---
id: pr-sglang-9928
repo: sgl-project/sglang
pr: 9928
title: support using fa4 on deepseek on blackwell
author: cicirori
date: '2025-09-16'
url: https://github.com/sgl-project/sglang/pull/9928
source_category: upstream-code
architectures:
- sm100
tags:
- attention
techniques: []
hardware_features: []
kernel_types:
- attention
languages:
- python
captured_at: '2026-04-27'
status: merged
merge_sha: a2f7218a2e2351a08f0aae5807bdbea633e27fe3
inclusion_reason: kernel file changes
changed_paths:
- python/sglang/srt/entrypoints/engine.py
- python/sglang/srt/layers/attention/flashattention_backend.py
- python/sglang/srt/layers/attention/hybrid_attn_backend.py
- python/sglang/srt/model_executor/model_runner.py
- python/sglang/srt/models/deepseek_v2.py
- python/sglang/srt/server_args.py
- sgl-kernel/python/sgl_kernel/_fa4_interface.py
head_ref_oid: 6eca665c0ebbc2100c3b3e018fdf63f3e9fce186
artifact_dir: evidence/pull-bundles/sglang/gh-9928
---
# support using fa4 on deepseek on blackwell

- Repository: `sgl-project/sglang`
- PR: [9928](https://github.com/sgl-project/sglang/pull/9928)
- Decision: `kernel file changes`
- Reason: kernel file changes

## Changed Paths

- `python/sglang/srt/entrypoints/engine.py`
- `python/sglang/srt/layers/attention/flashattention_backend.py`
- `python/sglang/srt/layers/attention/hybrid_attn_backend.py`
- `python/sglang/srt/model_executor/model_runner.py`
- `python/sglang/srt/models/deepseek_v2.py`
- `python/sglang/srt/server_args.py`
- `sgl-kernel/python/sgl_kernel/_fa4_interface.py`

## Evidence Bundle

`evidence/pull-bundles/sglang/gh-9928`
