---
id: pr-sglang-16335
repo: sgl-project/sglang
pr: 16335
title: '[diffusion] Fix RuntimeError in SageAttention3 on Nvidia Blackwell with Qwen-Image'
author: qimcis
date: '2026-01-03'
url: https://github.com/sgl-project/sglang/pull/16335
source_category: upstream-code
architectures:
- sm100
tags:
- attention
- kernel-fusion
techniques:
- kernel-fusion
hardware_features: []
kernel_types:
- attention
languages:
- cuda-cpp
- python
captured_at: '2026-04-27'
status: merged
merge_sha: dcacc492d04c402fd12dc425829cf72985f5e047
inclusion_reason: kernel file changes
changed_paths:
- python/sglang/multimodal_gen/runtime/layers/attention/backends/sage_attn3.py
- python/sglang/multimodal_gen/runtime/platforms/cuda.py
head_ref_oid: 4b5bb99b3a2ab27aa3774d9396ef4304faa5a1f1
artifact_dir: evidence/pull-bundles/sglang/gh-16335
---
# [diffusion] Fix RuntimeError in SageAttention3 on Nvidia Blackwell with Qwen-Image

- Repository: `sgl-project/sglang`
- PR: [16335](https://github.com/sgl-project/sglang/pull/16335)
- Decision: `kernel file changes`
- Reason: kernel file changes

## Changed Paths

- `python/sglang/multimodal_gen/runtime/layers/attention/backends/sage_attn3.py`
- `python/sglang/multimodal_gen/runtime/platforms/cuda.py`

## Evidence Bundle

`evidence/pull-bundles/sglang/gh-16335`
