Skip to content

[Model] Add ModelConfig class for GraniteMoeHybrid to override default max_seq_len_to_capture #20923

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 2 commits into from
Jul 16, 2025

Conversation

tdoublep
Copy link
Member

@tdoublep tdoublep commented Jul 14, 2025

Essential Elements of an Effective PR Description Checklist

  • The purpose of the PR, such as "Fix some issue (link existing issues this PR will resolve)".
  • The test plan, such as providing test command.
  • The test results, such as pasting the results comparison before and after, or e2e results
  • (Optional) The necessary documentation update, such as updating supported_models.md and examples for a new model.

Purpose

Granite 4.0 models support long context (e.g., 128k) but right now the default value of max_seq_len_to_capture is set to 8192. This is repeatedly tripping people up, when trying to do benchmarking on long contexts. We find it really affects the performance for this model when using small batches (probably because the mamba implementation uses many Triton kernels which incur launch overhead).

This PR introduces a ModelConfig class to override the default value by setting it to max_model_len. This change would ensure that anyone deploying Granite 4.0 models will get optimized configuration without needing to manually change things.

Test Plan

python -m pytest tests/models/language/generation/test_hybrid.py::test_models[5-64-ibm-granite/granite-4.0-tiny-preview]

Test Result

Passes locally.

(Optional) Documentation Update

…q_len_to_capture

Signed-off-by: Thomas Parnell <tpa@zurich.ibm.com>
Copy link

👋 Hi! Thank you for contributing to the vLLM project.

💬 Join our developer Slack at https://slack.vllm.ai to discuss your PR in #pr-reviews, coordinate on features in #feat- channels, or join special interest groups in #sig- channels.

Just a reminder: PRs would not trigger full CI run by default. Instead, it would only run fastcheck CI which starts running only a small and essential subset of CI tests to quickly catch errors. You can run other CI tests on top of those by going to your fastcheck build on Buildkite UI (linked in the PR checks section) and unblock them. If you do not have permission to unblock, ping simon-mo or khluu to add you in our Buildkite org.

Once the PR is approved and ready to go, your PR reviewer(s) can run CI to test the changes comprehensively before merging.

To run CI, PR reviewers can either: Add ready label to the PR or enable auto-merge.

🚀

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 @tdoublep, 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 enhances the configuration system by adding a dedicated model configuration class for Granite 4.0 models. The primary goal is to automatically optimize performance for long contexts by ensuring the max_seq_len_to_capture parameter aligns with the model's maximum supported sequence length, thereby improving efficiency and user experience.

Highlights

  • Model Configuration: A new GraniteMoeHybridModelConfig class has been introduced to provide specific configuration overrides for Granite 4.0 models.
  • Automatic Sequence Length Optimization: The max_seq_len_to_capture parameter for GraniteMoeHybrid models is now automatically set to max_model_len, ensuring that CUDA graph capture covers the full supported sequence length. This addresses performance issues observed with smaller batch sizes and long contexts.
  • Improved User Experience: This change removes the need for users to manually adjust max_seq_len_to_capture when deploying Granite 4.0 models, providing an optimized default configuration out-of-the-box.
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 is currently in preview and 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 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 introduces a ModelConfig class for GraniteMoeHybrid to override the default max_seq_len_to_capture and set it to max_model_len. This ensures optimized configuration for Granite 4.0 models, especially when dealing with long contexts. A potential issue is the unconditional override of max_seq_len_to_capture, which might ignore a user's explicit configuration. This has been raised in the review comments.

Comment on lines +209 to +213
logger.info(
"Setting max_seq_len_to_capture to %d "
"to ensure that CUDA graph capture "
"covers sequences of length up to max_model_len.",
config.max_model_len)
Copy link
Contributor

Choose a reason for hiding this comment

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

high

Consider adding a warning log message if max_seq_len_to_capture is being overridden, to inform the user that their specified value is not being used. This will help in debugging and understanding the configuration.

Suggested change
logger.info(
"Setting max_seq_len_to_capture to %d "
"to ensure that CUDA graph capture "
"covers sequences of length up to max_model_len.",
config.max_model_len)
if hasattr(config, 'max_seq_len_to_capture') and config.max_seq_len_to_capture != config.max_model_len:
logger.warning(
"Overriding user-specified max_seq_len_to_capture to %d "
"to ensure that CUDA graph capture "
"covers sequences of length up to max_model_len.",
config.max_model_len)

MODELS_CONFIG_MAP: dict[str, type[VerifyAndUpdateConfig]] = {
"GteModel": SnowflakeGteNewModelConfig,
"GteNewModel": GteNewModelConfig,
"NomicBertModel": NomicBertModelConfig,
"Qwen3ForSequenceClassification": Qwen3ForSequenceClassificationConfig,
"XLMRobertaModel": JinaRobertaModelConfig,
"JinaVLForRanking": JinaVLForSequenceClassificationConfig,
"GraniteMoeHybridForCausalLM": GraniteMoeHybridModelConfig,
Copy link
Contributor

Choose a reason for hiding this comment

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

high

Consider adding GraniteMoeHybridForCausalLM to __all__ in vllm/model_executor/models/__init__.py to ensure it is accessible for external use and doesn't break any implicit API contracts.

@staticmethod
def verify_and_update_config(vllm_config: "VllmConfig") -> None:
config = vllm_config.model_config
config.max_seq_len_to_capture = config.max_model_len
Copy link
Contributor

Choose a reason for hiding this comment

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

medium

The implementation unconditionally sets config.max_seq_len_to_capture = config.max_model_len. Consider checking if config.max_seq_len_to_capture already has a user-defined value before overriding it. This would prevent unexpected behavior if a user has explicitly configured this value.

if not hasattr(config, 'max_seq_len_to_capture'):
    config.max_seq_len_to_capture = config.max_model_len

Signed-off-by: Thomas Parnell <tpa@zurich.ibm.com>
@DarkLight1337 DarkLight1337 enabled auto-merge (squash) July 15, 2025 12:56
@github-actions github-actions bot added the ready ONLY add when PR is ready to merge/full CI is needed label Jul 15, 2025
@tdoublep
Copy link
Member Author

@DarkLight1337 IDK why TPU test keeps failing (I can't figure it out from the logs) but don't see how it can be related to these changes.

@tdoublep
Copy link
Member Author

tdoublep commented Jul 15, 2025

I guess TPU CI failure is fixed by #21007

@vllm-bot vllm-bot merged commit 6cbc4d4 into vllm-project:main Jul 16, 2025
70 of 73 checks passed
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Labels
ready ONLY add when PR is ready to merge/full CI is needed
Projects
None yet
Development

Successfully merging this pull request may close these issues.

3 participants