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#based off https://github.com/catid/dora/blob/main/dora.py | |
import math | |
import torch | |
import torch.nn as nn | |
import torch.nn.functional as F | |
from typing import TYPE_CHECKING, Union, List | |
from optimum.quanto import QBytesTensor, QTensor | |
from toolkit.network_mixins import ToolkitModuleMixin, ExtractableModuleMixin | |
if TYPE_CHECKING: | |
from toolkit.lora_special import LoRASpecialNetwork | |
# diffusers specific stuff | |
LINEAR_MODULES = [ | |
'Linear', | |
'LoRACompatibleLinear' | |
# 'GroupNorm', | |
] | |
CONV_MODULES = [ | |
'Conv2d', | |
'LoRACompatibleConv' | |
] | |
def transpose(weight, fan_in_fan_out): | |
if not fan_in_fan_out: | |
return weight | |
if isinstance(weight, torch.nn.Parameter): | |
return torch.nn.Parameter(weight.T) | |
return weight.T | |
class DoRAModule(ToolkitModuleMixin, ExtractableModuleMixin, torch.nn.Module): | |
# def __init__(self, d_in, d_out, rank=4, weight=None, bias=None): | |
def __init__( | |
self, | |
lora_name, | |
org_module: torch.nn.Module, | |
multiplier=1.0, | |
lora_dim=4, | |
alpha=1, | |
dropout=None, | |
rank_dropout=None, | |
module_dropout=None, | |
network: 'LoRASpecialNetwork' = None, | |
use_bias: bool = False, | |
**kwargs | |
): | |
self.can_merge_in = False | |
"""if alpha == 0 or None, alpha is rank (no scaling).""" | |
ToolkitModuleMixin.__init__(self, network=network) | |
torch.nn.Module.__init__(self) | |
self.lora_name = lora_name | |
self.scalar = torch.tensor(1.0) | |
self.lora_dim = lora_dim | |
if org_module.__class__.__name__ in CONV_MODULES: | |
raise NotImplementedError("Convolutional layers are not supported yet") | |
if type(alpha) == torch.Tensor: | |
alpha = alpha.detach().float().numpy() # without casting, bf16 causes error | |
alpha = self.lora_dim if alpha is None or alpha == 0 else alpha | |
self.scale = alpha / self.lora_dim | |
# self.register_buffer("alpha", torch.tensor(alpha)) # 定数として扱える eng: treat as constant | |
self.multiplier: Union[float, List[float]] = multiplier | |
# wrap the original module so it doesn't get weights updated | |
self.org_module = [org_module] | |
self.dropout = dropout | |
self.rank_dropout = rank_dropout | |
self.module_dropout = module_dropout | |
self.is_checkpointing = False | |
d_out = org_module.out_features | |
d_in = org_module.in_features | |
std_dev = 1 / torch.sqrt(torch.tensor(self.lora_dim).float()) | |
# self.lora_up = nn.Parameter(torch.randn(d_out, self.lora_dim) * std_dev) # lora_A | |
# self.lora_down = nn.Parameter(torch.zeros(self.lora_dim, d_in)) # lora_B | |
self.lora_up = nn.Linear(self.lora_dim, d_out, bias=False) # lora_B | |
# self.lora_up.weight.data = torch.randn_like(self.lora_up.weight.data) * std_dev | |
self.lora_up.weight.data = torch.zeros_like(self.lora_up.weight.data) | |
# 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) | |
self.lora_down = nn.Linear(d_in, self.lora_dim, bias=False) # lora_A | |
# self.lora_down.weight.data = torch.zeros_like(self.lora_down.weight.data) | |
self.lora_down.weight.data = torch.randn_like(self.lora_down.weight.data) * std_dev | |
# m = Magnitude column-wise across output dimension | |
weight = self.get_orig_weight() | |
weight = weight.to(self.lora_up.weight.device, dtype=self.lora_up.weight.dtype) | |
lora_weight = self.lora_up.weight @ self.lora_down.weight | |
weight_norm = self._get_weight_norm(weight, lora_weight) | |
self.magnitude = nn.Parameter(weight_norm.detach().clone(), requires_grad=True) | |
def apply_to(self): | |
self.org_forward = self.org_module[0].forward | |
self.org_module[0].forward = self.forward | |
# del self.org_module | |
def get_orig_weight(self): | |
weight = self.org_module[0].weight | |
if isinstance(weight, QTensor) or isinstance(weight, QBytesTensor): | |
return weight.dequantize().data.detach() | |
else: | |
return weight.data.detach() | |
def get_orig_bias(self): | |
if hasattr(self.org_module[0], 'bias') and self.org_module[0].bias is not None: | |
return self.org_module[0].bias.data.detach() | |
return None | |
# def dora_forward(self, x, *args, **kwargs): | |
# lora = torch.matmul(self.lora_A, self.lora_B) | |
# adapted = self.get_orig_weight() + lora | |
# column_norm = adapted.norm(p=2, dim=0, keepdim=True) | |
# norm_adapted = adapted / column_norm | |
# calc_weights = self.magnitude * norm_adapted | |
# return F.linear(x, calc_weights, self.get_orig_bias()) | |
def _get_weight_norm(self, weight, scaled_lora_weight) -> torch.Tensor: | |
# calculate L2 norm of weight matrix, column-wise | |
weight = weight + scaled_lora_weight.to(weight.device) | |
weight_norm = torch.linalg.norm(weight, dim=1) | |
return weight_norm | |
def apply_dora(self, x, scaled_lora_weight): | |
# ref https://github.com/huggingface/peft/blob/1e6d1d73a0850223b0916052fd8d2382a90eae5a/src/peft/tuners/lora/layer.py#L192 | |
# lora weight is already scaled | |
# magnitude = self.lora_magnitude_vector[active_adapter] | |
weight = self.get_orig_weight() | |
weight = weight.to(scaled_lora_weight.device, dtype=scaled_lora_weight.dtype) | |
weight_norm = self._get_weight_norm(weight, scaled_lora_weight) | |
# 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() | |
dora_weight = transpose(weight + scaled_lora_weight, False) | |
return (self.magnitude / weight_norm - 1).view(1, -1) * F.linear(x.to(dora_weight.dtype), dora_weight) | |