---
id: pr-flash-attention-2504
repo: Dao-AILab/flash-attention
pr: 2504
title: '[SM100] Guard gO None in empty-tile correction'
author: geruome
date: '2026-04-27'
url: https://github.com/Dao-AILab/flash-attention/pull/2504
source_category: upstream-code
architectures:
- sm100
tags:
- attention
- attention kernel
- cuda kernel
- cute
- sm100
- tma
techniques:
- async-copy
hardware_features:
- blackwell
- tma
kernel_types:
- attention
languages:
- cuda-cpp
- cute-dsl
captured_at: '2026-05-16'
status: merged
merge_sha: 547031aaac1fa613b63ec03a1babc1cf5fd1967d
inclusion_reason: Search-matched CUDA kernel optimization PR; materialize diff/source before synthesis.
changed_paths:
- flash_attn/cute/block_sparse_utils.py
artifact_dir: evidence/pull-bundles/flash-attention/gh-2504
head_ref_oid: c2297ca47cf7455629ae43004ab2af8f75c3a9ca
---
# [SM100] Guard gO None in empty-tile correction

- Repository: `Dao-AILab/flash-attention`
- PR: [2504](https://github.com/Dao-AILab/flash-attention/pull/2504)
- 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/block_sparse_utils.py`

## Evidence Bundle

`evidence/pull-bundles/flash-attention/gh-2504`
