KohyaSS/networks/resize_lora.py
2023-03-10 11:44:52 -05:00

336 lines
12 KiB
Python

# Convert LoRA to different rank approximation (should only be used to go to lower rank)
# This code is based off the extract_lora_from_models.py file which is based on https://github.com/cloneofsimo/lora/blob/develop/lora_diffusion/cli_svd.py
# Thanks to cloneofsimo
import argparse
import torch
from safetensors.torch import load_file, save_file, safe_open
from tqdm import tqdm
from library import train_util, model_util
import numpy as np
MIN_SV = 1e-6
def load_state_dict(file_name, dtype):
if model_util.is_safetensors(file_name):
sd = load_file(file_name)
with safe_open(file_name, framework="pt") as f:
metadata = f.metadata()
else:
sd = torch.load(file_name, map_location='cpu')
metadata = None
for key in list(sd.keys()):
if type(sd[key]) == torch.Tensor:
sd[key] = sd[key].to(dtype)
return sd, metadata
def save_to_file(file_name, model, state_dict, dtype, metadata):
if dtype is not None:
for key in list(state_dict.keys()):
if type(state_dict[key]) == torch.Tensor:
state_dict[key] = state_dict[key].to(dtype)
if model_util.is_safetensors(file_name):
save_file(model, file_name, metadata)
else:
torch.save(model, file_name)
def index_sv_cumulative(S, target):
original_sum = float(torch.sum(S))
cumulative_sums = torch.cumsum(S, dim=0)/original_sum
index = int(torch.searchsorted(cumulative_sums, target)) + 1
if index >= len(S):
index = len(S) - 1
return index
def index_sv_fro(S, target):
S_squared = S.pow(2)
s_fro_sq = float(torch.sum(S_squared))
sum_S_squared = torch.cumsum(S_squared, dim=0)/s_fro_sq
index = int(torch.searchsorted(sum_S_squared, target**2)) + 1
if index >= len(S):
index = len(S) - 1
return index
# Modified from Kohaku-blueleaf's extract/merge functions
def extract_conv(weight, lora_rank, dynamic_method, dynamic_param, device, scale=1):
out_size, in_size, kernel_size, _ = weight.size()
U, S, Vh = torch.linalg.svd(weight.reshape(out_size, -1).to(device))
param_dict = rank_resize(S, lora_rank, dynamic_method, dynamic_param, scale)
lora_rank = param_dict["new_rank"]
U = U[:, :lora_rank]
S = S[:lora_rank]
U = U @ torch.diag(S)
Vh = Vh[:lora_rank, :]
param_dict["lora_down"] = Vh.reshape(lora_rank, in_size, kernel_size, kernel_size).cpu()
param_dict["lora_up"] = U.reshape(out_size, lora_rank, 1, 1).cpu()
del U, S, Vh, weight
return param_dict
def extract_linear(weight, lora_rank, dynamic_method, dynamic_param, device, scale=1):
out_size, in_size = weight.size()
U, S, Vh = torch.linalg.svd(weight.to(device))
param_dict = rank_resize(S, lora_rank, dynamic_method, dynamic_param, scale)
lora_rank = param_dict["new_rank"]
U = U[:, :lora_rank]
S = S[:lora_rank]
U = U @ torch.diag(S)
Vh = Vh[:lora_rank, :]
param_dict["lora_down"] = Vh.reshape(lora_rank, in_size).cpu()
param_dict["lora_up"] = U.reshape(out_size, lora_rank).cpu()
del U, S, Vh, weight
return param_dict
def merge_conv(lora_down, lora_up, device):
in_rank, in_size, kernel_size, k_ = lora_down.shape
out_size, out_rank, _, _ = lora_up.shape
assert in_rank == out_rank and kernel_size == k_, f"rank {in_rank} {out_rank} or kernel {kernel_size} {k_} mismatch"
lora_down = lora_down.to(device)
lora_up = lora_up.to(device)
merged = lora_up.reshape(out_size, -1) @ lora_down.reshape(in_rank, -1)
weight = merged.reshape(out_size, in_size, kernel_size, kernel_size)
del lora_up, lora_down
return weight
def merge_linear(lora_down, lora_up, device):
in_rank, in_size = lora_down.shape
out_size, out_rank = lora_up.shape
assert in_rank == out_rank, f"rank {in_rank} {out_rank} mismatch"
lora_down = lora_down.to(device)
lora_up = lora_up.to(device)
weight = lora_up @ lora_down
del lora_up, lora_down
return weight
def rank_resize(S, rank, dynamic_method, dynamic_param, scale=1):
param_dict = {}
if dynamic_method=="sv_ratio":
# Calculate new dim and alpha based off ratio
max_sv = S[0]
min_sv = max_sv/dynamic_param
new_rank = max(torch.sum(S > min_sv).item(),1)
new_alpha = float(scale*new_rank)
elif dynamic_method=="sv_cumulative":
# Calculate new dim and alpha based off cumulative sum
new_rank = index_sv_cumulative(S, dynamic_param)
new_rank = max(new_rank, 1)
new_alpha = float(scale*new_rank)
elif dynamic_method=="sv_fro":
# Calculate new dim and alpha based off sqrt sum of squares
new_rank = index_sv_fro(S, dynamic_param)
new_rank = min(max(new_rank, 1), len(S)-1)
new_alpha = float(scale*new_rank)
else:
new_rank = rank
new_alpha = float(scale*new_rank)
if S[0] <= MIN_SV: # Zero matrix, set dim to 1
new_rank = 1
new_alpha = float(scale*new_rank)
elif new_rank > rank: # cap max rank at rank
new_rank = rank
new_alpha = float(scale*new_rank)
# Calculate resize info
s_sum = torch.sum(torch.abs(S))
s_rank = torch.sum(torch.abs(S[:new_rank]))
S_squared = S.pow(2)
s_fro = torch.sqrt(torch.sum(S_squared))
s_red_fro = torch.sqrt(torch.sum(S_squared[:new_rank]))
fro_percent = float(s_red_fro/s_fro)
param_dict["new_rank"] = new_rank
param_dict["new_alpha"] = new_alpha
param_dict["sum_retained"] = (s_rank)/s_sum
param_dict["fro_retained"] = fro_percent
param_dict["max_ratio"] = S[0]/S[new_rank]
return param_dict
def resize_lora_model(lora_sd, new_rank, save_dtype, device, dynamic_method, dynamic_param, verbose):
network_alpha = None
network_dim = None
verbose_str = "\n"
fro_list = []
# Extract loaded lora dim and alpha
for key, value in lora_sd.items():
if network_alpha is None and 'alpha' in key:
network_alpha = value
if network_dim is None and 'lora_down' in key and len(value.size()) == 2:
network_dim = value.size()[0]
if network_alpha is not None and network_dim is not None:
break
if network_alpha is None:
network_alpha = network_dim
scale = network_alpha/network_dim
if dynamic_method:
print(f"Dynamically determining new alphas and dims based off {dynamic_method}: {dynamic_param}, max rank is {new_rank}")
lora_down_weight = None
lora_up_weight = None
o_lora_sd = lora_sd.copy()
block_down_name = None
block_up_name = None
with torch.no_grad():
for key, value in tqdm(lora_sd.items()):
if 'lora_down' in key:
block_down_name = key.split(".")[0]
lora_down_weight = value
if 'lora_up' in key:
block_up_name = key.split(".")[0]
lora_up_weight = value
weights_loaded = (lora_down_weight is not None and lora_up_weight is not None)
if (block_down_name == block_up_name) and weights_loaded:
conv2d = (len(lora_down_weight.size()) == 4)
if conv2d:
full_weight_matrix = merge_conv(lora_down_weight, lora_up_weight, device)
param_dict = extract_conv(full_weight_matrix, new_rank, dynamic_method, dynamic_param, device, scale)
else:
full_weight_matrix = merge_linear(lora_down_weight, lora_up_weight, device)
param_dict = extract_linear(full_weight_matrix, new_rank, dynamic_method, dynamic_param, device, scale)
if verbose:
max_ratio = param_dict['max_ratio']
sum_retained = param_dict['sum_retained']
fro_retained = param_dict['fro_retained']
if not np.isnan(fro_retained):
fro_list.append(float(fro_retained))
verbose_str+=f"{block_down_name:75} | "
verbose_str+=f"sum(S) retained: {sum_retained:.1%}, fro retained: {fro_retained:.1%}, max(S) ratio: {max_ratio:0.1f}"
if verbose and dynamic_method:
verbose_str+=f", dynamic | dim: {param_dict['new_rank']}, alpha: {param_dict['new_alpha']}\n"
else:
verbose_str+=f"\n"
new_alpha = param_dict['new_alpha']
o_lora_sd[block_down_name + "." + "lora_down.weight"] = param_dict["lora_down"].to(save_dtype).contiguous()
o_lora_sd[block_up_name + "." + "lora_up.weight"] = param_dict["lora_up"].to(save_dtype).contiguous()
o_lora_sd[block_up_name + "." "alpha"] = torch.tensor(param_dict['new_alpha']).to(save_dtype)
block_down_name = None
block_up_name = None
lora_down_weight = None
lora_up_weight = None
weights_loaded = False
del param_dict
if verbose:
print(verbose_str)
print(f"Average Frobenius norm retention: {np.mean(fro_list):.2%} | std: {np.std(fro_list):0.3f}")
print("resizing complete")
return o_lora_sd, network_dim, new_alpha
def resize(args):
def str_to_dtype(p):
if p == 'float':
return torch.float
if p == 'fp16':
return torch.float16
if p == 'bf16':
return torch.bfloat16
return None
if args.dynamic_method and not args.dynamic_param:
raise Exception("If using dynamic_method, then dynamic_param is required")
merge_dtype = str_to_dtype('float') # matmul method above only seems to work in float32
save_dtype = str_to_dtype(args.save_precision)
if save_dtype is None:
save_dtype = merge_dtype
print("loading Model...")
lora_sd, metadata = load_state_dict(args.model, merge_dtype)
print("Resizing Lora...")
state_dict, old_dim, new_alpha = resize_lora_model(lora_sd, args.new_rank, save_dtype, args.device, args.dynamic_method, args.dynamic_param, args.verbose)
# update metadata
if metadata is None:
metadata = {}
comment = metadata.get("ss_training_comment", "")
if not args.dynamic_method:
metadata["ss_training_comment"] = f"dimension is resized from {old_dim} to {args.new_rank}; {comment}"
metadata["ss_network_dim"] = str(args.new_rank)
metadata["ss_network_alpha"] = str(new_alpha)
else:
metadata["ss_training_comment"] = f"Dynamic resize with {args.dynamic_method}: {args.dynamic_param} from {old_dim}; {comment}"
metadata["ss_network_dim"] = 'Dynamic'
metadata["ss_network_alpha"] = 'Dynamic'
model_hash, legacy_hash = train_util.precalculate_safetensors_hashes(state_dict, metadata)
metadata["sshs_model_hash"] = model_hash
metadata["sshs_legacy_hash"] = legacy_hash
print(f"saving model to: {args.save_to}")
save_to_file(args.save_to, state_dict, state_dict, save_dtype, metadata)
if __name__ == '__main__':
parser = argparse.ArgumentParser()
parser.add_argument("--save_precision", type=str, default=None,
choices=[None, "float", "fp16", "bf16"], help="precision in saving, float if omitted / 保存時の精度、未指定時はfloat")
parser.add_argument("--new_rank", type=int, default=4,
help="Specify rank of output LoRA / 出力するLoRAのrank (dim)")
parser.add_argument("--save_to", type=str, default=None,
help="destination file name: ckpt or safetensors file / 保存先のファイル名、ckptまたはsafetensors")
parser.add_argument("--model", type=str, default=None,
help="LoRA model to resize at to new rank: ckpt or safetensors file / 読み込むLoRAモデル、ckptまたはsafetensors")
parser.add_argument("--device", type=str, default=None, help="device to use, cuda for GPU / 計算を行うデバイス、cuda でGPUを使う")
parser.add_argument("--verbose", action="store_true",
help="Display verbose resizing information / rank変更時の詳細情報を出力する")
parser.add_argument("--dynamic_method", type=str, default=None, choices=[None, "sv_ratio", "sv_fro", "sv_cumulative"],
help="Specify dynamic resizing method, --new_rank is used as a hard limit for max rank")
parser.add_argument("--dynamic_param", type=float, default=None,
help="Specify target for dynamic reduction")
args = parser.parse_args()
resize(args)