Skip to content

Conversation

@danielhanchen
Copy link
Contributor

No description provided.

andrewor14 and others added 22 commits November 19, 2025 23:51
* Enable FP8 + RL training for bf16 models

**Summary:** Enable FP8 + RL training using TorchAO for 1.33x faster training and 42% less model memory usage:
- We quantize the frozen LoRA weights into fp8 and keep the LoRA adapters in bf16
- We leverage TorchAO's `Float8Tensor`, which calls into fbgemm's fp8 x fp8 rowwise matmul kernel
- For now, we need to do an offline quantization first, because vllm doesn't support on-the-fly quantization for torchao yet  (this is in progress: vllm-project/vllm#26327)

**Example usage:**
```
model, tokenizer = FastLanguageModel.from_pretrained(
    model_name = "unsloth/Qwen3-8B-Base",
    max_seq_length = 2048,
    load_in_4bit = False,
    fast_inference = True,
    max_lora_rank = 32,
    load_in_fp8 = True,  # set this to True
)

\# the rest is the same as before
model = FastLanguageModel.get_peft_model(...)
```

**Initial results:**
```
\# fp8
{'train_runtime': 1725.4337, 'train_samples_per_second': 0.232, 'train_steps_per_second': 0.058, 'train_loss': 0.00015715716748673002, 'epoch': 0.01}

\# bf16
{'train_runtime': 2297.8145, 'train_samples_per_second': 0.174, 'train_steps_per_second': 0.044, 'train_loss': 0.00016081033063528594, 'epoch': 0.01}
```

<img width="1199" height="448" alt="Screenshot 2025-11-11 at 4 10 50 PM" src="https://github.com/user-attachments/assets/b6304afd-89e9-42b1-8064-775807e17b23" />

Test script: https://gist.github.com/andrewor14/5b85119fae46845d07b608d420907423

**Requires:**
- pytorch/ao#3158 (torchao nightly or 0.15.0+)
- unslothai/unsloth-zoo#351

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

* Update utils.py

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

* _get_inference_mode_context_manager

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

* Update utils.py

* Update utils.py

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

---------

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Co-authored-by: Daniel Han <danielhanchen@gmail.com>
* make loading gpt-oss-BF16 faster. Linked to unsloth-zoo PR #314

* fix model loading and clean merged model directory

* revert default quant

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

* revert mapper.py

---------

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
* Add 128x128 PerBlock FP8 + RL

**Summary:** Following #3440,
this PR extends torchao FP8 + RL support to also handle 128x128
PerBlock granularity (in addition to PerRow).

**Example usage:**

```
model, tokenizer = FastLanguageModel.from_pretrained(
    model_name = "unsloth/Qwen3-8B-Base",
    max_seq_length = 2048,
    load_in_4bit = False,
    fast_inference = True,
    max_lora_rank = 32,
    load_in_fp8 = "block",  # or "row" or True
)
```

**Initial results:** TBD

**Note:**
- Requires pytorch/ao#3370

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

---------

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
@gemini-code-assist
Copy link
Contributor

Summary of Changes

Hello @danielhanchen, I'm Gemini Code Assist1! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

This pull request significantly expands the project's capabilities by introducing robust support for Float8 (FP8) quantization, which can lead to substantial memory savings and performance gains, especially on newer GPUs. It also updates the project's compatibility with the latest PyTorch and CUDA versions, refines the model loading process to seamlessly integrate FP8, and includes several key stability and integration improvements across various modules, including RL training and dependency management.

Highlights

  • Float8 (FP8) Quantization Support: Introduced comprehensive support for Float8 (FP8) quantization using torchao, allowing for more memory-efficient and potentially faster inference on compatible hardware. This includes dynamic checks for FBGEMM kernel compatibility on the GPU.
  • Expanded PyTorch and CUDA Compatibility: Updated installation instructions and internal version checks to support a wider range of PyTorch versions (up to 2.9.x) and CUDA versions (up to 13.0), ensuring broader system compatibility.
  • Improved Model Loading Logic: Enhanced the model loading mechanism to intelligently handle FP8 quantization, including offline quantization for models not natively available in FP8, and introduced new utility functions for managing torchao configurations.
  • Robustness Improvements: Implemented fixes for bitsandbytes module reloading when it's not installed and added a workaround for a PyTorch bug related to torch.inference_mode() with torchao quantized tensor subclasses, improving overall stability.
  • RL Training Integration: Integrated the new inference mode context manager into RL training components and added a patch to ensure wandb.finish() is called correctly for multiple runs in RL training.
Using Gemini Code Assist

The full guide for Gemini Code Assist can be found on our documentation page, here are some quick tips.

Invoking Gemini

You can request assistance from Gemini at any point by creating a comment using either /gemini <command> or @gemini-code-assist <command>. Below is a summary of the supported commands on the current page.

Feature Command Description
Code Review /gemini review Performs a code review for the current pull request in its current state.
Pull Request Summary /gemini summary Provides a summary of the current pull request in its current state.
Comment @gemini-code-assist Responds in comments when explicitly tagged, both in pull request comments and review comments.
Help /gemini help Displays a list of available commands.

Customization

To customize Gemini Code Assist for GitHub experience, repository maintainers can create a configuration file and/or provide a custom code review style guide (such as PEP-8 for Python) by creating and adding files to a .gemini/ folder in the base of the repository. Detailed instructions can be found here.

Limitations & Feedback

Gemini Code Assist may make mistakes. Please leave feedback on any instances where its feedback is incorrect or counter productive. You can react with 👍 and 👎 on @gemini-code-assist comments. If you're interested in giving your feedback about your experience with Gemini Code Assist for Github and other Google products, sign up here.

You can also get AI-powered code generation, chat, as well as code reviews directly in the IDE at no cost with the Gemini Code Assist IDE Extension.

Footnotes

  1. Review the Privacy Notices, Generative AI Prohibited Use Policy, Terms of Service, and learn how to configure Gemini Code Assist in GitHub here. Gemini can make mistakes, so double check it and use code with caution.

@danielhanchen danielhanchen merged commit aa086ea into main Nov 25, 2025
4 checks passed
Copy link
Contributor

@gemini-code-assist gemini-code-assist bot left a comment

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Code Review

The pull request introduces comprehensive support for FP8 quantization using torchao and fbgemm_gpu, enhancing performance and memory efficiency. Key changes include dynamic compatibility checks for FBGEMM, a robust workaround for a PyTorch inference mode bug with torchao quantized models, and updated dependency management. The changes are well-integrated across various modules, from installation scripts and pyproject.toml to core kernel functions and model loading utilities. However, there is some code duplication in the model loading logic that could be refactored for better maintainability. Additionally, some error messages and TODOs indicate areas for further investigation and refinement.

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment

Labels

None yet

4 participants