Skip to content

Conversation

wenchen76
Copy link
Contributor

@wenchen76 wenchen76 commented Jul 29, 2025

Motivation

To resolve #8487 and close #8468, adapt mllama4 to support Vision attention

Modifications

Accuracy Test

WIP

Benchmark & Profiling

WIP

Checklist

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.

Summary of Changes

Hello @wenchen76, 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!

I've implemented changes to the mllama4 model to introduce comprehensive support for Vision attention. This work directly addresses issue #8487, aiming to enable the model to process and understand visual inputs by integrating a dedicated vision pipeline and associated components.

Highlights

  • Vision Model Integration: I've integrated a comprehensive vision model pipeline, including components for patch embedding, positional embeddings, and a dedicated vision encoder, to enable the model to process visual inputs.
  • Custom Multi-Modal Projector: I've re-implemented the multi-modal projector within the codebase to specifically handle the projection of vision features into the text model's hidden space, ensuring compatibility and efficient data flow.
  • Modular Vision Components: I've introduced several new modular classes, such as Llama4VisionMLP, Llama4VisionEncoderLayer, Llama4VisionEncoder, Llama4UnfoldConvolution, and Llama4VisionPixelShuffleMLP, to build out the necessary vision processing capabilities.
  • Quantization and Parallelism Support: The newly added vision components are designed to support quantization configurations and various data parallelism strategies (e.g., ColumnParallelLinear, RowParallelLinear, ReplicatedLinear) for optimized and efficient execution.
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 in your pull request via creating an issue comment (i.e. comment on the pull request page) using either /gemini <command> or @gemini-code-assist <command>. Below is a summary of the supported commands.

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 issue 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 or fill out our survey to provide feedback.

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.

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

This pull request adapts mllama4 to support Vision attention by reimplementing vision components from transformers within sglang. The changes are extensive and introduce new classes for the vision pipeline. My review focuses on ensuring the new components are correctly integrated and configured. I've identified a critical issue with an incompatible API change that will cause a runtime error, a high-severity bug related to missing arguments during instantiation, and a couple of medium-severity issues regarding code clarity and potential bugs with data parallelism. The PR is marked as WIP, so these findings should help in finalizing the implementation.

@mickqian mickqian force-pushed the mllama4-vision-attention branch from d443cf8 to a138126 Compare July 31, 2025 17:07
@mickqian
Copy link
Collaborator

server command:

python3 -m sglang.launch_server --model-path meta-llama/Llama-4-Scout-17B-16E-Instruct --port 9080 --tp 8 --mem-fraction-static 0.8 --context-length 8192 --attention-backend fa3 --enable-multimodal

peak mem is tested with a request containing 3 images

version peak mem (MB) mmmu
before 116292.06 MB 0.364
Vision Attention 116070.00 MB
Vision Attention + fa3 116070.00 MB 0.389

@mickqian mickqian marked this pull request as ready for review July 31, 2025 17:12
@mickqian mickqian changed the title Adapt mllama4 to support Vision attention model: adapt mllama4 to VisionAttention Jul 31, 2025
@mickqian mickqian marked this pull request as draft August 1, 2025 02:54
@mickqian mickqian marked this pull request as ready for review August 1, 2025 08:57
@mickqian mickqian enabled auto-merge (squash) August 1, 2025 09:04
@zhyncs zhyncs disabled auto-merge August 2, 2025 07:39
@zhyncs zhyncs merged commit ea93079 into sgl-project:main Aug 2, 2025
201 of 221 checks passed
lifuhuang pushed a commit that referenced this pull request Aug 3, 2025
Co-authored-by: root <mickjagger19@icloud.com>
htiennv pushed a commit to htiennv/sglang that referenced this pull request Aug 5, 2025
Co-authored-by: root <mickjagger19@icloud.com>
ShangmingCai pushed a commit that referenced this pull request Aug 5, 2025
Co-authored-by: root <mickjagger19@icloud.com>
ShangmingCai pushed a commit that referenced this pull request Aug 5, 2025
Co-authored-by: root <mickjagger19@icloud.com>
narutolhy pushed a commit to narutolhy/sglang that referenced this pull request Aug 17, 2025
Co-authored-by: root <mickjagger19@icloud.com>
narutolhy pushed a commit to narutolhy/sglang that referenced this pull request Aug 18, 2025
Co-authored-by: root <mickjagger19@icloud.com>
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Labels
None yet
Projects
None yet
Development

Successfully merging this pull request may close these issues.

[Feature] Adapt mllama4 to support Vision attention. [Bug] Llama4 Maverick-FP8 OOM when sending images
4 participants