mlx-examples/llms/qwen/convert.py
Awni Hannun 3cf436b529
Quantize example (#162)
* testing quantization

* conversion + quantization working

* one config processor

* quantization in mistral / nits in llama

* args for quantization

* llama / mistral conversion in good shape

* phi2 quantized

* mixtral

* qwen conversion
2023-12-21 12:59:37 -08:00

111 lines
3.0 KiB
Python

import argparse
import copy
import json
from pathlib import Path
import mlx.core as mx
import mlx.nn as nn
import numpy as np
import torch
from mlx.utils import tree_flatten, tree_map, tree_unflatten
from qwen import ModelArgs, Qwen
from transformers import AutoModelForCausalLM
def replace_key(key: str) -> str:
if key.startswith("transformer."):
# remove transformer prefix
key = key.replace("transformer.", "")
return key
def quantize(weights, config, args):
quantized_config = copy.deepcopy(config)
# Load the model:
model_args = ModelArgs()
model_args.vocab_size = config["vocab_size"]
model_args.hidden_size = config["hidden_size"]
model_args.num_attention_heads = config["num_attention_heads"]
model_args.num_hidden_layers = config["num_hidden_layers"]
model_args.kv_channels = config["kv_channels"]
model_args.max_position_embeddings = config["max_position_embeddings"]
model_args.layer_norm_epsilon = config["layer_norm_epsilon"]
model_args.intermediate_size = config["intermediate_size"]
model_args.no_bias = config["no_bias"]
model = Qwen(model_args)
weights = tree_map(mx.array, weights)
model.update(tree_unflatten(list(weights.items())))
# Quantize the model:
nn.QuantizedLinear.quantize_module(model, args.q_group_size, args.q_bits)
# Update the config:
quantized_config["quantization"] = {
"group_size": args.q_group_size,
"bits": args.q_bits,
}
quantized_weights = dict(tree_flatten(model.parameters()))
return quantized_weights, quantized_config
def convert(args):
mlx_path = Path(args.mlx_path)
mlx_path.mkdir(parents=True, exist_ok=True)
model = AutoModelForCausalLM.from_pretrained(
args.model, trust_remote_code=True, torch_dtype=torch.float16
)
state_dict = model.state_dict()
weights = {replace_key(k): v.numpy() for k, v in state_dict.items()}
config = model.config.to_dict()
if args.quantize:
print("[INFO] Quantizing")
weights, config = quantize(weights, config, args)
np.savez(str(mlx_path / "weights.npz"), **weights)
# write config
with open(mlx_path / "config.json", "w") as f:
json.dump(config, f, indent=4)
if __name__ == "__main__":
parser = argparse.ArgumentParser(description="Convert Qwen model to npz")
parser.add_argument(
"--model",
help="The huggingface model to be converted",
default="Qwen/Qwen-1_8B",
)
parser.add_argument(
"--mlx-path",
type=str,
default="mlx_model",
help="The path to save the MLX model.",
)
parser.add_argument(
"-q",
"--quantize",
help="Generate a quantized model.",
action="store_true",
)
parser.add_argument(
"--q_group_size",
help="Group size for quantization.",
type=int,
default=64,
)
parser.add_argument(
"--q_bits",
help="Bits per weight for quantization.",
type=int,
default=4,
)
args = parser.parse_args()
convert(args)