Add cuda graph status to prefill log

[ispobock]

Motivation

• Log prefill after forward
• Add prefill cuda graph status to log

Modifications

Accuracy Tests

Benchmarking and Profiling

Checklist

• Format your code according to the Format code with pre-commit.
• Add unit tests according to the Run and add unit tests.
• Update documentation according to Write documentations.
• Provide accuracy and speed benchmark results according to Test the accuracy and Benchmark the speed.
• Follow the SGLang code style guidance.

Review Process

1. Ping Merge Oncalls to start the PR flow. See the PR Merge Process.
2. Get approvals from CODEOWNERS and other reviewers.
3. Trigger CI tests with comments or contact authorized users to do so.
   • /tag-run-ci-label, /rerun-failed-ci, /tag-and-rerun-ci
4. After green CI and required approvals, ask Merge Oncalls to merge.

[gemini-code-assist]

Summary of Changes

Hello @ispobock, 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 refactors the prefill logging mechanism to enhance observability and accuracy. By deferring the logging of prefill statistics until after the forward pass, the system can now include crucial information such as CUDA graph utilization directly within the logs. This change provides a more comprehensive view of prefill performance and helps in debugging and optimizing CUDA graph usage.

Highlights

• Prefill Logging Timing: Prefill statistics logging has been re-timed to occur after the forward pass, ensuring that all relevant metrics, including CUDA graph status, are captured post-execution.
• CUDA Graph Status in Logs: The prefill log messages now explicitly include whether a CUDA graph was successfully utilized for the forward operation, providing clearer insights into performance.
• forward_extend Return Value: The forward_extend method in the model runner now returns a boolean flag indicating if a CUDA graph was used, allowing this information to be propagated for logging.

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[ispobock]

/tag-and-rerun-ci

[gemini-code-assist]

Code Review

The pull request successfully implements the logging of CUDA graph status for prefill operations, addressing the stated motivation. The changes involve deferring the log_prefill_stats call to after the forward pass and passing the can_run_cuda_graph status. The modifications are consistent across the relevant files, updating method signatures and variable assignments as needed.

[ispobock]

It seems embedding models ci failed. I'll have a check.

[ispobock]

/rerun-stage unit-test-backend-8-gpu-h200

[github-actions]

✅ Triggered unit-test-backend-8-gpu-h200 to run independently (skipping dependencies).

[github-actions]

🔗 View workflow run