Support conditional torch.compile per module

[sarckk]

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

Required fro #22628

#21044 shows an example of compiling multiple submodules within a model. We also want to provide the user the flexibility of triggering this on/off.

This PR adds a new arg enable_if to the support_torch_compile decorator, which is a function that takes in VllmConfig and returns a bool of whether to enable compile or not.

Test Plan

added new unit tests

pytest tests/compile/test_decorator.py
pytest tests/compile/piecewise/test_multiple_graphs.py

Test Result

Tests pass

cc: @zou3519 @BoyuanFeng

[github-actions]

👋 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.

🚀

[gemini-code-assist]

Code Review

This pull request introduces a compile_cond argument to the support_torch_compile decorator, allowing for conditional compilation of models. The implementation is clean and well-tested. I've found one minor issue in the new test file that should be addressed. Overall, this is a great addition that increases the flexibility of the compilation framework.

[zou3519]

minor nit around the name but otherwise lgtm

[DarkLight1337]

Can you merge from main to fix the CI failures?