[CK_TILE] Grouped GEMM tile loop (#2146)

* Add trait to use a persistent kernel and split the entrypoints in grouped gemm

* Some helper functions for persistent kernel case

* Get max occupancy grid using device properties

* Implement tile loop in main entry point to grouped gemm

* Enable GridSize() on device

* Handle offset tile index using real current block index

* Add persistent kernel choice to grouped gemm example

* Use a for-loop for iterating over the group

* Reduce VGPR spills by early-exit

* Enable persistent kernel choice in grouped_gemm example

* Add persistent kernel option to grouped_gemm test

* Fix formatting with remod.py

* Remove GridUpdateBlocks as blocks are now iteratively computed

* Add comment about VGPR spilling

* Fix formatting

* Use CK_TILE_HOST instead of __host__

* Enable all Row/Col combinations in grouped gemm unit test

* Add some KBatch=2 cases to grouped gemm tests

* Fix SplitK for grouped gemm

* Enable pipeline hotloop/tailnumber selection in-kernel for grouped gemm

* Add type traits

* Split examples to regular and tileloop

* Formatting

* Use hipExtStreamGetCUMask to get current active CUs for the given stream

* Align test and example kernel config, and disable validation for splitk repeats

* Remove debug options from CMakeLists.txt

* Separate the code paths for persistent/non-persistent in test

* Fix formatting

* Address review comments

---------

Co-authored-by: Adam Osewski <19374865+aosewski@users.noreply.github.com>
This commit is contained in:
Sami Remes
2025-05-20 17:18:57 +03:00
committed by GitHub
parent c4929225f6
commit d1e6f0982d
15 changed files with 908 additions and 146 deletions

View File

@@ -195,6 +195,22 @@ struct OffsettedTile1DPartitioner
const auto [iM, iN] = TilePartitioner{M, N}.GetOutputTileIndex(blockIdx.x - block_start);
return make_tuple(iM, iN);
}
/**
* @brief The function subtracts the block's start (offset) from a given block index.
* @param [in] block_start Workgroup offset.
* @param [in] M Gemm's M dimension.
* @param [in] N Gemm's N dimension.
* @param [in] block_idx Current block index of the workgroup.
* @return Returns a `tuple` [Im, In] with shifted index.
*/
[[nodiscard]] CK_TILE_DEVICE static auto
GetOffsetedTileIndex(index_t block_start, index_t M, index_t N, index_t block_idx) noexcept
-> const tuple<index_t, index_t>
{
const auto [iM, iN] = TilePartitioner{M, N}.GetOutputTileIndex(block_idx - block_start);
return make_tuple(iM, iN);
}
};
/**
@@ -230,7 +246,7 @@ struct GemmSpatiallyLocalTilePartitioner
* @param N GEMM's N dimension.
* @return index_t A total number of workgroups.
*/
CK_TILE_HOST static auto
CK_TILE_HOST_DEVICE static auto
GridSize(index_t M, index_t N) noexcept(noexcept(MPerBlock != 0 && NPerBlock != 0)) -> index_t
{
const index_t GridDimX = integer_divide_ceil(M, MPerBlock);

View File

@@ -5,10 +5,15 @@
#include "ck_tile/core/numeric/math.hpp"
#include "ck_tile/core/utility/literals.hpp"
#include "ck_tile/core/utility/type_traits.hpp"
#include "ck_tile/host/stream_utils.hpp"
#include "ck_tile/ops/gemm/pipeline/gemm_pipeline_ag_bg_cr_comp_v3.hpp"
#include "ck_tile/ops/gemm/pipeline/gemm_pipeline_ag_bg_cr_scheduler.hpp"
#include "ck_tile/ops/gemm/kernel/gemm_kernel.hpp"
#include "ck_tile/host.hpp"
#include <hip/hip_runtime.h>
namespace ck_tile {
struct GemmTransKernelArg
@@ -22,6 +27,8 @@ struct GemmTransKernelArg
: group_karg{karg}, block_start{bl_start}, block_end{bl_end}
{
}
GemmTransKernelArg(GemmKernelArgs&& karg) : group_karg{karg}, block_start{0}, block_end{0} {}
};
template <typename TilePartitioner_, typename GemmPipeline_, typename EpiloguePipeline_>
@@ -40,8 +47,10 @@ struct GroupedGemmKernel : public GemmKernel<TilePartitioner_, GemmPipeline_, Ep
using OffsetTile1DPartitioner = OffsettedTile1DPartitioner<TilePartitioner>;
using Base = GemmKernel<TilePartitioner_, GemmPipeline_, EpiloguePipeline_>;
using Kernel = GroupedGemmKernel<TilePartitioner, GemmPipeline, EpiloguePipeline>;
static constexpr index_t KernelBlockSize = GemmPipeline::BlockSize;
static constexpr index_t KernelBlockSize = GemmPipeline::BlockSize;
static constexpr bool UsePersistentKernel = GemmPipeline::UsePersistentKernel;
[[nodiscard]] CK_TILE_HOST static const std::string GetName()
{
@@ -51,19 +60,42 @@ struct GroupedGemmKernel : public GemmKernel<TilePartitioner_, GemmPipeline_, Ep
return concat('_', "gemm_grouped", gemm_prec_str<ADataType, BDataType>,
concat('x', P_::MPerBlock, P_::NPerBlock, P_::KPerBlock),
concat('x', P_::GetVectorSizeA(), P_::GetVectorSizeB(), P_::GetVectorSizeC()),
concat('x', P_::kPadM, P_::kPadN, P_::kPadK));
concat('x', P_::kPadM, P_::kPadN, P_::kPadK),
(UsePersistentKernel ? "Persistent" : "NonPersistent"));
// clang-format on
}
__host__ static auto GetWorkSpaceSize(const std::vector<GemmHostArgs>& gemm_descs)
CK_TILE_HOST static auto GetWorkSpaceSize(const std::vector<GemmHostArgs>& gemm_descs)
-> std::size_t
{
return gemm_descs.size() * sizeof(GemmTransKernelArg);
}
__host__ static constexpr auto BlockSize() -> dim3 { return dim3(KernelBlockSize); }
CK_TILE_HOST static auto GetWorkSpaceSize(index_t group_count) -> std::size_t
{
return group_count * sizeof(GemmTransKernelArg);
}
__host__ static constexpr auto GridSize(const std::vector<GemmHostArgs>& gemm_descs)
CK_TILE_HOST static constexpr auto BlockSize() -> dim3 { return dim3(KernelBlockSize); }
/**
* @brief Get the maximum occupancy grid size for the persistent kernel on the current device.
* @return The maximum occupancy grid size.
* @note This function queries the maximum occupancy of the kernel using
* `hipOccupancyMaxActiveBlocksPerMultiprocessor`.
*/
CK_TILE_HOST static auto MaxOccupancyGridSize(const stream_config& s) -> dim3
{
using ConstantPointer = const void CK_CONSTANT_ADDRESS_SPACE*;
const auto kernel = kentry<KernelBlockSize, 1, Kernel, ConstantPointer, index_t>;
int occupancy;
HIP_CHECK_ERROR(
hipOccupancyMaxActiveBlocksPerMultiprocessor(&occupancy, kernel, KernelBlockSize, 0));
const int grid_size = get_available_compute_units(s) * occupancy;
return dim3(grid_size, 1, 1);
}
CK_TILE_HOST static constexpr auto GridSize(const std::vector<GemmHostArgs>& gemm_descs)
{
index_t grid_size = 0;
for(const auto& it_desc : gemm_descs)
@@ -121,39 +153,165 @@ struct GroupedGemmKernel : public GemmKernel<TilePartitioner_, GemmPipeline_, Ep
return gemm_kernel_args_;
}
CK_TILE_HOST static bool IsSupportedArgument(const std::vector<GemmTransKernelArg>& kargs)
{
for(const auto& karg : kargs)
{
if(!Base::IsSupportedArgument(karg.group_karg))
{
return false;
}
}
return true;
}
CK_TILE_HOST_DEVICE static constexpr auto GetSmemSize() -> index_t
{
return max(GemmPipeline::GetSmemSize(), EpiloguePipeline::GetSmemSize());
}
CK_TILE_DEVICE void Run(const GemmTransKernelArg& kargs) const
CK_TILE_DEVICE void Run(const GemmTransKernelArg& kargs,
const tuple<index_t, index_t>& block_idx_2d,
const index_t block_idx_z) const
{
const auto [iM, iN] = OffsetTile1DPartitioner::GetOffsetedTileIndex(
kargs.block_start, kargs.group_karg.M, kargs.group_karg.N);
Run(kargs.group_karg, block_idx_2d, block_idx_z);
}
CK_TILE_DEVICE void Run(const GemmKernelArgs& kargs,
const tuple<index_t, index_t>& block_idx_2d,
const index_t block_idx_z) const
{
const auto [iM, iN] = block_idx_2d;
const index_t i_m = __builtin_amdgcn_readfirstlane(iM * TilePartitioner::MPerBlock);
const index_t i_n = __builtin_amdgcn_readfirstlane(iN * TilePartitioner::NPerBlock);
const typename Base::SplitKBatchOffset splitk_batch_offset(kargs.group_karg, blockIdx.z);
const typename Base::SplitKBatchOffset splitk_batch_offset(kargs, block_idx_z);
const ADataType* a_ptr = static_cast<const ADataType*>(kargs.group_karg.a_ptr);
const BDataType* b_ptr = static_cast<const BDataType*>(kargs.group_karg.b_ptr);
CDataType* c_ptr = static_cast<CDataType*>(kargs.group_karg.c_ptr);
const ADataType* a_ptr =
static_cast<const ADataType*>(kargs.a_ptr) + splitk_batch_offset.a_k_split_offset;
const BDataType* b_ptr =
static_cast<const BDataType*>(kargs.b_ptr) + splitk_batch_offset.b_k_split_offset;
CDataType* c_ptr = static_cast<CDataType*>(kargs.c_ptr);
// allocate LDS
__shared__ char smem_ptr[GetSmemSize()];
this->RunGemm(
a_ptr, b_ptr, c_ptr, smem_ptr, kargs.group_karg, splitk_batch_offset, i_m, i_n);
if constexpr(UsePersistentKernel)
{
RunGemmWithPipelineSelection(
a_ptr, b_ptr, c_ptr, smem_ptr, kargs, splitk_batch_offset, i_m, i_n);
}
else
{
this->RunGemm(a_ptr, b_ptr, c_ptr, smem_ptr, kargs, splitk_batch_offset, i_m, i_n);
}
}
CK_TILE_DEVICE void operator()(const void CK_CONSTANT_ADDRESS_SPACE* gemm_descs_const,
index_t group_count) const
/**
* @brief Runs single GEMM problem cooperatively by whole workgroup.
*
* @note The GEMM pipeline is selected in-kernel based on the number of K-loops
* and the tail-number. This is needed for the persistent tile-loop when
* we didn't have access to the K dimension on the host.
*
* @param a_ptr input A pointer
* @param b_ptr input B pointer
* @param c_ptr output C pointer
* @param smem_ptr_0 The start memory pointer of the shared memory block.
* @param kargs GEMM kernel arguments
* @param splitk_batch_offset splitk_batch_offset Utility structure used to calculate k batch.
* @param block_idx_m The GEMM's output M dimension tile index processed by this workgroup.
* @param block_idx_n The GEMM's output N dimension tile index processed by this workgroup.
*
*/
CK_TILE_DEVICE static void
RunGemmWithPipelineSelection(const ADataType* a_ptr,
const BDataType* b_ptr,
CDataType* c_ptr,
void* smem_ptr_0,
const GemmKernelArgs& kargs,
const typename Base::SplitKBatchOffset& splitk_batch_offset,
const index_t block_idx_m,
const index_t block_idx_n)
{
const index_t block_id = ck_tile::get_block_1d_id();
const auto gemm_desc_ptr = reinterpret_cast<const GemmTransKernelArg*>(
cast_pointer_to_generic_address_space(gemm_descs_const));
// Create Gemm tensor views, pad views and tile windows
const auto& gemm_tensor_views_tuple =
Base::template MakeGemmTensorViews<EpiloguePipeline::MemoryOperation>(
a_ptr, b_ptr, c_ptr, kargs, splitk_batch_offset);
const auto& gemm_pad_views = Base::MakeGemmPadViews(gemm_tensor_views_tuple);
auto gemm_tile_windows =
Base::MakeGemmTileWindows(gemm_pad_views, block_idx_m, block_idx_n);
const auto& a_block_window = gemm_tile_windows.at(Base::I0);
const auto& b_block_window = gemm_tile_windows.at(Base::I1);
// Get hot-loop and tail configuration
const index_t num_loop = __builtin_amdgcn_readfirstlane(
TilePartitioner::GetLoopNum(splitk_batch_offset.splitted_k));
const bool has_hot_loop = GemmPipeline::BlockHasHotloop(num_loop);
const TailNumber tail_num = GemmPipeline::GetBlockLoopTailNum(num_loop);
const auto RunEpilogue = [&](auto& c_block_tile) {
// Run Epilogue Pipeline
auto& c_block_window = gemm_tile_windows.at(Base::I2);
EpiloguePipeline{}
.template operator()<decltype(c_block_window), decltype(c_block_tile)>(
c_block_window, c_block_tile, smem_ptr_0);
};
if constexpr(is_specialization_of<GemmPipeline, GemmPipelineAgBgCrCompV3>::value)
{
// Run the specific implementation with hotloop+tailnum config
using PipelineImpl =
typename GemmPipeline::template PipelineImpl<GemmPipeline::Scheduler>;
const auto PassThrough = [](const auto& a) { return a; };
if(has_hot_loop && tail_num == TailNumber::Full)
{
const auto& c_block_tile =
PipelineImpl{}.template operator()<true, TailNumber::Full>(a_block_window,
PassThrough,
b_block_window,
PassThrough,
num_loop,
smem_ptr_0);
RunEpilogue(c_block_tile);
}
else if(has_hot_loop && tail_num == TailNumber::Odd)
{
const auto& c_block_tile =
PipelineImpl{}.template operator()<true, TailNumber::Odd>(a_block_window,
PassThrough,
b_block_window,
PassThrough,
num_loop,
smem_ptr_0);
RunEpilogue(c_block_tile);
}
else if(has_hot_loop && tail_num == TailNumber::Even)
{
const auto& c_block_tile =
PipelineImpl{}.template operator()<true, TailNumber::Even>(a_block_window,
PassThrough,
b_block_window,
PassThrough,
num_loop,
smem_ptr_0);
RunEpilogue(c_block_tile);
}
}
else
{
ignore = a_block_window;
ignore = b_block_window;
static_assert(false, "GemmPipeline specialization not supported!");
}
}
CK_TILE_DEVICE index_t FindGroupId(const GemmTransKernelArg* gemm_desc_ptr,
index_t block_id,
index_t group_count) const
{
index_t left = 0;
index_t right = group_count;
index_t group_id = index_t((left + right) >> 1);
@@ -173,7 +331,61 @@ struct GroupedGemmKernel : public GemmKernel<TilePartitioner_, GemmPipeline_, Ep
group_id = index_t((left + right) >> 1);
}
Run(gemm_desc_ptr[group_id]);
return group_id;
}
// For non-persistent kernels
template <bool U = UsePersistentKernel, typename = std::enable_if_t<!U>>
CK_TILE_DEVICE void operator()(const void CK_CONSTANT_ADDRESS_SPACE* gemm_descs_const,
index_t group_count) const
{
const index_t block_id = ck_tile::get_block_1d_id();
const auto gemm_desc_ptr = reinterpret_cast<const GemmTransKernelArg*>(
cast_pointer_to_generic_address_space(gemm_descs_const));
const index_t group_id = FindGroupId(gemm_desc_ptr, block_id, group_count);
const auto& kargs = gemm_desc_ptr[group_id];
const auto grid_size_2d = TilePartitioner::GridSize(kargs.group_karg.M, kargs.group_karg.N);
const auto block_idx_2d = OffsetTile1DPartitioner::GetOffsetedTileIndex(
0,
kargs.group_karg.M,
kargs.group_karg.N,
(block_id - kargs.block_start) % grid_size_2d);
Run(kargs, block_idx_2d, (block_id - kargs.block_start) / grid_size_2d);
}
// For persistent kernels
template <bool U = UsePersistentKernel,
typename = std::enable_if_t<U>,
typename = void> // extra template parameter to avoid redefinition
CK_TILE_DEVICE void operator()(const void CK_CONSTANT_ADDRESS_SPACE* gemm_descs_const,
const index_t group_count) const
{
const index_t grid_size = ck_tile::get_grid_size();
const auto gemm_desc_ptr = reinterpret_cast<const GemmTransKernelArg*>(
cast_pointer_to_generic_address_space(gemm_descs_const));
index_t block_id = ck_tile::get_block_1d_id(); // initial block_id
index_t cum_grid_size = 0;
for(index_t group_id = 0; group_id < group_count; ++group_id)
{
const auto& kargs = gemm_desc_ptr[group_id].group_karg;
const auto& k_batch = kargs.k_batch;
const auto block_start = cum_grid_size;
cum_grid_size += TilePartitioner::GridSize(kargs.M, kargs.N) * k_batch;
while(block_id < cum_grid_size)
{
const auto grid_size_2d = TilePartitioner::GridSize(kargs.M, kargs.N);
const auto block_idx_2d = OffsetTile1DPartitioner::GetOffsetedTileIndex(
0, kargs.M, kargs.N, (block_id - block_start) % grid_size_2d);
Run(kargs, block_idx_2d, (block_id - block_start) / grid_size_2d);
block_id = block_id + grid_size; // advance to next block
// NOTE: this check is redundant but helps the compiler avoid spilling some VGPR
if(block_id >= cum_grid_size)
{
break; // exit the loop if all blocks are processed
}
}
}
}
};