---
id: pr-flash-attention-2108
repo: Dao-AILab/flash-attention
pr: 2108
title: '[NVIDIA] Enable Jetson Thor FA4'
author: johnnynunez
date: '2025-12-29'
url: https://github.com/Dao-AILab/flash-attention/pull/2108
source_category: upstream-code
architectures:
- sm100
tags:
- FA4
- arch_pipeline
- attention_kv
- blackwell
- compiler_runtime
techniques:
- pipeline-stages
hardware_features:
- blackwell
- tcgen05
- tmem
kernel_types:
- attention
- compiler
- runtime
languages:
- cute-dsl
- ptx
captured_at: '2026-05-16'
status: merged
merge_sha: d2340513165f54e76de2bb8169f5c5bbb2511271
inclusion_reason: Preserve page/KV/layout and plan-run contracts; profile memory traffic separately from math utilization.
changed_paths:
- csrc/cutlass
- flash_attn/cute/interface.py
artifact_dir: evidence/pull-bundles/flash-attention/gh-2108
head_ref_oid: f8fac05186f85ed4592940ec420a3ed2db6bef6b
---
# [NVIDIA] Enable Jetson Thor FA4

- Repository: `Dao-AILab/flash-attention`
- PR: [2108](https://github.com/Dao-AILab/flash-attention/pull/2108)
- 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

- `csrc/cutlass`
- `flash_attn/cute/interface.py`

## Evidence Bundle

`evidence/pull-bundles/flash-attention/gh-2108`
