Harry Mellor ea7cf8db35 MoveVllmConfig from config/__init__.py to config/vllm.py (#25271)
Signed-off-by: Harry Mellor <19981378+hmellor@users.noreply.github.com>
Signed-off-by: yewentao256 <zhyanwentao@126.com>
2025-10-03 13:35:56 -07:00

345 lines
14 KiB
Python

# SPDX-License-Identifier: Apache-2.0
# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
import enum
from enum import Enum
from fractions import Fraction
from typing import TYPE_CHECKING, Any, Optional, Union
import torch
from safetensors.torch import _TYPES as _SAFETENSORS_TO_TORCH_DTYPE
from torch.nn.parameter import Parameter
from vllm import _custom_ops as ops
from vllm.model_executor.layers.fused_moe.layer import FusedMoE
from vllm.model_executor.layers.linear import LinearMethodBase
from vllm.model_executor.layers.quantization.base_config import (
QuantizationConfig, QuantizeMethodBase)
from vllm.model_executor.layers.quantization.utils.gptq_utils import (
get_linear_quant_method)
from vllm.model_executor.parameter import (ChannelQuantScaleParameter,
GroupQuantScaleParameter,
PackedColumnParameter,
PackedvLLMParameter,
RowvLLMParameter)
from vllm.transformers_utils.config import get_safetensors_params_metadata
from vllm.utils import is_list_of
if TYPE_CHECKING:
from vllm.model_executor.layers.quantization import QuantizationMethods
else:
QuantizationMethods = str
class GPTQConfig(QuantizationConfig):
"""Config class for GPTQ.
Reference: https://arxiv.org/abs/2210.17323
"""
def __init__(
self,
weight_bits: int,
group_size: int,
desc_act: bool,
lm_head_quantized: bool,
dynamic: dict[str, dict[str, Union[int, bool]]],
autoround_version: str = "",
modules_in_block_to_quantize: Optional[list[str]] = None,
) -> None:
# GPTQModel use `dynamic` config property to allow per module
# quantization config so each module can be individually optimized.
# Format is dict[str, dict] where key is a regex string that can
# perform both positive ("+:" prefixed) or negative ("-:" prefixed)
# matching of a module.
# Default to positive match, override base quant config mode, if no
# prefix is used. Value is in dict format of field key and override
# value.
# Negative matching will skip quantization init for this module
# entirely:
# non-quantized inference. More details and quantization examples can be
# found at: https://github.com/ModelCloud/GPTQModel
# Example:
# # last 1/2 of the layers 10-21 has 8bit vs 4bit for 0-9
# # last 1/4 of the layers 16-21 has 8bit and group_size 64
# dynamic = {
# #`.*\.` matches the layers_node prefix
# # positive match layer 10-15
# r"+:.*\.(?:1[0-5])\..*": {"bits": 8,},
# # positive match layer 16-21
# r"+:.*\.(?:1[6-9]|20|21)\..*": {"bits": 8, "group_size": 64,},
# r"-:.*\.moe\..*": {}, # negative match (skip) all `moe` layers
# }
super().__init__()
self.dynamic = dynamic
self.weight_bits = weight_bits
self.group_size = group_size
self.desc_act = desc_act
self.lm_head_quantized = lm_head_quantized
self.pack_factor = Fraction(32, self.weight_bits)
if self.weight_bits not in [2, 3, 4, 8]:
raise ValueError(
"Currently, only 2/3/4/8-bit weight quantization is "
f"supported for GPTQ, but got {self.weight_bits} bits.")
self.modules_in_block_to_quantize = modules_in_block_to_quantize or []
# used to identify GPTQ model quantized by autoround
self.autoround_version = autoround_version
def __repr__(self) -> str:
return (
f"GPTQConfig(weight_bits={self.weight_bits}, "
f"group_size={self.group_size}, "
f"desc_act={self.desc_act}), "
f"lm_head_quantized={self.lm_head_quantized}, "
f"dynamic={self.dynamic}, "
f"modules_in_block_to_quantize={self.modules_in_block_to_quantize})"
)
@classmethod
def get_name(cls) -> QuantizationMethods:
return "gptq"
@classmethod
def get_supported_act_dtypes(cls) -> list[torch.dtype]:
return [torch.half]
@classmethod
# Need to figure it out
def get_min_capability(cls) -> int:
return 60
@classmethod
def get_config_filenames(cls) -> list[str]:
return ["quantize_config.json"]
@classmethod
def from_config(cls, config: dict[str, Any]) -> "GPTQConfig":
dynamic = cls.get_from_keys_or(config, ["dynamic"], default={})
dynamic = {} if dynamic is None else dynamic
weight_bits = cls.get_from_keys(config, ["bits"])
group_size = cls.get_from_keys(config, ["group_size"])
desc_act = cls.get_from_keys(config, ["desc_act"])
lm_head_quantized = cls.get_from_keys_or(config, ["lm_head"],
default=False)
autoround_version = cls.get_from_keys_or(config, ["autoround_version"],
default="")
modules_in_block_to_quantize = cls.get_from_keys_or(
config, ["modules_in_block_to_quantize"], default=None)
return cls(weight_bits, group_size, desc_act, lm_head_quantized,
dynamic, autoround_version, modules_in_block_to_quantize)
def get_quant_method(
self, layer: torch.nn.Module, prefix: str
) -> Optional[Union["GPTQLinearMethod", "QuantizeMethodBase"]]:
if isinstance(layer, FusedMoE):
# GPTQ MoE support: fall back to MoeWNA16 for broad compatibility
from .moe_wna16 import MoeWNA16Config
config = {
"quant_method": "gptq",
"bits": self.weight_bits,
"group_size": self.group_size,
"sym": True, # GPTQ typically uses symmetric quantization
"lm_head": False,
}
return MoeWNA16Config.from_config(config).get_quant_method(
layer, prefix)
return get_linear_quant_method(self, layer, prefix, GPTQLinearMethod)
def apply_vllm_mapper(self, hf_to_vllm_mapper):
if self.modules_in_block_to_quantize is not None:
self.modules_in_block_to_quantize = hf_to_vllm_mapper.apply_list(
self.modules_in_block_to_quantize)
def maybe_update_config(self,
model_name: str,
revision: Optional[str] = None):
if self.modules_in_block_to_quantize:
if is_list_of(self.modules_in_block_to_quantize, list):
# original modules_in_block_to_quantize: list[list[str]]
# flatten original modules_in_block_to_quantize
self.modules_in_block_to_quantize = [
item for sublist in self.modules_in_block_to_quantize
for item in sublist
]
return
unquant_dtypes = [torch.float16, torch.bfloat16, torch.float32]
metadata = get_safetensors_params_metadata(model_name,
revision=revision)
quant_layers: set[str] = {
param_name.rsplit(".", 1)[0]
for param_name, info in metadata.items()
if (dtype := info.get('dtype', None))
and _SAFETENSORS_TO_TORCH_DTYPE[dtype] not in unquant_dtypes
}
self.modules_in_block_to_quantize = list(quant_layers)
class ExllamaState(Enum):
UNUSED = enum.auto()
UNINITIALIZED = enum.auto()
READY = enum.auto()
class GPTQLinearMethod(LinearMethodBase):
"""Linear method for GPTQ.
Args:
quant_config: The GPTQ quantization config.
"""
def __init__(self, quant_config: GPTQConfig):
self.quant_config = quant_config
def create_weights(
self,
layer: torch.nn.Module,
input_size_per_partition: int,
output_partition_sizes: list[int],
input_size: int,
output_size: int,
params_dtype: torch.dtype,
**extra_weight_attrs,
):
del output_size # Unused.
weight_loader = extra_weight_attrs.get("weight_loader")
if input_size_per_partition % self.quant_config.group_size != 0:
raise ValueError(
"The input size is not aligned with the quantized "
"weight shape. This can be caused by too large "
"tensor parallel size.")
output_size_per_partition = sum(output_partition_sizes)
if (output_size_per_partition % self.quant_config.pack_factor.numerator
!= 0):
raise ValueError(
"The output size is not aligned with the quantized "
"weight shape. This can be caused by too large "
"tensor parallel size.")
if self.quant_config.group_size != -1:
group_size = self.quant_config.group_size
else:
group_size = input_size
exllama_state = ExllamaState.UNINITIALIZED
scale_and_zero_size = input_size // group_size
scale_and_zero_input_dim = None
if (input_size != input_size_per_partition
and self.quant_config.group_size != -1):
# For act-order models, we cannot use Exllama for row parallel layer
if self.quant_config.desc_act:
exllama_state = ExllamaState.UNUSED
else:
# we need to partition qzeros and scales for exllama kernel
scale_and_zero_size = input_size_per_partition // group_size
scale_and_zero_input_dim = 0
qweight = PackedvLLMParameter(
data=torch.empty(
input_size_per_partition // self.quant_config.pack_factor,
output_size_per_partition,
dtype=torch.int32,
),
input_dim=0,
output_dim=1,
packed_dim=0,
packed_factor=self.quant_config.pack_factor,
weight_loader=weight_loader)
g_idx = RowvLLMParameter(data=torch.tensor(
[
i // self.quant_config.group_size
for i in range(input_size_per_partition)
],
dtype=torch.int32,
),
input_dim=0,
weight_loader=weight_loader)
qzeros_args = {
"data":
torch.empty(
scale_and_zero_size,
output_size_per_partition // self.quant_config.pack_factor,
dtype=torch.int32,
),
"weight_loader":
weight_loader
}
weight_scale_args = {
"data":
torch.empty(
scale_and_zero_size,
output_size_per_partition,
dtype=params_dtype,
),
"weight_loader":
weight_loader
}
if scale_and_zero_input_dim is None:
scales = ChannelQuantScaleParameter(output_dim=1,
**weight_scale_args)
qzeros = PackedColumnParameter(
output_dim=1,
packed_dim=1,
packed_factor=self.quant_config.pack_factor,
**qzeros_args)
else:
scales = GroupQuantScaleParameter(output_dim=1,
input_dim=0,
**weight_scale_args)
qzeros = PackedvLLMParameter(
input_dim=0,
output_dim=1,
packed_dim=1,
packed_factor=self.quant_config.pack_factor,
**qzeros_args)
layer.register_parameter("qweight", qweight)
layer.register_parameter("g_idx", g_idx)
layer.register_parameter("qzeros", qzeros)
layer.register_parameter("scales", scales)
layer.exllama_state = exllama_state
def process_weights_after_loading(self, layer: torch.nn.Module) -> None:
# for torch.compile
layer.qzeros = Parameter(layer.qzeros.data, requires_grad=False)
layer.qweight = Parameter(layer.qweight.data, requires_grad=False)
layer.g_idx = Parameter(layer.g_idx.data, requires_grad=False)
layer.scales = Parameter(layer.scales.data, requires_grad=False)
# exllama needs to shuffle the weight after the weight is loaded
# here we do the shuffle on first forward pass
if layer.exllama_state == ExllamaState.UNINITIALIZED:
if self.quant_config.desc_act:
layer.g_idx.data = torch.argsort(layer.g_idx).to(torch.int)
else:
layer.g_idx.data = torch.empty((0, ),
dtype=torch.int,
device=layer.g_idx.device)
layer.exllama_state = ExllamaState.READY
ops.gptq_shuffle(layer.qweight, layer.g_idx,
self.quant_config.weight_bits)
def apply(self,
layer: torch.nn.Module,
x: torch.Tensor,
bias: Optional[torch.Tensor] = None) -> torch.Tensor:
out_shape = x.shape[:-1] + (layer.qweight.shape[-1], )
reshaped_x = x.reshape(-1, x.shape[-1])
output = ops.gptq_gemm(reshaped_x, layer.qweight, layer.qzeros,
layer.scales, layer.g_idx,
layer.exllama_state == ExllamaState.READY,
self.quant_config.weight_bits)
if bias is not None:
output.add_(bias)
return output.reshape(out_shape)