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# 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. | |
from __future__ import annotations | |
import math | |
import warnings | |
from typing import Any, 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, check_adapters_to_merge | |
from peft.utils.integrations import dequantize_bnb_weight, gather_params_ctx | |
from peft.utils.other import transpose | |
from .config import LoraConfig | |
from einops import rearrange | |
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.use_dora: dict[str, bool] = {} | |
self.lora_magnitude_vector: Optional[torch.nn.ParameterDict] = None # for DoRA | |
self._caches: dict[str, Any] = {} | |
self.kwargs = kwargs | |
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 | |
elif hasattr(base_layer, "codebooks") and base_layer.__class__.__name__ == "QuantizedLinear": | |
# AQLM QuantLinear | |
in_features, out_features = base_layer.in_features, base_layer.out_features | |
elif hasattr(base_layer, "w_bit") and base_layer.__class__.__name__ == "WQLinear_GEMM": | |
# Awq layers | |
in_features, out_features = base_layer.in_features, base_layer.out_features | |
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, use_rslora, use_dora: bool = False | |
): | |
# This code works for linear layers, override for other layer types | |
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 | |
self.lora_A[adapter_name] = nn.Linear(self.in_features, r, bias=False) | |
self.lora_B[adapter_name] = nn.Linear(r, self.out_features, bias=False) | |
if use_rslora: | |
self.scaling[adapter_name] = lora_alpha / math.sqrt(r) | |
else: | |
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) | |
# check weight and qweight (for GPTQ) | |
for weight_name in ("weight", "qweight"): | |
weight = getattr(self.get_base_layer(), weight_name, 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) | |
break | |
if use_dora: | |
self.dora_init(adapter_name) | |
self.use_dora[adapter_name] = True | |
else: | |
self.use_dora[adapter_name] = False | |
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 _get_weight_norm(self, weight, lora_weight, scaling) -> torch.Tensor: | |
# calculate L2 norm of weight matrix, column-wise | |
weight = weight + scaling * lora_weight | |
weight_norm = torch.linalg.norm(weight, dim=1).to(weight.dtype) | |
return weight_norm | |
def dora_init(self, adapter_name: str) -> None: | |
lora_A = self.lora_A[adapter_name] | |
lora_B = self.lora_B[adapter_name] | |
scaling = self.scaling[adapter_name] | |
with gather_params_ctx(self.get_base_layer()): | |
weight = self.get_base_layer().weight | |
quant_state = getattr(self.get_base_layer(), "state", None) | |
weight = dequantize_bnb_weight(weight, state=quant_state) # no-op if not bnb | |
if weight.data.ndim == 4: # For handling LoRAs applied to Conv2Ds. | |
lora_weight = torch.mm(lora_B.weight.flatten(start_dim=1), lora_A.weight.flatten(start_dim=1)) | |
lora_weight = lora_weight.reshape(weight.shape) | |
else: | |
lora_weight = lora_B.weight @ lora_A.weight | |
weight_norm = self._get_weight_norm(weight, lora_weight, scaling) | |
self.lora_magnitude_vector = nn.ParameterDict() | |
self.lora_magnitude_vector[adapter_name] = nn.Parameter(weight_norm, requires_grad=True) | |
# add lora_magnitude_vector to the list of learnable parameters | |
self.adapter_layer_names = self.adapter_layer_names[:] + ("lora_magnitude_vector",) | |
def _cache_store(self, key: str, value: Any) -> None: | |
self._caches[key] = value | |
def _cache_pop(self, key: str) -> Any: | |
value = self._caches.pop(key) | |
return value | |
def _apply_dora(self, x, lora_A, lora_B, scaling, active_adapter): | |
""" | |
For DoRA, calculate the extra output from LoRA with DoRA applied. This should be added on top of the base layer | |
output. | |
""" | |
lora_weight = lora_B.weight @ lora_A.weight | |
magnitude = self.lora_magnitude_vector[active_adapter] | |
weight = self.get_base_layer().weight | |
quant_state = getattr(self.get_base_layer(), "state", None) | |
weight = dequantize_bnb_weight(weight, state=quant_state) # no-op if not bnb | |
weight = weight.to(x.dtype) | |
weight_norm = self._get_weight_norm(weight, lora_weight, scaling) | |
# see section 4.3 of DoRA (https://arxiv.org/abs/2402.09353) | |
# "[...] we suggest treating ||V +∆V ||_c in | |
# Eq. (5) as a constant, thereby detaching it from the gradient | |
# graph. This means that while ||V + ∆V ||_c dynamically | |
# reflects the updates of ∆V , it won’t receive any gradient | |
# during backpropagation" | |
weight_norm = weight_norm.detach() | |
mag_norm_scale = (magnitude / weight_norm).view(1, -1) | |
result_dora = (mag_norm_scale - 1) * ( | |
F.linear(x, transpose(weight, self.fan_in_fan_out)) | |
) + mag_norm_scale * lora_B(lora_A(x)) * scaling | |
# Note: Computation could potentially be accelerated by using the code below instead of calculating X@W again. | |
# This is only correct if dropout=0, otherwise results will differ: | |
# https://github.com/huggingface/peft/pull/1474#issuecomment-1964682771 | |
# bias = self.get_base_layer().bias | |
# if bias is not None: | |
# result = result - bias | |
# result = mag_norm_scale * result + mag_norm_scale * lora_B(lora_A(x)) * scaling | |
# if bias is not None: | |
# result = result + bias | |
return result_dora | |
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 | |
def _check_forward_args(self, x, *args, **kwargs): | |
"""Check if the arguments are compatible with the configs and state of the model""" | |
adapter_names = kwargs.get("adapter_names", None) | |
if adapter_names is None: | |
return | |
if len(x) != len(adapter_names): | |
msg = ( | |
"Length of `adapter_names` should be the same as the number of inputs, but got " | |
f"{len(adapter_names)} and {len(x)} respectively." | |
) | |
raise ValueError(msg) | |
if self.merged: | |
# It is unclear what would be the right thing to do if users pass adapter_names and there are merged | |
# adapters. Therefore, it is better to raise an error in this case. | |
msg = "Cannot pass `adapter_names` when there are merged adapters, please call `unmerge_adapter` first." | |
raise ValueError(msg) | |
unique_adapters = set(self.active_adapters) | |
for adapter_name in unique_adapters: | |
if self.use_dora.get(adapter_name, False): | |
msg = "Cannot pass `adapter_names` when DoRA is enabled." | |
raise ValueError(msg) | |
def _mixed_batch_forward( | |
self, x: torch.Tensor, *args: Any, adapter_names: list[str], **kwargs: Any | |
) -> torch.Tensor: | |
# This is a special method that handles the case when users pass the argument `adapter_names`. This is an | |
# extra argument that allows mixing different adapters in the same batch at inference time. | |
result = self.base_layer(x, *args, **kwargs) | |
torch_result_dtype = result.dtype | |
unique_adapters = set(adapter_names) | |
sub_batch_indices_list = [] | |
for adapter in unique_adapters: | |
sub_batch_indices_list.append([index for index, item in enumerate(adapter_names) if item == adapter]) | |
for i, active_adapter in enumerate(unique_adapters): | |
if active_adapter == "__base__": | |
continue | |
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] | |
# getting the sub-batch, passing it to LoRA layers and updating the corresponding indices of the linear | |
# layer output | |
sub_batch = x[sub_batch_indices_list[i]].to(lora_A.weight.dtype) | |
lora_output = lora_B(lora_A(dropout(sub_batch))) * scaling | |
result[sub_batch_indices_list[i]] += lora_output.to(torch_result_dtype) | |
return result | |
# 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, | |
use_rslora: bool = False, | |
use_dora: bool = False, | |
**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_alpha, | |
lora_dropout=lora_dropout, | |
init_lora_weights=init_lora_weights, | |
use_rslora=use_rslora, | |
use_dora=use_dora, | |
) | |
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`. | |
""" | |
adapter_names = check_adapters_to_merge(self, adapter_names) | |
if not adapter_names: | |
# no adapter to merge | |
return | |
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() | |
delta_weight = self.get_delta_weight(active_adapter) | |
if not self.use_dora[active_adapter]: | |
orig_weights = orig_weights + delta_weight | |
else: | |
# handle dora | |
# since delta_weight already includes scaling, set it to 1 here | |
weight_norm = self._get_weight_norm(orig_weights, delta_weight, scaling=1).detach() | |
# We need to cache weight_norm because it has to be based on the original weights. We | |
# cannot calculate it on the fly based on the merged weights when unmerging because its a | |
# different value | |
self._cache_store(f"{active_adapter}-weight_norm", weight_norm) | |
dora_factor = self.lora_magnitude_vector[active_adapter] / weight_norm | |
orig_weights = dora_factor.view(-1, 1) * (orig_weights + delta_weight) | |
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: | |
delta_weight = self.get_delta_weight(active_adapter) | |
if not self.use_dora[active_adapter]: | |
base_layer.weight.data = base_layer.weight.data + delta_weight | |
else: | |
# handle dora | |
# since delta_weight already includes scaling, set it to 1 here | |
weight_norm = self._get_weight_norm(base_layer.weight, delta_weight, scaling=1).detach() | |
# We need to cache weight_norm because it has to be based on the original weights. We | |
# cannot calculate it on the fly based on the merged weights when unmerging because its a | |
# different value | |
self._cache_store(f"{active_adapter}-weight_norm", weight_norm) | |
dora_factor = self.lora_magnitude_vector[active_adapter] / weight_norm | |
new_weight = dora_factor.view(-1, 1) * (base_layer.weight.data + delta_weight) | |
base_layer.weight.data = new_weight | |
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(): | |
weight = self.get_base_layer().weight | |
delta_weight = self.get_delta_weight(active_adapter) | |
if not self.use_dora[active_adapter]: | |
weight.data -= delta_weight | |
else: | |
weight_norm = self._cache_pop(f"{active_adapter}-weight_norm") | |
dora_factor = self.lora_magnitude_vector[active_adapter] / weight_norm | |
weight_orig = weight.data / dora_factor.view(-1, 1) - delta_weight | |
weight.data = weight_orig | |
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: | |
self._check_forward_args(x, *args, **kwargs) | |
adapter_names = kwargs.pop("adapter_names", None) | |
if self.disable_adapters: | |
if self.merged: | |
self.unmerge() | |
result = self.base_layer(x, *args, **kwargs) | |
elif adapter_names is not None: | |
result = self._mixed_batch_forward(x, *args, adapter_names=adapter_names, **kwargs) | |
elif self.merged: | |
result = self.base_layer(x, *args, **kwargs) | |
else: | |
result = self.base_layer(x, *args, **kwargs) | |
torch_result_dtype = result.dtype | |
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) | |
if not self.use_dora[active_adapter]: | |
result = result + lora_B(lora_A(dropout(x))) * scaling | |
else: | |
x = dropout(x) | |
result = result + self._apply_dora(x, lora_A, lora_B, scaling, active_adapter) | |
result = result.to(torch_result_dtype) | |
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, | |
use_rslora: bool = False, | |
use_dora: bool = False, | |
**kwargs, | |
) -> None: | |
super().__init__() | |
LoraLayer.__init__(self, base_layer) | |
if use_dora: | |
raise ValueError(f"{self.__class__.__name__} does not support DoRA yet, please set it to False") | |
self._active_adapter = adapter_name | |
self.update_layer( | |
adapter_name, | |
r, | |
lora_alpha=lora_alpha, | |
lora_dropout=lora_dropout, | |
init_lora_weights=init_lora_weights, | |
use_rslora=use_rslora, | |
use_dora=use_dora, | |
) | |
def update_layer(self, adapter_name, r, lora_alpha, lora_dropout, init_lora_weights, use_rslora, use_dora): | |
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 | |
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) | |
if use_rslora: | |
self.scaling[adapter_name] = lora_alpha / math.sqrt(r) | |
else: | |
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 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`. | |
""" | |
adapter_names = check_adapters_to_merge(self, adapter_names) | |
if not adapter_names: | |
# no adapter to merge | |
return | |
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.clone() | |
orig_weights = 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 = 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 _mixed_batch_forward( | |
self, x: torch.Tensor, *args: Any, adapter_names: list[str], **kwargs: Any | |
) -> torch.Tensor: | |
# This is a special method that handles the case when users pass the argument `adapter_names`. This is an | |
# extra argument that allows mixing different adapters in the same batch at inference time. | |
result = self.base_layer(x, *args, **kwargs) | |
unique_adapters = set(adapter_names) | |
sub_batch_indices_list = [] | |
for adapter in unique_adapters: | |
sub_batch_indices_list.append([index for index, item in enumerate(adapter_names) if item == adapter]) | |
for i, active_adapter in enumerate(unique_adapters): | |
if active_adapter == "__base__": | |
continue | |
if active_adapter not in self.lora_embedding_A.keys(): | |
continue | |
embedding_A = self.lora_embedding_A[active_adapter].T | |
embedding_B = self.lora_embedding_B[active_adapter].T | |
scaling = self.scaling[active_adapter] | |
# getting the sub-batch, passing it to LoRA layers and updating the corresponding indices of the linear | |
# layer output | |
sub_batch = x[sub_batch_indices_list[i]] | |
after_A = self._embed(sub_batch, embedding_A) | |
result[sub_batch_indices_list[i]] += (after_A @ embedding_B) * scaling | |
return result | |
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? | |
self._check_forward_args(x, *args, **kwargs) | |
adapter_names = kwargs.pop("adapter_names", None) | |
if self.disable_adapters: | |
if self.merged: | |
self.unmerge() | |
result = self.base_layer(x, *args, **kwargs) | |
elif adapter_names is not None: | |
result = self._mixed_batch_forward(x, *args, adapter_names=adapter_names, **kwargs) | |
elif self.merged: | |
result = self.base_layer(x, *args, **kwargs) | |
else: | |
result = self.base_layer(x, *args, **kwargs) | |
torch_result_dtype = result.dtype | |
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 = result + (after_A @ embedding_B) * scaling | |
result = result.to(torch_result_dtype) | |
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, | |
use_rslora: bool = False, | |
use_dora: bool = False, | |
**kwargs, | |
) -> None: | |
super().__init__() | |
LoraLayer.__init__(self, base_layer) | |
self._active_adapter = adapter_name | |
self.update_layer( | |
adapter_name, | |
r, | |
lora_alpha=lora_alpha, | |
lora_dropout=lora_dropout, | |
init_lora_weights=init_lora_weights, | |
use_rslora=use_rslora, | |
use_dora=use_dora, | |
) | |
def update_layer(self, adapter_name, r, lora_alpha, lora_dropout, init_lora_weights, use_rslora, use_dora): | |
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() | |
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) | |
if use_rslora: | |
self.scaling[adapter_name] = lora_alpha / math.sqrt(r) | |
else: | |
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) | |
if use_dora: | |
self.dora_init(adapter_name) | |
self.use_dora[adapter_name] = True | |
else: | |
self.use_dora[adapter_name] = False | |
self.set_adapter(self.active_adapters) | |
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`. | |
""" | |
adapter_names = check_adapters_to_merge(self, adapter_names) | |
if not adapter_names: | |
# no adapter to merge | |
return | |
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() | |
delta_weight = self.get_delta_weight(active_adapter) | |
if not self.use_dora[active_adapter]: | |
orig_weights = orig_weights + delta_weight | |
else: | |
# handle dora | |
# since delta_weight already includes scaling, set it to 1 here | |
weight_norm = self._get_weight_norm(orig_weights, delta_weight, scaling=1).detach() | |
# We need to cache weight_norm because it has to be based on the original weights. We | |
# cannot calculate it on the fly based on the merged weights when unmerging because its a | |
# different value | |
self._cache_store(f"{active_adapter}-weight_norm", weight_norm) | |
dora_factor = self.lora_magnitude_vector[active_adapter] / weight_norm | |
orig_weights = dora_factor.view(-1, 1, 1, 1) * (orig_weights + delta_weight) | |
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: | |
delta_weight = self.get_delta_weight(active_adapter) | |
if not self.use_dora[active_adapter]: | |
base_layer.weight.data = base_layer.weight.data + delta_weight | |
else: | |
# handle dora | |
# since delta_weight already includes scaling, set it to 1 here | |
weight_norm = self._get_weight_norm(base_layer.weight, delta_weight, scaling=1).detach() | |
# We need to cache weight_norm because it has to be based on the original weights. We | |
# cannot calculate it on the fly based on the merged weights when unmerging because its a | |
# different value | |
self._cache_store(f"{active_adapter}-weight_norm", weight_norm) | |
dora_factor = self.lora_magnitude_vector[active_adapter] / weight_norm | |
new_weight = dora_factor.view(-1, 1, 1, 1) * (base_layer.weight.data + delta_weight) | |
base_layer.weight.data = new_weight | |
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(): | |
weight = self.get_base_layer().weight | |
delta_weight = self.get_delta_weight(active_adapter) | |
if not self.use_dora[active_adapter]: | |
weight.data -= delta_weight | |
else: | |
weight_norm = self._cache_pop(f"{active_adapter}-weight_norm") | |
dora_factor = self.lora_magnitude_vector[active_adapter] / weight_norm | |
weight_orig = weight.data / dora_factor.view(-1, 1, 1, 1) - delta_weight | |
weight.data = weight_orig | |
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 _get_weight_norm(self, weight, lora_weight, scaling) -> torch.Tensor: | |
# calculate L2 norm of weight matrix, channel-wise | |
weight = weight + scaling * lora_weight | |
# the following is needed to have compatibility with the 4D weight tensors of Conv2D | |
weight_norm = weight.norm(p=2, dim=(1, 2, 3), keepdim=True).transpose(1, 0) | |
return weight_norm | |
def _apply_dora(self, x, lora_A, lora_B, scaling, active_adapter): | |
""" | |
For DoRA, calculate the extra output from LoRA with DoRA applied. This should be added on top of the base layer | |
output. | |
""" | |
base_layer = self.get_base_layer() | |
weight = base_layer.weight | |
lora_weight = torch.mm(lora_B.weight.flatten(start_dim=1), lora_A.weight.flatten(start_dim=1)) | |
lora_weight = lora_weight.reshape(weight.shape) | |
magnitude = self.lora_magnitude_vector[active_adapter] | |
weight_norm = self._get_weight_norm(weight, lora_weight, scaling) | |
# see section 4.3 of DoRA (https://arxiv.org/abs/2402.09353) | |
# "[...] we suggest treating ||V +∆V ||_c in | |
# Eq. (5) as a constant, thereby detaching it from the gradient | |
# graph. This means that while ||V + ∆V ||_c dynamically | |
# reflects the updates of ∆V , it won’t receive any gradient | |
# during backpropagation" | |
weight_norm = weight_norm.detach() | |
mag_norm_scale = magnitude / weight_norm | |
result_dora = (mag_norm_scale - 1) * ( | |
F.conv2d( | |
x, | |
weight, | |
bias=None, | |
stride=base_layer.stride, | |
padding=base_layer.padding, | |
dilation=base_layer.dilation, | |
groups=base_layer.groups, | |
) | |
) + mag_norm_scale * lora_B(lora_A(x)) * scaling | |
return result_dora | |
def forward(self, x: torch.Tensor, *args, **kwargs) -> torch.Tensor: | |
self._check_forward_args(x, *args, **kwargs) | |
adapter_names = kwargs.pop("adapter_names", None) | |
if self.disable_adapters: | |
if self.merged: | |
self.unmerge() | |
result = self.base_layer(x, *args, **kwargs) | |
elif adapter_names is not None: | |
result = self._mixed_batch_forward(x, *args, adapter_names=adapter_names, **kwargs) | |
elif self.merged: | |
result = self.base_layer(x, *args, **kwargs) | |
else: | |
result = self.base_layer(x, *args, **kwargs) | |
torch_result_dtype = result.dtype | |
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) | |
if not self.use_dora[active_adapter]: | |
result = result + lora_B(lora_A(dropout(x))) * scaling | |
else: | |
x = dropout(x) | |
result = result + self._apply_dora(x, lora_A, lora_B, scaling, active_adapter) | |
return result | |
def __repr__(self) -> str: | |
rep = super().__repr__() | |
return "lora." + rep | |
class InflatedConv3d(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, | |
use_rslora: bool = False, | |
use_dora: bool = False, | |
**kwargs, | |
) -> None: | |
super().__init__() | |
LoraLayer.__init__(self, base_layer) | |
self._active_adapter = adapter_name | |
self.update_layer( | |
adapter_name, | |
r, | |
lora_alpha=lora_alpha, | |
lora_dropout=lora_dropout, | |
init_lora_weights=init_lora_weights, | |
use_rslora=use_rslora, | |
use_dora=use_dora, | |
) | |
def update_layer(self, adapter_name, r, lora_alpha, lora_dropout, init_lora_weights, use_rslora, use_dora): | |
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() | |
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) | |
if use_rslora: | |
self.scaling[adapter_name] = lora_alpha / math.sqrt(r) | |
else: | |
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) | |
if use_dora: | |
self.dora_init(adapter_name) | |
self.use_dora[adapter_name] = True | |
else: | |
self.use_dora[adapter_name] = False | |
self.set_adapter(self.active_adapters) | |
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`. | |
""" | |
adapter_names = check_adapters_to_merge(self, adapter_names) | |
if not adapter_names: | |
# no adapter to merge | |
return | |
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() | |
delta_weight = self.get_delta_weight(active_adapter) | |
if not self.use_dora[active_adapter]: | |
orig_weights = orig_weights + delta_weight | |
else: | |
# handle dora | |
# since delta_weight already includes scaling, set it to 1 here | |
weight_norm = self._get_weight_norm(orig_weights, delta_weight, scaling=1).detach() | |
# We need to cache weight_norm because it has to be based on the original weights. We | |
# cannot calculate it on the fly based on the merged weights when unmerging because its a | |
# different value | |
self._cache_store(f"{active_adapter}-weight_norm", weight_norm) | |
dora_factor = self.lora_magnitude_vector[active_adapter] / weight_norm | |
orig_weights = dora_factor.view(-1, 1, 1, 1) * (orig_weights + delta_weight) | |
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: | |
delta_weight = self.get_delta_weight(active_adapter) | |
if not self.use_dora[active_adapter]: | |
base_layer.weight.data = base_layer.weight.data + delta_weight | |
else: | |
# handle dora | |
# since delta_weight already includes scaling, set it to 1 here | |
weight_norm = self._get_weight_norm(base_layer.weight, delta_weight, scaling=1).detach() | |
# We need to cache weight_norm because it has to be based on the original weights. We | |
# cannot calculate it on the fly based on the merged weights when unmerging because its a | |
# different value | |
self._cache_store(f"{active_adapter}-weight_norm", weight_norm) | |
dora_factor = self.lora_magnitude_vector[active_adapter] / weight_norm | |
new_weight = dora_factor.view(-1, 1, 1, 1) * (base_layer.weight.data + delta_weight) | |
base_layer.weight.data = new_weight | |
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(): | |
weight = self.get_base_layer().weight | |
delta_weight = self.get_delta_weight(active_adapter) | |
if not self.use_dora[active_adapter]: | |
weight.data -= delta_weight | |
else: | |
weight_norm = self._cache_pop(f"{active_adapter}-weight_norm") | |
dora_factor = self.lora_magnitude_vector[active_adapter] / weight_norm | |
weight_orig = weight.data / dora_factor.view(-1, 1, 1, 1) - delta_weight | |
weight.data = weight_orig | |
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 _get_weight_norm(self, weight, lora_weight, scaling) -> torch.Tensor: | |
# calculate L2 norm of weight matrix, channel-wise | |
weight = weight + scaling * lora_weight | |
# the following is needed to have compatibility with the 4D weight tensors of Conv2D | |
weight_norm = weight.norm(p=2, dim=(1, 2, 3), keepdim=True).transpose(1, 0) | |
return weight_norm | |
def _apply_dora(self, x, lora_A, lora_B, scaling, active_adapter): | |
""" | |
For DoRA, calculate the extra output from LoRA with DoRA applied. This should be added on top of the base layer | |
output. | |
""" | |
base_layer = self.get_base_layer() | |
weight = base_layer.weight | |
lora_weight = torch.mm(lora_B.weight.flatten(start_dim=1), lora_A.weight.flatten(start_dim=1)) | |
lora_weight = lora_weight.reshape(weight.shape) | |
magnitude = self.lora_magnitude_vector[active_adapter] | |
weight_norm = self._get_weight_norm(weight, lora_weight, scaling) | |
# see section 4.3 of DoRA (https://arxiv.org/abs/2402.09353) | |
# "[...] we suggest treating ||V +∆V ||_c in | |
# Eq. (5) as a constant, thereby detaching it from the gradient | |
# graph. This means that while ||V + ∆V ||_c dynamically | |
# reflects the updates of ∆V , it won’t receive any gradient | |
# during backpropagation" | |
weight_norm = weight_norm.detach() | |
mag_norm_scale = magnitude / weight_norm | |
result_dora = (mag_norm_scale - 1) * ( | |
F.conv2d( | |
x, | |
weight, | |
bias=None, | |
stride=base_layer.stride, | |
padding=base_layer.padding, | |
dilation=base_layer.dilation, | |
groups=base_layer.groups, | |
) | |
) + mag_norm_scale * lora_B(lora_A(x)) * scaling | |
return result_dora | |
def forward(self, x: torch.Tensor, *args, **kwargs) -> torch.Tensor: | |
self._check_forward_args(x, *args, **kwargs) | |
adapter_names = kwargs.pop("adapter_names", None) | |
ori_dim = x.ndim | |
if ori_dim == 5: | |
frames = x.shape[2] | |
x = rearrange(x, "b c f h w -> (b f) c h w") | |
if self.disable_adapters: | |
if self.merged: | |
self.unmerge() | |
result = self.base_layer(x, *args, **kwargs) | |
elif adapter_names is not None: | |
result = self._mixed_batch_forward(x, *args, adapter_names=adapter_names, **kwargs) | |
elif self.merged: | |
result = self.base_layer(x, *args, **kwargs) | |
else: | |
result = self.base_layer(x, *args, **kwargs) | |
torch_result_dtype = result.dtype | |
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) | |
if not self.use_dora[active_adapter]: | |
result = result + lora_B(lora_A(dropout(x))) * scaling | |
else: | |
x = dropout(x) | |
result = result + self._apply_dora(x, lora_A, lora_B, scaling, active_adapter) | |
result = result.to(torch_result_dtype) | |
if ori_dim == 5: | |
result = rearrange(result, "(b f) c h w -> b c f h w", f=frames) | |
return result | |
def __repr__(self) -> str: | |
rep = super().__repr__() | |
return "lora." + rep | |
def dispatch_default( | |
target: torch.nn.Module, | |
adapter_name: str, | |
lora_config: LoraConfig, | |
**kwargs, | |
) -> Optional[torch.nn.Module]: | |
new_module = None | |
if isinstance(target, BaseTunerLayer): | |
target_base_layer = target.get_base_layer() | |
else: | |
target_base_layer = target | |
if isinstance(target_base_layer, torch.nn.Embedding): | |
embedding_kwargs = kwargs.copy() | |
embedding_kwargs.pop("fan_in_fan_out", None) | |
embedding_kwargs.update(lora_config.loftq_config) | |
new_module = Embedding(target, adapter_name, **embedding_kwargs) | |
elif 'InflatedConv3d' in str(type(target_base_layer)): | |
kwargs.update(lora_config.loftq_config) | |
new_module = InflatedConv3d(target, adapter_name, **kwargs) | |
elif isinstance(target_base_layer, torch.nn.Conv2d): | |
kwargs.update(lora_config.loftq_config) | |
new_module = Conv2d(target, adapter_name, **kwargs) | |
elif isinstance(target_base_layer, torch.nn.Linear): | |
if kwargs["fan_in_fan_out"]: | |
warnings.warn( | |
"fan_in_fan_out is set to True but the target module is `torch.nn.Linear`. " | |
"Setting fan_in_fan_out to False." | |
) | |
kwargs["fan_in_fan_out"] = lora_config.fan_in_fan_out = False | |
kwargs.update(lora_config.loftq_config) | |
new_module = Linear(target, adapter_name, **kwargs) | |
elif isinstance(target_base_layer, Conv1D): | |
if not kwargs["fan_in_fan_out"]: | |
warnings.warn( | |
"fan_in_fan_out is set to False but the target module is `Conv1D`. " "Setting fan_in_fan_out to True." | |
) | |
kwargs["fan_in_fan_out"] = lora_config.fan_in_fan_out = True | |
kwargs.update(lora_config.loftq_config) | |
new_module = Linear(target, adapter_name, is_target_conv_1d_layer=True, **kwargs) | |
return new_module | |