---
id: pr-vllm-36059
repo: vllm-project/vllm
pr: 36059
title: '[BugFix] Fallback from FA4->FA2 for Batch Invariance'
author: frankwang28
date: '2026-03-05'
url: https://github.com/vllm-project/vllm/pull/36059
source_category: upstream-code
architectures:
- sm100
tags:
- attention
techniques: []
hardware_features: []
kernel_types:
- attention
languages:
- python
captured_at: '2026-04-27'
status: merged
merge_sha: a57c877f18188cb7bafc0fc5309b6c88fe2a8f66
inclusion_reason: kernel file changes
changed_paths:
- vllm/v1/attention/backends/fa_utils.py
head_ref_oid: 7db7994b37dd55bfc9d94db6364059772f052d48
artifact_dir: evidence/pull-bundles/vllm/gh-36059
---
# [BugFix] Fallback from FA4->FA2 for Batch Invariance

- Repository: `vllm-project/vllm`
- PR: [36059](https://github.com/vllm-project/vllm/pull/36059)
- Decision: `kernel file changes`
- Reason: kernel file changes

## Changed Paths

- `vllm/v1/attention/backends/fa_utils.py`

## Evidence Bundle

`evidence/pull-bundles/vllm/gh-36059`
