---
id: pr-flashinfer-1072
repo: flashinfer-ai/flashinfer
pr: 1072
title: 'bugfix: follow user-specified sm_scale for blackwell cutlass fmha'
author: yzh119
date: '2025-05-20'
url: https://github.com/flashinfer-ai/flashinfer/pull/1072
source_category: upstream-code
architectures:
- sm100
tags:
- attention
- flash-attention
- prefill
- tma
techniques: []
hardware_features:
- tma
kernel_types:
- attention
- flash-attention
- prefill
languages:
- cuda-cpp
captured_at: '2026-04-17'
status: merged
merge_sha: fc62e3f2f478e087cec570f3d4b20ff6848006f4
inclusion_reason: kernel file changes
changed_paths:
- flashinfer/prefill.py
- include/flashinfer/attention/blackwell/collective/sm100_fmha_fwd_mainloop_tma_warpspecialized.hpp
- include/flashinfer/attention/blackwell/fmha_cutlass_sm100.cuh
- tests/test_blackwell_fmha.py
head_ref_oid: dc6ef3864fd5ba6d7a12af066f750fbc125f7910
artifact_dir: evidence/pull-bundles/flashinfer/gh-1072
---
# bugfix: follow user-specified sm_scale for blackwell cutlass fmha

- Repository: `flashinfer-ai/flashinfer`
- PR: [1072](https://github.com/flashinfer-ai/flashinfer/pull/1072)
- Decision: `kernel file changes`
- Reason: kernel file changes

## Changed Paths

- `flashinfer/prefill.py`
- `include/flashinfer/attention/blackwell/collective/sm100_fmha_fwd_mainloop_tma_warpspecialized.hpp`
- `include/flashinfer/attention/blackwell/fmha_cutlass_sm100.cuh`
- `tests/test_blackwell_fmha.py`

## Evidence Bundle

`evidence/pull-bundles/flashinfer/gh-1072`
