Add LoraReduceRank

for testing
based on:
https://github.com/kohya-ss/sd-scripts/blob/main/networks/resize_lora.py
This commit is contained in:
kijai 2025-09-01 17:11:35 +03:00
parent ba9153cb06
commit d8b8c637fb
2 changed files with 360 additions and 0 deletions

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@ -212,6 +212,7 @@ NODE_CONFIG = {
#lora
"LoraExtractKJ": {"class": LoraExtractKJ, "name": "LoraExtractKJ"},
"LoraReduceRankKJ": {"class": LoraReduceRank, "name": "LoraReduceRank"}
}
def generate_node_mappings(node_config):

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@ -5,6 +5,7 @@ import folder_paths
import os
import logging
from tqdm import tqdm
import numpy as np
device = comfy.model_management.get_torch_device()
@ -190,3 +191,361 @@ NODE_CLASS_MAPPINGS = {
NODE_DISPLAY_NAME_MAPPINGS = {
"LoraExtractKJ": "LoraExtractKJ"
}
class LoraReduceRank:
def __init__(self):
self.output_dir = folder_paths.get_output_directory()
@classmethod
def INPUT_TYPES(s):
return {"required":
{
"lora_name": (folder_paths.get_filename_list("loras"), {"tooltip": "The name of the LoRA."}),
"new_rank": ("INT", {"default": 8, "min": 1, "max": 4096, "step": 1, "tooltip": "The new rank to resize the LoRA to when not using dynamic_method"}),
"dynamic_method": (["disabled", "sv_ratio", "sv_cumulative", "sv_fro"], {"default": "disabled", "tooltip": "Method to use for dynamically determining new alphas and dims"}),
"dynamic_param": ("FLOAT", {"default": 0.2, "min": 0.0, "max": 1.0, "step": 0.01, "tooltip": "Method to use for dynamically determining new alphas and dims"}),
"output_dtype": (["match_original", "fp16", "bf16", "fp32"], {"default": "match_original", "tooltip": "Data type to save the LoRA as."}),
"verbose": ("BOOLEAN", {"default": True}),
},
}
RETURN_TYPES = ()
FUNCTION = "save"
OUTPUT_NODE = True
EXPERIMENTAL = True
DESCRIPTION = "Resize a LoRA model by reducing it's rank. Based on kohya's sd-scripts: https://github.com/kohya-ss/sd-scripts/blob/main/networks/resize_lora.py"
CATEGORY = "KJNodes/lora"
def save(self, lora_name, new_rank, output_dtype, dynamic_method, dynamic_param, verbose):
lora_path = folder_paths.get_full_path("loras", lora_name)
lora_sd, metadata = comfy.utils.load_torch_file(lora_path, return_metadata=True)
if output_dtype == "fp16":
save_dtype = torch.float16
elif output_dtype == "bf16":
save_dtype = torch.bfloat16
elif output_dtype == "fp32":
save_dtype = torch.float32
elif output_dtype == "match_original":
first_weight_key = next(k for k in lora_sd if k.endswith(".weight") and isinstance(lora_sd[k], torch.Tensor))
save_dtype = lora_sd[first_weight_key].dtype
new_lora_sd = {}
for k, v in lora_sd.items():
new_lora_sd[k.replace(".default", "")] = v
del lora_sd
print("Resizing Lora...")
output_sd, old_dim, new_alpha, rank_list = resize_lora_model(new_lora_sd, new_rank, save_dtype, device, dynamic_method, dynamic_param, verbose)
# update metadata
if metadata is None:
metadata = {}
comment = metadata.get("ss_training_comment", "")
if dynamic_method == "disabled":
metadata["ss_training_comment"] = f"dimension is resized from {old_dim} to {new_rank}; {comment}"
metadata["ss_network_dim"] = str(new_rank)
metadata["ss_network_alpha"] = str(new_alpha)
else:
metadata["ss_training_comment"] = f"Dynamic resize with {dynamic_method}: {dynamic_param} from {old_dim}; {comment}"
metadata["ss_network_dim"] = "Dynamic"
metadata["ss_network_alpha"] = "Dynamic"
# cast to save_dtype before calculating hashes
for key in list(output_sd.keys()):
value = output_sd[key]
if type(value) == torch.Tensor and value.dtype.is_floating_point and value.dtype != save_dtype:
output_sd[key] = value.to(save_dtype)
output_filename_prefix = "loras/" + lora_name
full_output_folder, filename, counter, subfolder, filename_prefix = folder_paths.get_save_image_path(output_filename_prefix, self.output_dir)
output_dtype_str = f"_{output_dtype}" if output_dtype != "match_original" else ""
average_rank = str(int(np.mean(rank_list)))
rank_str = new_rank if dynamic_method == "disabled" else average_rank
output_checkpoint = f"{filename}_resized_from_{old_dim}_to_{rank_str}{output_dtype_str}_{counter:05}_.safetensors"
output_checkpoint = os.path.join(full_output_folder, output_checkpoint)
comfy.utils.save_torch_file(output_sd, output_checkpoint, metadata=metadata)
return {}
NODE_CLASS_MAPPINGS = {
"LoraExtractKJ": LoraExtractKJ
}
NODE_DISPLAY_NAME_MAPPINGS = {
"LoraExtractKJ": "LoraExtractKJ"
}
# 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
# This version is based on
# https://github.com/kohya-ss/sd-scripts/blob/main/networks/resize_lora.py
MIN_SV = 1e-6
LORA_DOWN_UP_FORMATS = [
("lora_down", "lora_up"), # sd-scripts LoRA
("lora_A", "lora_B"), # PEFT LoRA
("down", "up"), # ControlLoRA
]
# Indexing functions
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
index = max(1, min(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
index = max(1, min(index, len(S) - 1))
return index
def index_sv_ratio(S, target):
max_sv = S[0]
min_sv = max_sv / target
index = int(torch.sum(S > min_sv).item())
index = max(1, min(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()
if weight.dtype != torch.float32:
weight = weight.to(torch.float32)
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()
if weight.dtype != torch.float32:
weight = weight.to(torch.float32)
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
# Calculate new rank
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
new_rank = index_sv_ratio(S, dynamic_param) + 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) + 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) + 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 - 1]
return param_dict
def resize_lora_model(lora_sd, new_rank, save_dtype, device, dynamic_method, dynamic_param, verbose):
max_old_rank = None
new_alpha = None
verbose_str = "\n"
fro_list = []
rank_list = []
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
total_keys = len([k for k in lora_sd if k.endswith(".weight")])
pbar = comfy.utils.ProgressBar(total_keys)
for key, value in tqdm(lora_sd.items()):
key_parts = key.split(".")
block_down_name = None
for _format in LORA_DOWN_UP_FORMATS:
# Currently we only match lora_down_name in the last two parts of key
# because ("down", "up") are general words and may appear in block_down_name
if len(key_parts) >= 2 and _format[0] == key_parts[-2]:
block_down_name = ".".join(key_parts[:-2])
lora_down_name = "." + _format[0]
lora_up_name = "." + _format[1]
weight_name = "." + key_parts[-1]
break
if len(key_parts) >= 1 and _format[0] == key_parts[-1]:
block_down_name = ".".join(key_parts[:-1])
lora_down_name = "." + _format[0]
lora_up_name = "." + _format[1]
weight_name = ""
break
if block_down_name is None:
# This parameter is not lora_down
continue
# Now weight_name can be ".weight" or ""
# Find corresponding lora_up and alpha
block_up_name = block_down_name
lora_down_weight = value
lora_up_weight = lora_sd.get(block_up_name + lora_up_name + weight_name, None)
lora_alpha = lora_sd.get(block_down_name + ".alpha", None)
weights_loaded = lora_down_weight is not None and lora_up_weight is not None
if weights_loaded:
conv2d = len(lora_down_weight.size()) == 4
old_rank = lora_down_weight.size()[0]
max_old_rank = max(max_old_rank or 0, old_rank)
if lora_alpha is None:
scale = 1.0
else:
scale = lora_alpha / old_rank
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}"
print(verbose_str)
if verbose and dynamic_method:
verbose_str += f", dynamic | dim: {param_dict['new_rank']}, alpha: {param_dict['new_alpha']}\n"
else:
verbose_str += "\n"
new_alpha = param_dict["new_alpha"]
o_lora_sd[block_down_name + lora_down_name + weight_name] = param_dict["lora_down"].to(save_dtype).contiguous()
o_lora_sd[block_up_name + lora_up_name + weight_name] = param_dict["lora_up"].to(save_dtype).contiguous()
o_lora_sd[block_down_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
rank_list.append(param_dict["new_rank"])
del param_dict
pbar.update(1)
if verbose:
print(verbose_str)
print(f"Average Frobenius norm retention: {np.mean(fro_list):.2%} | std: {np.std(fro_list):0.3f}")
return o_lora_sd, max_old_rank, new_alpha, rank_list