sglang0.4.5.post1/python/sglang/srt/models/dbrx.py

454 lines
15 KiB
Python

# Copyright 2023-2024 SGLang Team
# 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.
# ==============================================================================
# Adapted from:
# https://github.com/vllm-project/vllm/blob/c7f2cf2b7f67bce5842fedfdba508440fe257375/vllm/model_executor/models/dbrx.py#L1
from typing import Iterable, Optional, Tuple
import torch
import torch.nn as nn
from sglang.srt.configs import DbrxConfig
from sglang.srt.distributed import (
get_tensor_model_parallel_rank,
get_tensor_model_parallel_world_size,
tensor_model_parallel_all_reduce,
)
from sglang.srt.layers.linear import (
QKVParallelLinear,
ReplicatedLinear,
RowParallelLinear,
)
from sglang.srt.layers.logits_processor import LogitsProcessor
from sglang.srt.layers.moe.fused_moe_triton import fused_moe
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.vocab_parallel_embedding import (
DEFAULT_VOCAB_PADDING_SIZE,
ParallelLMHead,
VocabParallelEmbedding,
)
from sglang.srt.model_executor.forward_batch_info import ForwardBatch
from sglang.srt.model_loader.weight_utils import (
default_weight_loader,
maybe_remap_kv_scale_name,
)
from sglang.srt.utils import add_prefix, set_weight_attrs
class DbrxRouter(nn.Module):
"""A Router implementation for DBRX that returns logits for each expert
per token.
"""
def __init__(
self,
config: DbrxConfig,
params_dtype: Optional[torch.dtype] = None,
prefix: str = "",
):
super().__init__()
self.tp_size = get_tensor_model_parallel_world_size()
self.num_total_experts = config.ffn_config.moe_num_experts
self.d_model = config.d_model
self.layer = ReplicatedLinear(
self.d_model,
self.num_total_experts,
bias=False,
params_dtype=params_dtype,
quant_config=None,
)
def forward(self, hidden_states: torch.Tensor) -> torch.Tensor:
router_logits, _ = self.layer(hidden_states)
return router_logits
class DbrxExperts(nn.Module):
"""A tensor-parallel MoE implementation for DBRX.
Each expert's weights are sharded across all ranks and a fused MoE
kernel is used for the forward pass, and finally we reduce the outputs
across ranks.
"""
def __init__(
self,
config: DbrxConfig,
quant_config: Optional[QuantizationConfig] = None,
params_dtype: Optional[torch.dtype] = None,
prefix: str = "",
):
super().__init__()
self.tp_size = get_tensor_model_parallel_world_size()
self.num_total_experts = config.ffn_config.moe_num_experts
self.top_k = config.ffn_config.moe_top_k
self.d_model = config.d_model
self.intermediate_size = config.ffn_config.ffn_hidden_size // self.tp_size
if params_dtype is None:
params_dtype = torch.get_default_dtype()
self.params_dtype = params_dtype
self.router = DbrxRouter(config, self.params_dtype)
self.ws = nn.Parameter(
torch.empty(
self.num_total_experts,
2 * self.intermediate_size,
self.d_model,
device="cuda",
dtype=self.params_dtype,
)
)
self.w2s = nn.Parameter(
torch.empty(
self.num_total_experts,
self.d_model,
self.intermediate_size,
device="cuda",
dtype=self.params_dtype,
)
)
set_weight_attrs(
self.ws,
{
"weight_loader": self.weight_loader,
},
)
set_weight_attrs(
self.w2s,
{
"weight_loader": self.weight_loader,
},
)
def weight_loader(
self, param: nn.Parameter, loaded_weight: torch.Tensor, weight_name: str
):
tp_rank = get_tensor_model_parallel_rank()
param_data = param.data
shard_size = self.intermediate_size
shard = slice(tp_rank * shard_size, (tp_rank + 1) * shard_size)
# DBRX uses GLU for each experts.
# GLU has 3 linear layers: w1, v1 and w2.
if weight_name.endswith("w1"):
loaded_weight = torch.reshape(
loaded_weight,
[-1, self.intermediate_size * self.tp_size, self.d_model],
)
param_data[:, 0:shard_size, :] = loaded_weight[:, shard, :]
if weight_name.endswith("v1"):
loaded_weight = torch.reshape(
loaded_weight,
[-1, self.intermediate_size * self.tp_size, self.d_model],
)
param_data[:, shard_size : 2 * shard_size, :] = loaded_weight[:, shard, :]
if weight_name.endswith("w2"):
loaded_weight = torch.reshape(
loaded_weight,
[-1, self.intermediate_size * self.tp_size, self.d_model],
).transpose(1, 2)
param_data[:] = loaded_weight[:, :, shard]
def forward(self, hidden_states: torch.Tensor) -> torch.Tensor:
num_tokens, hidden_size = hidden_states.shape
hidden_states = hidden_states.view(-1, self.d_model)
# router_logits: (num_tokens, n_experts)
router_logits = self.router(hidden_states)
final_hidden_states = fused_moe(
hidden_states,
self.ws,
self.w2s,
router_logits,
self.top_k,
renormalize=True,
inplace=True,
)
if self.tp_size > 1:
final_hidden_states = tensor_model_parallel_all_reduce(final_hidden_states)
return final_hidden_states.view(num_tokens, hidden_size)
class DbrxAttention(nn.Module):
def __init__(
self,
config: DbrxConfig,
layer_id: int = 0,
quant_config: Optional[QuantizationConfig] = None,
prefix: str = "",
):
super().__init__()
self.d_model = config.d_model
self.total_num_heads = config.n_heads
self.head_dim = self.d_model // self.total_num_heads
self.total_num_kv_heads = config.attn_config.kv_n_heads
self.clip_qkv = config.attn_config.clip_qkv
self.rope_theta = config.attn_config.rope_theta
self.max_position = config.max_seq_len
# pylint: disable=invalid-name
self.Wqkv = QKVParallelLinear(
self.d_model,
self.head_dim,
self.total_num_heads,
self.total_num_kv_heads,
bias=False,
quant_config=quant_config,
prefix=add_prefix("Wqkv", prefix),
)
self.out_proj = RowParallelLinear(
self.d_model,
self.d_model,
bias=False,
quant_config=quant_config,
prefix=add_prefix("out_proj", prefix),
)
self.rotary_emb = get_rope(
self.head_dim,
rotary_dim=self.head_dim,
max_position=self.max_position,
base=int(self.rope_theta),
is_neox_style=True,
)
tp_world_size = get_tensor_model_parallel_world_size()
self.tp_size = tp_world_size
assert self.total_num_heads % tp_world_size == 0
self.num_heads = self.total_num_heads // tp_world_size
if self.total_num_kv_heads >= tp_world_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_world_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_world_size % self.total_num_kv_heads == 0
self.num_kv_heads = max(1, self.total_num_kv_heads // tp_world_size)
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.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 forward(
self,
position_ids: torch.Tensor,
hidden_states: torch.Tensor,
forward_batch: ForwardBatch,
) -> torch.Tensor:
qkv, _ = self.Wqkv(hidden_states)
if self.clip_qkv is not None:
qkv.clamp_(min=-self.clip_qkv, max=self.clip_qkv)
q, k, v = qkv.split([self.q_size, self.kv_size, self.kv_size], dim=-1)
q, k = self.rotary_emb(position_ids, q, k)
attn_output = self.attn(q, k, v, forward_batch)
hidden_states, _ = self.out_proj(attn_output)
return hidden_states
class DbrxFusedNormAttention(nn.Module):
def __init__(
self,
config: DbrxConfig,
layer_id: int = 0,
quant_config: Optional[QuantizationConfig] = None,
prefix: str = "",
):
super().__init__()
self.d_model = config.d_model
self.attn = DbrxAttention(
config,
layer_id,
quant_config=quant_config,
prefix=add_prefix("attn", prefix),
)
self.norm_1 = nn.LayerNorm(self.d_model)
self.norm_2 = nn.LayerNorm(self.d_model)
def forward(
self,
position_ids: torch.Tensor,
hidden_states: torch.Tensor,
forward_batch: ForwardBatch,
) -> torch.Tensor:
residual = hidden_states
hidden_states = self.norm_1(hidden_states)
x = self.attn(
position_ids=position_ids,
hidden_states=hidden_states,
forward_batch=forward_batch,
)
hidden_states = residual + x
residual = hidden_states
hidden_states = self.norm_2(hidden_states)
return hidden_states, residual
class DbrxBlock(nn.Module):
def __init__(
self,
config: DbrxConfig,
layer_id: int = 0,
quant_config: Optional[QuantizationConfig] = None,
prefix: str = "",
):
super().__init__()
self.norm_attn_norm = DbrxFusedNormAttention(
config,
layer_id,
quant_config=quant_config,
prefix=add_prefix("norm_attn_norm", prefix),
)
self.ffn = DbrxExperts(config, quant_config=quant_config)
def forward(
self,
position_ids: torch.Tensor,
hidden_states: torch.Tensor,
forward_batch: ForwardBatch,
) -> torch.Tensor:
hidden_states, residual = self.norm_attn_norm(
position_ids=position_ids,
hidden_states=hidden_states,
forward_batch=forward_batch,
)
hidden_states = self.ffn(hidden_states)
hidden_states = hidden_states + residual
return hidden_states
class DbrxModel(nn.Module):
def __init__(
self,
config: DbrxConfig,
quant_config: Optional[QuantizationConfig] = None,
prefix: str = "",
):
super().__init__()
self.wte = VocabParallelEmbedding(
config.vocab_size,
config.d_model,
)
self.blocks = nn.ModuleList(
[
DbrxBlock(
config,
i,
quant_config=quant_config,
prefix=add_prefix(f"blocks.{i}", prefix),
)
for i in range(config.n_layers)
]
)
self.norm_f = nn.LayerNorm(config.d_model, eps=1e-5)
for module in self.modules():
if hasattr(module, "bias") and isinstance(module.bias, nn.Parameter):
# Remove the bias term in Linear and LayerNorm.
module.register_parameter("bias", None)
def forward(
self,
input_ids: torch.Tensor,
position_ids: torch.Tensor,
forward_batch: ForwardBatch,
input_embeds: torch.Tensor = None,
) -> torch.Tensor:
if input_embeds is None:
hidden_states = self.wte(input_ids)
else:
hidden_states = input_embeds
for i in range(len(self.blocks)):
block = self.blocks[i]
hidden_states = block(position_ids, hidden_states, forward_batch)
hidden_states = self.norm_f(hidden_states)
return hidden_states
class DbrxForCausalLM(nn.Module):
def __init__(
self,
config: DbrxConfig,
quant_config: Optional[QuantizationConfig] = None,
prefix: str = "",
):
super().__init__()
self.config = config
self.quant_config = quant_config
self.unpadded_vocab_size = config.vocab_size
self.transformer = DbrxModel(
config, quant_config=quant_config, prefix=add_prefix("transformer", prefix)
)
self.lm_head = ParallelLMHead(
config.vocab_size,
config.d_model,
org_num_embeddings=config.vocab_size,
padding_size=DEFAULT_VOCAB_PADDING_SIZE,
prefix=add_prefix("lm_head", prefix),
)
self.logits_processor = LogitsProcessor(config)
@torch.no_grad()
def forward(
self,
input_ids: torch.Tensor,
positions: torch.Tensor,
forward_batch: ForwardBatch,
) -> torch.Tensor:
hidden_states = self.transformer(input_ids, positions, forward_batch)
return self.logits_processor(
input_ids, hidden_states, self.lm_head, forward_batch
)
def load_weights(self, weights: Iterable[Tuple[str, torch.Tensor]]):
expert_params_mapping = [
(
"ws" if weight_name in ["w1", "v1"] else "w2s",
f"experts.mlp.{weight_name}",
)
for weight_name in ["w1", "v1", "w2"]
]
params_dict = dict(self.named_parameters(remove_duplicate=False))
for name, loaded_weight in weights:
for param_name, weight_name in expert_params_mapping:
if weight_name not in name:
continue
name = name.replace(weight_name, param_name)
param = params_dict[name]
weight_loader = param.weight_loader
weight_loader(param, loaded_weight, weight_name)
break
else:
# Remapping the name of FP8 kv-scale.
name = maybe_remap_kv_scale_name(name, params_dict)
if name is None:
continue
param = params_dict[name]
weight_loader = getattr(param, "weight_loader", default_weight_loader)
weight_loader(param, loaded_weight)
EntryClass = DbrxForCausalLM