team-10/env/Lib/site-packages/transformers/quantizers/base.py
2025-08-02 07:34:44 +02:00

364 lines
15 KiB
Python

# Copyright 2024 The HuggingFace Inc. team. All rights reserved.
#
# 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.
from abc import ABC, abstractmethod
from typing import TYPE_CHECKING, Any, Optional, Union
from ..utils import is_torch_available
from ..utils.quantization_config import QuantizationConfigMixin, QuantizationMethod
from .quantizers_utils import get_module_from_name
if TYPE_CHECKING:
from ..modeling_utils import PreTrainedModel
if is_torch_available():
import torch
from torch.nn import ModuleList
else:
ModuleList = str
class HfQuantizer(ABC):
"""
Abstract class of the HuggingFace quantizer. Supports for now quantizing HF transformers models for inference and/or quantization.
This class is used only for transformers.PreTrainedModel.from_pretrained and cannot be easily used outside the scope of that method
yet.
Attributes
quantization_config (`transformers.utils.quantization_config.QuantizationConfigMixin`):
The quantization config that defines the quantization parameters of your model that you want to quantize.
modules_to_not_convert (`list[str]`, *optional*):
The list of module names to not convert when quantizing the model.
required_packages (`list[str]`, *optional*):
The list of required pip packages to install prior to using the quantizer
requires_calibration (`bool`):
Whether the quantization method requires to calibrate the model before using it.
requires_parameters_quantization (`bool`):
Whether the quantization method requires to create a new Parameter. For example, for bitsandbytes, it is
required to create a new xxxParameter in order to properly quantize the model.
"""
requires_calibration = False
required_packages = None
requires_parameters_quantization = False
def __init__(self, quantization_config: QuantizationConfigMixin, **kwargs):
self.quantization_config = quantization_config
# -- Handle extra kwargs below --
self.modules_to_not_convert = kwargs.pop("modules_to_not_convert", [])
self.pre_quantized = kwargs.pop("pre_quantized", True)
if not self.pre_quantized and self.requires_calibration:
raise ValueError(
f"The quantization method {quantization_config.quant_method} does require the model to be pre-quantized."
f" You explicitly passed `pre_quantized=False` meaning your model weights are not quantized. Make sure to "
f"pass `pre_quantized=True` while knowing what you are doing."
)
def update_torch_dtype(self, torch_dtype: "torch.dtype") -> "torch.dtype":
"""
Some quantization methods require to explicitly set the dtype of the model to a
target dtype. You need to override this method in case you want to make sure that behavior is
preserved
Args:
torch_dtype (`torch.dtype`):
The input dtype that is passed in `from_pretrained`
"""
return torch_dtype
def update_device_map(self, device_map: Optional[dict[str, Any]]) -> Optional[dict[str, Any]]:
"""
Override this method if you want to pass a override the existing device map with a new
one. E.g. for bitsandbytes, since `accelerate` is a hard requirement, if no device_map is
passed, the device_map is set to `"auto"``
Args:
device_map (`Union[dict, str]`, *optional*):
The device_map that is passed through the `from_pretrained` method.
"""
return device_map
def adjust_target_dtype(self, torch_dtype: "torch.dtype") -> "torch.dtype":
"""
Override this method if you want to adjust the `target_dtype` variable used in `from_pretrained`
to compute the device_map in case the device_map is a `str`. E.g. for bitsandbytes we force-set `target_dtype`
to `torch.int8` and for 4-bit we pass a custom enum `accelerate.CustomDtype.int4`.
Args:
torch_dtype (`torch.dtype`, *optional*):
The torch_dtype that is used to compute the device_map.
"""
return torch_dtype
def update_missing_keys(self, model, missing_keys: list[str], prefix: str) -> list[str]:
"""
Override this method if you want to adjust the `missing_keys`.
Args:
missing_keys (`list[str]`, *optional*):
The list of missing keys in the checkpoint compared to the state dict of the model
"""
return missing_keys
def update_unexpected_keys(self, model, unexpected_keys: list[str], prefix: str) -> list[str]:
"""
Override this method if you want to adjust the `unexpected_keys`.
Args:
unexpected_keys (`list[str]`, *optional*):
The list of unexpected keys in the checkpoint compared to the state dict of the model
"""
return unexpected_keys
def update_missing_keys_after_loading(self, model, missing_keys: list[str], prefix: str) -> list[str]:
"""
Override this method if you want to adjust the `missing_keys` after loading the model params,
but before the model is post-processed.
Args:
missing_keys (`list[str]`, *optional*):
The list of missing keys in the checkpoint compared to the state dict of the model
"""
return missing_keys
def update_expected_keys(self, model, expected_keys: list[str], loaded_keys: list[str]) -> list[str]:
"""
Override this method if you want to adjust the `update_expected_keys`.
Args:
expected_keys (`list[str]`, *optional*):
The list of the expected keys in the initialized model.
loaded_keys (`list[str]`, *optional*):
The list of the loaded keys in the checkpoint.
"""
return expected_keys
def get_special_dtypes_update(self, model, torch_dtype: "torch.dtype") -> dict[str, "torch.dtype"]:
"""
returns dtypes for modules that are not quantized - used for the computation of the device_map in case
one passes a str as a device_map. The method will use the `modules_to_not_convert` that is modified
in `_process_model_before_weight_loading`.
Args:
model (`~transformers.PreTrainedModel`):
The model to quantize
torch_dtype (`torch.dtype`):
The dtype passed in `from_pretrained` method.
"""
return {
name: torch_dtype
for name, _ in model.named_parameters()
if any(m in name for m in self.modules_to_not_convert)
}
def adjust_max_memory(self, max_memory: dict[str, Union[int, str]]) -> dict[str, Union[int, str]]:
"""adjust max_memory argument for infer_auto_device_map() if extra memory is needed for quantization"""
return max_memory
def check_quantized_param(
self,
model: "PreTrainedModel",
param_value: "torch.Tensor",
param_name: str,
state_dict: dict[str, Any],
**kwargs,
) -> bool:
"""
checks if a loaded state_dict component is part of quantized param + some validation; only defined if
requires_parameters_quantization == True for quantization methods that require to create a new parameters
for quantization.
"""
return False
def create_quantized_param(self, *args, **kwargs) -> "torch.nn.Parameter":
"""
takes needed components from state_dict and creates quantized param; only applicable if
requires_parameters_quantization == True
"""
if not self.requires_parameters_quantization:
raise AttributeError(
f"`.create_quantized_param()` method is not supported by quantizer class {self.__class__.__name__}."
)
def validate_environment(self, *args, **kwargs):
"""
This method is used to potentially check for potential conflicts with arguments that are
passed in `from_pretrained`. You need to define it for all future quantizers that are integrated with transformers.
If no explicit check are needed, simply return nothing.
"""
return
def update_tp_plan(self, config):
"updates the tp plan for the scales"
return config
def preprocess_model(self, model: "PreTrainedModel", **kwargs):
"""
Setting model attributes and/or converting model before weights loading. At this point
the model should be initialized on the meta device so you can freely manipulate the skeleton
of the model in order to replace modules in-place. Make sure to override the abstract method `_process_model_before_weight_loading`.
Args:
model (`~transformers.PreTrainedModel`):
The model to quantize
kwargs (`dict`, *optional*):
The keyword arguments that are passed along `_process_model_before_weight_loading`.
"""
model.is_quantized = True
model.quantization_method = self.quantization_config.quant_method
if self.pre_quantized:
self._convert_model_for_quantization(model)
return self._process_model_before_weight_loading(model, **kwargs)
def postprocess_model(self, model: "PreTrainedModel", **kwargs):
"""
Post-process the model post weights loading.
Make sure to override the abstract method `_process_model_after_weight_loading`.
Args:
model (`~transformers.PreTrainedModel`):
The model to quantize
kwargs (`dict`, *optional*):
The keyword arguments that are passed along `_process_model_after_weight_loading`.
"""
return self._process_model_after_weight_loading(model, **kwargs)
def dequantize(self, model):
"""
Potentially dequantize the model to retrieve the original model, with some loss in accuracy / performance.
Note not all quantization schemes support this.
"""
model = self._dequantize(model)
# Delete quantizer and quantization config
del model.hf_quantizer
del model.config.quantization_config
del model.config._pre_quantization_dtype
del model.quantization_method
model.is_quantized = False
return model
def get_cuda_warm_up_factor(self):
"""
The factor to be used in `caching_allocator_warmup` to get the number of bytes to pre-allocate to warm up cuda.
A factor of 2 means we allocate all bytes in the empty model (since we allocate in fp16), a factor of 4 means
we allocate half the memory of the weights residing in the empty model, etc...
"""
# By default we return 4, i.e. half the model size (this corresponds to the case where the model is not
# really pre-processed, i.e. we do not have the info that weights are going to be 8 bits before actual
# weight loading)
return 4
def _dequantize(self, model):
raise NotImplementedError(
f"{self.quantization_config.quant_method} has no implementation of `dequantize`, please raise an issue on GitHub."
)
@staticmethod
def get_modules_to_not_convert(
model: "PreTrainedModel",
skip_modules: Optional[list[str]] = None,
keep_in_fp32_modules: Optional[list[str]] = None,
add_default_skips: bool = False,
):
from ..integrations import get_keys_to_not_convert
if skip_modules is None or add_default_skips:
modules_to_not_convert = get_keys_to_not_convert(model)
else:
modules_to_not_convert = []
if skip_modules is not None:
modules_to_not_convert.extend(skip_modules)
if keep_in_fp32_modules is not None:
modules_to_not_convert.extend(keep_in_fp32_modules)
return modules_to_not_convert
@property
def is_qat_trainable(self) -> bool:
"""Flag indicating whether the quantized model can carry out quantization aware training"""
return False
@property
def is_compileable(self) -> bool:
"""Flag indicating whether the quantized model can be compiled"""
return False
@abstractmethod
def _process_model_before_weight_loading(self, model, **kwargs): ...
@abstractmethod
def _process_model_after_weight_loading(self, model, **kwargs): ...
@abstractmethod
def is_serializable(self, safe_serialization=None): ...
@property
@abstractmethod
def is_trainable(self): ...
def _convert_model_for_quantization(self, model):
from accelerate import init_empty_weights
for name, module in model.named_modules():
module_class_name = module.__class__.__name__
if module_class_name in MODULES_TO_PATCH_FOR_QUANTIZATION.keys() and (
self.quantization_config.quant_method
in MODULES_TO_PATCH_FOR_QUANTIZATION[module_class_name]["quantization_methods"]
):
with init_empty_weights():
parent_module, name = get_module_from_name(model, name)
parent_module._modules[name] = MODULES_TO_PATCH_FOR_QUANTIZATION[module_class_name]["module_name"](
model.config.get_text_config()
)
class SequentialLlama4TextExperts(ModuleList):
"""
A module that implements a compressed version of a list of expert modules.
This is specifically designed to work with Llama4TextExperts in MoE layers.
"""
def __init__(self, config):
from transformers.models.llama4.modeling_llama4 import Llama4TextMLP
super().__init__([Llama4TextMLP(config) for _ in range(config.num_local_experts)])
self.num_experts = config.num_local_experts
def forward(
self,
hidden_states: "torch.Tensor",
) -> "torch.Tensor":
hidden_states = hidden_states.reshape(self.num_experts, -1, hidden_states.shape[-1])
routed_out = torch.zeros_like(hidden_states)
for expert_idx in range(self.num_experts):
routed_out[expert_idx] = self[expert_idx](hidden_states[expert_idx])
return routed_out
MODULES_TO_PATCH_FOR_QUANTIZATION = {
"Llama4TextExperts": {
"module_name": SequentialLlama4TextExperts,
"quantization_methods": [
QuantizationMethod.COMPRESSED_TENSORS,
QuantizationMethod.BITS_AND_BYTES,
],
}
}