config.make_vocab_size_divisible_by},
),
policy=policy,
target_key=MistralModel,
)
# optimization configuration
if self.shard_config.enable_fused_normalization:
self.append_or_create_submodule_replacement(
description=[
SubModuleReplacementDescription(
suffix="input_layernorm",
target_module=FusedRMSNorm,
),
SubModuleReplacementDescription(
suffix="post_attention_layernorm",
target_module=FusedRMSNorm,
),
],
policy=policy,
target_key=MistralDecoderLayer,
)
self.append_or_create_submodule_replacement(
description=SubModuleReplacementDescription(
suffix="norm",
target_module=FusedRMSNorm,
),
policy=policy,
target_key=MistralModel,
)
if self.shard_config.enable_flash_attention:
self.append_or_create_method_replacement(
description={
"forward": get_mistral_flash_attention_forward(self.shard_config),
},
policy=policy,
target_key=attn_cls,
)
if self.pipeline_stage_manager is None:
# replace llama model forward method
self.append_or_create_method_replacement(
description={
"forward": get_mistral_model_forward_for_flash_attn(self.shard_config),
},
policy=policy,
target_key=MistralModel,
)
return policy
def postprocess(self):
return self.model
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 is None:
return
stage_manager = self.pipeline_stage_manager
if self.model.__class__.__name__ == "MistralModel":
module = self.model
else:
module = self.model.model
if stage_manager.is_interleave:
layers_per_stage = stage_manager.distribute_layers(len(module.layers))
stage_manager.stage_indices = stage_manager.get_stage_index(layers_per_stage)
method_replacement = {
"forward": partial(new_forward, stage_manager=stage_manager, shard_config=self.shard_config)
}
else:
layers_per_stage = stage_manager.distribute_layers(len(module.layers))
stage_index = stage_manager.get_stage_index(layers_per_stage)
method_replacement = {
"forward": partial(
new_forward, stage_manager=stage_manager, stage_index=stage_index, shard_config=self.shard_config
)
}
self.append_or_create_method_replacement(description=method_replacement, policy=policy, target_key=model_cls)
def get_held_layers(self) -> List[Module]:
"""Get pipeline layers for current stage."""
assert self.pipeline_stage_manager is not None
if self.model.__class__.__name__ == "MistralModel":
module = self.model
else:
module = self.model.model
stage_manager = self.pipeline_stage_manager
held_layers = []
if stage_manager.is_interleave:
assert stage_manager.num_model_chunks is not None
layers_per_stage = stage_manager.distribute_layers(len(module.layers))
stage_indices = stage_manager.get_stage_index(layers_per_stage)
if stage_manager.is_first_stage(ignore_chunk=True):
held_layers.append(module.embed_tokens)
for start_idx, end_idx in stage_indices:
held_layers.extend(module.layers[start_idx:end_idx])
if stage_manager.is_last_stage(ignore_chunk=True):
held_layers.append(module.norm)
else:
layers_per_stage = stage_manager.distribute_layers(len(module.layers))
if stage_manager.is_first_stage():
held_layers.append(module.embed_tokens)
start_idx, end_idx = stage_manager.get_stage_index(layers_per_stage)
held_layers.extend(module.layers[start_idx:end_idx])
if stage_manager.is_last_stage():
held_layers.append(module.norm)
return held_layers
class MistralModelPolicy(MistralPolicy):
def __init__(self) -> None:
super().__init__()
def module_policy(self):
policy = super().module_policy()
from transformers.models.mistral.modeling_mistral import MistralModel
if self.pipeline_stage_manager:
self.set_pipeline_forward(
model_cls=MistralModel, new_forward=MistralForwards.mistral_model_forward, policy=policy
)
return policy
def get_held_layers(self) -> List[Module]:
"""Get pipeline layers for current stage."""
held_layers = super().get_held_layers()
return held_layers
def get_shared_params(self) -> List[Dict[int, Tensor]]:
"""No shared params in mistral model"""
return []
class MistralForCausalLMPolicy(MistralPolicy):
def module_policy(self):
from transformers import MistralForCausalLM
policy = super().module_policy()
if self.shard_config.enable_tensor_parallelism:
# add a new item for casual lm
new_item = {
MistralForCausalLM: ModulePolicyDescription(
sub_module_replacement=[
SubModuleReplacementDescription(
suffix="lm_head",
target_module=VocabParallelLMHead1D,
kwargs={
"gather_output": not self.shard_config.parallel_output,
"make_vocab_size_divisible_by": self.shard_config.make_vocab_size_divisible_by,
},
)
]
)
}
if self.shard_config.parallel_output:
new_item[MistralForCausalLM].method_replacement = {
"forward": get_lm_forward_with_dist_cross_entropy(self.shard_config)
}
else:
new_item = {
MistralForCausalLM: ModulePolicyDescription(
sub_module_replacement=[
SubModuleReplacementDescription(
suffix="lm_head",
target_module=PaddingLMHead,
kwargs=dict(make_vocab_size_divisible_by=self.shard_config.make_vocab_size_divisible_by),
)
]
)
}
policy.update(new_item)
if self.pipeline_stage_manager:
# set None as default
self.set_pipeline_forward(
model_cls=MistralForCausalLM, new_forward=MistralForwards.mistral_for_causal_lm_forward, policy=policy
)
return policy
def get_held_layers(self) -> List[Module]:
"""Get pipeline layers for current stage."""
stage_manager = self.pipeline_stage_manager
held_layers = super().get_held_layers()
if stage_manager.is_last_stage(ignore_chunk=True):
held_layers.append(self.model.lm_head)
return held_layers
def get_shared_params(self) -> List[Dict[int, Tensor]]:
mistral_model = self.model.model
if self.pipeline_stage_manager and self.pipeline_stage_manager.num_stages > 1:
if (
id(mistral_model.embed_tokens.weight) == id(self.model.lm_head.weight)
and self.pipeline_stage_manager.num_stages > 1
):
# tie weights
return [
{
0: mistral_model.embed_tokens.weight,
self.pipeline_stage_manager.num_stages - 1: self.model.lm_head.weight,
}
]
return []
class MistralForSequenceClassificationPolicy(MistralPolicy):
def module_policy(self):
from transformers import MistralForSequenceClassification
policy = super().module_policy()
if self.shard_config.enable_tensor_parallelism:
# add a new item for sequence classification
new_item = {
MistralForSequenceClassification: ModulePolicyDescription(
sub_module_replacement=[
SubModuleReplacementDescription(
suffix="score", target_module=Linear1D_Col, kwargs=dict(gather_output=True)
)
]
)
}
policy.update(new_item)
if self.pipeline_stage_manager:
# set None as default
self.set_pipeline_forward(
model_cls=MistralForSequenceClassification,
new_forward=MistralForwards.mistral_for_sequence_classification_forward,
policy=policy,
)
return policy
def get_held_layers(self) -> List[Module]:
"""Get pipeline layers for current stage."""
stage_manager = self.pipeline_stage_manager
held_layers = super().get_held_layers()
if stage_manager.is_last_stage(ignore_chunk=True):
held_layers.append(self.model.score)
return held_layers
def get_shared_params(self) -> List[Dict[int, Tensor]]:
"""No shared params in llama for sequence classification model"""
return []