---
id: pr-vllm-38814
repo: vllm-project/vllm
pr: 38814
title: '[FlashAttention] Symlink FA4 instead of copying when using `VLLM_FLASH_ATTN_SRC_DIR`'
author: MatthewBonanni
date: '2026-04-08'
url: https://github.com/vllm-project/vllm/pull/38814
source_category: upstream-code
architectures:
- sm100
tags:
- attention
techniques: []
hardware_features: []
kernel_types:
- attention
languages:
- python
captured_at: '2026-04-17'
status: merged
merge_sha: 308cec5864890f5c0724e1d4531d9fe2ee0a8209
inclusion_reason: semantic match with file changes
changed_paths:
- cmake/external_projects/vllm_flash_attn.cmake
- vllm/vllm_flash_attn/__init__.py
head_ref_oid: 736b7600f93e36170bf3afed182001a3e3e83e6f
artifact_dir: evidence/pull-bundles/vllm/gh-38814
---
# [FlashAttention] Symlink FA4 instead of copying when using `VLLM_FLASH_ATTN_SRC_DIR`

- Repository: `vllm-project/vllm`
- PR: [38814](https://github.com/vllm-project/vllm/pull/38814)
- Decision: `semantic match with file changes`
- Reason: semantic match with file changes

## Changed Paths

- `cmake/external_projects/vllm_flash_attn.cmake`
- `vllm/vllm_flash_attn/__init__.py`

## Evidence Bundle

`evidence/pull-bundles/vllm/gh-38814`
