Files
composable_kernel/example/ck_tile
Po Yen Chen a11f53564f [rocm-libraries] ROCm/rocm-libraries#7530 (commit 378e049)
[CK] Fix FMHA sink dispatch when init_sink_value is set (#7530)

## Summary
- Fix `traits.has_sink` in `fmha_fwd_runner.hpp` to also check
`init_sink_value != 0`, so the GPU kernel dispatches with sink support
when `-init_sink=1` is passed.
- Gate `run_sink_mask_tests` (StreamLLM) and `run_sink_init_tests`
(GPT-OSS) behind opt-in flags `-m` and `-g` in `smoke_test_fwd.sh`.
These tests require sink=true kernel instances which are excluded by the
`BUILD_TESTING` CMake filter (`*_nsink*`), causing unconditional "not
supported yet" failures (48 tests in CI). The opt-in flag approach was
borrowed from PR #6057.

## Why gate tests instead of compiling sink=true kernels?

The `BUILD_TESTING` filter in `CMakeLists.txt` uses `*_nsink*` glob
patterns for the `fwd` and `fwd_splitkv` APIs, excluding sink=true
kernel instances from compilation. We chose opt-in flags over widening
the filter because:

- **Compile time**: Enabling sink=true kernels doubles the kernel
variants for `fwd` and `fwd_splitkv` APIs. The filter exists
specifically to reduce CI build times.
- **Incremental enablement**: Sink support (StreamLLM / GPT-OSS) is
still maturing. Gating lets teams opt in explicitly (`smoke_test_fwd.sh
-g`) while keeping the default CI path fast.
- **Precedent**: splitkv (`-s`) and appendkv (`-a`) tests already follow
this opt-in pattern.

## Test plan
- [ ] Run `smoke_test_fwd.sh -g` with sink=true kernels compiled and
verify sink-enabled kernels are dispatched
- [ ] Verify `smoke_test_fwd.sh` still passes without `-m` / `-g` flags
- [ ] Confirm CI no longer fails on sink tests (they are now opt-in)
2026-05-19 00:09:23 +08:00
..

CK Tile Example Suite

This directory contains a comprehensive suite of examples demonstrating the CK Tile programming model for high-performance GPU kernels. Each example illustrates a key deep learning or HPC operation, implemented using tile-based parallelism, modular pipelines, and data movement policy.


What is CK Tile?

CK Tile is a composable GPU programming API that expresses kernels as a composition of "tiles"—rectangular blocks of computation and data movement. The pipeline & policy orchestrates data movement (global <-> LDS <-> registers), computation, and synchronization, enabling high efficiency and flexibility.


Example Index

Example Operation Description
01_fmha Fused Multi-Head Attention Tile-based FMHA with masking, quantization, and epilogue fusion
02_layernorm2d LayerNorm2D Blockwise layer normalization with fusion and quantization
03_gemm GEMM Matrix multiplication with tilewise parallelism
04_img2col im2col Image-to-column transformation for GEMM-based convolution
05_reduce Reduction Tilewise sum, max, mean reductions
06_permute Permute Generic tensor permutation (up to rank-8)
09_topk_softmax TopK-Softmax Rowwise softmax and top-k selection for MoE gating
10_rmsnorm2d RMSNorm2D Root mean square normalization for LLMs
11_add_rmsnorm2d_rdquant Add + RMSNorm2D + RDQuant Fused add, RMSNorm, and rowwise dynamic quantization
12_smoothquant SmoothQuant Per-channel scaling and quantization for int8 inference
13_moe_sorting MoE Sorting Token-to-expert rearrangement for MoE dispatch
14_moe_smoothquant MoE-SmoothQuant Expert-dependent quantization fused with top-k selection
15_fused_moe Fused MoE End-to-end fused MoE block: sorting, group-GEMM, activation, weighting
16_batched_gemm Batched GEMM Parallel computation of multiple GEMMs
17_grouped_gemm Grouped GEMM Multiple independent GEMMs with different shapes
18_flatmm FLATMM Flattened matrix multiplication for packed layouts
19_gemm_multi_d Multi-D GEMM GEMM with multiple side inputs (bias, residual, etc.)
35_batched_transpose Batched Transpose NCHW <-> NHWC and other layout conversions
36_copy Copy Minimal example for tile-based memory movement
37_transpose Block Transpose High-performance tiled transpose for large tensors

Technical Highlights


How to Build & Run

mkdir build && cd build
sh ../script/cmake-ck-dev.sh ../ <arch>
make -j

Each example produces its own executable in build/bin/.


Learning and Extending


References


Back to Composable Kernel Examples