unsloth/unsloth/trainer.py
2026-05-06 07:22:56 +00:00

623 lines
22 KiB
Python

# Copyright 2023-present Daniel Han-Chen & the Unsloth team. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import logging
import os
import psutil
import warnings
from dataclasses import dataclass, field
from typing import Optional, List
from functools import wraps
import trl
import inspect
from trl import SFTTrainer
# why: bypass partially-initialised unsloth ns during _gpu_init load
from .models._utils import is_bfloat16_supported
from unsloth.utils import (
configure_padding_free,
configure_sample_packing,
enable_padding_free_metadata,
enable_sample_packing,
)
from unsloth_zoo.training_utils import (
unsloth_train as _unsloth_train,
)
from unsloth_zoo.vision_utils import (
UnslothVisionDataCollator,
)
from unsloth_zoo.hf_utils import get_transformers_model_type
from unsloth_zoo.utils import Version
import dataclasses
__all__ = [
"UnslothTrainingArguments",
"UnslothTrainer",
"unsloth_train",
"_patch_trl_trainer",
"UnslothVisionDataCollator",
"QGaloreConfig",
]
logger = logging.getLogger(__name__)
_AUTO_PADDING_FREE_ENV_DISABLED = os.environ.get(
"UNSLOTH_DISABLE_AUTO_PADDING_FREE", ""
).strip().lower() in {"1", "true", "yes", "on"}
PADDING_FREE_BLOCKLIST = {
"gemma2", # - gemma2: Uses slow_attention_softcapping which has torch.compile issues
"gpt_oss", # - gpt_oss: Uses Flex Attention which doesn't handle padding_free correctly
}
def _should_pack(config) -> bool:
if config is None or not getattr(config, "packing", False):
return False
return not getattr(config, "_unsloth_disable_auto_packing", False)
def _should_auto_padding_free(config) -> bool:
if (
config is None
or _AUTO_PADDING_FREE_ENV_DISABLED
or getattr(config, "packing", False)
):
return False
return getattr(config, "padding_free", None) is None
def _disable_sample_packing(config):
if config is None:
return
for attr, value in (("packing", False), ("padding_free", False)):
if hasattr(config, attr):
setattr(config, attr, value)
if hasattr(config, "remove_unused_columns"):
setattr(config, "remove_unused_columns", True)
setattr(config, "_unsloth_disable_auto_packing", True)
_AUTO_PACK_SKIP_MESSAGES = (
"packing is not supported",
"padding-free training",
"passing a custom data collator",
)
def _should_skip_auto_packing_error(exc: Exception) -> bool:
message = str(exc).lower()
return any(msg in message for msg in _AUTO_PACK_SKIP_MESSAGES)
# Unsloth gradient accumulation fix:
from transformers import __version__ as transformers_version, ProcessorMixin
if Version(transformers_version) > Version("4.45.2"):
def unsloth_train(trainer, *args, **kwargs):
return trainer.train(*args, **kwargs)
else:
def unsloth_train(trainer, *args, **kwargs):
if len(args) != 0 or len(kwargs) != 0:
raise RuntimeError(
"Unsloth: Our custom gradient accumulation fixed trainer does not support other arguments.\n"
"If you want to use our fix inside of HF, please update `transformers` to the latest version via:\n"
"`pip uninstall transformers -y && pip install --upgrade --no-cache-dir transformers`"
)
print(
"Unsloth: Using our custom gradient accumulation fixed trainer, which is not feature complete.\n"
"If you want to use our fix inside of HF, please update `transformers` to the latest version via:\n"
"`pip uninstall transformers -y && pip install --upgrade --no-cache-dir transformers`"
)
return _unsloth_train(trainer)
try:
from trl import SFTConfig as TrainingArguments
except:
from transformers import TrainingArguments
@dataclass
class QGaloreConfig:
"""Configuration for Q-GaLore optimizer integration.
Pass an instance of this class to ``UnslothTrainingArguments`` (via
``q_galore_config``) to enable Q-GaLore training.
"""
rank: int = 256
update_proj_gap: int = 200
scale: float = 0.25
proj_quant: bool = True
proj_quant_group_size: int = -1
proj_quant_n_bit: int = 4
weight_quant: bool = False
stochastic_round: bool = True
weight_group_size: int = 128
cos_threshold: float = 0.4
gamma_proj: float = 2.0
queue_size: int = 5
target_modules: Optional[List[str]] = None
class UnslothTrainingArguments(TrainingArguments):
def __init__(
self,
embedding_learning_rate: float = None,
q_galore_config: Optional[QGaloreConfig] = None,
*args,
**kwargs,
):
self.q_galore_config = q_galore_config
self.embedding_learning_rate = embedding_learning_rate
super().__init__(*args, **kwargs)
self.embedding_learning_rate = embedding_learning_rate
def _create_unsloth_optimizer(
model,
optimizer_cls,
optimizer_kwargs,
embedding_lr = 5e-5,
):
lr = optimizer_kwargs["lr"]
weight_decay = optimizer_kwargs.get("weight_decay", 0.0)
param_groups = {
"non_embeddings": {},
"embeddings": {},
}
for name, param in model.named_parameters():
if not param.requires_grad:
continue
if name.endswith("modules_to_save.default.weight"):
partial_name = name[: -len(".modules_to_save.default.weight")]
partial_name = partial_name[partial_name.rfind(".") + 1 :]
print(
f"Unsloth: Setting lr = {embedding_lr:.2e} instead of {lr:.2e} for {partial_name}."
)
param_groups["embeddings"][name] = param
else:
param_groups["non_embeddings"][name] = param
optimizer_grouped_parameters = [
{
"params": list(param_groups["non_embeddings"].values()),
"weight_decay": weight_decay,
"lr": lr,
},
{
"params": list(param_groups["embeddings"].values()),
"weight_decay": weight_decay,
"lr": embedding_lr,
},
]
optimizer = optimizer_cls(optimizer_grouped_parameters, **optimizer_kwargs)
return optimizer
class UnslothTrainer(SFTTrainer):
def create_optimizer(self):
# --- Q-GaLore optimizer ---
q_galore_config = getattr(self.args, "q_galore_config", None)
if q_galore_config is not None and self.optimizer is None:
embedding_lr = getattr(self.args, "embedding_learning_rate", None)
return self._create_q_galore_optimizer(q_galore_config, embedding_lr)
# --- Embedding-LR optimizer ---
embedding_learning_rate = getattr(self.args, "embedding_learning_rate", None)
if embedding_learning_rate is None:
return super().create_optimizer()
if self.optimizer is None:
optimizer_cls, optimizer_kwargs = SFTTrainer.get_optimizer_cls_and_kwargs(
self.args
)
self.optimizer = _create_unsloth_optimizer(
self.model,
optimizer_cls,
optimizer_kwargs,
embedding_learning_rate,
)
return self.optimizer
def _create_q_galore_optimizer(self, config: "QGaloreConfig", embedding_lr = None):
"""Build the Q-GaLore optimizer from a QGaloreConfig."""
from unsloth.optimizers.q_galore_adamw import (
QGaLoreAdamW8bit,
make_q_galore_param_groups,
install_weight_quant_hooks,
)
lr = self.args.learning_rate
weight_decay = self.args.weight_decay
param_groups = make_q_galore_param_groups(
self.model,
lr = lr,
weight_decay = weight_decay,
rank = config.rank,
update_proj_gap = config.update_proj_gap,
scale = config.scale,
proj_quant = config.proj_quant,
proj_quant_group_size = config.proj_quant_group_size,
proj_quant_n_bit = config.proj_quant_n_bit,
weight_quant = config.weight_quant,
stochastic_round = config.stochastic_round,
weight_group_size = config.weight_group_size,
cos_threshold = config.cos_threshold,
gamma_proj = config.gamma_proj,
queue_size = config.queue_size,
target_modules = config.target_modules,
)
# --- Split embedding params with custom LR (Fix #2) ---
if embedding_lr is not None:
# Build a fast param->name lookup (O(N) instead of O(N*M))
param_to_name = {id(p): name for name, p in self.model.named_parameters()}
new_groups = []
for group in param_groups:
if "rank" in group:
# GaLore group — keep as-is (embeddings are never in here)
new_groups.append(group)
continue
# Non-GaLore group: split out embedding params
embed_params = []
other_params = []
for p in group["params"]:
# Check if this param belongs to a modules_to_save embedding
name = param_to_name.get(id(p))
if name and name.endswith("modules_to_save.default.weight"):
partial_name = name[: -len(".modules_to_save.default.weight")]
partial_name = partial_name[partial_name.rfind(".") + 1 :]
print(
f"Unsloth: Setting lr = {embedding_lr:.2e} instead of {lr:.2e} for {partial_name}."
)
embed_params.append(p)
else:
other_params.append(p)
if other_params:
other_group = dict(group)
other_group["params"] = other_params
new_groups.append(other_group)
if embed_params:
embed_group = dict(group)
embed_group["params"] = embed_params
embed_group["lr"] = embedding_lr
new_groups.append(embed_group)
param_groups = new_groups
# --- Forward optimizer hyperparameters (Fix #3) ---
self.optimizer = QGaLoreAdamW8bit(
param_groups,
lr = lr,
weight_decay = weight_decay,
betas = (self.args.adam_beta1, self.args.adam_beta2),
eps = self.args.adam_epsilon,
)
# Initialize INT8 weight quantization if enabled
if config.weight_quant:
QGaLoreAdamW8bit.init_weight_quantization(
self.model,
param_groups,
group_size = config.weight_group_size,
stochastic = config.stochastic_round,
)
# Forward pre-hooks dequantize INT8 weights to float before each
# forward pass, allowing the optimizer to free float weight memory
# between steps.
install_weight_quant_hooks(self.model)
n_galore = sum(len(g["params"]) for g in param_groups if "rank" in g)
n_other = sum(len(g["params"]) for g in param_groups if "rank" not in g)
print(
f"🦥 Unsloth: Q-GaLore enabled — "
f"{n_galore} GaLore params (rank={config.rank}), "
f"{n_other} standard params."
)
return self.optimizer
# From `trl>=0.13.0`, they changed how to pass several params to the trainer
# We need to patch to make the transition smooth
def _resolve_trainer_params(trainer_class, init_fn):
"""Resolve the real named parameters for a trainer __init__.
Some TRL trainers (e.g., ORPOTrainer in TRL 0.27.1) are thin wrappers
with only ``def __init__(self, *args, **kwargs)``. For those, walk the
MRO and return the first parent class that has real named parameters.
"""
params = inspect.signature(init_fn).parameters
named = {
k
for k, v in params.items()
if v.kind
in (inspect.Parameter.POSITIONAL_OR_KEYWORD, inspect.Parameter.KEYWORD_ONLY)
and k != "self"
}
if named:
return set(params.keys())
# Thin wrapper detected - walk MRO for real signature
for cls in trainer_class.__mro__[1:]:
if cls is object:
continue
parent_init = cls.__dict__.get("__init__")
if parent_init is None:
continue
try:
parent_params = inspect.signature(parent_init).parameters
parent_named = {
k
for k, v in parent_params.items()
if v.kind
in (
inspect.Parameter.POSITIONAL_OR_KEYWORD,
inspect.Parameter.KEYWORD_ONLY,
)
and k != "self"
}
if parent_named:
return set(parent_params.keys())
except (ValueError, TypeError):
continue
return set(params.keys())
def _backwards_compatible_trainer(trainer_class, config_class):
original_init = trainer_class.__init__
@wraps(original_init)
def new_init(self, *args, **kwargs):
# All Trainer tokenizer are now called processing_class
trainer_params = _resolve_trainer_params(trainer_class, original_init)
if "processing_class" in trainer_params and "tokenizer" in kwargs:
kwargs["processing_class"] = kwargs.pop("tokenizer")
if ("args" in kwargs) and (Version(trl) >= Version("0.13.0.dev0")):
training_args = kwargs.pop("args", None)
# Get parameters that Trainer.__init__ actually expects
trainer_params.remove("self")
trainer_params.remove("args")
# Get fields that should be passed to Config init
config_fields = {
field.name: field
for field in dataclasses.fields(config_class)
if field.init
}
# Create config dict with valid fields from training_args
config_dict = {
name: getattr(training_args, name)
for name in config_fields
if hasattr(training_args, name)
}
# Get parameters that exist in Config but not in TrainingArguments
from transformers import TrainingArguments
moved_params = set(inspect.signature(config_class).parameters.keys()) - set(
inspect.signature(TrainingArguments).parameters.keys()
)
# Separate kwargs into trainer kwargs and config kwargs
trainer_kwargs = {}
additional_config_kwargs = {}
for key, value in kwargs.items():
if key in trainer_params:
trainer_kwargs[key] = value
elif key in moved_params or key in config_fields:
additional_config_kwargs[key] = value
else:
additional_config_kwargs[key] = value
# Update config_dict with additional kwargs
config_dict.update(additional_config_kwargs)
# Create Config with all the collected parameters
# Reinitialising config class with parameters (that were none initially but populated on first init)
# causes the 2nd init to fail as there are mutual exclusive checks on pairs of parameters.
# Refer: https://github.com/huggingface/trl/blob/main/trl/trainer/grpo_config.py#L499-L502 for example
# So we only create config class if the previous init was not TrainingArguments
if not isinstance(training_args, TrainingArguments):
config = config_class(**config_dict)
else:
config = training_args
# Reconstruct kwargs for Trainer
kwargs = trainer_kwargs
kwargs["args"] = config
original_init(self, *args, **kwargs)
return new_init
def _patch_sft_trainer_auto_packing(trl_module):
sft_trainer = getattr(trl_module, "SFTTrainer", None)
if sft_trainer is None:
return
if getattr(sft_trainer, "_unsloth_auto_packing_wrapped", False):
return
original_init = sft_trainer.__init__
@wraps(original_init)
def new_init(self, *args, **kwargs):
config_arg = None
if len(args) >= 2:
config_arg = args[1]
else:
config_arg = kwargs.get("args")
# Check if model type is unsupported for padding_free
model = kwargs.get("model")
is_unsupported_model = False
is_vlm = False
if model is not None:
model_config = getattr(model, "config", None)
if model_config is not None:
model_types = get_transformers_model_type(model_config)
# Blocklist: models that don't work correctly with padding_free
is_unsupported_model = any(
x in PADDING_FREE_BLOCKLIST for x in model_types
)
# Check if VLM
architectures = getattr(model_config, "architectures", None)
if architectures is None:
architectures = []
is_vlm = any(
x.endswith("ForConditionalGeneration") for x in architectures
)
is_vlm = is_vlm or hasattr(model_config, "vision_config")
processing_class = kwargs.get("processing_class") or kwargs.get("tokenizer")
data_collator = kwargs.get("data_collator")
# We also disable vision language models for padding free collators
blocked = (
(data_collator is not None)
or isinstance(processing_class, ProcessorMixin)
or is_vlm
or is_unsupported_model
or (
os.environ.get("UNSLOTH_RETURN_LOGITS", "0") == "1"
) # Disable padding free on forced logits
)
requested_pack = bool(getattr(config_arg, "packing", False))
if blocked:
if hasattr(config_arg, "packing"):
setattr(config_arg, "packing", False)
if hasattr(config_arg, "padding_free"):
setattr(config_arg, "padding_free", False)
if blocked and requested_pack:
reason = "custom data collator"
if data_collator is None and isinstance(processing_class, ProcessorMixin):
reason = "processor-based model"
elif is_vlm:
reason = "vision-language model"
elif is_unsupported_model:
reason = f"unsupported model type(s): {', '.join(model_types)}"
message = "Unsloth: Sample packing skipped " f"({reason} detected)."
print(message)
packing_active = False
if _should_pack(config_arg) and not blocked:
configure_sample_packing(config_arg)
packing_active = True
logger.info("Unsloth: Sample packing enabled for SFTTrainer instance.")
# Resolve padding_free: None (default) = auto-enable unless env-disabled or packing
auto_padding_free_active = False
padding_free_requested = getattr(config_arg, "padding_free", None) is True
if not blocked:
if padding_free_requested:
configure_padding_free(config_arg)
elif _should_auto_padding_free(config_arg):
configure_padding_free(config_arg)
auto_padding_free_active = True
logger.info(
"Unsloth: Padding-free batching auto-enabled for SFTTrainer instance."
)
try:
original_init(self, *args, **kwargs)
except ValueError as exc:
if packing_active and _should_skip_auto_packing_error(exc):
logger.info(
"Unsloth: Auto sample packing failed because trainer reported an incompatible setup (%s).",
exc,
)
_disable_sample_packing(config_arg)
packing_active = False
original_init(self, *args, **kwargs)
else:
raise
trainer_args = getattr(self, "args", None)
trainer_packing = bool(trainer_args and getattr(trainer_args, "packing", False))
trainer_padding_free = bool(
trainer_args and getattr(trainer_args, "padding_free", False)
)
if blocked and trainer_args is not None:
# Mirror the block on the trainer args to avoid re-enabling later
setattr(trainer_args, "packing", False)
setattr(trainer_args, "padding_free", False)
if (
not blocked
and trainer_packing
and (packing_active or _should_pack(trainer_args))
):
enable_sample_packing(self.model, self)
print(
"🦥 Unsloth: Packing enabled - training is >2x faster and uses less VRAM!"
)
elif not blocked and trainer_padding_free:
enable_padding_free_metadata(self.model, self)
message = (
"🦥 Unsloth: Padding-free auto-enabled, enabling faster training."
if auto_padding_free_active
else "🦥 Unsloth: Padding-free enabled, enabling faster training."
)
print(message)
sft_trainer.__init__ = new_init
sft_trainer._unsloth_auto_packing_wrapped = True
def _patch_trl_trainer():
import trl
if hasattr(trl, "__UNSLOTH_BACKWARDS_COMPATIBLE__"):
return
if Version(trl) <= Version("0.11.0"):
return
import trl.trainer
trl_classes = dir(trl.trainer)
trl_trainers = set(
x[: -len("Trainer")] for x in trl_classes if x.endswith("Trainer")
)
trl_configs = set(x[: -len("Config")] for x in trl_classes if x.endswith("Config"))
trl_classes = list(trl_trainers & trl_configs)
for x in trl_classes:
try:
exec(
f"trl.{x}Trainer.__init__ = _backwards_compatible_trainer(trl.{x}Trainer, trl.{x}Config)",
globals(),
)
except:
continue
_patch_sft_trainer_auto_packing(trl)
trl.__UNSLOTH_BACKWARDS_COMPATIBLE__ = True