[gpt-oss] raise error for flashinfer backend without trtllm #24482
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Signed-off-by: Chen Zhang <zhangch99@outlook.com>
heheda12345
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This pull request adds checks to prevent using attention sinks with the FlashInfer backend when TRT-LLM is not available, as this configuration is unsupported. My feedback focuses on improving the robustness of these checks by replacing assert statements with explicit NotImplementedError exceptions. This ensures that the checks are not bypassed when assertions are disabled, providing more reliable error handling for unsupported configurations.
yeqcharlotte
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Sep 9, 2025
Comment on lines
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| raise NotImplementedError( | ||
| "FlashInfer backend currently does not support attention " | ||
| "sinks, please use trtllm on blackwell or flash attention on " | ||
| "earlier GPUs.") |
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possibly coordinate with #24470. we see accuracy regression for 0.2.14 actually which is fixed in >=0.3.0.
LucasWilkinson
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Sep 9, 2025
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LGTM; assuming this isn't addressed by: https://github.com/vllm-project/vllm/pull/24482/files#r2332475619
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@LucasWilkinson I'm sure it is not addressed by https://github.com/vllm-project/vllm/pull/24482/files#r2332475619. We need to pass the sink to the flashinfer kernels and I'm waiting for an interface update about this. |
mgoin
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Sep 10, 2025
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…ject#24482) Signed-off-by: Chen Zhang <zhangch99@outlook.com>
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yzh119
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Sep 15, 2025
<!-- .github/pull_request_template.md --> ## 📌 Description This PR adds a wrapper class around the JiT implementation of `AttentionSink` (GPT-OSS style) for FlashInfer backend `BatchPrefillWithPagedKVCacheWrapper`. The user should not be aware of the JiT args or backend selections. <!-- What does this PR do? Briefly describe the changes and why they’re needed. --> ## 🔍 Related Issues This should backup vllm-project/vllm#24482 <!-- Link any related issues here --> ## 🚀 Pull Request Checklist Thank you for contributing to FlashInfer! Before we review your pull request, please make sure the following items are complete. ### ✅ Pre-commit Checks - [x] I have installed `pre-commit` by running `pip install pre-commit` (or used your preferred method). - [x] I have installed the hooks with `pre-commit install`. - [x] I have run the hooks manually with `pre-commit run --all-files` and fixed any reported issues. > If you are unsure about how to set up `pre-commit`, see [the pre-commit documentation](https://pre-commit.com/). ## 🧪 Tests - [ ] Tests have been added or updated as needed. - [ ] All tests are passing (`unittest`, etc.). ## Reviewer Notes @yzh119 Current `use_sliding_window` implementation in both FA2(https://github.com/flashinfer-ai/flashinfer/blob/bc29697ba20b7e6bdb728ded98f04788e16ee021/include/flashinfer/attention/variants.cuh#L89) and FA3(https://github.com/flashinfer-ai/flashinfer/blob/bc29697ba20b7e6bdb728ded98f04788e16ee021/include/flashinfer/attention/hopper/utils.cuh#L40) don't consider `causal=False`, where qo_idx has no effect on the boundary of the sliding window. Some of the unit tests in `test_attention_sink.py` may fail due to this. <!-- Optional: anything you'd like reviewers to focus on, concerns, etc. --> cc @heheda12345 --------- Co-authored-by: happierpig <zhaoyilong217@sjtu.edn.cn>
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Sep 25, 2025
…ject#24482) Signed-off-by: Chen Zhang <zhangch99@outlook.com>
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…ject#24482) Signed-off-by: Chen Zhang <zhangch99@outlook.com> Signed-off-by: xuebwang-amd <xuebwang@amd.com>
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…ject#24482) Signed-off-by: Chen Zhang <zhangch99@outlook.com> Signed-off-by: xuebwang-amd <xuebwang@amd.com>
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Purpose
The attention sink is not integrated into flashinfer backend yet. Raise an error.
Test Plan
VLLM_ATTENTION_BACKEND=FLASHINFER vllm serve openai/gpt-oss-20bon hopperTest Result
raise the newly added error.
Essential Elements of an Effective PR Description Checklist
supported_models.mdandexamplesfor a new model.