File size: 6,172 Bytes
7d52396
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
# This mimics GPTQ's evaluation metrics: https://github.com/IST-DASLab/gptq/
# Thanks to E. Frantar et al GPTQ: Accurate Post-training Compression for GPT, arXiv:2210.17323
import math
import sys
import time
from pathlib import Path
from typing import Optional

import lightning as L
import torch
import tqdm

# support running without installing as a package
wd = Path(__file__).parent.parent.resolve()
sys.path.append(str(wd))

from lit_llama import LLaMA, Tokenizer
from lit_llama.utils import EmptyInitOnDevice, lazy_load, llama_model_lookup
from lit_llama.lora import lora
from scripts.prepare_alpaca import generate_prompt

from datasets import load_dataset

instruction_tuning = True
lora_r = 8
lora_alpha = 16
lora_dropout = 0.05


def load_eval_data(dataset_name: str) -> str:
    # this mimics gptq datautils
    if dataset_name == "wikitext":
        # traindata = load_dataset('wikitext', 'wikitext-2-raw-v1', split='train')
        testdata = load_dataset("wikitext", "wikitext-2-raw-v1", split="test")
        testdata = "\n\n".join(testdata["text"])
    elif dataset_name == "ptb":
        testdata = load_dataset("ptb_text_only", "penn_treebank", split="test")
        testdata = "\n\n".join(testdata["sentence"])
    elif dataset_name == "c4":
        testdata = load_dataset(
            "allenai/c4",
            "allenai--c4",
            data_files={"validation": "en/c4-validation.00000-of-00008.json.gz"},
            split="validation",
        )
        testdata = " ".join(testdata[:1100]["text"])

    else:
        raise ValueError("invalid dataset name (wikitext, ptb, c4 are allowed)")
    return testdata


def main(
    datasets: str = "wikitext,ptb,c4",
    *,
    # compilation fails as it does not support torch.complex64 for RoPE
    # compile: bool = False,
    accelerator: str = "auto",
    lora_path: Path = Path("out/lora/alpaca/lit-llama-lora-finetuned.pth"),
    checkpoint_path: Path = Path("checkpoints/lit-llama/7B/lit-llama.pth"),
    tokenizer_path: Path = Path("checkpoints/lit-llama/tokenizer.model"),
    dtype: str = "float32",
    quantize: Optional[str] = None,
) -> None:
    """Generates text samples based on a pre-trained LLaMA model and tokenizer
       finetuned with LoRA.

    Args:
        datasets: The datasets to use as a comma separated string
        # compile: Whether to compile the model.
        accelerator: The hardware to run on. Possible choices are:
            ``"cpu"``, ``"cuda"``, ``"mps"``, ``"gpu"``, ``"tpu"``, ``"auto"``.
        lora_path: Path to the checkpoint with trained LoRA weights, which are the output of
            `finetune_lora.py`.
        checkpoint_path: The checkpoint path to load.
        tokenizer_path: The tokenizer path to load.
        dtype: The tensor dtype for choosing the floating-point precision 
        quantize: Whether to quantize the model and using which method:
            ``"llm.int8"``: LLM.int8() mode,
            ``"gptq.int4"``: GPTQ 4-bit mode.
    """
    assert lora_path.is_file()
    assert checkpoint_path.is_file()
    assert tokenizer_path.is_file()

    if quantize is not None:
        raise NotImplementedError("Quantization in LoRA is not supported yet")

    fabric = L.Fabric(accelerator=accelerator, devices=1)

    dt = getattr(torch, dtype, None)
    if not isinstance(dt, torch.dtype):
        raise ValueError(f"{dtype} is not a valid dtype.")
    dtype = dt

    print("Loading model ...", file=sys.stderr)
    t0 = time.time()

    with lazy_load(checkpoint_path) as pretrained_checkpoint, lazy_load(lora_path) as lora_checkpoint:
        name = llama_model_lookup(pretrained_checkpoint)

        with EmptyInitOnDevice(
                device=fabric.device, dtype=dtype, quantization_mode=quantize
        ), lora(r=lora_r, alpha=lora_alpha, dropout=lora_dropout, enabled=True):
            model = LLaMA.from_name(name)

            # 1. Load the pretrained weights
            model.load_state_dict(pretrained_checkpoint, strict=False)
            # 2. Load the fine-tuned lora weights
            model.load_state_dict(lora_checkpoint, strict=False)

    print(f"Time to load model: {time.time() - t0:.02f} seconds.", file=sys.stderr)

    model.eval()

    # if compile:
    #     model = torch.compile(model)

    total_toks = 0
    model = fabric.setup_module(model)

    tokenizer = Tokenizer(tokenizer_path)

    for dsname in datasets.split(","):
        test_string = load_eval_data(dsname)

        if instruction_tuning:
            sample = {"instruction": test_string, "input": input}
            test_string = generate_prompt(sample)
        
        encoded_text = tokenizer.encode(
            test_string, bos=True, eos=False, device=fabric.device
        )
        encoded_text = encoded_text[
            None, : 256 * model.config.block_size
        ]  # add batch dimension, trim like gptq implementation
        t0 = time.perf_counter()

        nlls = 0
        toks = 0
        with torch.inference_mode():
            block_size = 2048  # this is for compat with gptq, and indeed we get much worse beyond this (https://github.com/facebookresearch/llama/blob/57b0eb62de0636e75af471e49e2f1862d908d9d8/llama/model.py#L30)
            for i in tqdm.tqdm(range(0, encoded_text.shape[1], block_size)):
                inp = encoded_text[:, i : i + block_size]
                logits = model(inp)[0]
                nll = torch.nn.functional.cross_entropy(
                    logits[:-1], inp[0, 1:].to(dtype=torch.long), reduction="sum"
                )
                toks += inp.size(1) - 1
                nlls += nll.item()

        print(encoded_text.shape, logits.shape)
        ppl = math.exp(nlls / toks)
        print(f"Perplexity on {dsname}: {ppl:.2f}")
        total_toks += toks

    t = time.perf_counter() - t0
    print(
        f"\n\nTime for inference: {t:.02f} sec total, {total_toks / t:.02f} tokens/sec",
        file=sys.stderr,
    )
    print(
        f"Memory used: {torch.cuda.max_memory_reserved() / 1e9:.02f} GB",
        file=sys.stderr,
    )


if __name__ == "__main__":
    from jsonargparse import CLI

    torch.set_float32_matmul_precision("high")
    CLI(main)