Files
composable_kernel/example/ck_tile
Jeff Huang cc75a1dc5f [FMHA] Batch Prefill Support Improvements: Change KV Cache Layout & Large Page Size Support (#3442)
* add page_block_size parameter

* add is_sglang_layout to  parameters

* add kv_offset_array_transform to batch async for page size 16

* add kv_last_page_lens to kernel

* change kv layout to [num_total_pages, page_block_size, hdim]

* format

* - enable codegen of batch_prefill kernels
- create new problem struct BlockFmhaBatchPrefillPipelineProblem for
  batch prefill kernels
- generate different page sizes of batch prefill kernels (1, 16)

* 1. fix wrong calculation of page id in kv_offset_array_transform in gfx950
2. support page size 1024

* fix python format

* change kv cache layout to [num_blocks, num_kv_heads, head_size/x,
block_size, x] and [num_blocks, num_kv_heads, block_size/X, head_size, X]

* 1. Introduced `kVectorSize` in BlockFmhaBatchPrefillPipelineProblem instead of using hardcode values
2. Makes batch prefill kernel traits structures inherent from fmha fwd
   traits
3. Add some static check for Page size, vector size, hdim, ..., etc.

* [Refactor] Replace is_sglang_layout with Enums for KV cache configuration

Refactored `fmha_batch_prefill` to use `BlockAttentionKVCacheMemoryLayoutEnum` (VECTORIZED/LINEAR) and `BlockAttentionKVCacheLookupTableEnum` (SGLANG_1D/VLLM_2D) instead of a single
boolean.

**Changes:**
*   Added Enum definitions in `block_attention_kvcache_layout_enum.hpp`.
*   Updated Kernel, Pipeline, and Traits to template on these Enums.
*   Implemented `kv_offset_array_transform` logic based on `kKVMemoryLayout`.
*   Refactored `PageBlockTableKargs` to adapt to `kKVLookupTable`.
*   Updated CodeGen scripts to support new parameters.

This decouples memory layout from the paging mechanism, enabling flexible KV cache configurations.

* 1. remove batch prefill pipeline with sk_pad=false
2. correct some comments
3. add static assert to make sure v offsets is in same page within a tile.

* fix vgpr spill count

* remove unnecessary t2s functions

* add fp8 support for receipt 200 and 600 in fmha_bath_prefill.py

* support linear kv cache layout

* Remove block_table_ptr from fwd_batch_prefill_args. Instead, reuse
kv_page_indices as a pointer of the lookup table.

* 1. merge multiple transforms into single transform.
2. add static check to make sure vlayout is row-major.

* move FmhaFwdCommonKargs::seqlen_k_ptr to VllmPageTableKargs.

* update changelog

---------

Co-authored-by: ltqin <letaoqin@amd.com>
Co-authored-by: PoYen, Chen <PoYen.Chen@amd.com>
2026-01-05 18:41:47 +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