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sglang/python/sglang/srt/models/qwen3.py
2025-07-03 09:58:20 -07:00

435 lines
16 KiB
Python

# Adapted from qwen2.py
import logging
from functools import partial
from typing import Any, Dict, Iterable, Optional, Tuple
import torch
from torch import nn
from sglang.srt.distributed import (
get_pp_group,
get_tensor_model_parallel_rank,
get_tensor_model_parallel_world_size,
split_tensor_along_last_dim,
tensor_model_parallel_all_gather,
)
from sglang.srt.layers.communicator import LayerCommunicator, LayerScatterModes
from sglang.srt.layers.dp_attention import get_attention_tp_rank, get_attention_tp_size
from sglang.srt.layers.layernorm import RMSNorm
from sglang.srt.layers.linear import QKVParallelLinear, RowParallelLinear
from sglang.srt.layers.logits_processor import LogitsProcessor
from sglang.srt.layers.pooler import Pooler, PoolingType
from sglang.srt.layers.quantization.base_config import QuantizationConfig
from sglang.srt.layers.radix_attention import RadixAttention
from sglang.srt.layers.rotary_embedding import get_rope
from sglang.srt.layers.utils import PPMissingLayer, get_layer_id
from sglang.srt.layers.vocab_parallel_embedding import ParallelLMHead
from sglang.srt.model_executor.forward_batch_info import ForwardBatch, PPProxyTensors
from sglang.srt.model_loader.weight_utils import default_weight_loader
from sglang.srt.models.qwen2 import Qwen2MLP as Qwen3MLP
from sglang.srt.models.qwen2 import Qwen2Model
from sglang.srt.utils import add_prefix
Qwen3Config = None
logger = logging.getLogger(__name__)
class Qwen3Attention(nn.Module):
def __init__(
self,
hidden_size: int,
num_heads: int,
num_kv_heads: int,
layer_id: int = 0,
rope_theta: float = 1000000,
rope_scaling: Optional[Dict[str, Any]] = None,
head_dim: Optional[int] = None,
max_position_embeddings: int = 32768,
quant_config: Optional[QuantizationConfig] = None,
rms_norm_eps: float = None,
attention_bias: bool = False,
prefix: str = "",
) -> None:
super().__init__()
self.hidden_size = hidden_size
self.tp_size = get_tensor_model_parallel_world_size()
self.total_num_heads = num_heads
attn_tp_rank = get_attention_tp_rank()
attn_tp_size = get_attention_tp_size()
assert self.total_num_heads % attn_tp_size == 0
self.num_heads = self.total_num_heads // attn_tp_size
self.total_num_kv_heads = num_kv_heads
if self.total_num_kv_heads >= attn_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 % attn_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 attn_tp_size % self.total_num_kv_heads == 0
self.num_kv_heads = max(1, self.total_num_kv_heads // attn_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.max_position_embeddings = max_position_embeddings
self.tp_rank = get_tensor_model_parallel_rank()
self.q_norm = RMSNorm(self.head_dim, eps=rms_norm_eps)
self.k_norm = RMSNorm(self.head_dim, eps=rms_norm_eps)
self.qkv_proj = QKVParallelLinear(
hidden_size,
self.head_dim,
self.total_num_heads,
self.total_num_kv_heads,
bias=attention_bias,
quant_config=quant_config,
tp_rank=attn_tp_rank,
tp_size=attn_tp_size,
prefix=add_prefix("qkv_proj", prefix),
)
self.o_proj = RowParallelLinear(
self.total_num_heads * self.head_dim,
hidden_size,
bias=attention_bias,
quant_config=quant_config,
tp_rank=attn_tp_rank,
tp_size=attn_tp_size,
reduce_results=False,
prefix=add_prefix("o_proj", prefix),
)
self.rotary_emb = get_rope(
self.head_dim,
rotary_dim=self.head_dim,
max_position=max_position_embeddings,
base=rope_theta,
rope_scaling=rope_scaling,
)
self.attn = RadixAttention(
self.num_heads,
self.head_dim,
self.scaling,
num_kv_heads=self.num_kv_heads,
layer_id=layer_id,
prefix=add_prefix("attn", prefix),
)
def _apply_qk_norm(
self, q: torch.Tensor, k: torch.Tensor
) -> Tuple[torch.Tensor, torch.Tensor]:
q_by_head = q.reshape(-1, self.head_dim)
q_by_head = self.q_norm(q_by_head)
q = q_by_head.view(q.shape)
k_by_head = k.reshape(-1, self.head_dim)
k_by_head = self.k_norm(k_by_head)
k = k_by_head.view(k.shape)
return q, k
def forward(
self,
positions: torch.Tensor,
hidden_states: torch.Tensor,
forward_batch: ForwardBatch,
) -> 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._apply_qk_norm(q, k)
q, k = self.rotary_emb(positions, q, k)
attn_output = self.attn(q, k, v, forward_batch)
output, _ = self.o_proj(attn_output)
return output
class Qwen3DecoderLayer(nn.Module):
def __init__(
self,
config: Qwen3Config,
layer_id: int = 0,
quant_config: Optional[QuantizationConfig] = None,
prefix: str = "",
) -> None:
super().__init__()
self.hidden_size = config.hidden_size
rope_theta = getattr(config, "rope_theta", 1000000)
rope_scaling = getattr(config, "rope_scaling", None)
max_position_embeddings = getattr(config, "max_position_embeddings", 32768)
head_dim = getattr(config, "head_dim", None)
self.self_attn = Qwen3Attention(
hidden_size=self.hidden_size,
num_heads=config.num_attention_heads,
num_kv_heads=config.num_key_value_heads,
layer_id=layer_id,
rope_theta=rope_theta,
rope_scaling=rope_scaling,
head_dim=head_dim,
max_position_embeddings=max_position_embeddings,
quant_config=quant_config,
rms_norm_eps=config.rms_norm_eps,
attention_bias=config.attention_bias,
prefix=add_prefix("self_attn", prefix),
)
self.mlp = Qwen3MLP(
hidden_size=self.hidden_size,
intermediate_size=config.intermediate_size,
hidden_act=config.hidden_act,
quant_config=quant_config,
prefix=add_prefix("mlp", prefix),
)
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
)
self.layer_scatter_modes = LayerScatterModes.init_new(
layer_id=layer_id,
num_layers=config.num_hidden_layers,
is_layer_sparse=False,
is_previous_layer_sparse=False,
)
self.layer_communicator = LayerCommunicator(
layer_scatter_modes=self.layer_scatter_modes,
input_layernorm=self.input_layernorm,
post_attention_layernorm=self.post_attention_layernorm,
)
def forward(
self,
positions: torch.Tensor,
hidden_states: torch.Tensor,
forward_batch: ForwardBatch,
residual: Optional[torch.Tensor],
) -> Tuple[torch.Tensor, torch.Tensor]:
# Self Attention
hidden_states, residual = self.layer_communicator.prepare_attn(
hidden_states, residual, forward_batch
)
if hidden_states.shape[0] != 0:
hidden_states = self.self_attn(
positions=positions,
hidden_states=hidden_states,
forward_batch=forward_batch,
)
# Fully Connected
hidden_states, residual = self.layer_communicator.prepare_mlp(
hidden_states, residual, forward_batch
)
hidden_states = self.mlp(hidden_states)
hidden_states, residual = self.layer_communicator.postprocess_layer(
hidden_states, residual, forward_batch
)
return hidden_states, residual
class Qwen3Model(Qwen2Model):
def __init__(
self,
config: Qwen3Config,
quant_config: Optional[QuantizationConfig] = None,
prefix: str = "",
) -> None:
super().__init__(
config=config,
quant_config=quant_config,
prefix=prefix,
decoder_layer_type=Qwen3DecoderLayer,
)
class Qwen3ForCausalLM(nn.Module):
# BitandBytes specific attributes
default_bitsandbytes_target_modules = [
".gate_proj.",
".down_proj.",
".up_proj.",
".q_proj.",
".k_proj.",
".v_proj.",
".o_proj.",
]
bitsandbytes_stacked_params_mapping = {
# shard_name, weight_name, index
"q_proj": ("qkv_proj", 0),
"k_proj": ("qkv_proj", 1),
"v_proj": ("qkv_proj", 2),
"gate_proj": ("gate_up_proj", 0),
"up_proj": ("gate_up_proj", 1),
}
def __init__(
self,
config: Qwen3Config,
quant_config: Optional[QuantizationConfig] = None,
prefix: str = "",
) -> None:
super().__init__()
self.pp_group = get_pp_group()
self.config = config
self.quant_config = quant_config
self.model = Qwen3Model(
config, quant_config=quant_config, prefix=add_prefix("model", prefix)
)
# handle the lm head on different pp ranks
if self.pp_group.is_last_rank:
if self.pp_group.world_size == 1 and config.tie_word_embeddings:
self.lm_head = self.model.embed_tokens
else:
self.lm_head = ParallelLMHead(
config.vocab_size,
config.hidden_size,
quant_config=quant_config,
prefix=add_prefix("lm_head", prefix),
)
else:
# ranks other than the last rank will have a placeholder layer
self.lm_head = PPMissingLayer()
# perform weight tying for PP
if self.pp_group.world_size > 1 and config.tie_word_embeddings:
if self.pp_group.is_first_rank:
self.pp_group.send(
self.model.embed_tokens.weight, dst=self.pp_group.last_rank
)
else:
emb_token_weight = self.pp_group.recv(
size=(config.vocab_size, config.hidden_size),
dtype=next(self.model.parameters()).dtype,
src=self.pp_group.first_rank,
)
self.lm_head.weight.copy_(emb_token_weight)
self.logits_processor = LogitsProcessor(config)
self.pooler = Pooler(pooling_type=PoolingType.LAST, normalize=True)
def get_input_embeddings(self, input_ids: torch.Tensor) -> torch.Tensor:
return self.model.get_input_embeddings(input_ids)
@torch.no_grad()
def forward(
self,
input_ids: torch.Tensor,
positions: torch.Tensor,
forward_batch: ForwardBatch,
input_embeds: torch.Tensor = None,
get_embedding: bool = False,
pp_proxy_tensors: Optional[PPProxyTensors] = None,
) -> torch.Tensor:
hidden_states = self.model(
input_ids,
positions,
forward_batch,
input_embeds,
pp_proxy_tensors=pp_proxy_tensors,
)
if self.pp_group.is_last_rank:
if not get_embedding:
return self.logits_processor(
input_ids, hidden_states, self.lm_head, forward_batch
)
else:
return self.pooler(hidden_states, forward_batch)
else:
return hidden_states
@property
def start_layer(self):
return self.model.start_layer
@property
def end_layer(self):
return self.model.end_layer
def load_weights(self, weights: Iterable[Tuple[str, torch.Tensor]]):
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 weights:
if "Embedding" in self.config.name_or_path:
name = add_prefix(name, "model")
layer_id = get_layer_id(name)
if (
layer_id is not None
and hasattr(self.model, "start_layer")
and (
layer_id < self.model.start_layer
or layer_id >= self.model.end_layer
)
):
continue
if "rotary_emb.inv_freq" in name or "projector" in name:
continue
if "rotary_emb.cos_cached" in name or "rotary_emb.sin_cached" in name:
# Models trained using ColossalAI may include these tensors in
# the checkpoint. Skip them.
continue
if self.config.tie_word_embeddings and "lm_head.weight" in name:
if self.pp_group.world_size > 1 and self.pp_group.is_last_rank:
# Handle pp weight tying here
# find the embed_tokens.weight in the weights
embed_token_weights = next(
filter(lambda x: x[0] == "model.embed_tokens.weight", weights)
)[1]
loaded_weight = embed_token_weights
else:
continue
if name.startswith("model.vision_tower") and name not in params_dict:
continue
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
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
if name in params_dict.keys():
param = params_dict[name]
weight_loader = getattr(
param, "weight_loader", default_weight_loader
)
weight_loader(param, loaded_weight)
else:
logger.warning(f"Parameter {name} not found in params_dict")
def get_embed_and_head(self):
return self.model.embed_tokens.weight, self.lm_head.weight
def set_embed_and_head(self, embed, head):
del self.model.embed_tokens.weight
del self.lm_head.weight
self.model.embed_tokens.weight = embed
self.lm_head.weight = head
torch.cuda.empty_cache()
torch.cuda.synchronize()
def load_kv_cache_scales(self, quantization_param_path: str) -> None:
self.model.load_kv_cache_scales(quantization_param_path)
EntryClass = Qwen3ForCausalLM