RWKV-Runner/finetune/lora/merge_lora.py
2023-07-07 20:16:35 +08:00

69 lines
2.3 KiB
Python
Vendored

from collections import OrderedDict
import os
import sys
from typing import Dict
import typing
import torch
try:
if "-h" in sys.argv or "--help" in sys.argv:
print(
f"Usage: python3 {sys.argv[0]} [--use-gpu] <lora_alpha> <base_model.pth> <lora_checkpoint.pth> <output.pth>"
)
if sys.argv[1] == "--use-gpu":
device = "cuda"
lora_alpha, base_model, lora, output = (
float(sys.argv[2]),
sys.argv[3],
sys.argv[4],
sys.argv[5],
)
else:
device = "cpu"
lora_alpha, base_model, lora, output = (
float(sys.argv[1]),
sys.argv[2],
sys.argv[3],
sys.argv[4],
)
with torch.no_grad():
w: Dict[str, torch.Tensor] = torch.load(base_model, map_location="cpu")
# merge LoRA-only slim checkpoint into the main weights
w_lora: Dict[str, torch.Tensor] = torch.load(lora, map_location="cpu")
for k in w_lora.keys():
w[k] = w_lora[k]
output_w: typing.OrderedDict[str, torch.Tensor] = OrderedDict()
# merge LoRA weights
keys = list(w.keys())
for k in keys:
if k.endswith(".weight"):
prefix = k[: -len(".weight")]
lora_A = prefix + ".lora_A"
lora_B = prefix + ".lora_B"
if lora_A in keys:
assert lora_B in keys
print(f"merging {lora_A} and {lora_B} into {k}")
assert w[lora_B].shape[1] == w[lora_A].shape[0]
lora_r = w[lora_B].shape[1]
w[k] = w[k].to(device=device)
w[lora_A] = w[lora_A].to(device=device)
w[lora_B] = w[lora_B].to(device=device)
w[k] += w[lora_B] @ w[lora_A] * (lora_alpha / lora_r)
output_w[k] = w[k].to(device="cpu", copy=True)
del w[k]
del w[lora_A]
del w[lora_B]
continue
if "lora" not in k:
print(f"retaining {k}")
output_w[k] = w[k].clone()
del w[k]
torch.save(output_w, output)
except Exception as e:
with open("error.txt", "w") as f:
f.write(str(e))