additional RL trainers SP support

* feat: improve visibility for merge doc

* feat: add tip on reuse config between modes

.github/workflows/main.yml

@@ -31,6 +31,11 @@ jobs:
             python_version: "3.11"
             pytorch: 2.7.0
             axolotl_extras:
+          - cuda: 128
+            cuda_version: 12.8.1
+            python_version: "3.11"
+            pytorch: 2.7.0
+            axolotl_extras:
     runs-on: axolotl-gpu-runner
     steps:
       - name: Checkout
@@ -94,6 +99,11 @@ jobs:
             python_version: "3.11"
             pytorch: 2.7.0
             axolotl_extras:
+          - cuda: 128
+            cuda_version: 12.8.1
+            python_version: "3.11"
+            pytorch: 2.7.0
+            axolotl_extras:
     runs-on: axolotl-gpu-runner
     steps:
       - name: Checkout

.github/workflows/tests.yml

@@ -295,6 +295,7 @@ jobs:
           find "$(pip cache dir)/http-v2" -type f -mtime +14 -exec rm {} \;
 
   docker-e2e-tests-1st:
+    # Run this job first as a gate for running the remainder of the test matrix
     if: ${{ ! contains(github.event.commits[0].message, '[skip e2e]') && github.repository_owner == 'axolotl-ai-cloud' }}
     # this job needs to be run on self-hosted GPU runners...
     runs-on: [self-hosted, modal]
@@ -341,6 +342,8 @@ jobs:
     # this job needs to be run on self-hosted GPU runners...
     runs-on: [self-hosted, modal]
     timeout-minutes: 90
+    # Only run the remainder of the matrix if the first e2e check passed;
+    # this is to save on wasted compute costs for known failures that get caught in the first run
     needs: [pre-commit, pytest, docker-e2e-tests-1st]
 
     strategy:
@@ -365,6 +368,12 @@ jobs:
             pytorch: 2.7.0
             num_gpus: 1
             axolotl_extras:
+          - cuda: 128
+            cuda_version: 12.8.1
+            python_version: "3.11"
+            pytorch: 2.7.0
+            num_gpus: 1
+            axolotl_extras:
     steps:
       - name: Checkout
         uses: actions/checkout@v4

_quarto.yml

@@ -139,7 +139,8 @@ quartodoc:
         - utils.optimizers.adopt
         - utils.data.pretraining
         - utils.data.sft
-        - utils.gradient_checkpointing.unsloth
+        - utils.gradient_checkpointing.offload_cpu
+        - utils.gradient_checkpointing.offload_disk
     - title: Schemas
       desc: Pydantic data models for Axolotl config
       contents:

docs/config.qmd

@@ -539,7 +539,7 @@ train_on_inputs: false
 # Note that training loss may have an oscillating pattern with this enabled.
 group_by_length: false
 
-# Whether to use gradient checkpointing. Available options are: true, false, "offload".
+# Whether to use gradient checkpointing. Available options are: true, false, "offload", "offload_disk".
 # https://huggingface.co/docs/transformers/v4.18.0/en/performance#gradient-checkpointing
 gradient_checkpointing: false
 # additional kwargs to pass to the trainer for gradient checkpointing

docs/getting-started.qmd

@@ -104,7 +104,7 @@ the `alpaca` dataset format, which has the following format:
 Please see our [Dataset Formats](dataset-formats) for more dataset formats and how to
 format them.
 
-2. Prepare your JSONL data in the specified format (in this case, the expected `alpaca
+2. Prepare your JSONL data in the specified format (in this case, the expected `alpaca`
 format):
 
 ```json
@@ -120,6 +120,12 @@ axolotl train my_training.yml
 
 ## Common Tasks {#sec-common-tasks}
 
+::: {.callout-tip}
+
+The same yaml file is used for training, inference, and merging.
+
+:::
+
 ### Testing Your Model {#sec-testing}
 
 After training, test your model:
@@ -128,6 +134,16 @@ After training, test your model:
 axolotl inference my_training.yml --lora-model-dir="./outputs/lora-out"
 ```
 
+More details can be found in [Inference](inference.qmd).
+
+### Using a UI {#sec-ui}
+
+Launch a Gradio interface:
+
+```bash
+axolotl inference my_training.yml --lora-model-dir="./outputs/lora-out" --gradio
+```
+
 ### Preprocessing Data {#sec-preprocessing}
 
 For large datasets, preprocess first:
@@ -136,14 +152,22 @@ For large datasets, preprocess first:
 axolotl preprocess my_training.yml
 ```
 
-### Using a UI {#sec-ui}
+Please make sure to set `dataset_prepared_path: ` in your config to set the path to save the prepared dataset.
 
-Launch a Gradio interface:
+More details can be found in [Dataset Preprocessing](dataset_preprocessing.qmd).
+
+### Merging LoRA weights {#sec-merging-lora}
+
+To merge the LoRA weights back into the base model, run:
 
 ```bash
-axolotl inference my_training.yml --lora-model-dir="./outputs/lora-out" --gradio
+axolotl merge-lora my_training.yml --lora-model-dir="./outputs/lora-out"
 ```
 
+The merged model will be saved in the `{output_dir}/merged` directory.
+
+More details can be found in [Merging LoRA weights](inference.qmd#sec-merging).
+
 ## Next Steps {#sec-next-steps}
 
 Now that you have the basics, you might want to:
@@ -156,6 +180,7 @@ Now that you have the basics, you might want to:
 Check our other guides for details on these topics:
 
 - [Configuration Guide](config.qmd) - Full configuration options
+- [Dataset Loading](dataset-loading.qmd) - Loading datasets from various sources
 - [Dataset Formats](dataset-formats) - Working with different data formats
 - [Multi-GPU Training](multi-gpu.qmd)
 - [Multi-Node Training](multi-node.qmd)

src/axolotl/cli/main.py

@@ -342,13 +342,6 @@ def delinearize_llama4(model: str, output: str) -> None:
     do_delinearize_llama4(model, output)
 
 
-@cli.command()
-def wizard():
-    from axolotl.cli.wizard import do_wizard
-
-    do_wizard()
-
-
 cli.add_command(lm_eval)
 
 

src/axolotl/cli/wizard.py

@@ -1,429 +0,0 @@
-"""Wizard for creating yaml configs."""
-
-import click
-import torch
-import yaml
-from packaging import version
-from transformers.training_args import OptimizerNames
-
-from axolotl.cli.art import print_axolotl_text_art
-from axolotl.utils.dict import DictDefault
-from axolotl.utils.models import load_model_config
-from axolotl.utils.schemas.enums import CustomSupportedOptimizers
-
-
-def do_wizard():
-    print_axolotl_text_art()
-
-    # Ask where to save the config
-    cfg = DictDefault({})
-    config_path = click.prompt(
-        "Where do you want to save the config?", type=str, default="config.yaml"
-    )
-
-    # Ask base model
-    base_model = click.prompt("What base model do you want to use?", type=str)
-    cfg["base_model"] = base_model.strip()
-
-    # Ask whether want to enable Vision model
-    # TODO: check if model has vision layers instead of asking user
-    train_vision_model = click.confirm(
-        "If this model has vision layers, do you want to train them?", default=False
-    )
-
-    if train_vision_model:
-        cfg["processor_type"] = "AutoProcessor"
-        cfg["skip_prepare_dataset"] = True
-        cfg["remove_unused_columns"] = False
-        cfg["sample_packing"] = False
-
-    # Ask whether they want to set any advanced model features (custom tokenizer, custom config, etc)
-    advanced_model_features = click.confirm(
-        "Do you want to set any advanced model features? (custom tokenizer, custom config, remote code etc)",
-        default=False,
-    )
-
-    if advanced_model_features:
-        # Ask whether they want to use a custom config
-        base_model_config = click.prompt(
-            "What model config do you want to use? (leave blank for default)",
-            type=str,
-            default="",
-        )
-
-        if base_model_config:
-            cfg["base_model_config"] = base_model_config
-
-        # Ask whether they want to use a specific revision of the model
-        revision_of_model = click.prompt(
-            "What revision of the model do you want to use? (leave blank for default)",
-            type=str,
-            default="",
-        )
-
-        if revision_of_model:
-            cfg["revision_of_model"] = revision_of_model
-
-        # Ask whether they want to use a custom tokenizer
-        tokenizer_config = click.prompt(
-            "What tokenizer do you want to use? (leave blank for default)",
-            type=str,
-            default="",
-        )
-
-        if tokenizer_config:
-            cfg["tokenizer_config"] = tokenizer_config
-
-        # Ask whether they want to use remote code
-        trust_remote_code = click.confirm(
-            "Do you want to use remote code?", default=False
-        )
-
-        if trust_remote_code:
-            cfg["trust_remote_code"] = trust_remote_code
-
-        # Whether to resize token embeddings
-        resize_token_embeddings_to_32x = click.confirm(
-            "Do you want to resize token embeddings to 32x?", default=False
-        )
-
-        if resize_token_embeddings_to_32x:
-            cfg["resize_token_embeddings_to_32x"] = resize_token_embeddings_to_32x
-
-        # Whether to shrink embeddings to len(tokenizer)
-        shrink_embeddings = click.confirm(
-            "Do you want to shrink embeddings to len(tokenizer)?", default=False
-        )
-
-        if shrink_embeddings:
-            cfg["shrink_embeddings"] = shrink_embeddings
-
-        # Whether to skip upcast embeddings
-        embeddings_skip_upcast = click.confirm(
-            "Do you want to skip upcast embeddings?", default=False
-        )
-
-        if embeddings_skip_upcast:
-            cfg["embeddings_skip_upcast"] = embeddings_skip_upcast
-
-        # Whether to random init weights
-        random_init_weights = click.confirm(
-            "Do you want to random init weights?", default=False
-        )
-
-        if random_init_weights:
-            cfg["random_init_weights"] = random_init_weights
-
-    # Get model type
-    config = load_model_config(cfg)
-    model_type = config.model_type
-
-    # Ask sequence length
-    sequence_length = click.prompt("What sequence length do you want to use?", type=int)
-    cfg["sequence_length"] = sequence_length
-
-    # Whether to turn on sample packing
-    if cfg["sample_packing"] is None:
-        cfg["sample_packing"] = click.confirm(
-            "Do you want to turn on sample packing? This will speed up training by packing multiple samples into a single batch.",
-            default=True,
-        )
-
-        if cfg["sample_packing"]:
-            cfg["pad_to_sequence_len"] = True
-
-        # Whether to turn off eval sample packing
-        no_eval_sample_packing = click.confirm(
-            "Do you want to turn off eval sample packing? This will slow down evaluation but is recommended if you are using a small validation set.",
-            default=False,
-        )
-
-        if no_eval_sample_packing:
-            cfg["eval_sample_packing"] = False
-
-    # Hardware check
-    try:
-        is_ampere_or_newer = torch.cuda.get_device_capability()[0] >= 8
-    except RuntimeError:
-        is_ampere_or_newer = False
-    except AssertionError:  # this is raised if no cuda is available
-        is_ampere_or_newer = False
-
-    # Get num gpus
-    try:
-        num_gpus = torch.cuda.device_count()
-    except RuntimeError:
-        num_gpus = 0
-
-    # Get torch version
-    torch_version = str(torch.__version__).split("+", maxsplit=1)[0]
-
-    is_torch_2_6_or_newer = version.parse(torch_version) >= version.parse("2.6.0")
-
-    # Whether to turn on attention
-    opt = ["xformers", "sdp"]
-
-    if is_ampere_or_newer:
-        opt.append("flash")
-
-    if is_torch_2_6_or_newer:
-        opt.append("flex")
-
-    if cfg["sample_packing"]:
-        if "flash" in opt:
-            default_opt = "flash"
-        elif "flex" in opt:
-            default_opt = "flex"
-        else:
-            default_opt = opt[0]
-
-        attention = click.prompt(
-            "Which attention backend do you want to use? Sample packing requires an attention backend to be set.",
-            type=click.Choice(opt),
-            default=default_opt,
-        )
-    else:
-        # non-sample packing supports no attention and S2
-        opt.extend(["none", "s2"])
-
-        attention = click.prompt(
-            "Which attention backend do you want to use?",
-            type=click.Choice(opt),
-            default="none",
-        )
-
-        if attention == "none":
-            attention = None
-
-    # TODO: if xformers, check if FA is installed
-    # TODO: flex doc mentioned requiring seq len to be divisible by 128. Unclear if limitation still exists
-
-    # TODO: requires #2489
-    cfg["attention"] = attention
-
-    # Whether to turn on gradient checkpointing
-    # TODO: need to wait for offload_disk PR to be merged
-    gradient_checkpointing = click.prompt(
-        "Which gradient checkpointing strategy do you want to use?",
-        type=click.Choice(["none", "true", "offload", "offload_disk"]),
-        default="true",
-    )
-
-    if gradient_checkpointing == "none":
-        gradient_checkpointing = False
-    elif gradient_checkpointing == "true":
-        gradient_checkpointing = True
-
-    # Ask whether to set use_reentrant
-    # TODO: get correct defaults based on SFT/RL mode and single/multigpu
-    # use_reentrant = click.confirm(
-    #     "Do you want to set use_reentrant?",
-    #     default=True,
-    # )
-
-    # if use_reentrant:
-    #     cfg["use_reentrant"] = use_reentrant
-
-    # Optimizer
-    cfg["optimizer"] = click.prompt(
-        "Which optimizer do you want to use?",
-        type=click.Choice((OptimizerNames | CustomSupportedOptimizers)),
-        default=OptimizerNames.ADAMW_TORCH_FUSED,
-    )
-
-    cfg["lr_scheduler"] = click.prompt(
-        "Which learning rate scheduler do you want to use?",
-        type=click.Choice(
-            [
-                "cosine",
-                "one_cycle",
-                "rex",
-                "log_sweep",
-                "linear",
-                "cosine_with_restarts",
-                "polynomial",
-                "constant",
-                "constant_with_warmup",
-                "inverse_sqrt",
-                "reduce_lr_on_plateau",
-                "cosine_with_min_lr",
-                "warmup_stable_decay",
-            ]
-        ),
-        default="cosine",
-    )
-
-    # Plugins
-
-    cfg["plugins"] = []
-
-    # Whether to turn on cut cross entropy
-    if is_ampere_or_newer:
-        # Note: This may error if users don't have CCE installed
-        from axolotl.integrations.cut_cross_entropy.monkeypatch.patch import (
-            CUT_CROSS_ENTROPY_MODEL_MAPPING,
-        )
-
-        if model_type in CUT_CROSS_ENTROPY_MODEL_MAPPING:
-            cut_cross_entropy = click.confirm(
-                "Do you want to turn on cut cross entropy? This will save VRAM if the model has a large vocab size.",
-                default=True,
-            )
-
-            if cut_cross_entropy:
-                cfg["plugins"].append(
-                    "axolotl.integrations.cut_cross_entropy.CutCrossEntropyPlugin"
-                )
-
-                cfg["cut_cross_entropy"] = True
-
-    use_liger_kernel = click.confirm(
-        "Do you want to use the liger kernel? This will speed up training and save VRAM.",
-        default=True,
-    )
-
-    if use_liger_kernel:
-        cfg["plugins"].append("axolotl.integrations.liger.LigerPlugin")
-
-        cfg["liger_rope"] = click.confirm(
-            "Do you want to enable liger rope?",
-            default=True,
-        )
-
-        cfg["liger_rms_norm"] = click.confirm(
-            "Do you want to enable liger rms norm?",
-            default=True,
-        )
-
-        cfg["liger_glu_activation"] = click.confirm(
-            "Do you want to enable liger glu activation?",
-            default=True,
-        )
-
-        cfg["liger_layer_norm"] = click.confirm(
-            "Do you want to enable liger layer norm?",
-            default=True,
-        )
-
-        if cfg["cut_cross_entropy"] is not True:
-            cfg["liger_fused_linear_cross_entropy"] = click.confirm(
-                "Do you want to enable liger fused linear cross entropy?",
-                default=True,
-            )
-
-    # TODO: lora kernels (but they auto enable via validator already)
-
-    # TODO: is there incompat between torch compile and liger?
-    cfg["torch_compile"] = click.confirm(
-        "Do you want to enable torch compile?",
-        default=True,
-    )
-
-    # Multi-gpu
-    if num_gpus > 1:
-        # Ask whether to use DDP/Deepspeed/FSDP
-        multi_gpu_mode = click.prompt(
-            "Which multi-gpu mode do you want to use?",
-            type=click.Choice(["ddp", "deepspeed", "fsdp"]),
-            default="ddp",
-        )
-
-        if multi_gpu_mode == "deepspeed":
-            # Ask which deepspeed config to use
-            cfg["deepspeed"] = click.prompt(
-                "Which deepspeed config do you want to use? The higher the number, the more VRAM you will save, but the slower it will run.",
-                type=click.Choice(
-                    [
-                        "zero1.json",
-                        "zero1_torch_compile.json",
-                        "zero2.json",
-                        "zero3.json",
-                        "zero3_bf16.json",
-                        "zero3_bf16_cpuoffload_all.json",
-                        "zero3_bf16_cpuoffload_params.json",
-                    ]
-                ),
-                default="zero1.json",
-            )
-        elif multi_gpu_mode == "fsdp":
-            fsdp_version = click.prompt(
-                "Which fsdp version do you want to use?",
-                type=click.Choice([1, 2]),
-                default=2,
-            )
-
-            # TODO: Handle FSDP config
-
-            if fsdp_version == 1:
-                cfg["fsdp"] = ["full_shard", "auto_wrap"]
-
-                # Ask which state dict type to use
-                fsdp_state_dict_type = click.prompt(
-                    "Which fsdp state dict type do you want to use?",
-                    type=click.Choice(["FULL_STATE_DICT", "SHARDED_STATE_DICT"]),
-                    default="FULL_STATE_DICT",
-                )
-
-                fsdp_offload_params = click.confirm(
-                    "Do you want to offload parameters?",
-                    default=True,
-                )
-
-                # TODO: can we load the model class and auto pull a default for this?
-                fsdp_transformer_layer_cls_to_wrap = click.prompt(
-                    "Which transformer layer class to wrap? It is usually the Decoder layer class.",
-                    type=str,
-                )
-
-                # TODO: add other options
-
-                cfg["fsdp_config"] = {
-                    "state_dict_type": fsdp_state_dict_type,
-                    "offload_params": fsdp_offload_params,
-                    "transformer_layer_cls_to_wrap": fsdp_transformer_layer_cls_to_wrap,
-                }
-
-            elif fsdp_version == 2:
-                raise NotImplementedError()
-
-    # Training mode (sft or rl)
-    training_mode = click.prompt(
-        "Which training mode do you want to use?",
-        type=click.Choice(["sft", "rl"]),
-        default="sft",
-    )
-
-    if training_mode == "rl":
-        cfg["rl"] = click.prompt(
-            "Which rl mode do you want to use?",
-            type=click.Choice(["dpo", "ipo", "orpo", "kto", "grpo", "simpo"]),
-        )
-
-        # TODO: handle RL options
-
-    # Whether to use adapter
-
-    # Get batch/grad accu
-
-    # Get learning rate
-
-    # Get weight decay
-
-    # Get max grad norm
-
-    # Get num train epochs
-
-    # Get warmup ratio
-
-    # Get save ratio
-
-    # Get eval ratio
-
-    # Get dataset config
-
-    # Load metric tracker
-
-    # Save config to yaml
-    # TODO: improve output yaml formatting. Need to add comments to help separate sections
-    with open(config_path, "w", encoding="utf-8") as f:
-        yaml.dump(cfg.to_dict(), f, sort_keys=False)

src/axolotl/core/trainers/base.py

@@ -156,6 +156,9 @@ class AxolotlTrainer(
         Helper method to get the sampler for evaluation. Handles sequence parallelism
         and sample packing cases.
 
+        Args:
+            eval_dataset: Evaluation dataset.
+
         Returns:
             If the dataset is non-empty, a sampler is returned, the type of which
                 depends on the passed training args.
@@ -237,9 +240,6 @@ class AxolotlTrainer(
             self.accelerator.even_batches = False
 
         # Return unprepared dataloader if using sequence parallelism
-        # TODO(djsaunde): We might be able to use `accelerate`'s dataloader preparation
-        # if we use `dispatch_batches` and `slice_fn_for_dispatch` properly (i.e.,
-        # slice each batch along the sequence dimension).
         if self.args.sequence_parallel_degree > 1:
             return dataloader
 

src/axolotl/core/trainers/dpo/trainer.py

@@ -1,33 +1,25 @@
-"""
+"""DPO trainer for Axolotl"""
-DPO trainer for axolotl
-"""
 
 import gc
-import random
 from functools import wraps
-from typing import Any, Dict, Optional, Union
+from typing import Any, Dict, Union
 
-import pandas as pd
 import torch
-import wandb
+from datasets import Dataset
-from accelerate import PartialState
-from datasets import Dataset, IterableDataset
 from peft.optimizers import create_loraplus_optimizer
 from torch import nn
-from torch.utils.data import DataLoader
+from torch.utils.data import Sampler
 from transformers import (
-    BaseImageProcessor,
-    FeatureExtractionMixin,
-    PreTrainedTokenizerBase,
-    ProcessorMixin,
     Trainer,
 )
-from transformers.trainer_utils import EvalLoopOutput
 from transformers.utils import is_sagemaker_mp_enabled
-from trl import DPOConfig, DPOTrainer, maybe_apply_chat_template, maybe_extract_prompt
+from trl import DPOTrainer
-from trl.trainer.utils import log_table_to_comet_experiment
 
-from axolotl.core.trainers.mixins import RngLoaderMixin, SchedulerMixin
+from axolotl.core.trainers.mixins import (
+    RngLoaderMixin,
+    SchedulerMixin,
+    SequenceParallelMixin,
+)
 from axolotl.core.trainers.utils import (
     sanitize_kwargs_for_ds_tagging,
     sanitize_kwargs_for_tagging,
@@ -37,10 +29,10 @@ if is_sagemaker_mp_enabled():
     import smdistributed.modelparallel.torch as smp
 
 
-class AxolotlDPOTrainer(RngLoaderMixin, SchedulerMixin, DPOTrainer):
+class AxolotlDPOTrainer(
-    """
+    RngLoaderMixin, SchedulerMixin, SequenceParallelMixin, DPOTrainer
-    Extend the base DPOTrainer for axolotl helpers
+):
-    """
+    """Extend the base DPOTrainer for axolotl helpers"""
 
     tag_names = ["axolotl", "dpo"]
 
@@ -95,64 +87,6 @@ class AxolotlDPOTrainer(RngLoaderMixin, SchedulerMixin, DPOTrainer):
 
         return super().push_to_hub(*args, **kwargs)
 
-    # TODO: remove this once https://github.com/huggingface/trl/pull/3377 is in a release
-    def _prepare_dataset(
-        self,
-        dataset: Union[Dataset, IterableDataset],
-        processing_class: Union[
-            PreTrainedTokenizerBase,
-            BaseImageProcessor,
-            FeatureExtractionMixin,
-            ProcessorMixin,
-        ],
-        args: DPOConfig,
-        dataset_name: str,
-    ) -> Union[Dataset, IterableDataset]:
-        # Build the kwargs for the `map` function
-        map_kwargs: Dict[str, Any] = {"writer_batch_size": 10}
-        if isinstance(dataset, Dataset):  # IterableDataset does not support num_proc
-            map_kwargs["num_proc"] = args.dataset_num_proc
-
-        with PartialState().main_process_first():
-            # Extract prompt if needed
-            if isinstance(
-                dataset, Dataset
-            ):  # `IterableDataset.map` does not support `desc`
-                map_kwargs["desc"] = f"Extracting prompt in {dataset_name} dataset"
-            dataset = dataset.map(maybe_extract_prompt, **map_kwargs)
-
-            # Apply the chat template if needed
-            if isinstance(
-                dataset, Dataset
-            ):  # `IterableDataset.map` does not support `desc`
-                map_kwargs["desc"] = f"Applying chat template to {dataset_name} dataset"
-            dataset = dataset.map(
-                maybe_apply_chat_template,
-                fn_kwargs={"tokenizer": processing_class, "tools": args.tools},
-                **map_kwargs,
-            )
-
-            # Tokenize the dataset
-            if isinstance(
-                dataset, Dataset
-            ):  # `IterableDataset.map` does not support `desc`
-                map_kwargs["desc"] = f"Tokenizing {dataset_name} dataset"
-
-            dataset = dataset.map(
-                self.tokenize_row if not self.is_vision_model else self.process_row,
-                remove_columns=["chosen", "rejected"],
-                fn_kwargs={
-                    "processing_class": processing_class,
-                    "max_prompt_length": args.max_prompt_length,
-                    "max_completion_length": args.max_completion_length,
-                    # for enc-dec, we add the special tokens ([bos_token] + prompt + [eos_token]; completion + [eos_token])
-                    "add_special_tokens": False,
-                },
-                **map_kwargs,
-            )
-
-        return dataset
-
     @staticmethod
     def tokenize_row(
         features,
@@ -193,68 +127,48 @@ class AxolotlDPOTrainer(RngLoaderMixin, SchedulerMixin, DPOTrainer):
         torch.cuda.empty_cache()
         return loss
 
-    # TODO: remove this once https://github.com/huggingface/trl/pull/3377 is in a release
+    def _get_train_sampler(self) -> Sampler | None:
-    def evaluation_loop(
-        self,
-        dataloader: DataLoader,
-        description: str,
-        prediction_loss_only: Optional[bool] = None,
-        ignore_keys: Optional[list[str]] = None,
-        metric_key_prefix: str = "eval",
-    ) -> EvalLoopOutput:
         """
-        Overriding built-in evaluation loop to store metrics for each batch.
+        Helper method to get the sampler for training. Handles cases for sequence
-        Prediction/evaluation loop, shared by `Trainer.evaluate()` and `Trainer.predict()`.
+        parallelism, sample packing, and curriculum sampling (sequential).
 
-        Works both with or without labels.
+        Returns:
+            If the dataset is non-empty, a sampler is returned, the type of which
+                depends on the passed training args.
         """
+        import torch.distributed as dist
 
-        # Sample and save to game log if requested (for one batch to save time)
+        if dist.get_rank() == 0:
-        if self.generate_during_eval:
+            import ipdb
-            # Generate random indices within the range of the total number of samples
-            num_samples = len(dataloader.dataset)
-            random_indices = random.sample(
-                range(num_samples), k=self.args.eval_batch_size
-            )
 
-            # Use dataloader.dataset.select to get the random batch without iterating over the DataLoader
+            ipdb.set_trace()
-            random_batch_dataset = dataloader.dataset.select(random_indices)
+        dist.barrier()
-            random_batch = self.data_collator(random_batch_dataset)
+        if dist.get_rank() == 1:
-            random_batch = self._prepare_inputs(random_batch)
+            import ipdb
 
-            policy_output_decoded, ref_output_decoded = (
+            ipdb.set_trace()
-                self.generate_from_model_and_ref(self.model, random_batch)
+        dist.barrier()
-            )
 
-            table = pd.DataFrame(
+        if self.args.sequence_parallel_degree > 1:
-                columns=["Prompt", "Policy", "Ref Model"],
+            return self._sp_get_train_sampler(self.train_dataset)
-                data=[
-                    [prompt, pol[len(prompt) :], ref[len(prompt) :]]
-                    for prompt, pol, ref in zip(
-                        random_batch_dataset["prompt"],
-                        policy_output_decoded,
-                        ref_output_decoded,
-                    )
-                ],
-            )
-            if "wandb" in self.args.report_to and self.accelerator.is_main_process:
-                wandb.log({"game_log": wandb.Table(data=table)})
 
-            if "comet_ml" in self.args.report_to:
+        return super()._get_train_sampler()
-                log_table_to_comet_experiment(
-                    name="game_log.csv",
-                    table=table,
-                )
 
-        # Base evaluation
+    def _get_eval_sampler(self, eval_dataset: Dataset | None = None) -> Sampler | None:
-        initial_output = super(  # pylint: disable=bad-super-call
+        """
-            DPOTrainer, self
+        Helper method to get the sampler for evaluation. Handles sequence parallelism
-        ).evaluation_loop(
+        and sample packing cases.
-            dataloader,
-            description,
-            prediction_loss_only,
-            ignore_keys,
-            metric_key_prefix,
-        )
 
-        return initial_output
+        Args:
+            eval_dataset: Evaluation dataset.
+
+        Returns:
+            If the dataset is non-empty, a sampler is returned, the type of which
+                depends on the passed training args.
+        """
+        eval_dataset = eval_dataset if eval_dataset is not None else self.eval_dataset
+
+        if self.args.sequence_parallel_degree > 1:
+            return self._sp_get_eval_sampler(eval_dataset)
+
+        return super()._get_eval_sampler(eval_dataset)

src/axolotl/core/trainers/grpo/trainer.py

@@ -266,9 +266,6 @@ class AxolotlGRPOSequenceParallelTrainer(AxolotlGRPOTrainer):
             self.accelerator.even_batches = False
 
         # Return unprepared dataloader if using sequence parallelism
-        # TODO(djsaunde): We might be able to use `accelerate`'s dataloader preparation
-        # if we use `dispatch_batches` and `slice_fn_for_dispatch` properly (i.e.,
-        # slice each batch along the sequence dimension).
         if self.args.sequence_parallel_degree > 1:
             return dataloader
 

src/axolotl/integrations/cut_cross_entropy/monkeypatch/cohere.py

@@ -20,25 +20,15 @@ from cut_cross_entropy.transformers.utils import (
 from transformers.cache_utils import Cache
 from transformers.modeling_outputs import CausalLMOutputWithPast
 from transformers.models.cohere.modeling_cohere import (
-    _CONFIG_FOR_DOC,
-    COHERE_INPUTS_DOCSTRING,
     KwargsForCausalLM,
 )
 from transformers.processing_utils import Unpack
-from transformers.utils import (
-    add_start_docstrings_to_model_forward,
-    replace_return_docstrings,
-)
 from transformers.utils.deprecation import deprecate_kwarg
 
 _PATCH_OPTS: PatchOptions | None = None
 
 
 @deprecate_kwarg("num_logits_to_keep", version="4.50", new_name="logits_to_keep")
-@add_start_docstrings_to_model_forward(COHERE_INPUTS_DOCSTRING)
-@replace_return_docstrings(
-    output_type=CausalLMOutputWithPast, config_class=_CONFIG_FOR_DOC
-)
 def cce_forward(
     self,
     input_ids: torch.LongTensor | None = None,

src/axolotl/integrations/cut_cross_entropy/monkeypatch/gemma.py

@@ -17,25 +17,15 @@ from cut_cross_entropy.transformers.utils import (
 from transformers.cache_utils import Cache
 from transformers.modeling_outputs import CausalLMOutputWithPast
 from transformers.models.gemma.modeling_gemma import (
-    _CONFIG_FOR_DOC,
-    GEMMA_INPUTS_DOCSTRING,
     KwargsForCausalLM,
 )
 from transformers.processing_utils import Unpack
-from transformers.utils import (
-    add_start_docstrings_to_model_forward,
-    replace_return_docstrings,
-)
 from transformers.utils.deprecation import deprecate_kwarg
 
 _PATCH_OPTS: PatchOptions | None = None
 
 
 @deprecate_kwarg("num_logits_to_keep", version="4.50", new_name="logits_to_keep")
-@add_start_docstrings_to_model_forward(GEMMA_INPUTS_DOCSTRING)
-@replace_return_docstrings(
-    output_type=CausalLMOutputWithPast, config_class=_CONFIG_FOR_DOC
-)
 def cce_forward(
     self,
     input_ids: torch.LongTensor | None = None,

src/axolotl/integrations/cut_cross_entropy/monkeypatch/gemma3.py

@@ -20,15 +20,11 @@ from torch import nn
 from transformers.cache_utils import Cache, HybridCache
 from transformers.modeling_outputs import CausalLMOutputWithPast
 from transformers.models.gemma3.modeling_gemma3 import (
-    _CONFIG_FOR_DOC,
-    GEMMA3_INPUTS_DOCSTRING,
     Gemma3CausalLMOutputWithPast,
     logger,
 )
 from transformers.utils import (
-    add_start_docstrings_to_model_forward,
     is_torchdynamo_compiling,
-    replace_return_docstrings,
 )
 from transformers.utils.deprecation import deprecate_kwarg
 
@@ -38,10 +34,6 @@ _PATCH_OPTS: PatchOptions | None = None
 
 
 @deprecate_kwarg("num_logits_to_keep", version="4.50", new_name="logits_to_keep")
-@add_start_docstrings_to_model_forward(GEMMA3_INPUTS_DOCSTRING)
-@replace_return_docstrings(
-    output_type=CausalLMOutputWithPast, config_class=_CONFIG_FOR_DOC
-)
 def cce_forward(
     self,
     input_ids: torch.LongTensor | None = None,
@@ -170,10 +162,6 @@ def cce_forward(
 
 
 @deprecate_kwarg("num_logits_to_keep", version="4.50", new_name="logits_to_keep")
-@add_start_docstrings_to_model_forward(GEMMA3_INPUTS_DOCSTRING)
-@replace_return_docstrings(
-    output_type=Gemma3CausalLMOutputWithPast, config_class=_CONFIG_FOR_DOC
-)
 def cce_forward_multimodal(
     self,
     input_ids: torch.LongTensor | None = None,

src/axolotl/integrations/cut_cross_entropy/monkeypatch/llama.py

@@ -19,15 +19,9 @@ from transformers.modeling_outputs import (
     CausalLMOutputWithPast,
 )
 from transformers.models.llama.modeling_llama import (
-    _CONFIG_FOR_DOC,
-    LLAMA_INPUTS_DOCSTRING,
     KwargsForCausalLM,
 )
 from transformers.processing_utils import Unpack
-from transformers.utils import (
-    add_start_docstrings_to_model_forward,
-    replace_return_docstrings,
-)
 from transformers.utils.deprecation import deprecate_kwarg
 from transformers.utils.generic import can_return_tuple
 
@@ -36,10 +30,6 @@ _PATCH_OPTS: PatchOptions | None = None
 
 @can_return_tuple
 @deprecate_kwarg("num_logits_to_keep", version="4.50", new_name="logits_to_keep")
-@add_start_docstrings_to_model_forward(LLAMA_INPUTS_DOCSTRING)
-@replace_return_docstrings(
-    output_type=CausalLMOutputWithPast, config_class=_CONFIG_FOR_DOC
-)
 def cce_forward(
     self,
     input_ids: Optional[torch.LongTensor] = None,

src/axolotl/integrations/cut_cross_entropy/monkeypatch/llama4.py

@@ -16,22 +16,12 @@ from torch import nn
 from transformers.cache_utils import Cache
 from transformers.modeling_outputs import CausalLMOutputWithPast
 from transformers.models.llama4.modeling_llama4 import (
-    _CONFIG_FOR_DOC,
-    LLAMA4_INPUTS_DOCSTRING,
     Llama4CausalLMOutputWithPast,
 )
-from transformers.utils import (
-    add_start_docstrings_to_model_forward,
-    replace_return_docstrings,
-)
 
 _PATCH_OPTS: PatchOptions | None = None
 
 
-@add_start_docstrings_to_model_forward(LLAMA4_INPUTS_DOCSTRING)
-@replace_return_docstrings(
-    output_type=CausalLMOutputWithPast, config_class=_CONFIG_FOR_DOC
-)
 def cce_forward(
     self,
     input_ids: torch.LongTensor | None = None,
@@ -160,9 +150,6 @@ def cce_forward(
     )
 
 
-@replace_return_docstrings(
-    output_type=Llama4CausalLMOutputWithPast, config_class=_CONFIG_FOR_DOC
-)
 def cce_forward_multimodal(
     self,
     input_ids: torch.LongTensor | None = None,  # type: ignore

src/axolotl/integrations/cut_cross_entropy/monkeypatch/mistral3.py

@@ -19,15 +19,11 @@ from transformers.models.mistral3.modeling_mistral3 import (
     Mistral3CausalLMOutputWithPast,
 )
 from transformers.models.mistral.modeling_mistral import (
-    _CONFIG_FOR_DOC,
-    MISTRAL_INPUTS_DOCSTRING,
     KwargsForCausalLM,
 )
 from transformers.processing_utils import Unpack
 from transformers.utils import (
-    add_start_docstrings_to_model_forward,
     is_torchdynamo_compiling,
-    replace_return_docstrings,
 )
 from transformers.utils.deprecation import deprecate_kwarg
 
@@ -35,10 +31,6 @@ _PATCH_OPTS: PatchOptions | None = None
 
 
 @deprecate_kwarg("num_logits_to_keep", version="4.50", new_name="logits_to_keep")
-@add_start_docstrings_to_model_forward(MISTRAL_INPUTS_DOCSTRING)
-@replace_return_docstrings(
-    output_type=CausalLMOutputWithPast, config_class=_CONFIG_FOR_DOC
-)
 def cce_forward(
     self,
     input_ids: torch.LongTensor | None = None,

src/axolotl/integrations/cut_cross_entropy/monkeypatch/qwen2_moe.py

@@ -13,16 +13,10 @@ from cut_cross_entropy.transformers.utils import (
     apply_lce,
 )
 from transformers.models.qwen2_moe.modeling_qwen2_moe import (
-    _CONFIG_FOR_DOC,
-    QWEN2MOE_INPUTS_DOCSTRING,
     MoeCausalLMOutputWithPast,
     MoeModelOutputWithPast,
     load_balancing_loss_func,
 )
-from transformers.utils import (
-    add_start_docstrings_to_model_forward,
-    replace_return_docstrings,
-)
 from transformers.utils.deprecation import deprecate_kwarg
 from transformers.utils.generic import can_return_tuple
 
@@ -31,10 +25,6 @@ _PATCH_OPTS: PatchOptions | None = None
 
 @can_return_tuple
 @deprecate_kwarg("num_logits_to_keep", version="4.50", new_name="logits_to_keep")
-@add_start_docstrings_to_model_forward(QWEN2MOE_INPUTS_DOCSTRING)
-@replace_return_docstrings(
-    output_type=MoeCausalLMOutputWithPast, config_class=_CONFIG_FOR_DOC
-)
 def forward(
     self,
     input_ids: Optional[torch.LongTensor] = None,

src/axolotl/integrations/cut_cross_entropy/monkeypatch/qwen2_vl.py

@@ -14,22 +14,12 @@ from cut_cross_entropy.transformers.utils import (
 )
 from torch.nn import CrossEntropyLoss
 from transformers.models.qwen2_vl.modeling_qwen2_vl import (
-    _CONFIG_FOR_DOC,
-    QWEN2_VL_INPUTS_DOCSTRING,
     Qwen2VLCausalLMOutputWithPast,
 )
-from transformers.utils import (
-    add_start_docstrings_to_model_forward,
-    replace_return_docstrings,
-)
 
 _PATCH_OPTS: PatchOptions | None = None
 
 
-@add_start_docstrings_to_model_forward(QWEN2_VL_INPUTS_DOCSTRING)
-@replace_return_docstrings(
-    output_type=Qwen2VLCausalLMOutputWithPast, config_class=_CONFIG_FOR_DOC
-)
 def cce_forward_multimodal(
     self,
     input_ids: Optional[torch.LongTensor] = None,

src/axolotl/integrations/cut_cross_entropy/monkeypatch/qwen3_moe.py

@@ -12,20 +12,13 @@ from cut_cross_entropy.transformers.utils import (
     TransformersModelT,
     apply_lce,
 )
-from transformers.modeling_outputs import CausalLMOutputWithPast
 from transformers.models.qwen3_moe.modeling_qwen3_moe import (
-    _CONFIG_FOR_DOC,
-    QWEN3_MOE_INPUTS_DOCSTRING,
     KwargsForCausalLM,
     MoeCausalLMOutputWithPast,
     MoeModelOutputWithPast,
     load_balancing_loss_func,
 )
 from transformers.processing_utils import Unpack
-from transformers.utils import (
-    add_start_docstrings_to_model_forward,
-    replace_return_docstrings,
-)
 from transformers.utils.deprecation import deprecate_kwarg
 from transformers.utils.generic import can_return_tuple
 
@@ -34,10 +27,6 @@ _PATCH_OPTS: PatchOptions | None = None
 
 @can_return_tuple
 @deprecate_kwarg("num_logits_to_keep", version="4.50", new_name="logits_to_keep")
-@add_start_docstrings_to_model_forward(QWEN3_MOE_INPUTS_DOCSTRING)
-@replace_return_docstrings(
-    output_type=CausalLMOutputWithPast, config_class=_CONFIG_FOR_DOC
-)
 def forward(
     self,
     input_ids: Optional[torch.LongTensor] = None,

src/axolotl/integrations/liger/models/deepseekv2.py

@@ -14,10 +14,6 @@ from torch.nn import CrossEntropyLoss
 from transformers.modeling_outputs import CausalLMOutputWithPast
 
 
-# @add_start_docstrings_to_model_forward(DeepseekV2_INPUTS_DOCSTRING)
-# @replace_return_docstrings(
-#    output_type=CausalLMOutputWithPast, config_class=_CONFIG_FOR_DOC
-# )
 def lce_forward(
     self,
     input_ids: torch.LongTensor = None,

src/axolotl/integrations/liger/models/jamba.py

@@ -13,21 +13,11 @@ from liger_kernel.transformers.fused_linear_cross_entropy import (
 from torch.nn import CrossEntropyLoss
 from transformers.modeling_outputs import MoeCausalLMOutputWithPast
 from transformers.models.jamba.modeling_jamba import (
-    _CONFIG_FOR_DOC,
-    JAMBA_INPUTS_DOCSTRING,
     HybridMambaAttentionDynamicCache,
     load_balancing_loss_func,
 )
-from transformers.utils import (
-    add_start_docstrings_to_model_forward,
-    replace_return_docstrings,
-)
 
 
-@add_start_docstrings_to_model_forward(JAMBA_INPUTS_DOCSTRING)
-@replace_return_docstrings(
-    output_type=MoeCausalLMOutputWithPast, config_class=_CONFIG_FOR_DOC
-)
 def lce_forward(
     self,
     input_ids: torch.LongTensor = None,

src/axolotl/monkeypatch/gemma3.py

@@ -7,24 +7,16 @@ from typing import Optional, Tuple, Union
 import torch
 from transformers.cache_utils import Cache
 from transformers.models.gemma3.modeling_gemma3 import (
-    _CONFIG_FOR_DOC,
-    GEMMA3_INPUTS_DOCSTRING,
     Gemma3CausalLMOutputWithPast,
     logger,
 )
 from transformers.utils import (
-    add_start_docstrings_to_model_forward,
     is_torchdynamo_compiling,
-    replace_return_docstrings,
 )
 from transformers.utils.deprecation import deprecate_kwarg
 
 
 @deprecate_kwarg("num_logits_to_keep", version="4.50", new_name="logits_to_keep")
-@add_start_docstrings_to_model_forward(GEMMA3_INPUTS_DOCSTRING)
-@replace_return_docstrings(
-    output_type=Gemma3CausalLMOutputWithPast, config_class=_CONFIG_FOR_DOC
-)
 def new_forward(
     self,
     input_ids: torch.LongTensor = None,

src/axolotl/utils/ctx_managers/sequence_parallel.py

@@ -1,6 +1,7 @@
 """Module for Axolotl trainer sequence parallelism manager and utilities"""
 
 import functools
+import inspect
 
 import torch
 import torch.distributed as dist
@@ -32,7 +33,7 @@ def apply_sequence_parallelism(
     to only keep the last N tokens in the sequence during generation.
 
     Args:
-        batch: Batch dictionary (e.g., input_ids, attention_mask, etc.).
+        batch: Dictionary of model arguments (e.g., input_ids, attention_mask, etc.).
         local_rank: Local rank in the sequence parallel group.
         local_world_size: World size of the sequence parallel group.
         gradient_accumulation_steps: Number of steps to accumulate gradients over.
@@ -206,12 +207,26 @@ class SequenceParallelContextManager:
     def __enter__(self):
         # Forward pre-hook to apply sequence parallelism
         def sequence_parallel_pre_hook(_, args, kwargs):
-            # Apply sequence parallelism to kwargs and get original sequence length and padding info
+            # Convert all args to kwargs using the model's forward function signature
-            kwargs, self.original_seq_len, self.pad_len = (
+            updated_kwargs = kwargs.copy()
-                self.apply_sequence_parallelism(batch=kwargs)
+
+            # Get parameter names from the model's forward function
+            forward_params = list(
+                inspect.signature(self.models[0].forward).parameters.keys()
             )
 
-            return args, kwargs
+            # Map args to their parameter names
+            for i, arg in enumerate(args):
+                if i < len(forward_params):
+                    param_name = forward_params[i]
+                    updated_kwargs[param_name] = arg
+
+            # Apply sequence parallelism to empty args and updated kwargs
+            updated_kwargs, self.original_seq_len, self.pad_len = (
+                self.apply_sequence_parallelism(updated_kwargs)
+            )
+
+            return (), updated_kwargs
 
         # Forward post-hook to gather outputs
         def sequence_parallel_post_hook(_, __, output: ModelOutput) -> ModelOutput:

src/axolotl/utils/data/rl.py

@@ -72,6 +72,7 @@ def map_dataset(cfg, data_set, ds_transform_fn, tokenizer, **map_kwargs):
     data_set = data_set.map(
         ds_transform_fn,
         desc="Mapping RL Dataset",
+        num_proc=cfg.dataset_processes,
         **map_kwargs,
     )
 

src/axolotl/utils/data/sft.py

@@ -484,7 +484,7 @@ def get_dataset_wrapper(
     }
 
     LOG.info(
-        f"Loading dataset with base_type: {d_base_type} and prompt_style: {d_prompt_style}"
+        f"Loading dataset: {config_dataset['path']} with base_type: {d_base_type} and prompt_style: {d_prompt_style}"
     )
 
     if (

src/axolotl/utils/gradient_checkpointing/__init__.py

@@ -5,8 +5,11 @@ from functools import partial
 
 from packaging import version
 
-from axolotl.utils.gradient_checkpointing.unsloth import (
+from axolotl.utils.gradient_checkpointing.offload_cpu import (
-    Unsloth_Offloaded_Gradient_Checkpointer,
+    CPU_Offloaded_Gradient_Checkpointer,
+)
+from axolotl.utils.gradient_checkpointing.offload_disk import (
+    Disco,
 )
 
 transformers_version = version.parse(importlib.metadata.version("transformers"))
@@ -26,12 +29,31 @@ def hf_grad_checkpoint_offload_wrapper(
     decoder_layer, *args, use_reentrant=None
 ):  # pylint: disable=unused-argument
     if uses_gc_layers(decoder_layer):
-        return Unsloth_Offloaded_Gradient_Checkpointer.apply(
+        return CPU_Offloaded_Gradient_Checkpointer.apply(
             decoder_layer,
             *args,
         )
 
-    return Unsloth_Offloaded_Gradient_Checkpointer.apply(
+    return CPU_Offloaded_Gradient_Checkpointer.apply(
+        (
+            decoder_layer.func.__self__
+            if isinstance(decoder_layer, partial)
+            else decoder_layer.__self__
+        ),
+        *args,
+    )
+
+
+def hf_grad_checkpoint_disk_offload_wrapper(
+    decoder_layer, *args, use_reentrant=None
+):  # pylint: disable=unused-argument
+    if uses_gc_layers(decoder_layer):
+        return Disco.apply(
+            decoder_layer,
+            *args,
+        )
+
+    return Disco.apply(
         (
             decoder_layer.func.__self__
             if isinstance(decoder_layer, partial)

src/axolotl/utils/gradient_checkpointing/offload_cpu.py

@@ -1,4 +1,4 @@
-"""Unsloth checkpointing"""
+"""CPU offloaded checkpointing"""
 
 # Copyright 2023-present Daniel Han-Chen & the Unsloth team. All rights reserved.
 #
@@ -26,7 +26,7 @@ else:
     torch_cuda_amp_custom_bwd = torch.amp.custom_bwd(device_type="cuda")
 
 
-class Unsloth_Offloaded_Gradient_Checkpointer(  # pylint: disable=invalid-name
+class CPU_Offloaded_Gradient_Checkpointer(  # pylint: disable=invalid-name
     torch.autograd.Function
 ):
     """

src/axolotl/utils/gradient_checkpointing/offload_disk.py

@@ -0,0 +1,531 @@
+"""
+DISCO - DIsk-based Storage and Checkpointing with Optimized prefetching
+"""
+
+# Copyright 2025 Axolotl AI. 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 atexit
+import concurrent.futures
+import logging
+import os
+import queue
+import shutil
+import tempfile
+import threading
+import time
+import uuid
+from collections import deque
+from concurrent.futures import Future
+from typing import Dict
+
+import torch
+
+torch_cuda_amp_custom_fwd = torch.amp.custom_fwd(device_type="cuda")
+torch_cuda_amp_custom_bwd = torch.amp.custom_bwd(device_type="cuda")
+
+# Setup logger
+logger = logging.getLogger(__name__)
+
+
+class DiskOffloadManager:
+    """
+    Manages offloaded tensors and handles prefetching in a separate thread.
+    Includes synchronization to prevent race conditions.
+    """
+
+    def __init__(
+        self,
+        prefetch_size: int = 3,
+        prefetch_to_gpu: bool = True,
+        save_workers: int = 4,
+    ):
+        """
+        Args:
+            prefetch_size: Maximum number of tensors to prefetch in the background.
+            prefetch_to_gpu: Whether to prefetch tensors directly to GPU memory.
+            save_workers: Maximum number of concurrent save operations.
+        """
+        self.temp_dir = tempfile.mkdtemp(prefix="disco_")
+
+        # Track tensor paths and their status
+        self.tensor_paths: deque = deque()  # Ordered history of tensor paths (LIFO)
+        self.file_locks: Dict[str, threading.Lock] = (
+            {}
+        )  # Maps file_path -> threading.Lock()
+        # Maps file_path -> status ("saving", "ready", "prefetching", "loaded", "deleted")
+        self.file_status: Dict[str, str] = {}
+
+        self.max_prefetch = prefetch_size
+        self.prefetch_to_gpu = prefetch_to_gpu
+
+        # Thread synchronization
+        self.manager_lock = threading.RLock()  # Used for thread-safe operations
+
+        # Prefetch queue and cache
+        self.prefetch_queue: queue.Queue = queue.Queue()
+        self.prefetch_cache: Dict[str, torch.Tensor] = {}  # Maps file_path -> tensor
+
+        # Save queue and thread pool
+        self.save_queue: queue.Queue = queue.Queue()
+        self.save_pool = concurrent.futures.ThreadPoolExecutor(max_workers=save_workers)
+        self.save_futures: Dict[str, Future] = {}
+        self.save_semaphore = threading.Semaphore(
+            save_workers * 2
+        )  # Limit concurrent save operations
+
+        # Start prefetch worker thread
+        self.stop_event = threading.Event()
+        # start multiple threads for prefetching
+        self.prefetch_worker_count = 2
+        self.prefetch_workers = []
+        for _ in range(self.prefetch_worker_count):
+            worker = threading.Thread(target=self._prefetch_worker, daemon=True)
+            worker.start()
+            self.prefetch_workers.append(worker)
+
+        # Start save worker thread
+        self.save_worker = threading.Thread(target=self._save_worker, daemon=True)
+        self.save_worker.start()
+        self.idx = 0
+
+        atexit.register(self.cleanup)
+
+    def _save_worker(self):
+        """Background thread that processes the save queue"""
+        while not self.stop_event.is_set():
+            try:
+                save_item = self.save_queue.get(timeout=0.5)
+                if save_item is None:
+                    continue
+
+                tensor, file_path = save_item
+
+                # Submit the save task to the thread pool
+                future = self.save_pool.submit(
+                    self._save_tensor_to_disk, tensor, file_path
+                )
+                with self.manager_lock:
+                    self.save_futures[file_path] = future
+
+                self.save_queue.task_done()
+
+            except queue.Empty:
+                time.sleep(0.01)  # Small sleep to prevent CPU spinning
+                continue
+
+    def _save_tensor_to_disk(self, tensor: torch.Tensor, file_path: str):
+        """Actually save the tensor to disk"""
+        try:
+            # Save tensor to disk
+            cpu_tensor = tensor.detach().cpu()
+            torch.save(cpu_tensor, file_path)
+            del cpu_tensor
+
+            with self.manager_lock:
+                # Mark file as ready
+                self.file_status[file_path] = "ready"
+
+            # Release semaphore
+            self.save_semaphore.release()
+
+            return True
+        except FileNotFoundError as e:
+            logger.error(f"Error saving tensor to {file_path}: {e}")
+            with self.manager_lock:
+                self.file_status[file_path] = "error"
+
+            # Release semaphore
+            self.save_semaphore.release()
+
+            return False
+
+    def _prefetch_worker(self):
+        """Background thread that loads tensors from disk ahead of time"""
+        while not self.stop_event.is_set():
+            try:
+                file_path = self.prefetch_queue.get(timeout=0.5)
+                if file_path is None:
+                    continue
+
+                # Check if file is available and not already in cache
+                with self.manager_lock:
+                    if (
+                        file_path not in self.file_status
+                        or self.file_status[file_path] == "deleted"
+                    ):
+                        self.prefetch_queue.task_done()
+                    if file_path in self.prefetch_cache:
+                        self.prefetch_queue.task_done()
+                        continue
+
+                    # If file is still being saved, wait for it
+                    if (
+                        self.file_status[file_path] == "saving"
+                        and file_path in self.save_futures
+                    ):
+                        # Re-queue this prefetch request with a little delay
+                        self.prefetch_queue.task_done()
+                        time.sleep(0.1)
+                        self.prefetch_queue.put(file_path)
+                        continue
+
+                    # Mark file as being prefetched
+                    self.file_status[file_path] = "prefetching"
+
+                # Load tensor from disk and store in cache
+                try:
+                    if os.path.exists(file_path):
+                        if self.prefetch_to_gpu:
+                            tensor = torch.load(
+                                file_path,
+                                map_location=torch.device("cuda"),
+                                weights_only=True,
+                            )
+                        else:
+                            tensor = torch.load(file_path, weights_only=True)
+
+                        with self.manager_lock:
+                            self.prefetch_cache[file_path] = tensor
+                            self.file_status[file_path] = "ready"
+                    else:
+                        with self.manager_lock:
+                            if self.file_status.get(file_path) != "deleted":
+                                logger.warning(
+                                    f"Prefetch error: File not found {file_path}"
+                                )
+                                self.file_status[file_path] = "missing"
+
+                except FileNotFoundError as e:
+                    with self.manager_lock:
+                        if self.file_status.get(file_path) != "deleted":
+                            logger.warning(f"Prefetch error for {file_path}: {e}")
+                            self.file_status[file_path] = "error"
+
+                self.prefetch_queue.task_done()
+
+            except queue.Empty:
+                time.sleep(0.01)  # Small sleep to prevent CPU spinning
+                continue
+
+    def save_tensor(self, tensor: torch.Tensor):
+        """Save tensor to disk asynchronously and return file path with thread-safe operations"""
+        # Generate unique file path
+        self.idx += 1
+        file_path: str = os.path.join(
+            self.temp_dir, f"{self.idx:06d}-{uuid.uuid4()}.pt"
+        )
+
+        with self.manager_lock:
+            # Mark file as being saved
+            self.file_locks[file_path] = threading.Lock()
+            self.file_status[file_path] = "saving"
+            # Add to history
+            self.tensor_paths.append(file_path)
+
+        # Acquire semaphore to limit concurrent save operations
+        self.save_semaphore.acquire()  # pylint: disable=consider-using-with
+        # Queue tensor for saving in background
+        self.save_queue.put((tensor.detach(), file_path))
+
+        return file_path
+
+    def wait_for_save(self, file_path, timeout=None) -> None:
+        """Wait for a tensor to be saved to disk"""
+        start_time = time.time()
+        while timeout is None or time.time() - start_time < timeout:
+            with self.manager_lock:
+                if self.file_status.get(file_path) == "ready":
+                    return
+                if self.file_status.get(file_path) in ["error", "missing", "deleted"]:
+                    return
+
+                if file_path in self.save_futures:
+                    future = self.save_futures[file_path]
+                    if future.done():
+                        return
+
+            # Small sleep to prevent CPU spinning
+            time.sleep(0.01)
+
+        # Timeout
+        logger.warning(f"Timeout waiting for tensor to be saved: {file_path}")
+        return
+
+    def load_tensor(self, file_path, target_device="cuda"):
+        """Load tensor from disk or prefetch cache with proper synchronization"""
+        # Wait for tensor to be saved if it's still in progress
+        self.wait_for_save(file_path)
+
+        tensor = None
+
+        # Try to get from cache first
+        with self.manager_lock:
+            # Check if tensor is already in cache
+            if file_path in self.prefetch_cache:
+                tensor = self.prefetch_cache[file_path]
+                del self.prefetch_cache[file_path]
+                self.file_status[file_path] = "loaded"
+
+        if tensor is not None:
+            # Ensure tensor is on correct device
+            if target_device != "cpu" and tensor.device.type == "cpu":
+                tensor = tensor.to(target_device, non_blocking=True)
+            return tensor
+
+        # If not in cache, load directly from disk
+        try:
+            if not os.path.exists(file_path):
+                logger.error(f"File not found for loading: {file_path}")
+                raise FileNotFoundError(f"File not found: {file_path}")
+
+            tensor = torch.load(file_path, weights_only=True)
+
+            with self.manager_lock:
+                self.file_status[file_path] = "loaded"
+
+            if target_device != "cpu":
+                tensor = tensor.to(target_device, non_blocking=True)
+
+            return tensor
+
+        except Exception as e:
+            logger.error(f"Error loading tensor from {file_path}: {e}")
+            raise
+
+    def _safe_delete_file(self, file_path):
+        """Safely delete a file with proper synchronization"""
+        with self.manager_lock:
+            # Make sure any save operation is completed
+            if file_path in self.save_futures:
+                future = self.save_futures[file_path]
+                try:
+                    if not future.done():
+                        future.cancel()
+                    del self.save_futures[file_path]
+                except FileNotFoundError as e:
+                    logger.warning(
+                        f"Error canceling save operation for {file_path}: {e}"
+                    )
+
+            # Only delete if file exists and is not being prefetched
+            status = self.file_status.get(file_path)
+            if status in ["ready", "loaded", "error", "missing"]:
+                try:
+                    if os.path.exists(file_path):
+                        os.remove(file_path)
+                    self.file_status[file_path] = "deleted"
+                    return True
+                except FileNotFoundError as e:
+                    logger.warning(f"Error deleting file {file_path}: {e}")
+            return False
+
+    def trigger_prefetch(self, n=None):
+        """Trigger prefetching of the next N tensors with proper synchronization"""
+        if n is None:
+            n = self.max_prefetch
+
+        prefetch_paths = []
+        with self.manager_lock:
+            # Find files that are ready to be prefetched (not already in cache or being prefetched)
+            for path in reversed(self.tensor_paths):
+                if (
+                    path not in self.prefetch_cache
+                    and self.file_status.get(path) == "ready"
+                ):
+                    prefetch_paths.append(path)
+                    if len(prefetch_paths) >= n:
+                        break
+
+        # Queue files for prefetching
+        for path in prefetch_paths:
+            self.prefetch_queue.put(path)
+
+    def cleanup_tensor(self, file_path: str):
+        """Clean up a specific tensor file after it's been used"""
+        with self.manager_lock:
+            if file_path in self.tensor_paths:
+                self.tensor_paths.remove(file_path)
+
+            # Remove from prefetch cache if present
+            if file_path in self.prefetch_cache:
+                del self.prefetch_cache[file_path]
+
+            # Remove from save futures if present
+            if file_path in self.save_futures:
+                future = self.save_futures[file_path]
+                if not future.done():
+                    future.cancel()
+                del self.save_futures[file_path]
+
+        # Try to delete the file
+        self._safe_delete_file(file_path)
+
+    def cleanup(self):
+        """Clean up all temp files and stop prefetch thread with proper synchronization"""
+        self.stop_event.set()
+
+        # Cancel all pending save operations
+        with self.manager_lock:
+            for _, future in self.save_futures.items():
+                if not future.done():
+                    future.cancel()
+            self.save_futures.clear()
+
+        # Drain the save queue
+        while not self.save_queue.empty():
+            try:
+                self.save_queue.get_nowait()
+                self.save_queue.task_done()
+            except queue.Empty:
+                break
+
+        # Shutdown the save pool
+        self.save_pool.shutdown(wait=False)
+
+        # Join the save worker thread
+        if self.save_worker.is_alive():
+            self.save_worker.join(timeout=2.0)
+
+        # Join the prefetch worker threads
+        for thread in self.prefetch_workers:
+            if thread.is_alive():
+                thread.join(timeout=2.0)
+
+        # Clear cache and remove all temporary files
+        with self.manager_lock:
+            self.prefetch_cache.clear()
+            paths_to_delete = list(self.tensor_paths)
+            self.tensor_paths.clear()
+
+        # Delete all temporary files
+        for path in paths_to_delete:
+            self._safe_delete_file(path)
+
+        # Remove temp directory
+        try:
+            if os.path.exists(self.temp_dir):
+                shutil.rmtree(self.temp_dir, ignore_errors=True)
+        except FileNotFoundError as e:
+            logger.warning(f"Error removing temporary directory {self.temp_dir}: {e}")
+
+
+class Disco(torch.autograd.Function):
+    """
+    Disco: DIsk-based Storage and Checkpointing with Optimized prefetching
+    Advanced disk-based gradient checkpointer with prefetching.
+    """
+
+    # Shared manager instance across all checkpointing operations
+    _manager = None
+
+    @staticmethod
+    def get_instance(prefetch_size=1, prefetch_to_gpu=True, save_workers=4):
+        """Get or create the offload manager"""
+        if Disco._manager is None:
+            Disco._manager = DiskOffloadManager(
+                prefetch_size=prefetch_size,
+                prefetch_to_gpu=prefetch_to_gpu,
+                save_workers=save_workers,
+            )
+        return Disco._manager
+
+    @staticmethod
+    @torch_cuda_amp_custom_fwd
+    def forward(
+        ctx,
+        forward_function,
+        hidden_states,
+        *args,
+        prefetch_size=1,
+        prefetch_to_gpu=True,
+        save_workers=4,
+    ):
+        """Forward pass that offloads activations to disk asynchronously"""
+        # Get or create the manager
+        manager = Disco.get_instance(
+            prefetch_size=prefetch_size,
+            prefetch_to_gpu=prefetch_to_gpu,
+            save_workers=save_workers,
+        )
+
+        # Save tensor to disk asynchronously
+        file_path = manager.save_tensor(hidden_states)
+
+        # Run forward pass immediately without waiting for save to complete
+        with torch.no_grad():
+            output = forward_function(hidden_states, *args)
+
+        # Store what we need for backward
+        ctx.save_for_backward(torch.tensor([0]))  # Dummy tensor
+        ctx.file_path = file_path
+        ctx.forward_function = forward_function
+        ctx.args = args
+
+        return output
+
+    @staticmethod
+    @torch_cuda_amp_custom_bwd
+    def backward(ctx, *grad_outputs):
+        """Backward pass that loads activations from disk with prefetching"""
+        # Get the manager
+        manager = Disco._manager
+
+        # Trigger prefetching for future tensors
+        # This happens at the start of backward, so should have time to complete
+        manager.trigger_prefetch()
+
+        # Load hidden states from disk or prefetch cache
+        file_path = ctx.file_path
+        try:
+            # Ensure the file is saved before we try to load it
+            manager.wait_for_save(file_path)
+
+            hidden_states = manager.load_tensor(file_path)
+            hidden_states.requires_grad = True
+
+            # Compute gradients
+            with torch.enable_grad():
+                output = ctx.forward_function(hidden_states, *ctx.args)
+
+                # Handle tuple outputs properly
+                if isinstance(output, tuple):
+                    if len(grad_outputs) == len(output):
+                        torch.autograd.backward(output, grad_outputs)
+                    else:
+                        torch.autograd.backward(output, grad_outputs[0])
+                else:
+                    torch.autograd.backward(output, grad_outputs[0])
+
+            # Clean up the file after we're done with it
+            manager.cleanup_tensor(file_path)
+
+            return (
+                (
+                    None,  # forward_function
+                    hidden_states.grad,  # hidden_states grad
+                )
+                + (None,) * len(ctx.args)  # for each arg
+                + (
+                    None,  # prefetch_size
+                    None,  # prefetch_to_gpu
+                    None,  # save_workers
+                )
+            )
+
+        except Exception as e:
+            logger.error(f"Error in backward pass: {e}")
+            # Clean up the file even on error
+            manager.cleanup_tensor(file_path)
+            raise

src/axolotl/utils/models.py

@@ -70,7 +70,10 @@ from axolotl.utils.distributed import (
     is_local_main_process,
     is_main_process,
 )
-from axolotl.utils.gradient_checkpointing import hf_grad_checkpoint_offload_wrapper
+from axolotl.utils.gradient_checkpointing import (
+    hf_grad_checkpoint_disk_offload_wrapper,
+    hf_grad_checkpoint_offload_wrapper,
+)
 from axolotl.utils.lora_embeddings import get_linear_embedding_layers
 from axolotl.utils.model_shard_quant import load_sharded_model, load_sharded_model_quant
 from axolotl.utils.schemas.enums import RLType
@@ -620,6 +623,10 @@ class ModelLoader:
 
         if self.cfg.gradient_checkpointing in ["unsloth", "offload"]:
             transformers.modeling_utils.checkpoint = hf_grad_checkpoint_offload_wrapper
+        if self.cfg.gradient_checkpointing == "offload_disk":
+            transformers.modeling_utils.checkpoint = (
+                hf_grad_checkpoint_disk_offload_wrapper
+            )
 
         if self.cfg.flash_attention:
             self.patch_attention()

src/axolotl/utils/schemas/config.py

@@ -83,7 +83,6 @@ class AxolotlInputConfig(
     # optionally shrink the embeddings when the tokenizer vocab size is smaller
     shrink_embeddings: bool | None = None
     embeddings_skip_upcast: bool | None = None
-    random_init_weights: bool | None = None
 
     rl: RLType | None = None
     trl: TRLConfig | None = Field(
@@ -179,7 +178,7 @@ class AxolotlInputConfig(
 
     # torch_dtype: torch.dtype | None
 
-    gradient_checkpointing: Literal["unsloth", "offload"] | bool | None = Field(
+    gradient_checkpointing: Literal["offload", "offload_disk"] | bool | None = Field(
         default=False
     )
     gradient_checkpointing_kwargs: dict[str, Any] | None = None

tests/e2e/patched/test_activation_checkpointing.py

@@ -26,10 +26,15 @@ class TestActivationCheckpointing:
     E2E tests for activation checkpointing
     """
 
+    @pytest.mark.parametrize(
+        "gradient_checkpointing",
+        ["offload", "offload_disk"],
+    )
     def test_activation_checkpointing_offload(
         self,
         temp_dir,
         fix_checkpoint_after_test,  # pylint: disable=unused-argument,redefined-outer-name
+        gradient_checkpointing,
     ):
         # pylint: disable=duplicate-code
         cfg = DictDefault(
@@ -64,7 +69,7 @@ class TestActivationCheckpointing:
                 "sample_packing": True,
                 "bf16": True,
                 "save_safetensors": True,
-                "gradient_checkpointing": "offload",
+                "gradient_checkpointing": gradient_checkpointing,
             }
         )