---
id: pr-flash-attention-2441
repo: Dao-AILab/flash-attention
pr: 2441
title: '[Cute,Sm100,Fwd] add MLA 64/512 with topk sparsity for MQA 128 heads'
author: jayhshah
date: '2026-04-15'
url: https://github.com/Dao-AILab/flash-attention/pull/2441
source_category: upstream-code
architectures:
- sm100
tags:
- FA4
- MLA
- arch_pipeline
- attention_kv
- benchmark_test
- cute
- moe_routing
- scheduler_autotune
- sm100
- varlen
techniques:
- async-copy
- autotuning
- persistent-kernels
- pipeline-stages
- tile-scheduling
hardware_features:
- blackwell
- tma
kernel_types:
- attention
- decode
- mla
- moe
- runtime
- scheduler
- softmax
languages:
- cuda-cpp
- cute-dsl
captured_at: '2026-05-16'
status: merged
merge_sha: f219c89c886c6ccbf9d3dbd9fe41b11ac64e9df8
inclusion_reason: Preserve page/KV/layout and plan-run contracts; profile memory traffic separately from math utilization.
changed_paths:
- .pre-commit-config.yaml
- benchmarks/benchmark_attn.py
- flash_attn/cute/bench_utils.py
- flash_attn/cute/cute_dsl_utils.py
- flash_attn/cute/flash_fwd_mla_sm100.py
- flash_attn/cute/interface.py
- flash_attn/cute/mask.py
- flash_attn/cute/named_barrier.py
- flash_attn/cute/softmax.py
- flash_attn/cute/testing.py
- flash_attn/cute/tile_scheduler.py
- flash_attn/cute/topk_gather_kv.py
- tests/cute/test_flash_attn.py
artifact_dir: evidence/pull-bundles/flash-attention/gh-2441
head_ref_oid: 75e37120ee9383c0f0033d1c99cc5f31f8035728
---
# [Cute,Sm100,Fwd] add MLA 64/512 with topk sparsity for MQA 128 heads

- Repository: `Dao-AILab/flash-attention`
- PR: [2441](https://github.com/Dao-AILab/flash-attention/pull/2441)
- 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

- `.pre-commit-config.yaml`
- `benchmarks/benchmark_attn.py`
- `flash_attn/cute/bench_utils.py`
- `flash_attn/cute/cute_dsl_utils.py`
- `flash_attn/cute/flash_fwd_mla_sm100.py`
- `flash_attn/cute/interface.py`
- `flash_attn/cute/mask.py`
- `flash_attn/cute/named_barrier.py`
- `flash_attn/cute/softmax.py`
- `flash_attn/cute/testing.py`
- `flash_attn/cute/tile_scheduler.py`
- `flash_attn/cute/topk_gather_kv.py`
- `tests/cute/test_flash_attn.py`

## Evidence Bundle

`evidence/pull-bundles/flash-attention/gh-2441`
