Files
axolotl/tests/test_packed_batch_sampler.py
Dan Saunders 47e0e71bc8 don't sort multipack sampler (#2657)
* don't sort multipack sampler

* increased packing efficiency increases loss

---------

Co-authored-by: Wing Lian <wing@axolotl.ai>
2025-05-09 20:28:58 -04:00

110 lines
3.3 KiB
Python

"""Module for testing streaming dataset sequence packing"""
import pytest
from datasets import concatenate_datasets
from torch.utils.data import DataLoader, RandomSampler
from transformers import AutoTokenizer
from axolotl.datasets import TokenizedPromptDataset
from axolotl.prompt_strategies.completion import load
from axolotl.utils.collators import V2BatchSamplerDataCollatorForSeq2Seq
from axolotl.utils.data.utils import drop_long_seq_in_dataset
from axolotl.utils.dict import DictDefault
from axolotl.utils.samplers import MultipackBatchSampler, get_dataset_lengths
from tests.hf_offline_utils import enable_hf_offline
@pytest.fixture(name="tokenizer")
def fixture_tokenizer():
tokenizer = AutoTokenizer.from_pretrained("huggyllama/llama-7b")
tokenizer.pad_token = "</s>"
return tokenizer
class TestBatchedSamplerPacking:
"""
Test class for packing streaming dataset sequences
"""
@pytest.mark.parametrize(
"batch_size, num_workers",
[
(1, 0),
(2, 0),
(1, 2),
(2, 2),
],
)
@pytest.mark.parametrize("max_seq_length", [4096, 512])
@pytest.mark.parametrize("sequential", [True, False])
@enable_hf_offline
def test_packing(
self,
dataset_winglian_tiny_shakespeare,
batch_size,
num_workers,
tokenizer,
max_seq_length,
sequential,
):
import axolotl.monkeypatch.data.batch_dataset_fetcher # pylint: disable=unused-import # noqa: F401
dataset = dataset_winglian_tiny_shakespeare["train"]
cfg = DictDefault(
{
"train_on_inputs": True,
"sequence_len": max_seq_length,
}
)
ds_cfg = DictDefault(
{
"field": "text",
}
)
completion_strategy = load(tokenizer, cfg, ds_cfg)
dataset_wrapper = TokenizedPromptDataset(
completion_strategy,
dataset,
)
train_dataset = concatenate_datasets([dataset_wrapper])
train_dataset = drop_long_seq_in_dataset(train_dataset, cfg)
lengths = get_dataset_lengths(train_dataset)
batch_sampler = MultipackBatchSampler(
sampler=RandomSampler(train_dataset),
lengths=lengths,
batch_size=batch_size,
batch_max_len=max_seq_length,
group_size=100000,
bin_size=200,
sequential=sequential,
)
loader = DataLoader(
train_dataset,
batch_sampler=batch_sampler,
collate_fn=V2BatchSamplerDataCollatorForSeq2Seq( # pylint: disable=unexpected-keyword-arg
tokenizer=tokenizer,
padding=True,
pad_to_multiple_of=max_seq_length,
return_tensors="pt",
),
num_workers=num_workers,
)
batch_idxs = []
for batch in batch_sampler:
for pack in batch:
batch_idxs.extend(pack)
for batch in loader:
assert batch["input_ids"].numel() <= batch_size * max_seq_length
assert batch["input_ids"].shape[1] == max_seq_length
original_idxs = set(range(len(train_dataset)))
assert original_idxs == set(batch_idxs)
assert len(batch_idxs) == len(set(batch_idxs))