---
id: pr-pytorch-171895
repo: pytorch/pytorch
pr: 171895
title: '[cherry-pick][cuDNN][SDPA] cuDNN SDPA off-by-default for cuDNN versions < 12.9 (#171627)'
author: atalman
date: '2026-01-07'
url: https://github.com/pytorch/pytorch/pull/171895
source_category: upstream-code
architectures:
- sm100
tags:
- gemm
techniques: []
hardware_features: []
kernel_types:
- gemm
languages:
- cuda-cpp
captured_at: '2026-04-17'
status: merged
merge_sha: e2457567a3fd09fc4ef8493dc10491f21749cebc
inclusion_reason: semantic match with file changes
changed_paths:
- aten/src/ATen/native/transformers/cuda/sdp_utils.cpp
head_ref_oid: 8d5580e85aa29ac5ebcd37863e5855ab54b45c0a
artifact_dir: evidence/pull-bundles/pytorch/gh-171895
---
# [cherry-pick][cuDNN][SDPA] cuDNN SDPA off-by-default for cuDNN versions < 12.9 (#171627)

- Repository: `pytorch/pytorch`
- PR: [171895](https://github.com/pytorch/pytorch/pull/171895)
- Decision: `semantic match with file changes`
- Reason: semantic match with file changes

## Changed Paths

- `aten/src/ATen/native/transformers/cuda/sdp_utils.cpp`

## Evidence Bundle

`evidence/pull-bundles/pytorch/gh-171895`
