[Kernel] CUTLASS grouped gemm fp8 MoE kernel (#13972)

Signed-off-by: ElizaWszola <eliza@neuralmagic.com>
Signed-off-by: ElizaWszola <ewszola@redhat.com>
Co-authored-by: Lucas Wilkinson <wilkinson.lucas@gmail.com>
This commit is contained in:
ElizaWszola
2025-03-27 01:54:44 +01:00
committed by GitHub
parent 7a6d45bc8a
commit 9239bf718e
22 changed files with 2317 additions and 15 deletions

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#pragma once
#include <cuda.h>
#include <torch/all.h>
#include <c10/cuda/CUDAStream.h>
#include "core/scalar_type.hpp"
#include "cutlass/bfloat16.h"
#include "cutlass/float8.h"
template <typename ElementAB, typename ElementC, typename ElementAccumulator>
__global__ void get_group_gemm_starts(
int32_t* expert_offsets, ElementAB** a_offsets, ElementAB** b_offsets,
ElementC** out_offsets, ElementAccumulator** a_scales_offsets,
ElementAccumulator** b_scales_offsets, ElementAB* a_base_as_int,
ElementAB* b_base_as_int, ElementC* out_base_as_int,
ElementAccumulator* a_scales_base_as_int,
ElementAccumulator* b_scales_base_as_int, int64_t n, int64_t k,
bool per_act_token, bool per_out_ch) {
int expert_id = threadIdx.x;
int64_t expert_offset = expert_offsets[expert_id];
a_offsets[expert_id] = a_base_as_int + expert_offset * k;
b_offsets[expert_id] = b_base_as_int + expert_id * k * n;
out_offsets[expert_id] = out_base_as_int + expert_offset * n;
a_scales_offsets[expert_id] =
a_scales_base_as_int + (per_act_token ? expert_offset : 0);
b_scales_offsets[expert_id] =
b_scales_base_as_int + (per_out_ch ? n * expert_id : expert_id);
}
#define __CALL_GET_STARTS_KERNEL(TENSOR_C_TYPE, C_TYPE) \
else if (out_tensors.dtype() == TENSOR_C_TYPE) { \
get_group_gemm_starts<cutlass::float_e4m3_t, C_TYPE, float> \
<<<1, num_experts, 0, stream>>>( \
static_cast<int32_t*>(expert_offsets.data_ptr()), \
static_cast<cutlass::float_e4m3_t**>(a_ptrs.data_ptr()), \
static_cast<cutlass::float_e4m3_t**>(b_ptrs.data_ptr()), \
static_cast<C_TYPE**>(out_ptrs.data_ptr()), \
static_cast<float**>(a_scales_ptrs.data_ptr()), \
static_cast<float**>(b_scales_ptrs.data_ptr()), \
static_cast<cutlass::float_e4m3_t*>(a_tensors.data_ptr()), \
static_cast<cutlass::float_e4m3_t*>(b_tensors.data_ptr()), \
static_cast<C_TYPE*>(out_tensors.data_ptr()), \
static_cast<float*>(a_scales.data_ptr()), \
static_cast<float*>(b_scales.data_ptr()), out_tensors.size(1), \
a_tensors.size(1), per_act_token, per_out_ch); \
}
namespace {
void run_get_group_gemm_starts(
torch::Tensor const& expert_offsets, torch::Tensor& a_ptrs,
torch::Tensor& b_ptrs, torch::Tensor& out_ptrs,
torch::Tensor& a_scales_ptrs, torch::Tensor& b_scales_ptrs,
torch::Tensor const& a_tensors, torch::Tensor const& b_tensors,
torch::Tensor& out_tensors, torch::Tensor const& a_scales,
torch::Tensor const& b_scales) {
TORCH_CHECK(a_tensors.dtype() == torch::kFloat8_e4m3fn);
TORCH_CHECK(b_tensors.dtype() == torch::kFloat8_e4m3fn);
TORCH_CHECK(a_scales.dtype() == torch::kFloat32);
TORCH_CHECK(b_scales.dtype() == torch::kFloat32);
int num_experts = static_cast<int>(expert_offsets.size(0));
bool per_act_token = a_scales.numel() != 1;
bool per_out_ch = b_scales.numel() != num_experts;
auto stream = at::cuda::getCurrentCUDAStream(a_tensors.device().index());
if (false) {
}
__CALL_GET_STARTS_KERNEL(torch::kBFloat16, cutlass::bfloat16_t)
__CALL_GET_STARTS_KERNEL(torch::kFloat16, half)
else {
TORCH_CHECK(false, "Invalid output type (must be float16 or bfloat16)");
}
}
} // namespace

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#include <cudaTypedefs.h>
#include <c10/cuda/CUDAGuard.h>
#include <torch/all.h>
#include "cutlass/cutlass.h"
#include "grouped_mm_c3x.cuh"
using namespace cute;
namespace {
template <typename InType, typename OutType,
template <typename, typename, typename> typename Epilogue>
struct sm90_fp8_config_default {
// M in (16, inf)
static_assert(std::is_same<InType, cutlass::float_e4m3_t>());
using KernelSchedule =
cutlass::gemm::KernelPtrArrayTmaWarpSpecializedPingpongFP8FastAccum;
using EpilogueSchedule =
cutlass::epilogue::PtrArrayTmaWarpSpecializedPingpong;
using TileShape = cute::Shape<cute::_64, cute::_256, cute::_128>;
using ClusterShape = cute::Shape<cute::_1, cute::_2, cute::_1>;
using Cutlass3xGemm =
cutlass_3x_group_gemm<InType, OutType, Epilogue, TileShape, ClusterShape,
KernelSchedule, EpilogueSchedule>;
};
template <typename InType, typename OutType,
template <typename, typename, typename> typename Epilogue>
struct sm90_fp8_config_M16 {
// M in [1, 16]
static_assert(std::is_same<InType, cutlass::float_e4m3_t>());
using KernelSchedule =
cutlass::gemm::KernelPtrArrayTmaWarpSpecializedPingpongFP8FastAccum;
using EpilogueSchedule =
cutlass::epilogue::PtrArrayTmaWarpSpecializedPingpong;
using TileShape = cute::Shape<cute::_64, cute::_64, cute::_128>;
using ClusterShape = cute::Shape<cute::_1, cute::_4, cute::_1>;
using Cutlass3xGemm =
cutlass_3x_group_gemm<InType, OutType, Epilogue, TileShape, ClusterShape,
KernelSchedule, EpilogueSchedule>;
};
template <typename InType, typename OutType,
template <typename, typename, typename> typename Epilogue>
struct sm90_fp8_config_K8192 {
// K in [8192, inf)
static_assert(std::is_same<InType, cutlass::float_e4m3_t>());
using KernelSchedule =
cutlass::gemm::KernelPtrArrayTmaWarpSpecializedPingpongFP8FastAccum;
using EpilogueSchedule =
cutlass::epilogue::PtrArrayTmaWarpSpecializedPingpong;
using TileShape = cute::Shape<cute::_128, cute::_128, cute::_128>;
using ClusterShape = cute::Shape<cute::_1, cute::_8, cute::_1>;
using Cutlass3xGemm =
cutlass_3x_group_gemm<InType, OutType, Epilogue, TileShape, ClusterShape,
KernelSchedule, EpilogueSchedule>;
};
template <typename InType, typename OutType,
template <typename, typename, typename> typename Epilogue>
struct sm90_fp8_config_N8192 {
// N in [8192, inf)
static_assert(std::is_same<InType, cutlass::float_e4m3_t>());
using KernelSchedule =
cutlass::gemm::KernelPtrArrayTmaWarpSpecializedPingpongFP8FastAccum;
using EpilogueSchedule =
cutlass::epilogue::PtrArrayTmaWarpSpecializedPingpong;
using TileShape = cute::Shape<cute::_64, cute::_128, cute::_256>;
using ClusterShape = cute::Shape<cute::_1, cute::_8, cute::_1>;
using Cutlass3xGemm =
cutlass_3x_group_gemm<InType, OutType, Epilogue, TileShape, ClusterShape,
KernelSchedule, EpilogueSchedule>;
};
template <typename InType, typename OutType>
void run_cutlass_moe_mm_sm90(
torch::Tensor& out_tensors, torch::Tensor const& a_tensors,
torch::Tensor const& b_tensors, torch::Tensor const& a_scales,
torch::Tensor const& b_scales, torch::Tensor const& expert_offsets,
torch::Tensor const& problem_sizes, torch::Tensor const& a_strides,
torch::Tensor const& b_strides, torch::Tensor const& c_strides) {
TORCH_CHECK(a_tensors.size(0) > 0, "No input A tensors provided.");
TORCH_CHECK(b_tensors.size(0) > 0, "No input B tensors provided.");
TORCH_CHECK(out_tensors.size(0) > 0, "No output tensors provided.");
TORCH_CHECK(a_tensors.dtype() == torch::kFloat8_e4m3fn,
"A tensors must be of type float8_e4m3fn.");
TORCH_CHECK(b_tensors.dtype() == torch::kFloat8_e4m3fn,
"B tensors must be of type float8_e4m3fn.");
TORCH_CHECK(a_tensors.dtype() == torch::kFloat8_e4m3fn);
TORCH_CHECK(b_tensors.dtype() == torch::kFloat8_e4m3fn);
using Cutlass3xGemmN8192 = typename sm90_fp8_config_N8192<
InType, OutType, vllm::c3x::ScaledEpilogueArray>::Cutlass3xGemm;
using Cutlass3xGemmK8192 = typename sm90_fp8_config_K8192<
InType, OutType, vllm::c3x::ScaledEpilogueArray>::Cutlass3xGemm;
using Cutlass3xGemmM16 = typename sm90_fp8_config_M16<
InType, OutType, vllm::c3x::ScaledEpilogueArray>::Cutlass3xGemm;
using Cutlass3xGemmDefault = typename sm90_fp8_config_default<
InType, OutType, vllm::c3x::ScaledEpilogueArray>::Cutlass3xGemm;
uint32_t const m = a_tensors.size(0);
uint32_t const n = out_tensors.size(1);
uint32_t const k = a_tensors.size(1);
if (n >= 8192) {
cutlass_group_gemm_caller<Cutlass3xGemmN8192>(
out_tensors, a_tensors, b_tensors, a_scales, b_scales, expert_offsets,
problem_sizes, a_strides, b_strides, c_strides);
} else if (k >= 8192) {
cutlass_group_gemm_caller<Cutlass3xGemmK8192>(
out_tensors, a_tensors, b_tensors, a_scales, b_scales, expert_offsets,
problem_sizes, a_strides, b_strides, c_strides);
} else if (m <= 16) {
cutlass_group_gemm_caller<Cutlass3xGemmM16>(
out_tensors, a_tensors, b_tensors, a_scales, b_scales, expert_offsets,
problem_sizes, a_strides, b_strides, c_strides);
} else {
cutlass_group_gemm_caller<Cutlass3xGemmDefault>(
out_tensors, a_tensors, b_tensors, a_scales, b_scales, expert_offsets,
problem_sizes, a_strides, b_strides, c_strides);
}
}
void dispatch_moe_mm_sm90(
torch::Tensor& out_tensors, torch::Tensor const& a_tensors,
torch::Tensor const& b_tensors, torch::Tensor const& a_scales,
torch::Tensor const& b_scales, torch::Tensor const& expert_offsets,
torch::Tensor const& problem_sizes, torch::Tensor const& a_strides,
torch::Tensor const& b_strides, torch::Tensor const& c_strides) {
if (out_tensors.dtype() == torch::kBFloat16) {
run_cutlass_moe_mm_sm90<cutlass::float_e4m3_t, cutlass::bfloat16_t>(
out_tensors, a_tensors, b_tensors, a_scales, b_scales, expert_offsets,
problem_sizes, a_strides, b_strides, c_strides);
} else {
run_cutlass_moe_mm_sm90<cutlass::float_e4m3_t, cutlass::half_t>(
out_tensors, a_tensors, b_tensors, a_scales, b_scales, expert_offsets,
problem_sizes, a_strides, b_strides, c_strides);
}
}
} // namespace
void cutlass_moe_mm_sm90(
torch::Tensor& out_tensors, torch::Tensor const& a_tensors,
torch::Tensor const& b_tensors, torch::Tensor const& a_scales,
torch::Tensor const& b_scales, torch::Tensor const& expert_offsets,
torch::Tensor const& problem_sizes, torch::Tensor const& a_strides,
torch::Tensor const& b_strides, torch::Tensor const& c_strides) {
dispatch_moe_mm_sm90(out_tensors, a_tensors, b_tensors, a_scales, b_scales,
expert_offsets, problem_sizes, a_strides, b_strides,
c_strides);
}

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#pragma once
#include "cutlass/cutlass.h"
#include "cutlass/gemm/collective/collective_builder.hpp"
#include "cutlass/epilogue/collective/collective_builder.hpp"
#include "cutlass/gemm/device/gemm_universal_adapter.h"
#include "cutlass_extensions/epilogue/scaled_mm_epilogues_c3x.hpp"
#include "cutlass_extensions/common.hpp"
#include "get_group_starts.cuh"
using namespace cute;
namespace {
using ProblemShape =
cutlass::gemm::GroupProblemShape<cute::Shape<int, int, int>>;
using ElementAccumulator = float;
using ArchTag = cutlass::arch::Sm90;
using OperatorClass = cutlass::arch::OpClassTensorOp;
using LayoutA = cutlass::layout::RowMajor;
using LayoutB = cutlass::layout::ColumnMajor;
using LayoutC = cutlass::layout::RowMajor;
template <typename ElementAB_, typename ElementC_,
template <typename, typename, typename> typename Epilogue_,
typename TileShape, typename ClusterShape, typename KernelSchedule,
typename EpilogueSchedule>
struct cutlass_3x_group_gemm {
using ElementAB = ElementAB_;
using ElementC = void;
using ElementD = ElementC_;
using ElementAccumulator = float;
using Epilogue = Epilogue_<ElementAccumulator, ElementD, TileShape>;
using StrideC =
cute::remove_pointer_t<cute::Stride<int64_t, cute::Int<1>, cute::Int<0>>>;
static constexpr int AlignmentAB =
128 / cutlass::sizeof_bits<ElementAB>::value;
static constexpr int AlignmentC = 128 / cutlass::sizeof_bits<ElementD>::value;
using EVTCompute = typename Epilogue::EVTCompute;
using CollectiveEpilogue =
typename cutlass::epilogue::collective::CollectiveBuilder<
ArchTag, OperatorClass, TileShape, ClusterShape,
cutlass::epilogue::collective::EpilogueTileAuto, ElementAccumulator,
ElementAccumulator, ElementC, LayoutC*, AlignmentC, ElementD,
LayoutC*, AlignmentC, EpilogueSchedule, EVTCompute>::CollectiveOp;
static constexpr size_t CEStorageSize =
sizeof(typename CollectiveEpilogue::SharedStorage);
using Stages = typename cutlass::gemm::collective::StageCountAutoCarveout<
static_cast<int>(CEStorageSize)>;
using CollectiveMainloop =
typename cutlass::gemm::collective::CollectiveBuilder<
ArchTag, OperatorClass, ElementAB, LayoutA*, AlignmentAB, ElementAB,
LayoutB*, AlignmentAB, ElementAccumulator, TileShape, ClusterShape,
Stages, KernelSchedule>::CollectiveOp;
using KernelType = enable_sm90_only<cutlass::gemm::kernel::GemmUniversal<
ProblemShape, CollectiveMainloop, CollectiveEpilogue>>;
struct GemmKernel : public KernelType {};
};
template <typename Gemm>
void cutlass_group_gemm_caller(
torch::Tensor& out_tensors, torch::Tensor const& a_tensors,
torch::Tensor const& b_tensors, torch::Tensor const& a_scales,
torch::Tensor const& b_scales, torch::Tensor const& expert_offsets,
torch::Tensor const& problem_sizes, torch::Tensor const& a_strides,
torch::Tensor const& b_strides, torch::Tensor const& c_strides) {
using ElementAB = typename Gemm::ElementAB;
using ElementD = typename Gemm::ElementD;
int num_experts = static_cast<int>(expert_offsets.size(0));
int k_size = a_tensors.size(1);
int n_size = out_tensors.size(1);
bool per_act_token = a_scales.numel() != 1;
bool per_out_ch = b_scales.numel() != num_experts;
auto stream = at::cuda::getCurrentCUDAStream(a_tensors.device().index());
auto options_int =
torch::TensorOptions().dtype(torch::kInt64).device(a_tensors.device());
torch::Tensor a_ptrs = torch::empty(num_experts, options_int);
torch::Tensor b_ptrs = torch::empty(num_experts, options_int);
torch::Tensor out_ptrs = torch::empty(num_experts, options_int);
torch::Tensor a_scales_ptrs = torch::empty(num_experts, options_int);
torch::Tensor b_scales_ptrs = torch::empty(num_experts, options_int);
run_get_group_gemm_starts(expert_offsets, a_ptrs, b_ptrs, out_ptrs,
a_scales_ptrs, b_scales_ptrs, a_tensors, b_tensors,
out_tensors, a_scales, b_scales);
using GemmKernel = typename Gemm::GemmKernel;
using StrideA = Stride<int64_t, Int<1>, Int<0>>;
using StrideB = Stride<int64_t, Int<1>, Int<0>>;
using StrideC = typename GemmKernel::InternalStrideC;
ProblemShape::UnderlyingProblemShape* problem_sizes_as_shapes =
static_cast<ProblemShape::UnderlyingProblemShape*>(
problem_sizes.data_ptr());
ProblemShape prob_shape{num_experts, problem_sizes_as_shapes, nullptr};
typename GemmKernel::MainloopArguments mainloop_args{
static_cast<const ElementAB**>(a_ptrs.data_ptr()),
static_cast<StrideA*>(a_strides.data_ptr()),
static_cast<const ElementAB**>(b_ptrs.data_ptr()),
static_cast<StrideB*>(b_strides.data_ptr())};
// Currently, we are only able to do broadcast on either all or none a_scales
// and on either all or none b_scales
typename GemmKernel::EpilogueArguments epilogue_args{
Gemm::Epilogue::prepare_args(
static_cast<const ElementAccumulator**>(a_scales_ptrs.data_ptr()),
static_cast<const ElementAccumulator**>(b_scales_ptrs.data_ptr()),
per_act_token, per_out_ch),
nullptr, static_cast<StrideC*>(c_strides.data_ptr()),
static_cast<ElementD**>(out_ptrs.data_ptr()),
static_cast<StrideC*>(c_strides.data_ptr())};
typename GemmKernel::Arguments args{
cutlass::gemm::GemmUniversalMode::kGrouped, prob_shape, mainloop_args,
epilogue_args};
using GemmOp = cutlass::gemm::device::GemmUniversalAdapter<GemmKernel>;
GemmOp gemm_op;
CUTLASS_CHECK(gemm_op.can_implement(args));
size_t workspace_size = gemm_op.get_workspace_size(args);
auto const workspace_options =
torch::TensorOptions().dtype(torch::kUInt8).device(a_tensors.device());
auto workspace = torch::empty(workspace_size, workspace_options);
cutlass::Status status = gemm_op.run(args, workspace.data_ptr(), stream);
CUTLASS_CHECK(status);
}
} // namespace

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#include <cudaTypedefs.h>
#include <c10/cuda/CUDAGuard.h>
#include <torch/all.h>
#include <iostream>
constexpr uint64_t THREADS_PER_EXPERT = 512;
__global__ void compute_problem_sizes(const int* __restrict__ topk_ids,
int32_t* problem_sizes1,
int32_t* problem_sizes2,
int32_t* atomic_buffer,
const int topk_length, const int n,
const int k) {
int expert_id = blockIdx.x;
int occurrences = 0;
for (int i = threadIdx.x; i < topk_length; i += THREADS_PER_EXPERT) {
occurrences += (topk_ids[i] == expert_id);
}
atomicAdd(&atomic_buffer[expert_id], occurrences);
__syncthreads();
if (threadIdx.x == 0) {
int final_occurrences = atomic_buffer[expert_id];
problem_sizes1[expert_id * 3] = final_occurrences;
problem_sizes1[expert_id * 3 + 1] = 2 * n;
problem_sizes1[expert_id * 3 + 2] = k;
problem_sizes2[expert_id * 3] = final_occurrences;
problem_sizes2[expert_id * 3 + 1] = k;
problem_sizes2[expert_id * 3 + 2] = n;
}
}
__global__ void compute_expert_offsets(
const int32_t* __restrict__ problem_sizes1, int32_t* expert_offsets,
int32_t* atomic_buffer, const int num_experts) {
int32_t tot_offset = 0;
expert_offsets[0] = 0;
for (int i = 0; i < num_experts; ++i) {
atomic_buffer[i] = tot_offset;
tot_offset += problem_sizes1[i * 3];
expert_offsets[i + 1] = tot_offset;
}
}
__global__ void compute_arg_sorts(const int* __restrict__ topk_ids,
int32_t* input_permutation,
int32_t* output_permutation,
int32_t* atomic_buffer, const int topk_length,
const int topk) {
int expert_id = blockIdx.x;
for (int i = threadIdx.x; i < topk_length; i += THREADS_PER_EXPERT) {
if (topk_ids[i] == expert_id) {
int start = atomicAdd(&atomic_buffer[expert_id], 1);
input_permutation[start] = i / topk;
output_permutation[i] = start;
}
}
}
void get_cutlass_moe_mm_data_caller(
const torch::Tensor& topk_ids, torch::Tensor& expert_offsets,
torch::Tensor& problem_sizes1, torch::Tensor& problem_sizes2,
torch::Tensor& input_permutation, torch::Tensor& output_permutation,
const int64_t num_experts, const int64_t n, const int64_t k) {
auto stream = at::cuda::getCurrentCUDAStream(topk_ids.device().index());
auto options_int32 =
torch::TensorOptions().dtype(torch::kInt32).device(topk_ids.device());
torch::Tensor atomic_buffer = torch::zeros(num_experts, options_int32);
int num_threads = min(THREADS_PER_EXPERT, topk_ids.numel());
compute_problem_sizes<<<num_experts, num_threads, 0, stream>>>(
static_cast<const int32_t*>(topk_ids.data_ptr()),
static_cast<int32_t*>(problem_sizes1.data_ptr()),
static_cast<int32_t*>(problem_sizes2.data_ptr()),
static_cast<int32_t*>(atomic_buffer.data_ptr()), topk_ids.numel(), n, k);
compute_expert_offsets<<<1, 1, 0, stream>>>(
static_cast<const int32_t*>(problem_sizes1.data_ptr()),
static_cast<int32_t*>(expert_offsets.data_ptr()),
static_cast<int32_t*>(atomic_buffer.data_ptr()), num_experts);
compute_arg_sorts<<<num_experts, num_threads, 0, stream>>>(
static_cast<const int32_t*>(topk_ids.data_ptr()),
static_cast<int32_t*>(input_permutation.data_ptr()),
static_cast<int32_t*>(output_permutation.data_ptr()),
static_cast<int32_t*>(atomic_buffer.data_ptr()), topk_ids.numel(),
topk_ids.size(1));
}