sglang0.4.5.post1/python/sglang/srt/models/gemma2.py

462 lines
16 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/56b325e977435af744f8b3dca7af0ca209663558/vllm/model_executor/models/gemma2.py
from typing import Iterable, Optional, Set, Tuple
import torch
from torch import nn
from transformers import PretrainedConfig
from sglang.srt.distributed import get_tensor_model_parallel_world_size
from sglang.srt.layers.activation import GeluAndMul
from sglang.srt.layers.layernorm import GemmaRMSNorm
from sglang.srt.layers.linear import (
MergedColumnParallelLinear,
QKVParallelLinear,
RowParallelLinear,
)
from sglang.srt.layers.logits_processor import LogitsProcessor
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 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, make_layers
# Aligned with HF's implementation, using sliding window inclusive with the last token
# SGLang assumes exclusive
def get_attention_sliding_window_size(config):
return config.sliding_window - 1
class Gemma2MLP(nn.Module):
def __init__(
self,
hidden_size: int,
intermediate_size: int,
hidden_act: str,
hidden_activation: 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=add_prefix("gate_up_proj", prefix),
)
self.down_proj = RowParallelLinear(
intermediate_size,
hidden_size,
bias=False,
quant_config=quant_config,
prefix=add_prefix("down_proj", prefix),
)
if not (hidden_act == hidden_activation == "gelu_pytorch_tanh"):
raise ValueError(
"Gemma2 uses `gelu_pytorch_tanh` as the hidden activation "
"function. Please set `hidden_act` and `hidden_activation` to "
"`gelu_pytorch_tanh`."
)
self.act_fn = GeluAndMul()
def forward(self, x: torch.Tensor) -> torch.Tensor:
gate_up, _ = self.gate_up_proj(x)
x = self.act_fn(gate_up)
x, _ = self.down_proj(x)
return x
class Gemma2Attention(nn.Module):
def __init__(
self,
layer_id: int,
config: PretrainedConfig,
hidden_size: int,
num_heads: int,
num_kv_heads: int,
head_dim: int,
max_position_embeddings: int,
rope_theta: float,
quant_config: Optional[QuantizationConfig] = None,
prefix: str = "",
) -> None:
super().__init__()
self.layer_id = layer_id
self.config = config
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
self.q_size = self.num_heads * self.head_dim
self.kv_size = self.num_kv_heads * self.head_dim
self.scaling = config.query_pre_attn_scalar**-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=config.attention_bias,
quant_config=quant_config,
prefix=add_prefix("qkv_proj", prefix),
)
self.o_proj = RowParallelLinear(
self.total_num_heads * self.head_dim,
hidden_size,
bias=config.attention_bias,
quant_config=quant_config,
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=self.rope_theta,
is_neox_style=True,
)
use_sliding_window = layer_id % 2 == 0 and hasattr(config, "sliding_window")
self.attn = RadixAttention(
self.num_heads,
self.head_dim,
self.scaling,
num_kv_heads=self.num_kv_heads,
layer_id=layer_id,
logit_cap=self.config.attn_logit_softcapping,
sliding_window_size=(
get_attention_sliding_window_size(config)
if use_sliding_window
else None
),
prefix=add_prefix("attn", prefix),
)
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.rotary_emb(positions, q, k)
attn_output = self.attn(q, k, v, forward_batch)
output, _ = self.o_proj(attn_output)
return output
class Gemma2DecoderLayer(nn.Module):
def __init__(
self,
layer_id: int,
config: PretrainedConfig,
quant_config: Optional[QuantizationConfig] = None,
prefix: str = "",
) -> None:
super().__init__()
self.hidden_size = config.hidden_size
self.self_attn = Gemma2Attention(
layer_id=layer_id,
config=config,
hidden_size=self.hidden_size,
num_heads=config.num_attention_heads,
num_kv_heads=config.num_key_value_heads,
head_dim=config.head_dim,
max_position_embeddings=config.max_position_embeddings,
rope_theta=config.rope_theta,
quant_config=quant_config,
prefix=add_prefix("self_attn", prefix),
)
self.hidden_size = config.hidden_size
self.mlp = Gemma2MLP(
hidden_size=self.hidden_size,
intermediate_size=config.intermediate_size,
hidden_act=config.hidden_act,
hidden_activation=config.hidden_activation,
quant_config=quant_config,
prefix=add_prefix("mlp", prefix),
)
self.input_layernorm = GemmaRMSNorm(config.hidden_size, eps=config.rms_norm_eps)
self.post_attention_layernorm = GemmaRMSNorm(
config.hidden_size, eps=config.rms_norm_eps
)
self.pre_feedforward_layernorm = GemmaRMSNorm(
config.hidden_size, eps=config.rms_norm_eps
)
self.post_feedforward_layernorm = GemmaRMSNorm(
config.hidden_size, eps=config.rms_norm_eps
)
def forward(
self,
positions: torch.Tensor,
hidden_states: torch.Tensor,
forward_batch: ForwardBatch,
residual: Optional[torch.Tensor],
) -> Tuple[torch.Tensor, torch.Tensor]:
if residual is None:
residual = hidden_states
hidden_states = self.input_layernorm(hidden_states)
else:
hidden_states, residual = self.input_layernorm(hidden_states, residual)
hidden_states = self.self_attn(
positions=positions,
hidden_states=hidden_states,
forward_batch=forward_batch,
)
hidden_states = self.post_attention_layernorm(hidden_states)
hidden_states, residual = self.pre_feedforward_layernorm(
hidden_states, residual
)
hidden_states = self.mlp(hidden_states)
hidden_states = self.post_feedforward_layernorm(hidden_states)
return hidden_states, residual
class Gemma2Model(nn.Module):
def __init__(
self,
config: PretrainedConfig,
quant_config: Optional[QuantizationConfig] = None,
prefix: str = "",
) -> None:
super().__init__()
self.config = config
self.embed_tokens = VocabParallelEmbedding(
config.vocab_size,
config.hidden_size,
)
self.layers = make_layers(
config.num_hidden_layers,
lambda idx, prefix: Gemma2DecoderLayer(
layer_id=idx,
config=config,
quant_config=quant_config,
),
prefix=add_prefix("layers", prefix),
)
self.norm = GemmaRMSNorm(config.hidden_size, eps=config.rms_norm_eps)
# Normalize the embedding by sqrt(hidden_size)
# The normalizer's data type should be downcasted to the model's
# data type such as bfloat16, not float32.
# See https://github.com/huggingface/transformers/pull/29402
normalizer = self.config.hidden_size**0.5
self.register_buffer("normalizer", torch.tensor(normalizer))
def forward(
self,
input_ids: torch.Tensor,
positions: torch.Tensor,
forward_batch: ForwardBatch,
input_embeds: torch.Tensor = None,
) -> torch.Tensor:
if input_embeds is None:
hidden_states = self.embed_tokens(input_ids)
else:
hidden_states = input_embeds
normalizer = torch.tensor(self.config.hidden_size**0.5, dtype=torch.float16)
hidden_states *= normalizer
residual = None
for i in range(len(self.layers)):
layer = self.layers[i]
hidden_states, residual = layer(
positions,
hidden_states,
forward_batch,
residual,
)
hidden_states, _ = self.norm(hidden_states, residual)
return hidden_states
class Gemma2ForCausalLM(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),
}
packed_modules_mapping = {
"qkv_proj": [
"q_proj",
"k_proj",
"v_proj",
],
"gate_up_proj": [
"gate_proj",
"up_proj",
],
}
# LoRA specific attributes
supported_lora_modules = [
"qkv_proj",
"o_proj",
"gate_up_proj",
"down_proj",
]
# Gemma does not apply LoRA to the embedding layer.
embedding_modules = {}
embedding_padding_modules = []
supports_lora = True
def __init__(
self,
config: PretrainedConfig,
quant_config: Optional[QuantizationConfig] = None,
prefix: str = "",
) -> None:
super().__init__()
self.config = config
self.quant_config = quant_config
self.model = Gemma2Model(
config, quant_config, prefix=add_prefix("model", prefix)
)
self.logits_processor = LogitsProcessor(config)
@torch.no_grad()
def forward(
self,
input_ids: torch.Tensor,
positions: torch.Tensor,
forward_batch: ForwardBatch,
input_embeds: torch.Tensor = None,
) -> torch.Tensor:
hidden_states = self.model(input_ids, positions, forward_batch, input_embeds)
return self.logits_processor(
input_ids, hidden_states, self.model.embed_tokens, forward_batch
)
def get_hidden_dim(self, module_name):
# return input_dim, output_dim
if module_name in ["q_proj", "qkv_proj"]:
return (
self.config.hidden_size,
self.config.head_dim * self.config.num_attention_heads,
)
elif module_name in ["o_proj"]:
return (
self.config.head_dim * self.config.num_attention_heads,
self.config.hidden_size,
)
elif module_name in ["kv_proj"]:
return (
self.config.hidden_size,
self.config.head_dim * self.config.num_key_value_heads,
)
elif module_name == "gate_up_proj":
return self.config.hidden_size, self.config.intermediate_size
elif module_name == "down_proj":
return self.config.intermediate_size, self.config.hidden_size
else:
raise NotImplementedError()
def get_module_name(self, name):
params_mapping = {
"q_proj": "qkv_proj",
"k_proj": "qkv_proj",
"v_proj": "qkv_proj",
"gate_proj": "gate_up_proj",
"up_proj": "gate_up_proj",
}
return params_mapping.get(name, name)
def get_attention_sliding_window_size(self):
return get_attention_sliding_window_size(self.config)
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())
loaded_params: Set[str] = set()
for name, loaded_weight in weights:
for param_name, shard_name, shard_id in stacked_params_mapping:
if shard_name not in name:
continue
name = name.replace(shard_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:
# lm_head is not used in vllm as it is tied with embed_token.
# To prevent errors, skip loading lm_head.weight.
if "lm_head.weight" in name:
continue
# 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
param = params_dict[name]
weight_loader = getattr(param, "weight_loader", default_weight_loader)
weight_loader(param, loaded_weight)
loaded_params.add(name)
EntryClass = Gemma2ForCausalLM