423 lines
16 KiB
Python

# coding=utf-8
# Adapted from
# https://github.com/huggingface/transformers/blob/v4.28.0/src/transformers/models/llama/modeling_llama.py
# Copyright 2023 The vLLM team.
# 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 LLaMA 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 Any, Dict, List, Optional, Tuple
import torch
from torch import nn
from transformers import LlamaConfig
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
from vllm.model_executor.layers.sampler import Sampler
from vllm.model_executor.layers.quantized_linear import ParallelLinear
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.layers import VocabParallelEmbedding
from vllm.model_executor.quantization_utils import QuantizationConfig
from vllm.model_executor.weight_utils import (
convert_pyslice_to_tensor, hf_model_weights_iterator,
load_tensor_parallel_weights, load_padded_tensor_parallel_vocab)
from vllm.sequence import SamplerOutput
KVCache = Tuple[torch.Tensor, torch.Tensor]
class LlamaMLP(nn.Module):
def __init__(
self,
hidden_size: int,
intermediate_size: int,
hidden_act: str,
quant_config: Optional[QuantizationConfig] = None,
) -> None:
super().__init__()
self.gate_up_proj = ParallelLinear.column(hidden_size,
2 * intermediate_size,
bias=False,
gather_output=False,
quant_config=quant_config)
self.down_proj = ParallelLinear.row(intermediate_size,
hidden_size,
bias=False,
input_is_parallel=True,
quant_config=quant_config)
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 LlamaAttention(nn.Module):
def __init__(
self,
hidden_size: int,
num_heads: int,
num_kv_heads: int,
rope_theta: float = 10000,
rope_scaling: Optional[Dict[str, Any]] = None,
max_position_embeddings: int = 8192,
quant_config: Optional[QuantizationConfig] = None,
) -> None:
super().__init__()
self.hidden_size = hidden_size
tp_size = get_tensor_model_parallel_world_size()
self.total_num_heads = num_heads
assert self.total_num_heads % tp_size == 0
self.num_heads = self.total_num_heads // tp_size
self.total_num_kv_heads = num_kv_heads
if self.total_num_kv_heads >= tp_size:
# Number of KV heads is greater than TP size, so we partition
# the KV heads across multiple tensor parallel GPUs.
assert self.total_num_kv_heads % tp_size == 0
else:
# Number of KV heads is less than TP size, so we replicate
# the KV heads across multiple tensor parallel GPUs.
assert tp_size % self.total_num_kv_heads == 0
self.num_kv_heads = max(1, self.total_num_kv_heads // tp_size)
num_kv_heads_replicas = max(1, tp_size // self.total_num_kv_heads)
self.head_dim = hidden_size // self.total_num_heads
self.q_size = self.num_heads * self.head_dim
self.kv_size = self.num_kv_heads * self.head_dim
self.scaling = self.head_dim**-0.5
self.rope_theta = rope_theta
self.max_position_embeddings = max_position_embeddings
self.qkv_proj = ParallelLinear.column(
hidden_size,
(self.total_num_heads +
2 * self.total_num_kv_heads * num_kv_heads_replicas) *
self.head_dim,
bias=False,
gather_output=False,
quant_config=quant_config,
)
self.o_proj = ParallelLinear.row(
self.total_num_heads * self.head_dim,
hidden_size,
bias=False,
input_is_parallel=True,
quant_config=quant_config,
)
self.attn = PagedAttentionWithRoPE(
self.num_heads,
self.head_dim,
self.scaling,
base=self.rope_theta,
max_position=self.max_position_embeddings,
rotary_dim=self.head_dim,
num_kv_heads=self.num_kv_heads,
rope_scaling=rope_scaling)
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.qkv_proj(hidden_states)
q, k, v = qkv.split([self.q_size, self.kv_size, self.kv_size], dim=-1)
k_cache, v_cache = kv_cache
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 LlamaDecoderLayer(nn.Module):
def __init__(
self,
config: LlamaConfig,
quant_config: Optional[QuantizationConfig] = None,
) -> None:
super().__init__()
self.hidden_size = config.hidden_size
# Requires transformers > 4.32.0
rope_theta = getattr(config, "rope_theta", 10000)
rope_scaling = getattr(config, "rope_scaling", None)
max_position_embeddings = getattr(config, "max_position_embeddings",
8192)
self.self_attn = LlamaAttention(
hidden_size=self.hidden_size,
num_heads=config.num_attention_heads,
num_kv_heads=config.num_key_value_heads,
rope_theta=rope_theta,
rope_scaling=rope_scaling,
max_position_embeddings=max_position_embeddings,
quant_config=quant_config,
)
self.mlp = LlamaMLP(
hidden_size=self.hidden_size,
intermediate_size=config.intermediate_size,
hidden_act=config.hidden_act,
quant_config=quant_config,
)
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 LlamaModel(nn.Module):
def __init__(
self,
config: LlamaConfig,
quant_config: Optional[QuantizationConfig] = None,
) -> None:
super().__init__()
self.config = config
self.padding_idx = config.pad_token_id
self.vocab_size = config.vocab_size
vocab_size = ((config.vocab_size + 63) // 64) * 64
self.embed_tokens = VocabParallelEmbedding(
vocab_size,
config.hidden_size,
)
self.layers = nn.ModuleList([
LlamaDecoderLayer(config, quant_config)
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 LlamaForCausalLM(nn.Module):
def __init__(
self,
config: LlamaConfig,
quant_config: Optional[QuantizationConfig] = None,
) -> None:
super().__init__()
self.config = config
self.quant_config = quant_config
self.model = LlamaModel(config, quant_config)
vocab_size = ((config.vocab_size + 63) // 64) * 64
# NOTE: The LM head is not quantized.
self.lm_head = ParallelLinear.column(config.hidden_size,
vocab_size,
bias=False,
gather_output=False,
quant_config=None)
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_layers = []
_row_parallel_layers = ["o_proj", "down_proj"]
def load_weights(self,
model_name_or_path: str,
cache_dir: Optional[str] = None,
load_format: str = "auto",
revision: Optional[str] = None):
if self.quant_config is None:
weight_suffixes = ["weight"]
else:
weight_suffixes = self.quant_config.get_tp_tensor_names()
column_parallel_weights: List[str] = []
for layer in self._column_parallel_layers:
for suffix in weight_suffixes:
column_parallel_weights.append(f"{layer}.{suffix}")
row_parallel_weights: List[str] = []
for layer in self._row_parallel_layers:
for suffix in weight_suffixes:
row_parallel_weights.append(f"{layer}.{suffix}")
tp_size = get_tensor_model_parallel_world_size()
tp_rank = get_tensor_model_parallel_rank()
q_proj_shard_size = (self.config.hidden_size // tp_size)
num_kv_heads_replicas = max(1,
tp_size // self.config.num_key_value_heads)
num_kv_heads_per_gpu = max(1,
self.config.num_key_value_heads // tp_size)
kv_proj_shard_size = (self.config.hidden_size //
self.config.num_attention_heads *
num_kv_heads_per_gpu)
attention_weight_specs = [
# (weight_name, shard_size, offset)
("q_proj", q_proj_shard_size, 0),
("k_proj", kv_proj_shard_size, q_proj_shard_size),
("v_proj", kv_proj_shard_size,
q_proj_shard_size + kv_proj_shard_size),
]
state_dict = self.state_dict()
for name, loaded_weight in hf_model_weights_iterator(
model_name_or_path, cache_dir, load_format, revision):
if "rotary_emb.inv_freq" in name:
continue
is_packed = False
is_transposed = False
if self.quant_config is not None:
is_packed = self.quant_config.is_packed(name)
is_transposed = self.quant_config.is_transposed(name)
if is_transposed:
loaded_weight = convert_pyslice_to_tensor(loaded_weight)
loaded_weight = loaded_weight.T
is_attention_weight = False
for weight_name, shard_size, offset in attention_weight_specs:
if weight_name not in name:
continue
param = state_dict[name.replace(weight_name, "qkv_proj")]
if is_transposed:
param = param.T
if is_packed:
shard_size //= self.quant_config.pack_factor
offset //= self.quant_config.pack_factor
if weight_name in ["k_proj", "v_proj"]:
shard_id = tp_rank // num_kv_heads_replicas
else:
shard_id = tp_rank
loaded_weight = loaded_weight[shard_size *
shard_id:shard_size *
(shard_id + 1)]
param_slice = param.data[offset:offset + shard_size]
assert param_slice.shape == loaded_weight.shape
param_slice.copy_(loaded_weight)
is_attention_weight = True
break
if is_attention_weight:
continue
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")]
if is_transposed:
param = param.T
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 is_transposed:
param = param.T
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,
column_parallel_weights,
row_parallel_weights, tp_rank)