llama.cpp/convert-ggml-to-pth.py
Justine Tunney 78ca9838ee Make loading weights 10-100x faster
This is a breaking change that's going to give you three benefits:

1. Your inference commands should load 100x faster
2. You may be able to safely load models 2x larger
3. You can run many concurrent inference processes

This was accomplished by changing the file format so we can mmap()
weights directly into memory without having to read() or copy them
thereby ensuring the kernel can make its file cache pages directly
accessible to our inference processes; and secondly, that the file
cache pages are much less likely to get evicted (which would force
loads to hit disk) because they're no longer competing with memory
pages that were needlessly created by gigabytes of standard i/o.

The new file format supports single-file models like LLaMA 7b, and
it also supports multi-file models like LLaMA 13B. Our Python tool
now merges the foo.1, foo.2, etc. files back into a single file so
that the C++ code which maps it doesn't need to reshape data every
time. That's made llama.cpp so much simpler. Much of its load code
has now been deleted.

Furthermore, this change ensures that tensors are aligned properly
on a 32-byte boundary. That opens the door to seeing if we can get
additional performance gains on some microprocessors, by using ops
that require memory alignment.

Lastly note that both POSIX and the Windows platform are supported

Fixes #91
2023-03-30 12:28:25 -07:00

299 lines
9.8 KiB
Python

# Author: github.com/ductai199x
import argparse
import os
import struct
import numpy as np
import torch
from numba import njit
from tqdm.auto import tqdm
def read_header(fin):
values = struct.unpack("i" * 9, fin.read(4 * 9))
_, _, vocab_size, dim, multiple_of, n_heads, n_layers, rot, ftype = values
return {
"vocab_size": vocab_size,
"dim": dim,
"multiple_of": multiple_of,
"n_heads": n_heads,
"n_layers": n_layers,
}, ftype
def read_tokens(fin, vocab_size):
tokens = []
for _ in range(vocab_size):
text_len = struct.unpack("i", fin.read(4))[0]
text_bytes = fin.read(text_len)
try:
text = text_bytes.decode("utf-8")
except UnicodeDecodeError:
text = text_bytes.decode("utf-8", "replace")
score = struct.unpack("f", fin.read(4))[0]
tokens.append((text, score))
return tokens
@njit
def dequantize_weights_numba(fin_data, n_rows, n_cols):
qk = 32
nb = n_cols // qk
bs = 4 + (qk // 2)
weights = np.zeros((n_rows, n_cols), dtype=np.float32)
data_pos = 0
for row in range(n_rows):
for block in range(nb):
d = np.frombuffer(fin_data[data_pos : data_pos + 4], dtype=np.float32)[0]
data_pos += 4
packed_values = fin_data[data_pos : data_pos + (qk // 2)]
data_pos += qk // 2
for i in range(qk // 2):
packed_value = packed_values[i]
v0 = np.float32((packed_value & 0b00001111) - 8) * d
v1 = np.float32((packed_value >> 4) - 8) * d
weights[row, block * qk + 2 * i] = v0
weights[row, block * qk + 2 * i + 1] = v1
return weights
def dequantize_weights(fin, n_rows, n_cols):
qk = 32
nb = n_cols // qk
data_size = n_rows * n_cols // 2 + n_rows * nb * 4
fin_data = fin.read(data_size)
return dequantize_weights_numba(fin_data, n_rows, n_cols)
def read_variables(fin):
model = {}
pbar = tqdm(total=os.path.getsize(fin.name), unit="B", unit_scale=True, desc="Reading variables")
while True:
start_pos = fin.tell()
try:
n_dims, name_length, ftype_cur = struct.unpack("iii", fin.read(4 * 3))
except struct.error:
break
shape = tuple(struct.unpack("i" * n_dims, fin.read(4 * n_dims)))
shape = shape[::-1]
name = fin.read(name_length).decode("utf-8")
# ensure tensor data is aligned
tensor_data_offset = fin.tell()
tensor_data_offset = (tensor_data_offset + 31) & -32
fin.seek(tensor_data_offset)
if ftype_cur == 2:
# 4-bit quantized weights
dtype = np.uint8
data = dequantize_weights(fin, shape[0], shape[1])
data = data.reshape(shape)
elif ftype_cur == 0:
dtype = np.float32
data_size = np.prod(shape)
data = np.fromfile(fin, dtype=dtype, count=data_size).reshape(shape)
elif ftype_cur == 1:
dtype = np.float16
data_size = np.prod(shape)
data = np.fromfile(fin, dtype=dtype, count=data_size).reshape(shape)
model[name] = torch.tensor(data, dtype=torch.float32 if dtype == np.float32 else torch.float16)
pbar.update(fin.tell() - start_pos)
return model
def convert_to_hf_format(model, hparams):
# This works for llama 7B, need to test with other models
n_layers = hparams["n_layers"]
n_heads = hparams["n_heads"]
dim = hparams["dim"]
dims_per_head = dim // n_heads
base = 10000.0
inv_freq = 1.0 / (base ** (torch.arange(0, dims_per_head, 2).float() / dims_per_head))
# permute for sliced rotary
def permute(w):
return w.view(n_heads, dim // n_heads // 2, 2, dim).transpose(1, 2).reshape(dim, dim)
state_dict = {}
for layer_i in range(n_layers):
state_dict.update(
{
f"model.layers.{layer_i}.self_attn.q_proj.weight": permute(
model[f"layers.{layer_i}.attention.wq.weight"]
),
f"model.layers.{layer_i}.self_attn.k_proj.weight": permute(
model[f"layers.{layer_i}.attention.wk.weight"]
),
f"model.layers.{layer_i}.self_attn.v_proj.weight": model[
f"layers.{layer_i}.attention.wv.weight"
],
f"model.layers.{layer_i}.self_attn.o_proj.weight": model[
f"layers.{layer_i}.attention.wo.weight"
],
f"model.layers.{layer_i}.mlp.gate_proj.weight": model[
f"layers.{layer_i}.feed_forward.w1.weight"
],
f"model.layers.{layer_i}.mlp.down_proj.weight": model[
f"layers.{layer_i}.feed_forward.w2.weight"
],
f"model.layers.{layer_i}.mlp.up_proj.weight": model[
f"layers.{layer_i}.feed_forward.w3.weight"
],
f"model.layers.{layer_i}.input_layernorm.weight": model[
f"layers.{layer_i}.attention_norm.weight"
],
f"model.layers.{layer_i}.post_attention_layernorm.weight": model[
f"layers.{layer_i}.ffn_norm.weight"
],
}
)
state_dict[f"model.layers.{layer_i}.self_attn.rotary_emb.inv_freq"] = inv_freq
state_dict.update(
{
"model.embed_tokens.weight": model["tok_embeddings.weight"],
"model.norm.weight": model["norm.weight"],
"lm_head.weight": model["output.weight"],
}
)
return state_dict
def chat(model, hparams, llama_dir):
from transformers import (GenerationConfig, LlamaForCausalLM,
LlamaTokenizer, StoppingCriteria,
StoppingCriteriaList)
from transformers.models.llama.configuration_llama import LlamaConfig
class StoppingCriteriaSub(StoppingCriteria):
def __init__(self):
super().__init__()
def __call__(self, input_ids: torch.LongTensor, scores: torch.FloatTensor, stops=[]):
print(tokenizer.decode(input_ids[0]), end="", flush=True)
if input_ids[0][-1] == 13:
return True
return False
config = LlamaConfig(
vocab_size=hparams["vocab_size"],
dim=hparams["dim"],
num_hidden_layers=hparams["n_layers"],
num_attention_heads=hparams["n_heads"],
)
llama = LlamaForCausalLM(config=config)
llama.load_state_dict(state_dict=model, strict=True)
tokenizer = LlamaTokenizer.from_pretrained(llama_dir)
device = torch.device("cpu")
llama = llama.to(device)
ctx = """You are AI.
This is a dialog, where User interacts with AI. AI is helpful, kind, obedient, honest, respectful, direct, concise, should try to protect User's privacy, and knows its own limits. Also, AI must answer User and AI cannot stop the conversation by itself.
User: Hello, AI.
AI: Hello! How can I assist you today?
"""
print(ctx.rstrip("\n"))
while True:
print("-" * 60)
prompt = input(f"User: ")
if ctx != "":
ctx = ctx + "User: " + prompt + "\n"
else:
ctx = prompt + "\nAI:"
ctx = (ctx[-1920:]) if len(ctx) >= 2048 else ctx
print("-" * 60)
if len(ctx.strip()) > 0:
input_ids = tokenizer(ctx, return_tensors="pt")["input_ids"].to(device)
generation_config = GenerationConfig(
temperature=0.8,
top_p=0.95,
top_k=50,
repetition_penalty=1.1764,
)
with torch.no_grad():
generation_output = llama.generate(
input_ids=input_ids,
generation_config=generation_config,
return_dict_in_generate=True,
output_scores=True,
max_length=2048,
do_sample=True,
stopping_criteria=StoppingCriteriaList([StoppingCriteriaSub()]),
)
s = generation_output.sequences[0]
decoded = tokenizer.decode(s)
ctx = decoded + "\n"
def main():
parser = argparse.ArgumentParser()
parser.add_argument(
"--input_dir", "-i", type=str, required=True, help="The input directory containing the ggml files."
)
parser.add_argument(
"--prefix",
"-p",
type=str,
required=True,
help="The prefix of the ggml files (ggml-model-f16 or ggml-model-q4_0).",
)
parser.add_argument(
"--hf",
action="store_true",
help="Whether to save the model in the huggingface format. (default: False)",
)
parser.add_argument(
"--chat", "-c", action="store_true", help="Whether to open a chat with the model. (default: False)"
)
args = parser.parse_args()
llama_dir = os.path.abspath(f"{args.input_dir}/../")
ggml_files = sorted(
[f"{args.input_dir}/{f}" for f in os.listdir(args.input_dir) if f.startswith(args.prefix)]
)
fin = open(ggml_files[0], "rb")
hparams, ftype = read_header(fin)
tokens = read_tokens(fin, hparams["vocab_size"])
model = read_variables(fin)
for f in tqdm(ggml_files[1:]):
fin = open(f, "rb")
read_header(fin)
read_tokens(fin, hparams["vocab_size"])
model.update(read_variables(fin))
if args.hf:
model = convert_to_hf_format(model, hparams)
pth_ckpt = {
"state_dict": model,
"hparams": hparams,
"tokens": tokens,
}
torch.save(pth_ckpt, f"{args.input_dir}/{args.prefix}-to-torch.pth")
if args.chat:
if not args.hf:
model = convert_to_hf_format(model, hparams)
chat(model, hparams, llama_dir)
if __name__ == "__main__":
main()