373 lines
14 KiB
Python

# coding=utf-8
# Copyright 2022 EleutherAI and the HuggingFace Inc. team. All rights reserved.
#
# This code is based on EleutherAI's GPT-NeoX library and the GPT-NeoX
# and OPT implementations in this library. It has been modified from its
# original forms to accommodate minor architectural differences compared
# to GPT-NeoX and OPT used by the Meta AI team that trained the model.
#
# 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 BaiChuan 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.
"""
import math
from typing import List, Optional, Tuple
import torch
from torch import nn
from vllm.model_executor.input_metadata import InputMetadata
from vllm.model_executor.layers.activation import SiluAndMul
from vllm.model_executor.layers.layernorm import RMSNorm
from vllm.model_executor.layers.attention import (PagedAttentionWithRoPE,
PagedAttentionWithALiBi)
from vllm.model_executor.layers.sampler import Sampler
from vllm.model_executor.weight_utils import (
hf_model_weights_iterator, load_padded_tensor_parallel_vocab,
load_tensor_parallel_weights)
from vllm.model_executor.parallel_utils.parallel_state import (
get_tensor_model_parallel_rank, get_tensor_model_parallel_world_size)
from vllm.model_executor.parallel_utils.tensor_parallel import (
VocabParallelEmbedding, ColumnParallelLinear, RowParallelLinear)
from vllm.sequence import SamplerOutput
from vllm.transformers_utils.configs.baichuan import BaiChuanConfig
KVCache = Tuple[torch.Tensor, torch.Tensor]
def _get_alibi_slopes(total_num_heads: int) -> torch.Tensor:
closest_power_of_2 = 2**math.floor(math.log2(total_num_heads))
base = torch.tensor(
2**(-(2**-(math.log2(closest_power_of_2) - 3))),
dtype=torch.float32,
)
powers = torch.arange(1, 1 + closest_power_of_2, dtype=torch.int32)
slopes = torch.pow(base, powers)
if closest_power_of_2 != total_num_heads:
extra_base = torch.tensor(
2**(-(2**-(math.log2(2 * closest_power_of_2) - 3))),
dtype=torch.float32,
)
num_remaining_heads = min(closest_power_of_2,
total_num_heads - closest_power_of_2)
extra_powers = torch.arange(start=1,
end=1 + 2 * num_remaining_heads,
step=2,
dtype=torch.int32)
slopes = torch.cat(
[slopes, torch.pow(extra_base, extra_powers)], dim=0)
return slopes
class BaiChuanMLP(nn.Module):
def __init__(
self,
hidden_size: int,
intermediate_size: int,
hidden_act: str,
):
super().__init__()
self.gate_up_proj = ColumnParallelLinear(hidden_size,
2 * intermediate_size,
bias=False,
gather_output=False,
perform_initialization=False)
self.down_proj = RowParallelLinear(intermediate_size,
hidden_size,
bias=False,
input_is_parallel=True,
perform_initialization=False)
if hidden_act != "silu":
raise ValueError(f"Unsupported activation: {hidden_act}. "
"Only silu is supported for now.")
self.act_fn = SiluAndMul()
def forward(self, x):
gate_up, _ = self.gate_up_proj(x)
x = self.act_fn(gate_up)
x, _ = self.down_proj(x)
return x
class BaiChuanAttention(nn.Module):
"""Multi-headed attention from 'Attention Is All You Need' paper"""
def __init__(
self,
hidden_size: int,
num_heads: int,
position_embedding: str,
):
super().__init__()
self.hidden_size = hidden_size
tensor_model_parallel_world_size = get_tensor_model_parallel_world_size(
)
self.total_num_heads = num_heads
assert self.total_num_heads % tensor_model_parallel_world_size == 0
self.num_heads = (self.total_num_heads //
tensor_model_parallel_world_size)
self.head_dim = hidden_size // self.total_num_heads
self.postion_embedding = position_embedding
# pylint: disable=invalid-name
self.W_pack = ColumnParallelLinear(
hidden_size,
3 * hidden_size,
bias=False,
gather_output=False,
perform_initialization=False,
)
self.o_proj = RowParallelLinear(
self.total_num_heads * self.head_dim,
hidden_size,
bias=False,
input_is_parallel=True,
perform_initialization=False,
)
# Create the alibi slopes and slice them.
if self.postion_embedding == "ALIBI":
tp_rank = get_tensor_model_parallel_rank()
head_start = tp_rank * self.num_heads
head_end = (tp_rank + 1) * self.num_heads
alibi_slopes = _get_alibi_slopes(self.total_num_heads)
alibi_slopes = alibi_slopes[head_start:head_end].tolist()
scaling = self.head_dim**-0.5
self.attn = PagedAttentionWithALiBi(self.num_heads, self.head_dim,
scaling, alibi_slopes)
else:
self.scaling = self.head_dim**-0.5
self.attn = PagedAttentionWithRoPE(self.num_heads,
self.head_dim,
self.scaling,
rotary_dim=self.head_dim)
def forward(
self,
positions: torch.Tensor,
hidden_states: torch.Tensor,
kv_cache: KVCache,
input_metadata: InputMetadata,
cache_event: Optional[torch.cuda.Event],
) -> torch.Tensor:
qkv, _ = self.W_pack(hidden_states)
q, k, v = qkv.chunk(chunks=3, dim=-1)
k_cache, v_cache = kv_cache
if self.postion_embedding == "ALIBI":
attn_output = self.attn(q, k, v, k_cache, v_cache, input_metadata,
cache_event)
else:
attn_output = self.attn(positions, q, k, v, k_cache, v_cache,
input_metadata, cache_event)
output, _ = self.o_proj(attn_output)
return output
class BaiChuanDecoderLayer(nn.Module):
def __init__(self, config: BaiChuanConfig, position_embedding: str):
super().__init__()
self.hidden_size = config.hidden_size
self.self_attn = BaiChuanAttention(
hidden_size=self.hidden_size,
num_heads=config.num_attention_heads,
position_embedding=position_embedding,
)
self.mlp = BaiChuanMLP(
hidden_size=self.hidden_size,
intermediate_size=config.intermediate_size,
hidden_act=config.hidden_act,
)
self.input_layernorm = RMSNorm(config.hidden_size,
eps=config.rms_norm_eps)
self.post_attention_layernorm = RMSNorm(config.hidden_size,
eps=config.rms_norm_eps)
def forward(
self,
positions: torch.Tensor,
hidden_states: torch.Tensor,
kv_cache: KVCache,
input_metadata: InputMetadata,
cache_event: Optional[torch.cuda.Event],
) -> torch.Tensor:
# Self Attention
residual = hidden_states
hidden_states = self.input_layernorm(hidden_states)
hidden_states = self.self_attn(
positions=positions,
hidden_states=hidden_states,
kv_cache=kv_cache,
input_metadata=input_metadata,
cache_event=cache_event,
)
hidden_states = residual + hidden_states
# Fully Connected
residual = hidden_states
hidden_states = self.post_attention_layernorm(hidden_states)
hidden_states = self.mlp(hidden_states)
hidden_states = residual + hidden_states
return hidden_states
class BaiChuanModel(nn.Module):
def __init__(self, config: BaiChuanConfig, position_embedding: str):
super().__init__()
self.config = config
self.padding_idx = config.pad_token_id
self.vocab_size = config.vocab_size
self.embed_tokens = VocabParallelEmbedding(
config.vocab_size,
config.hidden_size,
perform_initialization=False)
self.layers = nn.ModuleList([
BaiChuanDecoderLayer(config, position_embedding)
for _ in range(config.num_hidden_layers)
])
self.norm = RMSNorm(config.hidden_size, eps=config.rms_norm_eps)
def forward(
self,
input_ids: torch.Tensor,
positions: torch.Tensor,
kv_caches: List[KVCache],
input_metadata: InputMetadata,
cache_events: Optional[List[torch.cuda.Event]],
) -> torch.Tensor:
hidden_states = self.embed_tokens(input_ids)
for i in range(len(self.layers)):
if cache_events is None:
cache_event = None
else:
cache_event = cache_events[i]
layer = self.layers[i]
hidden_states = layer(
positions,
hidden_states,
kv_caches[i],
input_metadata,
cache_event,
)
hidden_states = self.norm(hidden_states)
return hidden_states
class BaiChuanBaseForCausalLM(nn.Module):
def __init__(self, config, position_embedding: str):
super().__init__()
self.config = config
self.model = BaiChuanModel(config, position_embedding)
self.lm_head = ColumnParallelLinear(config.hidden_size,
config.vocab_size,
bias=False,
gather_output=False,
perform_initialization=False)
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.model(input_ids, positions, kv_caches,
input_metadata, cache_events)
next_tokens = self.sampler(self.lm_head.weight, hidden_states,
input_metadata)
return next_tokens
_column_parallel_weights = []
_row_parallel_weights = ["o_proj.weight", "down_proj.weight"]
def load_weights(self,
model_name_or_path: str,
cache_dir: Optional[str] = None,
use_np_cache: bool = False):
tp_world_size = get_tensor_model_parallel_world_size()
tp_rank = get_tensor_model_parallel_rank()
state_dict = self.state_dict()
for name, loaded_weight in hf_model_weights_iterator(
model_name_or_path, cache_dir, use_np_cache):
if "rotary_emb.inv_freq" in name:
continue
if "W_pack" in name:
total_num_heads = self.config.num_attention_heads
hidden_size = self.config.hidden_size
head_size = hidden_size // total_num_heads
num_heads = total_num_heads // tp_world_size
head_start = tp_rank * num_heads
head_end = (tp_rank + 1) * num_heads
loaded_weight = loaded_weight.view(3, total_num_heads,
head_size, hidden_size)
loaded_weight = loaded_weight[:, head_start:head_end, :, :]
loaded_weight = loaded_weight.reshape(-1, hidden_size)
is_gate_up_weight = False
for stride_id, weight_name in enumerate(["gate_proj", "up_proj"]):
if weight_name not in name:
continue
param = state_dict[name.replace(weight_name, "gate_up_proj")]
shard_size = param.shape[0] // 2
loaded_weight = loaded_weight[shard_size * tp_rank:shard_size *
(tp_rank + 1)]
param_slice = param.data[shard_size * stride_id:shard_size *
(stride_id + 1)]
assert param_slice.shape == loaded_weight.shape
param_slice.copy_(loaded_weight)
is_gate_up_weight = True
break
if is_gate_up_weight:
continue
param = state_dict[name]
if "embed_tokens" in name or "lm_head" in name:
load_padded_tensor_parallel_vocab(param, loaded_weight,
tp_rank)
continue
load_tensor_parallel_weights(
param,
loaded_weight,
name,
self._column_parallel_weights,
self._row_parallel_weights,
tp_rank,
)
class BaichuanForCausalLM(BaiChuanBaseForCausalLM): # baichuan 13b
def __init__(self, config):
super().__init__(config, "ALIBI")
class BaiChuanForCausalLM(BaiChuanBaseForCausalLM): # baichuan 7b
def __init__(self, config):
super().__init__(config, "ROPE")