---
id: pr-flash-attention-1603
repo: Dao-AILab/flash-attention
pr: 1603
title: add sm_margin for hopper flash_attn_qkvpacked_func
author: TopIdiot
date: '2025-04-22'
url: https://github.com/Dao-AILab/flash-attention/pull/1603
source_category: upstream-code
architectures:
- sm90
tags:
- hopper
techniques: []
hardware_features:
- hopper
kernel_types:
- attention
languages: []
captured_at: '2026-05-16'
status: merged
merge_sha: 75f90d60f348af768625b6ab6ce13e800c5bc48a
inclusion_reason: Search-matched CUDA kernel optimization PR; materialize diff/source before synthesis.
changed_paths:
- hopper/flash_attn_interface.py
artifact_dir: evidence/pull-bundles/flash-attention/gh-1603
head_ref_oid: f71166a96332388bb1d7f531f84d53780adecf9f
---
# add sm_margin for hopper flash_attn_qkvpacked_func

- Repository: `Dao-AILab/flash-attention`
- PR: [1603](https://github.com/Dao-AILab/flash-attention/pull/1603)
- 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/flash_attn_interface.py`

## Evidence Bundle

`evidence/pull-bundles/flash-attention/gh-1603`
