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cutlass/examples/82_blackwell_distributed_gemm/82_blackwell_distributed_gemm.cu
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/*! \file
\brief Distributed GEMM (DistGEMM) for Blackwell.
This example runs Tensor Parallel GEMMs using the (experimental) Distributed GEMM API in
CUTLASS. For more information, please refer to README.md.
Note that Distributed GEMM assumes an any-to-any NVLink network topology.
To check whether your device is compatible, run:
$ nvidia-smi topo -m
and make sure there's an any-to-any NVLink topology. It would look like this:
GPU0 GPU1 GPU2 GPU3 GPU4 GPU5 GPU6 GPU7
GPU0 X NV18 NV18 NV18 NV18 NV18 NV18 NV18
GPU1 NV18 X NV18 NV18 NV18 NV18 NV18 NV18
GPU2 NV18 NV18 X NV18 NV18 NV18 NV18 NV18
GPU3 NV18 NV18 NV18 X NV18 NV18 NV18 NV18
GPU4 NV18 NV18 NV18 NV18 X NV18 NV18 NV18
GPU5 NV18 NV18 NV18 NV18 NV18 X NV18 NV18
GPU6 NV18 NV18 NV18 NV18 NV18 NV18 X NV18
GPU7 NV18 NV18 NV18 NV18 NV18 NV18 NV18 X
You should also additionally check if the driver enables peer to peer access:
$ nvidia-smi topo -p2p r
Output should be something like this:
GPU0 GPU1 GPU2 GPU3 GPU4 GPU5 GPU6 GPU7
GPU0 X OK OK OK OK OK OK OK
GPU1 OK X OK OK OK OK OK OK
GPU2 OK OK X OK OK OK OK OK
GPU3 OK OK OK X OK OK OK OK
GPU4 OK OK OK OK X OK OK OK
GPU5 OK OK OK OK OK X OK OK
GPU6 OK OK OK OK OK OK X OK
GPU7 OK OK OK OK OK OK OK X
It is recommended to build this target with the following flag to enable
Grid Dependency Control instructions (GDC) in CUTLASS:
- CUTLASS_ENABLE_GDC_FOR_SM100
Example:
$ mkdir build && cd build
$ cmake .. -DCUTLASS_NVCC_ARCHS="100a" -DCUTLASS_ENABLE_GDC_FOR_SM100=1
$ cd examples/82_blackwell_distributed_gemm
$ make
$ ./82_blackwell_distributed_gemm
*/
#include <iostream>
#include "cutlass/cutlass.h"
#include "cutlass/numeric_types.h"
#include "cute/tensor.hpp"
#include "cutlass/tensor_ref.h"
#include "cutlass/gemm/dispatch_policy.hpp"
#include "cutlass/gemm/collective/collective_builder.hpp"
#include "cutlass/gemm/device/gemm_universal_adapter.h"
#include "cutlass/gemm/kernel/gemm_universal.hpp"
#include "cutlass/epilogue/dispatch_policy.hpp"
#include "cutlass/epilogue/collective/collective_builder.hpp"
#include "cutlass/util/command_line.h"
#include "cutlass/util/distribution.h"
#include "cutlass/util/host_tensor.h"
#include "cutlass/util/packed_stride.hpp"
#include "cutlass/util/tensor_view_io.h"
#include "cutlass/util/reference/host/error_metrics.h"
#include "cutlass/util/reference/device/tensor_fill.h"
#include "cutlass/util/reference/host/tensor_fill.h"
#include "cutlass/util/reference/host/tensor_copy.h"
#include "cutlass/util/reference/host/tensor_compare.h"
#include "cutlass/util/reference/host/tensor_norm.h"
// Distributed GEMM headers
#include "cutlass/experimental/distributed/device/dist_gemm_universal_wrapper.hpp"
#include "cutlass/experimental/distributed/kernel/dist_gemm_kernel_wrapper.hpp"
#include "cutlass/experimental/distributed/schedules/dist_gemm_1d_schedules.hpp"
#include "helper.h"
// Distributed GEMM helpers
#include "dist_gemm_helpers.h"
using namespace cute;
/////////////////////////////////////////////////////////////////////////////////////////////////
/// Distributed GEMM configuration
/////////////////////////////////////////////////////////////////////////////////////////////////
// TP size (= number of processors/GPUs)
using TP = _8;
static constexpr int TP_ = TP{};
#if defined(CUTLASS_ARCH_MMA_SM100A_ENABLED) && \
(__CUDACC_VER_MAJOR__ > 12 || (__CUDACC_VER_MAJOR__ == 12 && __CUDACC_VER_MINOR__ >= 8))
// Distributed GEMM tiling/sharding schedule
// Choices:
//
// * All Gather + GEMM:
// * AllGather1D_TilingCD_RotatingA
// * AllGather1D_TilingCD_RotatingB
//
// * GEMM + Reduce Scatter:
// * ReduceScatter1D_TilingA_RotatingC
// * ReduceScatter1D_TilingB_RotatingC
using DistSchedule = cutlass::distributed::schedules::AllGather1D_TilingCD_RotatingA<TP>;
/////////////////////////////////////////////////////////////////////////////////////////////////
/// GEMM kernel configurations
/////////////////////////////////////////////////////////////////////////////////////////////////
// A matrix configuration
using ElementA = cutlass::float_e4m3_t; // Element type for A matrix operand
using LayoutA = cutlass::layout::RowMajor; // Layout type for A matrix operand
constexpr int AlignmentA = 128 / cutlass::sizeof_bits<ElementA>::value; // Memory access granularity/alignment of A matrix in units of elements (up to 16 bytes)
// B matrix configuration
using ElementB = cutlass::float_e4m3_t; // Element type for B matrix operand
using LayoutB = cutlass::layout::RowMajor; // Layout type for B matrix operand
constexpr int AlignmentB = 128 / cutlass::sizeof_bits<ElementB>::value; // Memory access granularity/alignment of B matrix in units of elements (up to 16 bytes)
// C/D matrix configuration
using ElementC = cutlass::float_e4m3_t; // Element type for C and D matrix operands
using LayoutC = cutlass::layout::RowMajor; // Layout type for C and D matrix operands
constexpr int AlignmentC = 128 / cutlass::sizeof_bits<ElementC>::value; // Memory access granularity/alignment of C matrix in units of elements (up to 16 bytes)
using ElementD = cutlass::float_e4m3_t; // Element type for C and D matrix operands
using LayoutD = cutlass::layout::RowMajor; // Layout type for C and D matrix operands
constexpr int AlignmentD = 128 / cutlass::sizeof_bits<ElementD>::value; // Memory access granularity/alignment of D matrix in units of elements (up to 16 bytes)
// Kernel functional config
using ElementAccumulator = float; // Element type for internal accumulation
using ElementCompute = float; // Element type for epilogue computation
using ArchTag = cutlass::arch::Sm100; // Tag indicating the minimum SM that supports the intended feature
using OperatorClass = cutlass::arch::OpClassTensorOp; // Operator class tag
// MMA and Cluster Tile Shapes
// Shape of the tile computed by tcgen05 MMA, could be across 2 SMs if Cluster Shape %2 == 0
using MmaTileShape_MNK = Shape<_256,_256,_128>;
// Shape of the threadblocks in a cluster
using ClusterShape_MNK = Shape<_2,_1,_1>;
// Shape of the tile computed by each SM
using PerSmTileShape_MNK = Shape<_128, _256, _128>;
// Build the epilogue
using CollectiveEpilogue = typename cutlass::epilogue::collective::CollectiveBuilder<
ArchTag, OperatorClass,
PerSmTileShape_MNK, ClusterShape_MNK,
cutlass::epilogue::collective::EpilogueTileAuto,
ElementAccumulator, ElementCompute,
ElementC, LayoutC, AlignmentC,
ElementD, LayoutD, AlignmentD,
cutlass::epilogue::collective::EpilogueScheduleAuto
>::CollectiveOp;
// Build the mainloop
using CollectiveMainloop = typename cutlass::gemm::collective::CollectiveBuilder<
ArchTag, OperatorClass,
ElementA, LayoutA, AlignmentA,
ElementB, LayoutB, AlignmentB,
ElementAccumulator,
MmaTileShape_MNK, ClusterShape_MNK,
cutlass::gemm::collective::StageCountAutoCarveout<static_cast<int>(sizeof(typename CollectiveEpilogue::SharedStorage))>,
cutlass::gemm::KernelTmaWarpSpecialized2SmSm100
>::CollectiveOp;
// Compose into a kernel
using GemmKernel = cutlass::gemm::kernel::GemmUniversal<
Shape<int,int,int, int>, // Indicates ProblemShape
CollectiveMainloop,
CollectiveEpilogue,
void>; // Default to ClusterLaunchControl (CLC) based tile scheduler
// We're going to use the single-device GEMM as reference
using Gemm = cutlass::gemm::device::GemmUniversalAdapter<GemmKernel>;
// Instantiate Distributed GEMM kernel
using DistGemmKernel = cutlass::distributed::kernel::DistributedGemmKernelWrapper<
GemmKernel,
DistSchedule
>;
using DistGemm = cutlass::distributed::device::DistributedGemmUniversalAdapter<DistGemmKernel>;
using StrideA = typename Gemm::GemmKernel::StrideA;
using StrideB = typename Gemm::GemmKernel::StrideB;
using StrideC = typename Gemm::GemmKernel::StrideC;
using StrideD = typename Gemm::GemmKernel::StrideD;
/// Initialization
StrideA stride_A;
StrideB stride_B;
StrideC stride_C;
StrideD stride_D;
uint64_t seed;
using HostTensorA = typename cutlass::HostTensor<ElementA, LayoutA>;
using HostTensorB = typename cutlass::HostTensor<ElementB, LayoutB>;
using HostTensorC = typename cutlass::HostTensor<ElementC, LayoutC>;
using HostTensorD = typename cutlass::HostTensor<ElementD, LayoutD>;
// Reference GEMM tensors
HostTensorA tensor_A;
HostTensorB tensor_B;
HostTensorC tensor_C;
HostTensorD tensor_D;
HostTensorD tensor_ref_D;
// DistGEMM tensors (multi-device)
HostTensorA tensor_A_arr[TP_];
HostTensorB tensor_B_arr[TP_];
HostTensorD tensor_C_arr[TP_];
HostTensorD tensor_D_arr[TP_];
#endif // (defined(CUTLASS_ARCH_MMA_SM100A_ENABLED) &&
// (__CUDACC_VER_MAJOR__ > 12 || (__CUDACC_VER_MAJOR__ == 12 && __CUDACC_VER_MINOR__ >= 8))
/////////////////////////////////////////////////////////////////////////////////////////////////
/// Testbed utility types
/////////////////////////////////////////////////////////////////////////////////////////////////
// Command line options parsing
struct Options {
bool help = false;
float alpha = 1.f, beta = 0.f;
int iterations = 100;
int warmup_iterations = 10;
int m = 16384, n = 106496, k = 16384, l = 1;
float eps = 0.f;
// Parses the command line
void parse(int argc, char const **args) {
cutlass::CommandLine cmd(argc, args);
if (cmd.check_cmd_line_flag("help")) {
help = true;
return;
}
cmd.get_cmd_line_argument("m", m);
cmd.get_cmd_line_argument("n", n);
cmd.get_cmd_line_argument("k", k);
cmd.get_cmd_line_argument("l", l);
cmd.get_cmd_line_argument("alpha", alpha);
cmd.get_cmd_line_argument("beta", beta);
cmd.get_cmd_line_argument("iterations", iterations);
cmd.get_cmd_line_argument("warmup-iterations", warmup_iterations);
cmd.get_cmd_line_argument("eps", eps);
}
/// Prints the usage statement.
std::ostream & print_usage(std::ostream &out) const {
out << "82_blackwell_distributed_gemm\n\n"
<< " Blackwell Distributed GEMM (DistGEMM). \n"
<< " For more details please refer to the source file.\n\n"
<< "Options:\n\n"
<< " --help If specified, displays this usage statement\n\n"
<< " --m=<int> Sets the M extent of the GEMM\n"
<< " --n=<int> Sets the N extent of the GEMM\n"
<< " --k=<int> Sets the K extent of the GEMM\n"
<< " --l=<int> Sets the L extent (batch) of the GEMM (default: 1)\n"
<< " --alpha=<f32> Epilogue scalar alpha (default: 1.0)\n"
<< " --beta=<f32> Epilogue scalar beta (default: 0.0)\n"
<< " --iterations=<int> Number of profiling iterations to perform (default: 100)\n"
<< " --warmup-iterations=<int> Number of warmup iterations prior to profiling (default: 10)\n"
<< " --eps=<f32> Threshold for error compared to reference "
<< "GEMM (default: 0.0)\n\n";
out
<< "\n\nExamples:\n\n"
<< "$ " << "82_blackwell_distributed_gemm" << " --m=16384 --n=106496 --k=16384 \n\n";
return out;
}
/// Compute performance in TFLOP/s
double tflops(double runtime_s) const {
// Two flops per multiply-add
uint64_t flop = uint64_t(2) * m * n * k * l / TP_;
double tflop = double(flop) / double(1.0e12);
return tflop / runtime_s;
}
};
/// Result structure
struct Result {
double avg_runtime_ms;
double tflops;
cutlass::Status status;
cudaError_t error;
bool passed;
Result(
double avg_runtime_ms = 0,
double tflops = 0,
cutlass::Status status = cutlass::Status::kSuccess,
cudaError_t error = cudaSuccess)
:
avg_runtime_ms(avg_runtime_ms), tflops(tflops), status(status), error(error), passed(false)
{}
};
#if defined(CUTLASS_ARCH_MMA_SM100A_ENABLED) && \
(__CUDACC_VER_MAJOR__ > 12 || (__CUDACC_VER_MAJOR__ == 12 && __CUDACC_VER_MINOR__ >= 8))
/////////////////////////////////////////////////////////////////////////////////////////////////
/// GEMM setup and evaluation
/////////////////////////////////////////////////////////////////////////////////////////////////
/// Helper to initialize a block of device data
template <typename Element, typename Layout>
bool initialize_tensor(
cutlass::TensorView<Element, Layout> view,
uint64_t seed,
bool is_device_tensor = false) {
double scope_max, scope_min;
int bits = cutlass::sizeof_bits<Element>::value;
if (bits == 1) {
scope_max = 2;
scope_min = 0;
}
else if (bits <= 16) {
scope_max = 2;
scope_min = -2;
}
else {
scope_max = 8;
scope_min = -8;
}
if (is_device_tensor) {
using Real = typename cutlass::RealType<Element>::Type;
cutlass::reference::device::TensorFillRandomUniform(
view, seed, static_cast<Real>(scope_max), static_cast<Real>(scope_min), 0);
cudaDeviceSynchronize();
} else {
cutlass::reference::host::TensorFillRandomUniform(
view, seed, scope_max, scope_min, 0);
}
return true;
}
/// Initialize operands to be used in the GEMM and reference GEMM
void initialize(const Options &options) {
auto problem_shape = cute::make_tuple(options.m, options.n, options.k, options.l);
// Setup (reference) GEMM tensors
auto shape_A = cute::select<0,2,3>(problem_shape);
auto shape_B = cute::select<1,2,3>(problem_shape);
auto shape_C = cute::select<0,1,3>(problem_shape);
auto shape_D = cute::select<0,1,3>(problem_shape);
stride_A = cutlass::make_cute_packed_stride(StrideA{}, shape_A);
stride_B = cutlass::make_cute_packed_stride(StrideB{}, shape_B);
stride_C = cutlass::make_cute_packed_stride(StrideC{}, shape_C);
stride_D = cutlass::make_cute_packed_stride(StrideD{}, shape_D);
auto a_coord = cutlass::make_Coord(size(shape_A), 1);
auto b_coord = cutlass::make_Coord(size(shape_B), 1);
auto c_coord = cutlass::make_Coord(size(shape_C), 1);
tensor_A.resize(a_coord);
tensor_B.resize(b_coord);
tensor_C.resize(c_coord);
tensor_D.resize(c_coord);
tensor_ref_D.resize(c_coord);
initialize_tensor(tensor_A.device_view(), seed + 2022, /* is_device_tensor = */ true);
initialize_tensor(tensor_B.device_view(), seed + 2023, /* is_device_tensor = */ true);
initialize_tensor(tensor_C.device_view(), seed + 2024, /* is_device_tensor = */ true);
tensor_A.sync_host();
tensor_B.sync_host();
tensor_C.sync_host();
tensor_D.sync_host();
tensor_ref_D.sync_host();
// Set up DistGEMM tensors
auto local_shape_A = DistSchedule::get_local_a_shape(problem_shape);
auto local_shape_B = DistSchedule::get_local_b_shape(problem_shape);
auto local_shape_C = DistSchedule::get_local_c_shape(problem_shape);
auto local_shape_D = DistSchedule::get_local_d_shape(problem_shape);
auto a_coord_device = cutlass::make_Coord(size(local_shape_A), 1);
auto b_coord_device = cutlass::make_Coord(size(local_shape_B), 1);
auto c_coord_device = cutlass::make_Coord(size(local_shape_C), 1);
int primary_device_idx;
CUDA_CHECK(cudaGetDevice(&primary_device_idx));
// Enable any-to-any access
for (int device_idx = 0; device_idx < TP_; ++device_idx) {
int can_access;
CUDA_CHECK(cudaSetDevice(device_idx));
for (int peer_idx = 0; peer_idx < TP_; ++peer_idx) {
if (peer_idx != device_idx) {
CUDA_CHECK(cudaDeviceCanAccessPeer(&can_access, device_idx, peer_idx));
if (not can_access) {
std::cerr << "FAILURE: Device " << device_idx << " can't access device " << peer_idx << "." <<
std::endl;
exit(EXIT_FAILURE);
}
CUDA_CHECK(cudaDeviceEnablePeerAccess(peer_idx, 0));
}
}
tensor_A_arr[device_idx].resize(a_coord_device);
tensor_B_arr[device_idx].resize(b_coord_device);
tensor_C_arr[device_idx].resize(c_coord_device);
tensor_D_arr[device_idx].resize(c_coord_device);
}
CUDA_CHECK(cudaSetDevice(primary_device_idx));
}
/// Commandline options -> Gemm/DistGemm Arguments
using GemmArguments = typename Gemm::Arguments;
GemmArguments gemm_args_from_options(const Options &options) {
typename Gemm::Arguments arguments{
cutlass::gemm::GemmUniversalMode::kGemm,
{options.m, options.n, options.k, options.l},
{tensor_A.device_data(), stride_A, tensor_B.device_data(), stride_B},
{
{static_cast<ElementCompute>(options.alpha), static_cast<ElementCompute>(options.beta)},
tensor_C.device_data(), stride_C,
tensor_ref_D.device_data(), stride_D
}
};
return arguments;
}
using DistGemmArguments = typename DistGemm::Arguments;
DistGemmArguments dist_gemm_args_from_options(
const Options &options,
int device_idx,
cudaStream_t stream) {
auto problem_shape = cute::make_tuple(options.m, options.n, options.k, options.l);
auto global_A = cute::make_tensor(tensor_A.device_data(),
cute::make_layout(cute::make_shape(options.m, options.k, options.l), stride_A));
auto global_B = cute::make_tensor(tensor_B.device_data(),
cute::make_layout(cute::make_shape(options.n, options.k, options.l), stride_B));
auto global_C = cute::make_tensor(tensor_C.device_data(),
cute::make_layout(cute::make_shape(options.m, options.n, options.l), stride_C));
auto global_A_device_slice = DistSchedule::get_device_slice_A(global_A, device_idx);
auto global_B_device_slice = DistSchedule::get_device_slice_B(global_B, device_idx);
auto global_C_device_slice = DistSchedule::get_device_slice_C(global_C, device_idx);
auto local_shape_A = DistSchedule::get_local_a_shape(problem_shape);
auto local_shape_B = DistSchedule::get_local_b_shape(problem_shape);
auto local_shape_C = DistSchedule::get_local_c_shape(problem_shape);
auto local_shape_D = DistSchedule::get_local_d_shape(problem_shape);
auto local_stride_A = cutlass::make_cute_packed_stride(StrideA{}, local_shape_A);
auto local_stride_B = cutlass::make_cute_packed_stride(StrideB{}, local_shape_B);
auto local_stride_C = cutlass::make_cute_packed_stride(StrideC{}, local_shape_C);
auto local_stride_D = cutlass::make_cute_packed_stride(StrideD{}, local_shape_D);
auto local_A = cute::make_tensor(
tensor_A_arr[device_idx].device_data(),
make_layout(local_shape_A, local_stride_A));
auto local_B = cute::make_tensor(
tensor_B_arr[device_idx].device_data(),
make_layout(local_shape_B, local_stride_B));
auto local_C = cute::make_tensor(
tensor_C_arr[device_idx].device_data(),
make_layout(local_shape_C, local_stride_C));
auto local_D = cute::make_tensor(
tensor_D_arr[device_idx].device_data(),
make_layout(local_shape_D, local_stride_D));
// Copy over tensor tiles for the first iteration
cutlass::device_copy(global_A_device_slice, local_A, stream);
cutlass::device_copy(global_B_device_slice, local_B, stream);
cutlass::device_copy(global_C_device_slice, local_C, stream);
DistGemmArguments arguments{
cutlass::gemm::GemmUniversalMode::kGemm, // mode
problem_shape, // problem shape
{
reinterpret_cast<const ElementA*>(local_A.data()),
local_A.stride(),
reinterpret_cast<const ElementB*>(local_B.data()),
local_B.stride()
}, // mainloop
{
{ // epilogue.thread
static_cast<ElementCompute>(options.alpha),
static_cast<ElementCompute>(options.beta)
},
reinterpret_cast<const ElementC*>(local_C.data()),
local_C.stride(),
reinterpret_cast<ElementD*>(local_D.data()),
local_D.stride(),
}, // epilogue
{}, // hw_info
{} // scheduler
};
return arguments;
}
// Gathers results, moves back to the original full-sized D tensor on the primary device.
void gather_results(const Options &options, int device_idx, cudaStream_t stream = nullptr) {
auto problem_shape = cute::make_tuple(options.m, options.n, options.k, options.l);
// Global dest
auto global_D = cute::make_tensor(tensor_D.device_data(),
cute::make_layout(cute::make_shape(options.m, options.n, options.l), stride_D));
auto global_D_device_slice = DistSchedule::get_device_slice_D(global_D, device_idx);
// Device_idx local dest
auto local_shape_D = DistSchedule::get_local_d_shape(problem_shape);
auto local_stride_D = cutlass::make_cute_packed_stride(StrideD{}, local_shape_D);
auto local_D = cute::make_tensor(
tensor_D_arr[device_idx].device_data(),
make_layout(local_shape_D, local_stride_D)
);
// Copy to global dest
cutlass::device_copy(local_D, global_D_device_slice, stream);
}
bool verify(const Options &options) {
tensor_D.sync_host();
tensor_ref_D.sync_host();
bool passed = false;
if (options.eps == 0.f) {
passed = cutlass::reference::host::TensorEquals(tensor_ref_D.host_view(), tensor_D.host_view());
} else {
double err = cutlass::reference::host::TensorRelativeErrorMetric(
tensor_D.host_view(),
tensor_ref_D.host_view());
passed = err < 1e-5;
}
if (options.m <= 64 && options.n <= 64) {
std::cout << "GEMM output:\n" << tensor_D.host_view() << "\n\n";
std::cout << "Reference output:\n" << tensor_ref_D.host_view() << "\n\n";
}
return passed;
}
/// Execute a given example GEMM computation
int run(Options &options) {
int primary_device_idx;
cudaError_t device_get_result = cudaGetDevice(&primary_device_idx);
if (device_get_result != cudaSuccess) {
throw std::runtime_error("cudaGetDevice() failed");
}
initialize(options);
// Reference single-GPU GEMM
Gemm reference_gemm;
cutlass::device_memory::allocation<uint8_t> reference_workspace;
auto reference_arguments = gemm_args_from_options(options);
size_t reference_workspace_size = Gemm::get_workspace_size(reference_arguments);
reference_workspace = cutlass::device_memory::allocation<uint8_t>(reference_workspace_size);
CUTLASS_CHECK(reference_gemm.can_implement(reference_arguments));
CUTLASS_CHECK(reference_gemm.initialize(reference_arguments, reference_workspace.get()));
CUTLASS_CHECK(reference_gemm.run());
using ElementBarrier = typename DistGemm::ElementBarrier;
using ElementFlag = typename DistGemmKernel::ElementFlag;
// Set up per-device streams
cudaStream_t stream_arr[TP_];
for (int device_idx = 0; device_idx < TP_; ++device_idx) {
CUDA_CHECK(cudaSetDevice(device_idx));
// Create stream
CUDA_CHECK(cudaStreamCreate(&stream_arr[device_idx]));
}
// Instantiate DistGEMM
DistGemm dist_gemm_arr[TP_]; // Distributed GEMM array for multiple devices
// Allocate workspace memory
cutlass::device_memory::allocation<uint8_t> workspace_arr[TP_];
cutlass::device_memory::allocation<uint8_t> exclusive_workspace_arr[TP_];
// Cross-device workspace pointer array for gemm.initialize()
void * workspace_ptr_arr[TP_];
void * exclusive_workspace_ptr_arr[TP_];
// Create a structure of gemm kernel arguments suitable for invoking an instance of Gemm
DistGemmArguments arguments_[TP_];
for (int device_idx = 0; device_idx < TP_; ++device_idx) {
CUDA_CHECK(cudaSetDevice(device_idx));
arguments_[device_idx] = dist_gemm_args_from_options(options, device_idx, stream_arr[device_idx]);
// Using the arguments, query for extra workspace required for matrix multiplication computation
size_t workspace_size = DistGemm::get_workspace_size(arguments_[device_idx]);
size_t exclusive_workspace_size = DistGemm::get_exclusive_workspace_size();
workspace_arr[device_idx] = cutlass::device_memory::allocation<uint8_t>(workspace_size);
exclusive_workspace_arr[device_idx] = cutlass::device_memory::allocation<uint8_t>(exclusive_workspace_size);
// Throw workspace pointers into arrays for gemm.initialize()
workspace_ptr_arr[device_idx] = workspace_arr[device_idx].get();
exclusive_workspace_ptr_arr[device_idx] = exclusive_workspace_arr[device_idx].get();
// Zero out exclusive workspace
cudaMemsetAsync(exclusive_workspace_ptr_arr[device_idx], 0, exclusive_workspace_size, stream_arr[device_idx]);
cudaDeviceSynchronize();
}
for (int device_idx = 0; device_idx < TP_; ++device_idx) {
CUDA_CHECK(cudaSetDevice(device_idx));
// Check if the problem size is supported or not
CUTLASS_CHECK(dist_gemm_arr[device_idx].can_implement(arguments_[device_idx]));
#if defined(CUTLASS_ENABLE_GDC_FOR_SM100)
bool launch_with_pdl = true;
#else
bool launch_with_pdl = false;
#endif
// Initialize CUTLASS kernel with arguments and workspace pointer
CUTLASS_CHECK(dist_gemm_arr[device_idx].initialize(
arguments_,
workspace_ptr_arr,
exclusive_workspace_ptr_arr,
device_idx,
stream_arr[device_idx],
launch_with_pdl
));
cudaDeviceSynchronize();
}
// Correctness / Warmup iteration
std::cout << std::endl << " running DistGEMM..." << std::endl;
for (int device_idx = 0; device_idx < TP_; ++device_idx) {
CUDA_CHECK(cudaSetDevice(device_idx));
CUTLASS_CHECK(dist_gemm_arr[device_idx].run(stream_arr[device_idx]));
}
for (int device_idx = 0; device_idx < TP_; ++device_idx) {
CUDA_CHECK(cudaStreamSynchronize(stream_arr[device_idx]));
CUDA_CHECK(cudaGetLastError());
gather_results(options, device_idx);
}
std::cout << " running DistGEMM finished without runtime errors" << std::endl;
//// Check if output from CUTLASS kernel and reference kernel are equal or not
Result result;
result.passed = verify(options);
std::cout << std::endl << " Disposition (eps: " << options.eps << "): " <<
(result.passed ? "Passed" : "Failed") << std::endl;
if (!result.passed) {
exit(-1);
}
// Run profiling loop
if (options.iterations > 0) {
float elapsed_ms = 0.f;
// Warmup
std::cout << " Warming up for " << options.warmup_iterations << " iterations." << std::endl;
for (int warmup_iter = 0; warmup_iter < options.warmup_iterations; ++warmup_iter) {
for (int device_idx = 0; device_idx < TP_; ++device_idx) {
CUDA_CHECK(cudaSetDevice(device_idx));
CUTLASS_CHECK(dist_gemm_arr[device_idx].run(stream_arr[device_idx]));
}
}
for (int device_idx = 0; device_idx < TP_; ++device_idx) {
CUDA_CHECK(cudaSetDevice(device_idx));
CUDA_CHECK(cudaStreamSynchronize(stream_arr[device_idx]));
}
CUDA_CHECK(cudaSetDevice(primary_device_idx));
// Benchmark
std::cout << " Profiling for " << options.iterations << " iterations." << std::endl;
using AtomicBoolean = cuda::atomic<bool>;
AtomicBoolean* atomic_flag_ptr;
CUDA_CHECK(cudaHostAlloc(&atomic_flag_ptr, sizeof(AtomicBoolean), cudaHostAllocPortable));
atomic_flag_ptr->store(false);
cutlass::DistGpuTimer<TP_> timer;
for (int device_idx = 0; device_idx < TP_; ++device_idx) {
CUDA_CHECK(cudaSetDevice(device_idx));
cutlass::delay_kernel<<<1, 1, 0, stream_arr[device_idx]>>>(atomic_flag_ptr);
CUDA_CHECK(cudaGetLastError());
}
for (int device_idx = 0; device_idx < TP_; ++device_idx) {
timer.start(device_idx, stream_arr[device_idx]);
}
atomic_flag_ptr->store(true);
for (int profile_iter = 0; profile_iter < options.iterations; ++profile_iter) {
for (int device_idx = 0; device_idx < TP_; ++device_idx) {
CUDA_CHECK(cudaSetDevice(device_idx));
CUTLASS_CHECK(dist_gemm_arr[device_idx].run(stream_arr[device_idx]));
}
}
for (int device_idx = 0; device_idx < TP_; ++device_idx) {
CUDA_CHECK(cudaSetDevice(device_idx));
timer.stop(device_idx, stream_arr[device_idx]);
}
CUDA_CHECK(cudaSetDevice(primary_device_idx));
for (int device_idx = 0; device_idx < TP_; ++device_idx) {
elapsed_ms = max(elapsed_ms, timer.elapsed_millis(device_idx));
}
// Compute average runtime and TFLOPs.
result.avg_runtime_ms = double(elapsed_ms) / double(options.iterations);
double avg_runtime_s = (double)(result.avg_runtime_ms / 1000.0);
result.tflops = options.tflops(avg_runtime_s);
auto [local_M, local_N, local_K, local_L] = DistSchedule::get_local_gemm_shape(
cute::make_tuple(options.m, options.n, options.k, options.l));
std::cout << std::endl;
std::cout << " TP: " << TP::value << std::endl;
std::cout << " Problem Size: " <<
options.m << " x " <<
options.n << " x " <<
options.k << " x " <<
options.l << std::endl;
std::cout << " Local GEMM Problem Size: " <<
local_M << " x " <<
local_N << " x " <<
local_K << " x " <<
local_L<< std::endl;
std::cout << " Avg runtime: " << result.avg_runtime_ms << " ms" << std::endl;
std::cout << " TFLOPS: " << result.tflops << std::endl;
}
return 0;
}
#endif // (defined(CUTLASS_ARCH_MMA_SM100A_ENABLED) &&
// (__CUDACC_VER_MAJOR__ > 12 || (__CUDACC_VER_MAJOR__ == 12 && __CUDACC_VER_MINOR__ >= 8))
///////////////////////////////////////////////////////////////////////////////////////////////////
int main(int argc, char const **args) {
// CUTLASS must be compiled with CUDA Toolkit 12.8 or newer to run Blackwell kernels.
if (__CUDACC_VER_MAJOR__ < 12 || (__CUDACC_VER_MAJOR__ == 12 && __CUDACC_VER_MINOR__ < 8)) {
std::cerr << "This example requires CUDA 12.8 or newer." << std::endl;
// Returning zero so this test passes on older Toolkits. Its actions are no-op.
return 0;
}
int num_devices;
CUDA_CHECK(cudaGetDeviceCount(&num_devices));
if (num_devices < TP_) {
std::cerr << "Distributed GEMM is compiled with TP = " << TP::value << ", but " <<
"found only " << num_devices << " devices." <<
std::endl;
// Returning zero so this test passes on older Toolkits. Its actions are no-op.
return 0;
}
cudaDeviceProp props;
int current_device_id;
CUDA_CHECK(cudaGetDevice(&current_device_id));
CUDA_CHECK(cudaGetDeviceProperties(&props, current_device_id));
cudaError_t error = cudaGetDeviceProperties(&props, 0);
if (props.major != 10 || props.minor != 0) {
std::cerr
<< "This example requires a GPU of NVIDIA's Blackwell Architecture "
<< "(compute capability 100), "
<< "got compute capability " << props.major * 10 + props.minor << "."
<< std::endl;
return 0;
}
//
// Parse options
//
Options options;
options.parse(argc, args);
if (options.help) {
options.print_usage(std::cout) << std::endl;
return 0;
}
//
// Evaluate CUTLASS kernels
//
#if (defined(CUTLASS_ARCH_MMA_SM100A_ENABLED) && (__CUDACC_VER_MAJOR__ > 12 || (__CUDACC_VER_MAJOR__ == 12 && __CUDACC_VER_MINOR__ >= 8)))
run(options);
#else
std::cerr
<< "This example must be compiled with `sm100a` and CUDA Toolkit 12.8 or later." << std::endl;
return 0;
#endif
return 0;
}