---
id: pr-flash-attention-1511
repo: Dao-AILab/flash-attention
pr: 1511
title: Fix CUDA 12.1 build
author: LucasWilkinson
date: '2025-03-01'
url: https://github.com/Dao-AILab/flash-attention/pull/1511
source_category: upstream-code
architectures:
- sm100
tags:
- tma
techniques:
- async-copy
hardware_features:
- tma
kernel_types:
- attention
languages:
- cuda-cpp
captured_at: '2026-05-16'
status: merged
merge_sha: 39e71975642daab365a5a37c959182c93ed5fc8a
inclusion_reason: Search-matched CUDA kernel optimization PR; materialize diff/source before synthesis.
changed_paths:
- hopper/mainloop_fwd_sm90_tma_gmma_ws.hpp
artifact_dir: evidence/pull-bundles/flash-attention/gh-1511
head_ref_oid: 49f0924022b9feb29e01cee31587371f414c55f0
---
# Fix CUDA 12.1 build

- Repository: `Dao-AILab/flash-attention`
- PR: [1511](https://github.com/Dao-AILab/flash-attention/pull/1511)
- Decision: `Search-matched CUDA kernel optimization PR; materialize diff/source before synthesis.`
- Reason: Search-matched CUDA kernel optimization PR; materialize diff/source before synthesis.

## Changed Paths

- `hopper/mainloop_fwd_sm90_tma_gmma_ws.hpp`

## Evidence Bundle

`evidence/pull-bundles/flash-attention/gh-1511`
