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from collections.abc import Iterable
from typing import Optional, Union
import torch
from torch import nn
from transformers import Qwen2Config
from vllm.attention import Attention, AttentionType
from vllm.compilation.decorators import support_torch_compile
from vllm.config import CacheConfig, VllmConfig
from vllm.distributed import get_pp_group, get_tensor_model_parallel_world_size
from vllm.logger import init_logger
from vllm.model_executor.layers.activation import SiluAndMul
from vllm.model_executor.layers.layernorm import RMSNorm
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from vllm.model_executor.layers.linear import MergedColumnParallelLinear, QKVParallelLinear, RowParallelLinear
from vllm.model_executor.layers.logits_processor import LogitsProcessor
from vllm.model_executor.layers.pooler import Pooler, PoolingType
from vllm.model_executor.layers.quantization import QuantizationConfig
from vllm.model_executor.layers.rotary_embedding import get_rope
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from vllm.model_executor.layers.vocab_parallel_embedding import ParallelLMHead, VocabParallelEmbedding
from vllm.model_executor.model_loader.weight_utils import default_weight_loader, maybe_remap_kv_scale_name
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from vllm.model_executor.models.interfaces import SupportsLoRA, SupportsPP
from vllm.model_executor.models.utils import (
AutoWeightsLoader,
PPMissingLayer,
WeightsMapper,
is_pp_missing_parameter,
make_empty_intermediate_tensors_factory,
make_layers,
maybe_prefix,
)
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from vllm.sequence import IntermediateTensors
from vllm.v1.outputs import PoolerOutput, SamplerOutput
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from vllm.v1.pool.metadata import PoolingMetadata
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from vllm.v1.sample.metadata import SamplingMetadata
from vllm.v1.sample.sampler import Sampler
logger = init_logger(__name__)
class Qwen2MLP(nn.Module):
def __init__(
self,
hidden_size: int,
intermediate_size: int,
hidden_act: str,
quant_config: Optional[QuantizationConfig] = None,
prefix: str = "",
) -> None:
super().__init__()
self.gate_up_proj = MergedColumnParallelLinear(
hidden_size,
[intermediate_size] * 2,
bias=False,
quant_config=quant_config,
prefix=f"{prefix}.gate_up_proj",
)
self.down_proj = RowParallelLinear(
intermediate_size,
hidden_size,
bias=False,
quant_config=quant_config,
prefix=f"{prefix}.down_proj",
)
if hidden_act != "silu":
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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 Qwen2Attention(nn.Module):
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def __init__(
self,
hidden_size: int,
num_heads: int,
num_kv_heads: int,
max_position: int = 4096 * 32,
rope_theta: float = 10000,
head_dim: Optional[int] = None,
cache_config: Optional[CacheConfig] = None,
quant_config: Optional[QuantizationConfig] = None,
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rope_scaling: Optional[tuple] = None,
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prefix: str = "",
attn_type: str = AttentionType.DECODER,
) -> 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)
self.head_dim = head_dim or (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.qkv_proj = QKVParallelLinear(
hidden_size,
self.head_dim,
self.total_num_heads,
self.total_num_kv_heads,
bias=True,
quant_config=quant_config,
prefix=f"{prefix}.qkv_proj",
)
self.o_proj = RowParallelLinear(
self.total_num_heads * self.head_dim,
hidden_size,
bias=False,
quant_config=quant_config,
prefix=f"{prefix}.o_proj",
)
self.rotary_emb = get_rope(
self.head_dim,
rotary_dim=self.head_dim,
max_position=max_position,
base=self.rope_theta,
rope_scaling=rope_scaling,
)
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self.attn = Attention(
self.num_heads,
self.head_dim,
self.scaling,
num_kv_heads=self.num_kv_heads,
cache_config=cache_config,
quant_config=quant_config,
prefix=f"{prefix}.attn",
attn_type=attn_type,
)
def forward(
self,
positions: torch.Tensor,
hidden_states: torch.Tensor,
) -> torch.Tensor:
qkv, _ = self.qkv_proj(hidden_states)
q, k, v = qkv.split([self.q_size, self.kv_size, self.kv_size], dim=-1)
q, k = self.rotary_emb(positions, q, k)
attn_output = self.attn(q, k, v)
output, _ = self.o_proj(attn_output)
return output
class Qwen2DecoderLayer(nn.Module):
def __init__(
self,
config: Qwen2Config,
cache_config: Optional[CacheConfig] = None,
quant_config: Optional[QuantizationConfig] = None,
prefix: str = "",
) -> None:
super().__init__()
self.hidden_size = config.hidden_size
# Requires transformers > 4.32.0
rope_theta = getattr(config, "rope_theta", 1000000)
rope_scaling = getattr(config, "rope_scaling", None)
# By default, Qwen2 uses causal attention as it is a decoder-only model.
# You can override the HF config with `is_causal=False` to enable
# bidirectional attention, which is used in some embedding models
# (e.g. Alibaba-NLP/gte-Qwen2-7B-instruct)
if getattr(config, "is_causal", True):
attn_type = AttentionType.DECODER
else:
attn_type = AttentionType.ENCODER_ONLY
self.self_attn = Qwen2Attention(
hidden_size=self.hidden_size,
num_heads=config.num_attention_heads,
max_position=config.max_position_embeddings,
num_kv_heads=config.num_key_value_heads,
rope_theta=rope_theta,
cache_config=cache_config,
quant_config=quant_config,
rope_scaling=rope_scaling,
head_dim=getattr(config, "head_dim", None),
prefix=f"{prefix}.self_attn",
attn_type=attn_type,
)
self.mlp = Qwen2MLP(
hidden_size=self.hidden_size,
intermediate_size=config.intermediate_size,
hidden_act=config.hidden_act,
quant_config=quant_config,
prefix=f"{prefix}.mlp",
)
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self.input_layernorm = RMSNorm(config.hidden_size, eps=config.rms_norm_eps)
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self.post_attention_layernorm = RMSNorm(config.hidden_size, eps=config.rms_norm_eps)
def forward(
self,
positions: torch.Tensor,
hidden_states: torch.Tensor,
residual: Optional[torch.Tensor],
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) -> tuple[torch.Tensor, torch.Tensor]:
# Self Attention
if residual is None:
residual = hidden_states
hidden_states = self.input_layernorm(hidden_states)
else:
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hidden_states, residual = self.input_layernorm(hidden_states, residual)
hidden_states = self.self_attn(
positions=positions,
hidden_states=hidden_states,
)
# Fully Connected
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hidden_states, residual = self.post_attention_layernorm(hidden_states, residual)
hidden_states = self.mlp(hidden_states)
return hidden_states, residual
@support_torch_compile(
dynamic_arg_dims={
"input_ids": 0,
# positions is of shape (3, seq_len) if mrope is enabled for qwen2-vl,
# otherwise (seq_len, ).
"positions": -1,
"intermediate_tensors": 0,
"inputs_embeds": 0,
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}
)
class Qwen2Model(nn.Module):
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def __init__(
self,
*,
vllm_config: VllmConfig,
prefix: str = "",
decoder_layer_type: type[nn.Module] = Qwen2DecoderLayer,
):
super().__init__()
config = vllm_config.model_config.hf_config
cache_config = vllm_config.cache_config
quant_config = vllm_config.quant_config
# TODO (@robertgshaw2): see if this can be moved out
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if cache_config.sliding_window is not None and hasattr(config, "max_window_layers"):
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raise ValueError(
"Sliding window for some but all layers is not "
"supported. This model uses sliding window "
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f"but `max_window_layers` = {config.max_window_layers} is less than "
f"`num_hidden_layers` = {config.num_hidden_layers}. Please open an issue "
"to discuss this feature."
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)
self.config = config
self.quant_config = quant_config
self.vocab_size = config.vocab_size
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if get_pp_group().is_first_rank or (config.tie_word_embeddings and get_pp_group().is_last_rank):
self.embed_tokens = VocabParallelEmbedding(
config.vocab_size,
getattr(config, "embedding_size", config.hidden_size),
quant_config=quant_config,
prefix=f"{prefix}.embed_tokens",
)
else:
self.embed_tokens = PPMissingLayer()
# Use the provided decoder layer type or default to Qwen2DecoderLayer
decoder_layer_type = decoder_layer_type or Qwen2DecoderLayer
self.start_layer, self.end_layer, self.layers = make_layers(
config.num_hidden_layers,
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lambda prefix: decoder_layer_type(
config=config,
cache_config=cache_config,
quant_config=quant_config,
prefix=prefix,
),
prefix=f"{prefix}.layers",
)
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self.make_empty_intermediate_tensors = make_empty_intermediate_tensors_factory(
["hidden_states", "residual"], config.hidden_size
)
if get_pp_group().is_last_rank:
self.norm = RMSNorm(config.hidden_size, eps=config.rms_norm_eps)
else:
self.norm = PPMissingLayer()
def get_input_embeddings(self, input_ids: torch.Tensor) -> torch.Tensor:
return self.embed_tokens(input_ids)
def forward(
self,
input_ids: torch.Tensor,
positions: torch.Tensor,
intermediate_tensors: Optional[IntermediateTensors] = None,
inputs_embeds: Optional[torch.Tensor] = None,
) -> Union[torch.Tensor, IntermediateTensors]:
if get_pp_group().is_first_rank:
if inputs_embeds is not None:
hidden_states = inputs_embeds
else:
hidden_states = self.get_input_embeddings(input_ids)
residual = None
else:
assert intermediate_tensors is not None
hidden_states = intermediate_tensors["hidden_states"]
residual = intermediate_tensors["residual"]
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for layer in self.layers[self.start_layer : self.end_layer]:
hidden_states, residual = layer(
positions,
hidden_states,
residual,
)
if not get_pp_group().is_last_rank:
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return IntermediateTensors({"hidden_states": hidden_states, "residual": residual})
hidden_states, _ = self.norm(hidden_states, residual)
return hidden_states
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def load_weights(self, weights: Iterable[tuple[str, torch.Tensor]]) -> set[str]:
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(remove_duplicate=False))
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loaded_params: set[str] = set()
for name, loaded_weight in weights:
if "rotary_emb.inv_freq" in name:
continue
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if self.quant_config is not None and (scale_name := self.quant_config.get_cache_scale(name)):
# Loading kv cache quantization scales
param = params_dict[scale_name]
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weight_loader = getattr(param, "weight_loader", default_weight_loader)
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loaded_weight = loaded_weight if loaded_weight.dim() == 0 else loaded_weight[0]
weight_loader(param, loaded_weight)
loaded_params.add(scale_name)
continue
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for param_name, weight_name, shard_id in stacked_params_mapping:
if weight_name not in name:
continue
name = name.replace(weight_name, param_name)
# Skip loading extra bias for GPTQ models.
if name.endswith(".bias") and name not in params_dict:
continue
if is_pp_missing_parameter(name, self):
continue
param = params_dict[name]
weight_loader = param.weight_loader
weight_loader(param, loaded_weight, shard_id)
break
else:
# Skip loading extra bias for GPTQ models.
if name.endswith(".bias") and name not in params_dict:
continue
# Remapping the name of FP8 kv-scale.
name = maybe_remap_kv_scale_name(name, params_dict)
if name is None:
continue
if is_pp_missing_parameter(name, self):
continue
param = params_dict[name]
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weight_loader = getattr(param, "weight_loader", default_weight_loader)
weight_loader(param, loaded_weight)
loaded_params.add(name)
return loaded_params
class Qwen2ForCausalLM(nn.Module, SupportsLoRA, SupportsPP):
packed_modules_mapping = {
"qkv_proj": [
"q_proj",
"k_proj",
"v_proj",
],
"gate_up_proj": [
"gate_proj",
"up_proj",
],
}
def __init__(self, *, vllm_config: VllmConfig, prefix: str = ""):
super().__init__()
config = vllm_config.model_config.hf_config
quant_config = vllm_config.quant_config
lora_config = vllm_config.lora_config
self.config = config
self.lora_config = lora_config
self.quant_config = quant_config
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self.model = Qwen2Model(vllm_config=vllm_config, prefix=maybe_prefix(prefix, "model"))
if get_pp_group().is_last_rank:
if config.tie_word_embeddings:
self.lm_head = self.model.embed_tokens
else:
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self.lm_head = ParallelLMHead(
config.vocab_size,
config.hidden_size,
quant_config=quant_config,
prefix=maybe_prefix(prefix, "lm_head"),
)
else:
self.lm_head = PPMissingLayer()
self.logits_processor = LogitsProcessor(config.vocab_size)
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self.sampler = Sampler()
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self.make_empty_intermediate_tensors = self.model.make_empty_intermediate_tensors
def get_input_embeddings(self, input_ids: torch.Tensor) -> torch.Tensor:
return self.model.get_input_embeddings(input_ids)
def forward(
self,
input_ids: torch.Tensor,
positions: torch.Tensor,
intermediate_tensors: Optional[IntermediateTensors] = None,
inputs_embeds: Optional[torch.Tensor] = None,
) -> Union[torch.Tensor, IntermediateTensors]:
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hidden_states = self.model(input_ids, positions, intermediate_tensors, inputs_embeds)
return hidden_states
def compute_logits(
self,
hidden_states: torch.Tensor,
) -> Optional[torch.Tensor]:
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logits = self.logits_processor(self.lm_head, hidden_states)
return logits
def sample(
self,
logits: torch.Tensor,
sampling_metadata: SamplingMetadata,
) -> Optional[SamplerOutput]:
next_tokens = self.sampler(logits, sampling_metadata)
return next_tokens
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def load_weights(self, weights: Iterable[tuple[str, torch.Tensor]]) -> set[str]:
loader = AutoWeightsLoader(
self,
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skip_prefixes=(["lm_head."] if self.config.tie_word_embeddings else None),
)
return loader.load_weights(weights)
class Qwen2EmbeddingModel(nn.Module, SupportsLoRA, SupportsPP):
packed_modules_mapping = {
"qkv_proj": [
"q_proj",
"k_proj",
"v_proj",
],
"gate_up_proj": [
"gate_proj",
"up_proj",
],
}
hf_to_vllm_mapper = WeightsMapper(orig_to_new_prefix={"model.": ""})
def __init__(self, *, vllm_config: VllmConfig, prefix: str = ""):
super().__init__()
config = vllm_config.model_config.hf_config
quant_config = vllm_config.quant_config
lora_config = vllm_config.lora_config
pooler_config = vllm_config.model_config.pooler_config
self.config = config
self.lora_config = lora_config
self.quant_config = quant_config
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self.model = Qwen2Model(vllm_config=vllm_config, prefix=maybe_prefix(prefix, "model"))
# TODO: Replace this model class with as_embedding_model(
# Qwen2ForCausalLM) after changing the default pooling method
if pooler_config.pooling_type is None:
logger.warning(
"This embedding model will default to last-token pooling in "
"an upcoming version. To avoid breaking changes, you should "
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'pass `--override-pooler-config \'{"pooling_type": "MEAN"}\'`'
" explicitly."
)
self._pooler = Pooler.from_config_with_defaults(
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pooler_config, pooling_type=PoolingType.MEAN, normalize=True, softmax=False
)
def forward(
self,
input_ids: torch.Tensor,
positions: torch.Tensor,
intermediate_tensors: Optional[IntermediateTensors] = None,
) -> torch.Tensor:
return self.model(input_ids, positions, intermediate_tensors)
def pooler(
self,
hidden_states: torch.Tensor,
pooling_metadata: PoolingMetadata,
) -> Optional[PoolerOutput]:
return self._pooler(hidden_states, pooling_metadata)
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def load_weights(self, weights: Iterable[tuple[str, torch.Tensor]]):
weights = self.hf_to_vllm_mapper.apply(weights)
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weights = ((name, data) for name, data in weights if not name.startswith("lm_head."))
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self.model.load_weights(weights)