File size: 5,191 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
# 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

from datasets import load_dataset


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",
    checkpoint_path: Optional[Path] = None,
    tokenizer_path: Path = Path("checkpoints/lit-llama/tokenizer.model"),
    model_size: str = "7B",
    dtype: str = "float32",
    quantize: Optional[str] = None,
) -> None:
    """Generates text samples based on a pre-trained LLaMA model and tokenizer.

    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"``.
        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.
    """
    if not checkpoint_path:
        checkpoint_path = Path(f"checkpoints/lit-llama/{model_size}/lit-llama.pth")
    assert checkpoint_path.is_file()
    assert tokenizer_path.is_file()

    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

    with EmptyInitOnDevice(
        device=fabric.device, dtype=dtype, quantization_mode=quantize
    ):
        print("Loading model ...", file=sys.stderr)
        t0 = time.time()
        model = LLaMA.from_name(model_size)
        checkpoint = torch.load(checkpoint_path)
        model.load_state_dict(checkpoint)
        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)
        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)