---
id: pr-flash-attention-2274
repo: Dao-AILab/flash-attention
pr: 2274
title: guard use_2cta_instrs on sm90
author: reubenconducts
date: '2026-02-25'
url: https://github.com/Dao-AILab/flash-attention/pull/2274
source_category: upstream-code
architectures:
- sm90
tags:
- sm90
techniques: []
hardware_features:
- hopper
kernel_types:
- attention
languages: []
captured_at: '2026-05-16'
status: merged
merge_sha: 0586d2e78aff94f53cca056744e9aa2e429c03e7
inclusion_reason: Search-matched CUDA kernel optimization PR; materialize diff/source before synthesis.
changed_paths:
- flash_attn/cute/interface.py
artifact_dir: evidence/pull-bundles/flash-attention/gh-2274
head_ref_oid: 904a0c33eb627ac7861a03bf65435797fb309c17
---
# guard use_2cta_instrs on sm90

- Repository: `Dao-AILab/flash-attention`
- PR: [2274](https://github.com/Dao-AILab/flash-attention/pull/2274)
- 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

- `flash_attn/cute/interface.py`

## Evidence Bundle

`evidence/pull-bundles/flash-attention/gh-2274`
