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@tdoublep tdoublep commented Jun 26, 2025

Hybrid models that mix mamba and attention layers (Bamba, Nemotron-H, Granite 4.0, Zamba2, Falcon H1) are becoming increasingly important to multiple different stakeholders. Currently, vLLM's support for these models is not verified as part of PR builds. The only way to test them in CI is to trigger the optional Language Models Test (Extended Generation) job. This job takes a long time (more than an hour) and contains a lot of flaky test (as one would expect for a job that is not run frequently on this codebase).

This PR proposes to add a new CI stage that runs by default for every PR and verifies that vLLM works well for the family of hybrid models.

Hopefully this job will run when I open this PR and I add a comment re: how long it takes to run after I observe it.

Signed-off-by: Thomas Parnell <tpa@zurich.ibm.com>
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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 introduces a new, mandatory CI job to validate vLLM's support for hybrid models (those mixing mamba and attention layers) on every pull request. This aims to significantly improve the reliability and verification of these increasingly important models, which were previously only tested in an optional and often flaky extended CI job.

Highlights

  • New CI Job for Hybrid Models: A new Language Models Test (Hybrid) CI job has been added to the .buildkite/test-pipeline.yaml configuration. This job is designed to run automatically for every pull request, specifically targeting tests for hybrid models that incorporate mamba layers.
  • Pytest Marker for Hybrid Models: A new hybrid_model marker has been defined in pyproject.toml. This marker serves to categorize and select tests specifically related to models that contain mamba layers, facilitating their inclusion in the new dedicated CI job.
  • Test Categorization: Existing tests within tests/models/language/generation/test_hybrid.py have been updated by applying the new @pytest.mark.hybrid_model decorator. This ensures these tests are properly identified and executed as part of the new hybrid model CI job.
  • CI Job Refinement: The Language Models Test (Extended Generation) job in .buildkite/test-pipeline.yaml has been modified to explicitly exclude tests marked with hybrid_model. This prevents redundant execution of these tests and helps maintain the efficiency and focus of the existing extended job, now that a dedicated hybrid model job is in place.
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@mergify mergify bot added the ci/build label Jun 26, 2025
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Code Review

This pull request introduces a new CI job to specifically test hybrid models, which is a great addition for improving test coverage and speed. The changes to the Buildkite pipeline and pyproject.toml are well-structured. I've provided a couple of suggestions to enhance maintainability and clarity in the test file and the marker definition.

tdoublep added 2 commits June 27, 2025 07:20
Signed-off-by: Thomas Parnell <tpa@zurich.ibm.com>
Signed-off-by: Thomas Parnell <tpa@zurich.ibm.com>
@DarkLight1337 DarkLight1337 enabled auto-merge (squash) June 27, 2025 07:28
@github-actions github-actions bot added the ready ONLY add when PR is ready to merge/full CI is needed label Jun 27, 2025
@vllm-bot vllm-bot merged commit 8615d97 into vllm-project:main Jun 28, 2025
98 of 105 checks passed
CSWYF3634076 pushed a commit to CSWYF3634076/vllm that referenced this pull request Jul 2, 2025
avigny pushed a commit to avigny/vllm that referenced this pull request Jul 31, 2025
…m-project#20147)

Signed-off-by: Thomas Parnell <tpa@zurich.ibm.com>
Signed-off-by: avigny <47987522+avigny@users.noreply.github.com>
googlercolin pushed a commit to googlercolin/vllm that referenced this pull request Aug 29, 2025
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