cleanup the old multipack dataloader (#841)

This commit is contained in:
Wing Lian
2023-11-12 05:39:09 -05:00
committed by GitHub
parent 105d0b350b
commit 1a6309c8a6
4 changed files with 25 additions and 364 deletions

View File

@@ -11,7 +11,7 @@ from abc import abstractmethod
from dataclasses import dataclass, field
from functools import partial
from pathlib import Path
from typing import Optional, Union
from typing import Optional
import torch
import transformers
@@ -31,7 +31,6 @@ from axolotl.utils.callbacks import (
log_prediction_callback_factory,
)
from axolotl.utils.collators import BatchSamplerDataCollatorForSeq2Seq
from axolotl.utils.dataloader import MultipackDistributedDataloader
from axolotl.utils.samplers import MultipackBatchSampler
from axolotl.utils.schedulers import get_cosine_schedule_with_quadratic_warmup
@@ -215,9 +214,7 @@ class AxolotlTrainer(Trainer):
)
return super().get_train_dataloader()
def get_eval_dataloader(
self, eval_dataset: Optional[Dataset] = None
) -> Union[DataLoader, MultipackDistributedDataloader]:
def get_eval_dataloader(self, eval_dataset: Optional[Dataset] = None) -> DataLoader:
if self.args.sample_packing and self.args.eval_sample_packing is not False:
eval_dataset = (
eval_dataset if eval_dataset is not None else self.eval_dataset
@@ -260,7 +257,7 @@ class AxolotlTrainer(Trainer):
def get_bench_dataloader(
self,
bench_dataset: Dataset,
) -> Union[DataLoader, MultipackDistributedDataloader]:
) -> DataLoader:
dataloader_params = {
"batch_size": self.args.eval_batch_size,
"collate_fn": self.bench_data_collator,

View File

@@ -22,7 +22,13 @@ class PromptStyle(Enum):
CHATML = "chatml"
class AlpacaPrompter:
class Prompter:
"""
Base prompter class for all prompters
"""
class AlpacaPrompter(Prompter):
"""
Base class for alpaca prompters
"""
@@ -159,7 +165,7 @@ class NomicGPT4AllPrompter(AlpacaPrompter):
"""
class ReflectAlpacaPrompter:
class ReflectAlpacaPrompter(Prompter):
"""
Prompter for ReflectAlpaca
"""
@@ -254,7 +260,7 @@ SHAREGPT_ASSERTION_FAILED_ROLE = (
)
class ShareGPTPrompter: # pylint: disable=too-few-public-methods
class ShareGPTPrompter(Prompter): # pylint: disable=too-few-public-methods
"""
A prompter that generates prompts for the ShareGPT
"""
@@ -349,7 +355,7 @@ class ShareGPTPrompterV2(ShareGPTPrompter):
)
class UnsupportedPrompter:
class UnsupportedPrompter(Prompter):
"""
A dummy class for custom prompters
"""

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@@ -3,7 +3,7 @@ import functools
import hashlib
import logging
from pathlib import Path
from typing import Any, Dict, List, Tuple, Union
from typing import Dict, List, Tuple, Union
import torch
from datasets import (
@@ -34,6 +34,7 @@ from axolotl.prompters import (
JeopardyPrompter,
MultipleChoiceConcisePrompter,
MultipleChoiceExplainPrompter,
Prompter,
ReflectAlpacaPrompter,
SummarizeTLDRPrompter,
UnsupportedPrompter,
@@ -90,7 +91,7 @@ def prepare_dataset(cfg, tokenizer):
def load_tokenized_prepared_datasets(
tokenizer, cfg, default_dataset_prepared_path
) -> DatasetDict:
) -> Tuple[DatasetDict, List[Prompter]]:
tokenizer_name = tokenizer.__class__.__name__
ds_hash = str(
md5(
@@ -302,7 +303,7 @@ def load_prepare_datasets(
tokenizer: PreTrainedTokenizerBase,
cfg,
default_dataset_prepared_path,
) -> Tuple[Dataset, Dataset, List[Any]]:
) -> Tuple[Dataset, Dataset, List[Prompter]]:
max_packed_sequence_len = (
cfg.max_packed_sequence_len if cfg.max_packed_sequence_len else cfg.sequence_len
)
@@ -311,7 +312,7 @@ def load_prepare_datasets(
) # make sure we don't accidentally set it larger than sequence_len
tokenizer_name = tokenizer.__class__.__name__
prompters = []
prompters: List[Prompter] = []
if cfg.max_packed_sequence_len is not None:
# see if we can go ahead and load the stacked dataset
seed = f"@{str(cfg.seed)}" if cfg.seed else ""
@@ -445,14 +446,13 @@ def load_prepare_datasets(
train_fingerprint = md5(to_hash_train)
test_fingerprint = md5(to_hash_test)
with zero_first(is_main_process()):
dataset = dataset.train_test_split(
test_size=cfg.val_set_size,
shuffle=False,
seed=cfg.seed or 42,
train_new_fingerprint=train_fingerprint,
test_new_fingerprint=test_fingerprint,
)
dataset = dataset.train_test_split(
test_size=cfg.val_set_size,
shuffle=False,
seed=cfg.seed or 42,
train_new_fingerprint=train_fingerprint,
test_new_fingerprint=test_fingerprint,
)
train_dataset = dataset["train"]
eval_dataset = dataset["test"]

View File

@@ -1,342 +0,0 @@
# pylint: skip-file
import hashlib
import itertools
import logging
import math
import time
from queue import Queue
from threading import Thread
from typing import Any, Callable, List, Union
import numba
import numpy as np
from torch.utils.data import DistributedSampler, Sampler
LOG = logging.getLogger("axolotl.utils.dataloader")
@numba.njit
def ffd_check(a: np.ndarray, c: int, n: int):
# First-fit-decreasing bin packing
# Check if a[] could fit in n bins with capacity c
# https://en.wikipedia.org/wiki/First-fit-decreasing_bin_packing
a = np.sort(a)[::-1]
bins = np.full((n,), c, dtype=a.dtype)
for size in a:
not_found = True
for idx in range(n):
if bins[idx] >= size:
bins[idx] -= size
not_found = False
break
if not_found:
return False
return True
@numba.njit
def ffd_with_result(a: np.ndarray, c: int, start_index: int):
# First-fit-decreasing bin packing (with result return)
indices = np.argsort(a)[::-1]
a = a[indices]
bins: List[Any] = []
bins_result: List[Any] = []
for a_id, size in enumerate(a):
add_new = True
for idx in range(len(bins)):
if bins[idx] >= size:
bins[idx] -= size
bins_result[idx].append(indices[a_id] + start_index)
add_new = False
break
if add_new:
bins.append(c - size)
bins_result.append([indices[a_id] + start_index])
return bins_result, len(a)
@numba.njit
def allocate(
lengths: np.ndarray, lengths_cumsum: np.ndarray, rank: int, c: int, n: int
):
"""
:param lengths: array of lengths of each sample
:param lengths_cumsum: cumulative sum of consecutive lengths
:param rank: rank for this process
:param c: length of tokens per batch
:param n: number of ranks
:return:
"""
# Dynamic batch allocator, similar to Multifit
# https://en.wikipedia.org/wiki/Multifit_algorithm
# ~99.5% efficiency on OpenChat training set (12 * 2048 ctx len)
s = 0
start_index = 0
result = []
result_totseqs = []
while True:
# binary search [left, right)
left = 1
right = 1 + np.searchsorted(lengths_cumsum[start_index:], s + c * n, "right")
while right - left > 1:
mid = (left + right) // 2
if ffd_check(lengths[start_index : start_index + mid], c, n):
left = mid
else:
right = mid
# use length left
batch, tot_seqs = ffd_with_result(
lengths[start_index : start_index + left], c, start_index
)
if len(batch) < n:
break
start_index += left
s = lengths_cumsum[start_index - 1]
# add local rank
result.append(batch[rank])
# add total seqs for all ranks
result_totseqs.append(tot_seqs)
# yield batch[rank], tot_seqs, s, len(result) * c * n
return result, result_totseqs, s, len(result) * c * n
def chunk(iterable, n):
"""
Chunk data into tuples of length n
"""
# batched('ABCDEFG', 3) --> ABC DEF G
if n < 1:
raise ValueError("n must be at least one")
it = iter(iterable)
while batch := tuple(itertools.islice(it, n)):
yield batch
def hash_indices(lst: List[int]) -> str:
# Convert the list of integers to a string representation
concatenated = ",".join(map(str, lst))
# Generate the hash
sha256 = hashlib.sha256()
sha256.update(concatenated.encode())
return sha256.hexdigest()
class MultipackDistributedDataloader:
"""Unpadded data loading using Multipack.
Adapted from https://github.com/imoneoi/openchat/blob/v3_fix_mle_loss/ochat/training_deepspeed/multipack_dataloader.py
Approximate (at most ~1.22x) the optimal solution of the identical-machines scheduling problem, which is NP-hard.
"""
def __init__(
self,
dataset: Any,
collate_fn: Callable,
seq_max_length: int = 2048,
batch_size: int = 1,
sampler: Union[Sampler, DistributedSampler] = None,
packing_efficiency_estimate: float = 1.0,
sample_packing_seq_len_multiplier: int = 1,
device_count: int = 1,
prefetch_max: int = 1000,
num_epochs: int = 1,
):
# Dataset
self.dataset = dataset
self.lengths = (
dataset.data.column("position_ids")
.to_pandas()
.apply(lambda x: x[-1] + 1)
.values
)
assert isinstance(self.lengths, np.ndarray)
assert batch_size % sample_packing_seq_len_multiplier == 0
assert batch_size >= sample_packing_seq_len_multiplier
self.sampler = sampler
self.batch_size = batch_size
self.sample_packing_seq_len_multiplier = sample_packing_seq_len_multiplier
self.seq_max_length = seq_max_length
self.batch_max_length = batch_size * seq_max_length
self.collate_fn = collate_fn
self.num_epochs = num_epochs
self.num_replicas = 1
self.rank = 0
# statistics
self.eff_total_used = 0
self.eff_total_slots = 0
self.packing_efficiency_estimate = packing_efficiency_estimate or 1.0
self.device_count = device_count
# maxsize is maximum number of samples in queue
self.prefetch_max = prefetch_max
self.queue: Queue = Queue(maxsize=prefetch_max)
self.thread = None
def _worker(self):
LOG.info(
f"[WORKER] Epochs: {self.num_epochs}, Samples: {self.len_w_stats()*self.batch_size}"
)
for epoch in range(self.num_epochs):
for sample in self._internal_batch_generator():
while True:
if self.queue.full():
time.sleep(1)
else:
break
self.queue.put(sample)
# stop the queue when epoch is done
self.queue.put(None)
def __iter__(self):
if hasattr(self.sampler, "set_epoch"):
new_epoch = self.sampler.epoch + 1
self.sampler.set_epoch(new_epoch)
LOG.info(f"calling sampler.set_epoch({new_epoch})")
if self.thread is None:
self.thread = Thread(target=self._worker, daemon=True)
self.thread.start()
while True:
item = self.queue.get()
if item is None:
break
yield item
def generate_batches(self, set_stats=False):
LOG.info("generating packed batches")
if self.sampler:
indices = [idx for idx in self.sampler]
else:
indices = range(0, len(self.dataset))
LOG.info(hash_indices(indices))
lengths = self.lengths[indices]
lengths_cumsum = np.cumsum(lengths)
batches, totseqs, total_used, total_slots = allocate(
lengths=lengths,
lengths_cumsum=lengths_cumsum,
rank=self.rank,
# c=self.batch_max_length,
c=self.seq_max_length * self.sample_packing_seq_len_multiplier,
n=self.num_replicas,
)
batches = [[indices[b_idx] for b_idx in batch] for batch in batches]
# statistics
if set_stats:
self.eff_total_used += total_used
self.eff_total_slots += total_slots
return batches, totseqs
def _internal_batch_generator(self):
all_batches, _ = self.generate_batches(set_stats=True)
features = self.dataset.features.keys()
len_remaining = self._len_est()
for batches in chunk(
all_batches, self.batch_size // self.sample_packing_seq_len_multiplier
):
chunked_data = []
attn_mask_cum_idx = 0
for batch in batches:
concatenated = {}
batched_data = [self.dataset[batch_idx] for batch_idx in batch]
for feature in features:
if feature == "length":
continue
if feature == "attention_mask":
arrays = [
(attn_mask_cum_idx + idx + 1) * np.array(item[feature])
for idx, item in enumerate(batched_data)
if feature in item
]
attn_mask_cum_idx += len(batched_data)
concatenated[feature] = np.concatenate(arrays)
else:
arrays = [
np.array(item[feature])
for item in batched_data
if feature in item
]
concatenated[feature] = np.concatenate(arrays)
chunked_data.append(concatenated)
yield self.collate_fn(chunked_data)
len_remaining -= 1
if not len_remaining:
return
# yield a no-op for cases where we don't have any data left to pack
for i in range(0, len_remaining):
yield self.collate_fn(
[
{
"input_ids": [0],
"labels": [-100],
"attention_mask": [True],
"position_ids": [0],
}
]
)
def _len_est(self):
lengths_sum = np.sum(self.lengths)
lengths_sum_per_device = lengths_sum // self.device_count
LOG.info(
f"packing_efficiency_estimate: {self.packing_efficiency_estimate} "
f"total_num_tokens per device: {lengths_sum_per_device}"
)
# shave off 1% + 1 for dealing with variance in packing from random sampler to sampler
return (
math.floor(
0.99
* lengths_sum_per_device
/ self.packing_efficiency_estimate
// self.seq_max_length
// self.batch_size
)
- 1
)
def __len__(self):
# this doesn't return the actual length b/c with distributed samplers, not all dataloaders get
# the same share of total tokens
# if not self.eff_total_used:
# batches, _ = self.generate_batches(set_stats=True)
# LOG.info(
# f"packing_efficiency_estimate: {self.packing_efficiency_estimate} "
# f"actual packing efficiency: {self.efficiency()}"
# )
return max(1, self._len_est())
def len_w_stats(self):
if not self.eff_total_used:
batches, _ = self.generate_batches(set_stats=True)
LOG.info(
f"packing_efficiency_estimate: {self.packing_efficiency_estimate} "
f"actual packing efficiency: {self.efficiency()}"
)
return max(1, self._len_est())
def efficiency(self):
return self.eff_total_used / self.eff_total_slots