---
id: pr-vllm-37303
repo: vllm-project/vllm
pr: 37303
title: '[Attention] Support distinguishing between short extends and decodes'
author: LucasWilkinson
date: '2026-03-20'
url: https://github.com/vllm-project/vllm/pull/37303
source_category: upstream-code
architectures:
- sm100
tags:
- attention
- decode
- prefill
techniques: []
hardware_features: []
kernel_types:
- attention
- decode
- prefill
languages:
- python
captured_at: '2026-04-17'
status: merged
merge_sha: e1d85e5c2454bd8d349dbe676679380cbe0e920a
inclusion_reason: kernel file changes
changed_paths:
- .buildkite/test_areas/engine.yaml
- tests/v1/attention/test_batch_reordering.py
- tests/v1/e2e/test_hybrid_chunked_prefill.py
- vllm/v1/attention/backend.py
- vllm/v1/attention/backends/mamba_attn.py
- vllm/v1/attention/backends/utils.py
- vllm/v1/worker/gpu_input_batch.py
- vllm/v1/worker/gpu_model_runner.py
- vllm/v1/worker/mamba_utils.py
artifact_dir: evidence/pull-bundles/vllm/gh-37303
head_ref_oid: f31161dfeb61c97cdd51ac66510e2af7874bea07
---
# [Attention] Support distinguishing between short extends and decodes

- Repository: `vllm-project/vllm`
- PR: [37303](https://github.com/vllm-project/vllm/pull/37303)
- Decision: `kernel file changes`
- Reason: kernel file changes

## Changed Paths

- `.buildkite/test_areas/engine.yaml`
- `tests/v1/attention/test_batch_reordering.py`
- `tests/v1/e2e/test_hybrid_chunked_prefill.py`
- `vllm/v1/attention/backend.py`
- `vllm/v1/attention/backends/mamba_attn.py`
- `vllm/v1/attention/backends/utils.py`
- `vllm/v1/worker/gpu_input_batch.py`
- `vllm/v1/worker/gpu_model_runner.py`
- `vllm/v1/worker/mamba_utils.py`

## Evidence Bundle

`evidence/pull-bundles/vllm/gh-37303`
