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layer.py
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layer.py
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# coding=utf-8
# Copyright 2023-present the HuggingFace Inc. 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.
import math
import warnings
from typing import Any, List, Optional, Union
import torch
import torch.nn as nn
import torch.nn.functional as F
from transformers.pytorch_utils import Conv1D
from peft.tuners.tuners_utils import BaseTunerLayer
from peft.utils.other import transpose
from peft.tuners.lora.qqq.quantize import QConv2d, QBatchNorm2d, QLinear, QLinear_1, QLinear_2, QLinear_3, QLinear_4, QLinear_5, QLinear_6, QLinear_7, quantize, QConv1
class LoraLayer(BaseTunerLayer):
# All names of layers that may contain (trainable) adapter weights
adapter_layer_names = ("lora_A", "lora_B", "lora_embedding_A", "lora_embedding_B")
# All names of other parameters that may contain adapter-related parameters
other_param_names = ("r", "lora_alpha", "scaling", "lora_dropout")
def __init__(self, base_layer: nn.Module, **kwargs) -> None:
self.base_layer = base_layer
self.r = {}
self.lora_alpha = {}
self.scaling = {}
self.lora_dropout = nn.ModuleDict({})
self.lora_A = nn.ModuleDict({})
self.lora_B = nn.ModuleDict({})
# For Embedding layer
self.lora_embedding_A = nn.ParameterDict({})
self.lora_embedding_B = nn.ParameterDict({})
# Mark the weight as unmerged
self._disable_adapters = False
self.merged_adapters = []
self.kwargs = kwargs
# base_layer: Linear4bit(in_features=512, out_features=1536, bias=True)
base_layer = self.get_base_layer()
if isinstance(base_layer, nn.Linear):
in_features, out_features = base_layer.in_features, base_layer.out_features
elif isinstance(base_layer, nn.Conv2d):
in_features, out_features = base_layer.in_channels, base_layer.out_channels
elif isinstance(base_layer, nn.Embedding):
in_features, out_features = base_layer.num_embeddings, base_layer.embedding_dim
elif isinstance(base_layer, Conv1D):
in_features, out_features = (
base_layer.weight.ds_shape if hasattr(base_layer.weight, "ds_shape") else base_layer.weight.shape
)
elif hasattr(base_layer, "infeatures") and hasattr(base_layer, "outfeatures"):
# QuantLinear
in_features, out_features = base_layer.infeatures, base_layer.outfeatures
elif hasattr(base_layer, "input_size") and hasattr(base_layer, "output_size"):
# Megatron ColumnParallelLinear,RowParallelLinear
in_features, out_features = base_layer.input_size, base_layer.output_size
else:
raise ValueError(f"Unsupported layer type {type(base_layer)}")
self.in_features = in_features
self.out_features = out_features
def update_layer(self, adapter_name, r, lora_alpha, lora_dropout, init_lora_weights):
if r <= 0:
raise ValueError(f"`r` should be a positive integer value but the value passed is {r}")
self.r[adapter_name] = r
self.lora_alpha[adapter_name] = lora_alpha
if lora_dropout > 0.0:
lora_dropout_layer = nn.Dropout(p=lora_dropout)
else:
lora_dropout_layer = nn.Identity()
self.lora_dropout.update(nn.ModuleDict({adapter_name: lora_dropout_layer}))
# Actual trainable parameters
if r > 0:
# qbara
self.lora_A[adapter_name] = nn.Linear(int(self.in_features / 2), int(r * 2), bias=False)
self.lora_B[adapter_name] = nn.Linear(int(r * 2), int(self.out_features / 2), bias=False)
self.scaling[adapter_name] = lora_alpha / r
# qahira
self.lora_A[adapter_name] = nn.Linear(int(self.in_features / 4), int(self.out_features / 8), bias=False)
# self.lora_B[adapter_name] = nn.Linear(int(r * 2), int(self.out_features / 2), bias=False)
self.scaling[adapter_name] = lora_alpha / r
if init_lora_weights == "loftq":
self.loftq_init(adapter_name)
elif init_lora_weights:
self.reset_lora_parameters(adapter_name, init_lora_weights)
weight = getattr(self.get_base_layer(), "weight", None)
if weight is not None:
# the layer is already completely initialized, this is an update
if weight.dtype.is_floating_point or weight.dtype.is_complex:
self.to(weight.device, dtype=weight.dtype)
else:
self.to(weight.device)
self.set_adapter(self.active_adapters)
def update_layer_conv2d(self, adapter_name, r, lora_alpha, lora_dropout, init_lora_weights):
if r <= 0:
raise ValueError(f"`r` should be a positive integer value but the value passed is {r}")
self.r[adapter_name] = r
self.lora_alpha[adapter_name] = lora_alpha
if lora_dropout > 0.0:
lora_dropout_layer = nn.Dropout(p=lora_dropout)
else:
lora_dropout_layer = nn.Identity()
self.lora_dropout[adapter_name] = lora_dropout_layer
# Actual trainable parameters
base_layer = self.get_base_layer()
if r > 0:
kernel_size = base_layer.kernel_size
stride = base_layer.stride
padding = base_layer.padding
self.lora_A[adapter_name] = nn.Conv2d(self.in_features, r, kernel_size, stride, padding, bias=False)
self.lora_B[adapter_name] = nn.Conv2d(r, self.out_features, (1, 1), (1, 1), bias=False)
self.scaling[adapter_name] = lora_alpha / r
if init_lora_weights == "loftq":
self.loftq_init(adapter_name)
elif init_lora_weights:
self.reset_lora_parameters(adapter_name, init_lora_weights)
weight = getattr(base_layer, "weight", None)
if weight is not None:
# the layer is already completely initialized, this is an update
self.to(base_layer.weight.device, dtype=weight.dtype)
self.set_adapter(self.active_adapters)
def update_layer_embedding(self, adapter_name, r, lora_alpha, lora_dropout, init_lora_weights):
if r <= 0:
raise ValueError(f"`r` should be a positive integer value but the value passed is {r}")
self.r[adapter_name] = r
self.lora_alpha[adapter_name] = lora_alpha
if lora_dropout > 0.0:
lora_dropout_layer = nn.Dropout(p=lora_dropout)
else:
lora_dropout_layer = nn.Identity()
self.lora_dropout[adapter_name] = lora_dropout_layer
# Actual trainable parameters
if r > 0:
weight_A = torch.randn((r, self.in_features))
weight_B = torch.randn((self.out_features, r))
self.lora_embedding_A[adapter_name] = nn.Parameter(weight_A)
self.lora_embedding_B[adapter_name] = nn.Parameter(weight_B)
self.scaling[adapter_name] = lora_alpha / r
if init_lora_weights == "loftq":
self.loftq_init(adapter_name)
elif init_lora_weights:
self.reset_lora_parameters(adapter_name, init_lora_weights)
base_layer = self.get_base_layer()
weight = getattr(base_layer, "weight", None)
if weight is not None:
# the layer is already completely initialized, this is an update
self.to(base_layer.weight.device, dtype=weight.dtype)
self.set_adapter(self.active_adapters)
def reset_lora_parameters(self, adapter_name, init_lora_weights):
if init_lora_weights is False:
return
if adapter_name in self.lora_A.keys():
if init_lora_weights is True:
# initialize A the same way as the default for nn.Linear and B to zero
# https://github.com/microsoft/LoRA/blob/a0a92e0f26c067cf94747bdbf1ce73793fa44d19/loralib/layers.py#L124
nn.init.kaiming_uniform_(self.lora_A[adapter_name].weight, a=math.sqrt(5))
elif init_lora_weights.lower() == "gaussian":
nn.init.normal_(self.lora_A[adapter_name].weight, std=1 / self.r[adapter_name])
else:
raise ValueError(f"Unknown initialization {init_lora_weights=}")
nn.init.zeros_(self.lora_B[adapter_name].weight)
if adapter_name in self.lora_embedding_A.keys():
# initialize a the same way as the default for nn.linear and b to zero
nn.init.zeros_(self.lora_embedding_A[adapter_name])
nn.init.normal_(self.lora_embedding_B[adapter_name])
def loftq_init(self, adapter_name):
from peft.utils.loftq_utils import loftq_init
weight = self.get_base_layer().weight
kwargs = {
"num_bits": self.kwargs.get("loftq_bits", 4),
"reduced_rank": self.r[adapter_name],
"num_iter": self.kwargs.get("loftq_iter", 1),
}
qweight, lora_A, lora_B = loftq_init(weight, **kwargs)
if adapter_name in self.lora_A.keys():
# initialize A the same way as the default for nn.Linear and B to zero
self.lora_A[adapter_name].weight.data = lora_A
self.lora_B[adapter_name].weight.data = lora_B
if adapter_name in self.lora_embedding_A.keys():
# initialize a the same way as the default for nn.linear and b to zero
self.lora_embedding_A[adapter_name].weight.data = lora_A
self.lora_embedding_B[adapter_name].weight.data = lora_B
self.get_base_layer().weight.data = qweight
def set_scale(self, adapter, scale):
if adapter not in self.scaling:
# Ignore the case where the adapter is not in the layer
return
self.scaling[adapter] = scale * self.lora_alpha[adapter] / self.r[adapter]
def scale_layer(self, scale: float) -> None:
if scale == 1:
return
for active_adapter in self.active_adapters:
if active_adapter not in self.lora_A.keys():
continue
self.scaling[active_adapter] *= scale
def unscale_layer(self, scale=None) -> None:
for active_adapter in self.active_adapters:
if active_adapter not in self.lora_A.keys():
continue
if scale is None:
self.scaling[active_adapter] = self.lora_alpha[active_adapter] / self.r[active_adapter]
else:
self.scaling[active_adapter] /= scale
# Below code is based on https://github.com/microsoft/LoRA/blob/main/loralib/layers.py
# and modified to work with PyTorch FSDP
# ------------------------------------------------------------------------------------------
# Copyright (c) Microsoft Corporation. All rights reserved.
# Licensed under the MIT License (MIT). See LICENSE in the repo root for license information.
# ------------------------------------------------------------------------------------------
class Linear(nn.Module, LoraLayer):
# Lora implemented in a dense layer
def __init__(
self,
base_layer,
adapter_name: str,
r: int = 0,
lora_alpha: int = 1,
lora_dropout: float = 0.0,
fan_in_fan_out: bool = False, # Set this to True if the layer to replace stores weight like (fan_in, fan_out)
is_target_conv_1d_layer: bool = False,
init_lora_weights: Union[bool, str] = True,
**kwargs,
) -> None:
super().__init__()
LoraLayer.__init__(self, base_layer, **kwargs)
self.fan_in_fan_out = fan_in_fan_out
self._active_adapter = adapter_name
self.update_layer(adapter_name, r, lora_alpha, lora_dropout, init_lora_weights)
self.is_target_conv_1d_layer = is_target_conv_1d_layer
def merge(self, safe_merge: bool = False, adapter_names: Optional[List[str]] = None) -> None:
"""
Merge the active adapter weights into the base weights
Args:
safe_merge (`bool`, *optional*):
If True, the merge operation will be performed in a copy of the original weights and check for NaNs
before merging the weights. This is useful if you want to check if the merge operation will produce
NaNs. Defaults to `False`.
adapter_names (`List[str]`, *optional*):
The list of adapter names that should be merged. If None, all active adapters will be merged. Defaults
to `None`.
"""
if self.merged:
warnings.warn(
f"Already following adapters were merged {','.join(self.merged_adapters)}. "
f"You are now additionally merging {','.join(self.active_adapters)}."
)
if adapter_names is None:
adapter_names = self.active_adapters
for active_adapter in adapter_names:
if active_adapter in self.lora_A.keys():
base_layer = self.get_base_layer()
if safe_merge:
# Note that safe_merge will be slower than the normal merge
# because of the copy operation.
orig_weights = base_layer.weight.data.clone()
orig_weights += self.get_delta_weight(active_adapter)
if not torch.isfinite(orig_weights).all():
raise ValueError(
f"NaNs detected in the merged weights. The adapter {active_adapter} seems to be broken"
)
base_layer.weight.data = orig_weights
else:
base_layer.weight.data += self.get_delta_weight(active_adapter)
self.merged_adapters.append(active_adapter)
def unmerge(self) -> None:
"""
This method unmerges all merged adapter layers from the base weights.
"""
if not self.merged:
warnings.warn("Already unmerged. Nothing to do.")
return
while len(self.merged_adapters) > 0:
active_adapter = self.merged_adapters.pop()
if active_adapter in self.lora_A.keys():
self.get_base_layer().weight.data -= self.get_delta_weight(active_adapter)
def get_delta_weight(self, adapter) -> torch.Tensor:
"""
Compute the delta weight for the given adapter.
Args:
adapter (str):
The name of the adapter for which the delta weight should be computed.
"""
device = self.lora_B[adapter].weight.device
dtype = self.lora_B[adapter].weight.dtype
# In case users wants to merge the adapter weights that are in
# float16 while being on CPU, we need to cast the weights to float32, perform the merge and then cast back to
# float16 because the `@` and matmul operation in general is not supported in torch + cpu + fp16.
cast_to_fp32 = device.type == "cpu" and dtype == torch.float16
weight_A = self.lora_A[adapter].weight
weight_B = self.lora_B[adapter].weight
if cast_to_fp32:
weight_A = weight_A.float()
weight_B = weight_B.float()
output_tensor = transpose(weight_B @ weight_A, self.fan_in_fan_out) * self.scaling[adapter]
if cast_to_fp32:
output_tensor = output_tensor.to(dtype=dtype)
# cast back the weights
self.lora_A[adapter].weight.data = weight_A.to(dtype)
self.lora_B[adapter].weight.data = weight_B.to(dtype)
return output_tensor
def forward(self, x: torch.Tensor, *args: Any, **kwargs: Any) -> torch.Tensor:
previous_dtype = x.dtype
if self.disable_adapters:
if self.merged:
self.unmerge()
result = self.base_layer(x, *args, **kwargs)
elif self.merged:
result = self.base_layer(x, *args, **kwargs)
else:
result = self.base_layer(x, *args, **kwargs)
for active_adapter in self.active_adapters:
if active_adapter not in self.lora_A.keys():
continue
lora_A = self.lora_A[active_adapter]
lora_B = self.lora_B[active_adapter]
dropout = self.lora_dropout[active_adapter]
scaling = self.scaling[active_adapter]
x = x.to(lora_A.weight.dtype)
result += lora_B(lora_A(dropout(x))) * scaling
result = result.to(previous_dtype)
# print('11111111111111111')
return result
def __repr__(self) -> str:
rep = super().__repr__()
return "lora." + rep
class Embedding(nn.Module, LoraLayer):
# LoRA implemented in a Embedding layer
def __init__(
self,
base_layer: nn.Module,
adapter_name: str,
r: int = 0,
lora_alpha: int = 1,
lora_dropout: float = 0.0,
init_lora_weights: Union[bool, str] = True,
**kwargs,
) -> None:
super().__init__()
LoraLayer.__init__(self, base_layer)
self._active_adapter = adapter_name
self.update_layer_embedding(adapter_name, r, lora_alpha, lora_dropout, init_lora_weights)
def merge(self, safe_merge: bool = False, adapter_names: Optional[List[str]] = None) -> None:
"""
Merge the active adapter weights into the base weights
Args:
safe_merge (`bool`, *optional*):
If True, the merge operation will be performed in a copy of the original weights and check for NaNs
before merging the weights. This is useful if you want to check if the merge operation will produce
NaNs. Defaults to `False`.
adapter_names (`List[str]`, *optional*):
The list of adapter names that should be merged. If None, all active adapters will be merged. Defaults
to `None`.
"""
if self.merged:
warnings.warn(
f"Already following adapters were merged {','.join(self.merged_adapters)}. "
f"You are now additionally merging {','.join(self.active_adapters)}."
)
if adapter_names is None:
adapter_names = self.active_adapters
for active_adapter in adapter_names:
if active_adapter in self.lora_embedding_A.keys():
base_layer = self.get_base_layer()
if safe_merge:
# Note that safe_merge will be slower than the normal merge
# because of the copy operation.
orig_weights = base_layer.weight.data.copy()
orig_weights += self.get_delta_weight(active_adapter)
if not torch.isfinite(orig_weights).all():
raise ValueError(
f"NaNs detected in the merged weights. The adapter {active_adapter} seems to be broken"
)
base_layer.weight.data = orig_weights
else:
base_layer.weight.data += self.get_delta_weight(active_adapter)
self.merged_adapters.append(active_adapter)
def unmerge(self) -> None:
"""
This method unmerges all merged adapter layers from the base weights.
"""
if not self.merged:
warnings.warn("Already unmerged. Nothing to do.")
return
while len(self.merged_adapters) > 0:
active_adapter = self.merged_adapters.pop()
if active_adapter in self.lora_embedding_A.keys():
self.get_base_layer().weight.data -= self.get_delta_weight(active_adapter)
def get_delta_weight(self, adapter) -> torch.Tensor:
"""
Compute the delta weight for the given adapter.
Args:
adapter (str):
The name of the adapter for which the delta weight should be computed.
"""
device = self.lora_embedding_B[adapter].device
dtype = self.lora_embedding_A[adapter].dtype
# In case users wants to merge the adapter weights that are in
# float16 while being on CPU, we need to cast the weights to float32, perform the merge and then cast back to
# float16 because the `@` and matmul operation in general is not supported in torch + cpu + fp16.
cast_to_fp32 = device.type == "cpu" and dtype == torch.float16
weight_A = self.lora_embedding_A[adapter]
weight_B = self.lora_embedding_B[adapter]
if cast_to_fp32:
weight_A = weight_A.float()
weight_B = weight_B.float()
output_tensor = transpose(weight_B @ weight_A, True) * self.scaling[adapter]
if cast_to_fp32:
output_tensor = output_tensor.to(dtype=dtype)
# cast back the weights
self.lora_embedding_A[adapter] = weight_A.to(dtype)
self.lora_embedding_B[adapter] = weight_B.to(dtype)
return output_tensor
def _embed(self, input: torch.Tensor, weight: torch.Tensor) -> torch.Tensor:
base_layer = self.get_base_layer()
return F.embedding(
input,
weight,
padding_idx=base_layer.padding_idx,
max_norm=base_layer.max_norm,
norm_type=base_layer.norm_type,
scale_grad_by_freq=base_layer.scale_grad_by_freq,
sparse=base_layer.sparse,
)
def forward(self, x: torch.Tensor, *args: Any, **kwargs: Any) -> torch.Tensor:
# TODO: no dtype conversion here, unlike in Linear, is that correct?
if self.disable_adapters:
if self.merged:
self.unmerge()
result = self.base_layer(x, *args, **kwargs)
elif self.merged:
result = self.base_layer(x, *args, **kwargs)
else:
result = self.base_layer(x, *args, **kwargs)
for active_adapter in self.active_adapters:
if active_adapter not in self.lora_embedding_A:
continue
embedding_A = self.lora_embedding_A[active_adapter].T
embedding_B = self.lora_embedding_B[active_adapter].T
scaling = self.scaling[active_adapter]
after_A = self._embed(x, embedding_A)
result += (after_A @ embedding_B) * scaling
return result
def __repr__(self) -> str:
rep = super().__repr__()
return "lora." + rep
class Conv2d(nn.Module, LoraLayer):
# Lora implemented in a conv2d layer
def __init__(
self,
base_layer: nn.Module,
adapter_name: str,
r: int = 0,
lora_alpha: int = 1,
lora_dropout: float = 0.0,
init_lora_weights: Union[bool, str] = True,
**kwargs,
) -> None:
super().__init__()
LoraLayer.__init__(self, base_layer)
self._active_adapter = adapter_name
self.update_layer_conv2d(adapter_name, r, lora_alpha, lora_dropout, init_lora_weights)
def merge(self, safe_merge: bool = False, adapter_names: Optional[List[str]] = None) -> None:
"""
Merge the active adapter weights inside the base weights
Args:
safe_merge (`bool`, *optional*):
If True, the merge operation will be performed in a copy of the original weights and check for NaNs
before merging the weights. This is useful if you want to check if the merge operation will produce
NaNs. Defaults to `False`.
adapter_names (`List[str]`, *optional*):
The list of adapter names that should be merged. If None, all active adapters will be merged. Defaults
to `None`.
"""
if self.merged:
warnings.warn(
f"Already following adapters were merged {','.join(self.merged_adapters)}. "
f"You are now additionally merging {','.join(self.active_adapters)}."
)
if adapter_names is None:
adapter_names = self.active_adapters
for active_adapter in adapter_names:
if active_adapter in self.lora_A.keys():
base_layer = self.get_base_layer()
if safe_merge:
# Note that safe_merge will be slower than the normal merge
# because of the copy operation.
orig_weights = base_layer.weight.data.copy()
orig_weights += self.get_delta_weight(active_adapter)
if not torch.isfinite(orig_weights).all():
raise ValueError(
f"NaNs detected in the merged weights. The adapter {active_adapter} seems to be broken"
)
base_layer.weight.data = orig_weights
else:
base_layer.weight.data += self.get_delta_weight(active_adapter)
self.merged_adapters.append(active_adapter)
def unmerge(self) -> None:
"""
This method unmerges all merged adapter layers from the base weights.
"""
if not self.merged:
warnings.warn("Already unmerged. Nothing to do.")
return
while len(self.merged_adapters) > 0:
active_adapter = self.merged_adapters.pop()
if active_adapter in self.lora_A.keys():
self.get_base_layer().weight.data -= self.get_delta_weight(active_adapter)
def get_delta_weight(self, adapter) -> torch.Tensor:
"""
Compute the delta weight for the given adapter.
Args:
adapter (str):
The name of the adapter for which the delta weight should be computed.
"""
device = self.lora_B[adapter].weight.device
dtype = self.lora_A[adapter].weight.dtype
# In case users wants to merge the adapter weights that are in
# float16 while being on CPU, we need to cast the weights to float32, perform the merge and then cast back to
# float16 because the `@` and matmul operation in general is not supported in torch + cpu + fp16.
cast_to_fp32 = device.type == "cpu" and dtype == torch.float16
weight_A = self.lora_A[adapter].weight
weight_B = self.lora_B[adapter].weight
if cast_to_fp32:
weight_A = weight_A.float()
weight_B = weight_B.float()
# https://github.com/bmaltais/kohya_ss/blob/feb6728762a8f463d15ba936d189d4c3abfaa1ab/networks/lora.py#L117
if self.get_base_layer().weight.size()[2:4] == (1, 1):
# conv2d 1x1
output_tensor = (weight_B.squeeze(3).squeeze(2) @ weight_A.squeeze(3).squeeze(2)).unsqueeze(2).unsqueeze(
3
) * self.scaling[adapter]
else:
# conv2d 3x3
output_tensor = (
F.conv2d(
weight_A.permute(1, 0, 2, 3),
weight_B,
).permute(1, 0, 2, 3)
* self.scaling[adapter]
)
if cast_to_fp32:
output_tensor = output_tensor.to(dtype=dtype)
# cast back the weights
self.lora_A[adapter].weight.data = weight_A.to(dtype)
self.lora_B[adapter].weight.data = weight_B.to(dtype)
return output_tensor
def forward(self, x: torch.Tensor, *args, **kwargs) -> torch.Tensor:
previous_dtype = x.dtype
if self.disable_adapters:
if self.merged:
self.unmerge()
result = self.base_layer(x, *args, **kwargs)
elif self.merged:
result = self.base_layer(x, *args, **kwargs)
else:
result = self.base_layer(x, *args, **kwargs)
for active_adapter in self.active_adapters:
if active_adapter not in self.lora_A.keys():
continue
lora_A = self.lora_A[active_adapter]
lora_B = self.lora_B[active_adapter]
dropout = self.lora_dropout[active_adapter]
scaling = self.scaling[active_adapter]
x = x.to(lora_A.weight.dtype)
result += lora_B(lora_A(dropout(x))) * scaling
result = result.to(previous_dtype)
return result
def __repr__(self) -> str:
rep = super().__repr__()
return "lora." + rep