2023-11-20 11:58:01 -08:00

281 lines
9.9 KiB
Python

# coding=utf-8
# Adapted from
# https://github.com/huggingface/transformers/blob/v4.28.0/src/transformers/models/gptj/modeling_gptj.py
# Copyright 2023 The vLLM team.
# Copyright 2021 The EleutherAI and HuggingFace Teams. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
"""Inference-only GPT-J model compatible with HuggingFace weights.
The input of the model is flattened to a 1D tensor of tokens. The model uses
InputMetadata to extract the original 2D shape of the input.
"""
from typing import List, Optional, Tuple
import torch
from torch import nn
from transformers import GPTJConfig
from vllm.model_executor.input_metadata import InputMetadata
from vllm.model_executor.layers.activation import get_act_fn
from vllm.model_executor.layers.attention import PagedAttentionWithRoPE
from vllm.model_executor.layers.linear import (ColumnParallelLinear,
LinearMethodBase,
QKVParallelLinear,
RowParallelLinear)
from vllm.model_executor.layers.sampler import Sampler
from vllm.model_executor.layers.vocab_parallel_embedding import (
VocabParallelEmbedding, ParallelLMHead)
from vllm.model_executor.parallel_utils.parallel_state import (
get_tensor_model_parallel_world_size)
from vllm.model_executor.weight_utils import (default_weight_loader,
hf_model_weights_iterator)
from vllm.sequence import SamplerOutput
KVCache = Tuple[torch.Tensor, torch.Tensor]
class GPTJAttention(nn.Module):
def __init__(
self,
config: GPTJConfig,
linear_method: Optional[LinearMethodBase] = None,
):
super().__init__()
self.total_num_heads = config.num_attention_heads
self.hidden_size = config.hidden_size
self.head_size = self.hidden_size // self.total_num_heads
self.qkv_proj = QKVParallelLinear(
config.hidden_size,
self.head_size,
self.total_num_heads,
bias=False,
linear_method=linear_method,
)
self.out_proj = RowParallelLinear(
config.hidden_size,
config.hidden_size,
bias=False,
linear_method=linear_method,
)
tp_world_size = get_tensor_model_parallel_world_size()
assert self.total_num_heads % tp_world_size == 0
self.num_heads = self.total_num_heads // tp_world_size
scaling = self.head_size**-0.5
assert getattr(config, "rotary", True)
assert config.rotary_dim % 2 == 0
rope_theta = getattr(config, "rope_theta", 10000)
max_position_embeddings = getattr(config, "max_position_embeddings",
8192)
self.attn = PagedAttentionWithRoPE(
self.num_heads,
self.head_size,
scaling,
config.rotary_dim,
base=rope_theta,
max_position=max_position_embeddings,
is_neox_style=False)
self.warmup = False
def forward(
self,
position_ids: torch.Tensor,
hidden_states: torch.Tensor,
kv_cache: KVCache,
input_metadata: InputMetadata,
cache_event: Optional[torch.cuda.Event],
) -> torch.Tensor:
qkv, _ = self.qkv_proj(hidden_states)
q, k, v = qkv.chunk(chunks=3, dim=-1)
k_cache, v_cache = kv_cache
attn_output = self.attn(position_ids, q, k, v, k_cache, v_cache,
input_metadata, cache_event)
attn_output, _ = self.out_proj(attn_output)
return attn_output
class GPTJMLP(nn.Module):
def __init__(
self,
intermediate_size: int,
config: GPTJConfig,
linear_method: Optional[LinearMethodBase] = None,
):
super().__init__()
hidden_size = config.n_embd
self.fc_in = ColumnParallelLinear(
hidden_size,
intermediate_size,
linear_method=linear_method,
)
self.fc_out = RowParallelLinear(
intermediate_size,
hidden_size,
linear_method=linear_method,
)
quant_config = getattr(linear_method, "quant_config", None)
self.act = get_act_fn(config.activation_function, quant_config,
intermediate_size)
def forward(self, hidden_states: torch.Tensor) -> torch.Tensor:
hidden_states, _ = self.fc_in(hidden_states)
hidden_states = self.act(hidden_states)
hidden_states, _ = self.fc_out(hidden_states)
return hidden_states
class GPTJBlock(nn.Module):
def __init__(
self,
config: GPTJConfig,
linear_method: Optional[LinearMethodBase] = None,
):
super().__init__()
inner_dim = 4 * config.n_embd if config.n_inner is None else config.n_inner
self.ln_1 = nn.LayerNorm(config.n_embd, eps=config.layer_norm_epsilon)
self.attn = GPTJAttention(config, linear_method)
self.mlp = GPTJMLP(inner_dim, config, linear_method)
def forward(
self,
position_ids: torch.Tensor,
hidden_states: torch.Tensor,
kv_cache: KVCache,
input_metadata: InputMetadata,
cache_event: Optional[torch.cuda.Event],
) -> torch.Tensor:
residual = hidden_states
hidden_states = self.ln_1(hidden_states)
attn_output = self.attn(
position_ids=position_ids,
hidden_states=hidden_states,
kv_cache=kv_cache,
input_metadata=input_metadata,
cache_event=cache_event,
)
mlp_output = self.mlp(hidden_states)
hidden_states = attn_output + mlp_output + residual
return hidden_states
class GPTJModel(nn.Module):
def __init__(
self,
config: GPTJConfig,
linear_method: Optional[LinearMethodBase] = None,
):
super().__init__()
self.config = config
self.embed_dim = config.n_embd
self.wte = VocabParallelEmbedding(
config.vocab_size,
self.embed_dim,
)
self.h = nn.ModuleList(
[GPTJBlock(config, linear_method) for _ in range(config.n_layer)])
self.ln_f = nn.LayerNorm(self.embed_dim, eps=config.layer_norm_epsilon)
def forward(
self,
input_ids: torch.Tensor,
position_ids: torch.Tensor,
kv_caches: List[KVCache],
input_metadata: InputMetadata,
cache_events: Optional[List[torch.cuda.Event]],
) -> torch.Tensor:
hidden_states = self.wte(input_ids)
for i in range(len(self.h)):
cache_event = None if cache_events is None else cache_events[i]
layer = self.h[i]
hidden_states = layer(
position_ids,
hidden_states,
kv_caches[i],
input_metadata,
cache_event,
)
hidden_states = self.ln_f(hidden_states)
return hidden_states
class GPTJForCausalLM(nn.Module):
def __init__(
self,
config: GPTJConfig,
linear_method: Optional[LinearMethodBase] = None,
):
super().__init__()
self.config = config
self.linear_method = linear_method
assert not config.tie_word_embeddings
self.transformer = GPTJModel(config, linear_method)
self.lm_head = ParallelLMHead(
config.vocab_size,
config.n_embd,
bias=True,
)
self.sampler = Sampler(config.vocab_size)
def forward(
self,
input_ids: torch.Tensor,
positions: torch.Tensor,
kv_caches: List[KVCache],
input_metadata: InputMetadata,
cache_events: Optional[List[torch.cuda.Event]],
) -> SamplerOutput:
hidden_states = self.transformer(input_ids, positions, kv_caches,
input_metadata, cache_events)
next_tokens = self.sampler(self.lm_head.weight, hidden_states,
input_metadata, self.lm_head.bias)
return next_tokens
def load_weights(self,
model_name_or_path: str,
cache_dir: Optional[str] = None,
load_format: str = "auto",
revision: Optional[str] = None):
stacked_params_mapping = [
# (param_name, shard_name, shard_id)
("qkv_proj", "q_proj", "q"),
("qkv_proj", "k_proj", "k"),
("qkv_proj", "v_proj", "v"),
("gate_up_proj", "gate_proj", 0),
("gate_up_proj", "up_proj", 1),
]
params_dict = dict(self.named_parameters())
for name, loaded_weight in hf_model_weights_iterator(
model_name_or_path, cache_dir, load_format, revision):
if "attn.bias" in name or "attn.masked_bias" in name:
continue
for (param_name, weight_name, shard_id) in stacked_params_mapping:
if weight_name not in name:
continue
param = params_dict[name.replace(weight_name, param_name)]
weight_loader = param.weight_loader
weight_loader(param, loaded_weight, shard_id)
break
else:
param = params_dict[name]
weight_loader = getattr(param, "weight_loader",
default_weight_loader)
weight_loader(param, loaded_weight)