---
id: pr-sglang-20576
repo: sgl-project/sglang
pr: 20576
title: '[Diffusion] Clean upstream fa3 in hopper'
author: BBuf
date: '2026-03-14'
url: https://github.com/sgl-project/sglang/pull/20576
source_category: upstream-code
architectures:
- sm90
tags:
- arch_pipeline
- attention_kv
- benchmark_test
- hopper
- norm_elementwise
techniques:
- kernel-fusion
- pipeline-stages
hardware_features:
- hopper
kernel_types:
- attention
- norm
- runtime
languages:
- cuda-cpp
captured_at: '2026-05-16'
status: merged
merge_sha: 5ab2cfe9a899d1d2dffae932fb0f6371014d0d71
inclusion_reason: Preserve page/KV/layout and plan-run contracts; profile memory traffic separately from math utilization.
changed_paths:
- python/sglang/multimodal_gen/.claude/skills/diffusion-kernel/scripts/bench_diffusion_denoise.py
- python/sglang/multimodal_gen/.claude/skills/diffusion-kernel/scripts/bench_diffusion_rmsnorm.py
- python/sglang/multimodal_gen/runtime/layers/attention/backends/flash_attn.py
artifact_dir: evidence/pull-bundles/sglang/gh-20576
head_ref_oid: aa693d6d77fd3cfb7b6daf40701fe7e269b9d7e2
---
# [Diffusion] Clean upstream fa3 in hopper

- Repository: `sgl-project/sglang`
- PR: [20576](https://github.com/sgl-project/sglang/pull/20576)
- Decision: `Preserve page/KV/layout and plan-run contracts; profile memory traffic separately from math utilization.`
- Reason: Preserve page/KV/layout and plan-run contracts; profile memory traffic separately from math utilization.

## Changed Paths

- `python/sglang/multimodal_gen/.claude/skills/diffusion-kernel/scripts/bench_diffusion_denoise.py`
- `python/sglang/multimodal_gen/.claude/skills/diffusion-kernel/scripts/bench_diffusion_rmsnorm.py`
- `python/sglang/multimodal_gen/runtime/layers/attention/backends/flash_attn.py`

## Evidence Bundle

`evidence/pull-bundles/sglang/gh-20576`
