---
id: pr-cutlass-2366
repo: NVIDIA/cutlass
pr: 2366
title: '[ex77] fix mla split; add fwd lse; add bwd varlen'
author: v0i0
date: '2025-06-05'
url: https://github.com/NVIDIA/cutlass/pull/2366
source_category: upstream-code
architectures:
- sm100
tags:
- epilogue-fusion
- flash-attention
- kernel-fusion
- mla
- tile-scheduling
- tma
techniques:
- epilogue-fusion
- kernel-fusion
- tile-scheduling
hardware_features:
- tma
kernel_types:
- flash-attention
- mla
languages:
- cuda-cpp
captured_at: '2026-04-17'
status: merged
merge_sha: f12b1d75c904c05b10650809af39511080a06ff3
inclusion_reason: kernel file changes
changed_paths:
- examples/77_blackwell_fmha/77_blackwell_fmha.cu
- examples/77_blackwell_fmha/77_blackwell_fmha_bwd.cu
- examples/77_blackwell_fmha/77_blackwell_fmha_gen.cu
- examples/77_blackwell_fmha/77_blackwell_mla.cu
- examples/77_blackwell_fmha/CMakeLists.txt
- examples/77_blackwell_fmha/collective/fmha_fusion.hpp
- examples/77_blackwell_fmha/collective/sm100_fmha_fwd_epilogue_tma_warpspecialized.hpp
- examples/77_blackwell_fmha/collective/sm100_fmha_fwd_mainloop_tma_warpspecialized.hpp
- examples/77_blackwell_fmha/device/fmha_device_bwd.hpp
- examples/77_blackwell_fmha/kernel/fmha_kernel_bwd_convert.hpp
- examples/77_blackwell_fmha/kernel/fmha_kernel_bwd_sum_OdO.hpp
- examples/77_blackwell_fmha/kernel/fmha_options.hpp
- examples/77_blackwell_fmha/kernel/fmha_tile_scheduler.hpp
- examples/77_blackwell_fmha/kernel/sm100_fmha_bwd_kernel_tma_warpspecialized.hpp
- examples/77_blackwell_fmha/kernel/sm100_fmha_fwd_kernel_tma_warpspecialized.hpp
- examples/77_blackwell_fmha/kernel/sm100_fmha_mla_reduction.hpp
- examples/77_blackwell_fmha/reference/fmha_bwd_reference.hpp
- examples/77_blackwell_fmha/reference/fmha_fwd_reference.hpp
- examples/77_blackwell_fmha/reference/reference_abs_error.hpp
head_ref_oid: 375e9ee08999c9fdd758aa76144cccd3ba384245
artifact_dir: evidence/pull-bundles/cutlass/gh-2366
---
# [ex77] fix mla split; add fwd lse; add bwd varlen

- Repository: `NVIDIA/cutlass`
- PR: [2366](https://github.com/NVIDIA/cutlass/pull/2366)
- Decision: `kernel file changes`
- Reason: kernel file changes

## Changed Paths

- `examples/77_blackwell_fmha/77_blackwell_fmha.cu`
- `examples/77_blackwell_fmha/77_blackwell_fmha_bwd.cu`
- `examples/77_blackwell_fmha/77_blackwell_fmha_gen.cu`
- `examples/77_blackwell_fmha/77_blackwell_mla.cu`
- `examples/77_blackwell_fmha/CMakeLists.txt`
- `examples/77_blackwell_fmha/collective/fmha_fusion.hpp`
- `examples/77_blackwell_fmha/collective/sm100_fmha_fwd_epilogue_tma_warpspecialized.hpp`
- `examples/77_blackwell_fmha/collective/sm100_fmha_fwd_mainloop_tma_warpspecialized.hpp`
- `examples/77_blackwell_fmha/device/fmha_device_bwd.hpp`
- `examples/77_blackwell_fmha/kernel/fmha_kernel_bwd_convert.hpp`
- `examples/77_blackwell_fmha/kernel/fmha_kernel_bwd_sum_OdO.hpp`
- `examples/77_blackwell_fmha/kernel/fmha_options.hpp`
- `examples/77_blackwell_fmha/kernel/fmha_tile_scheduler.hpp`
- `examples/77_blackwell_fmha/kernel/sm100_fmha_bwd_kernel_tma_warpspecialized.hpp`
- `examples/77_blackwell_fmha/kernel/sm100_fmha_fwd_kernel_tma_warpspecialized.hpp`
- `examples/77_blackwell_fmha/kernel/sm100_fmha_mla_reduction.hpp`
- `examples/77_blackwell_fmha/reference/fmha_bwd_reference.hpp`
- `examples/77_blackwell_fmha/reference/fmha_fwd_reference.hpp`
- `examples/77_blackwell_fmha/reference/reference_abs_error.hpp`

## Evidence Bundle

`evidence/pull-bundles/cutlass/gh-2366`
