cuda-samples/Samples/conjugateGradientCudaGraphs/conjugateGradientCudaGraphs.cu

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/* Copyright (c) 2019, NVIDIA CORPORATION. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* * Neither the name of NVIDIA CORPORATION nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS ``AS IS'' AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
* OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/*
* This sample implements a conjugate gradient solver on GPU
* using CUBLAS and CUSPARSE with CUDA Graphs
*
*/
// includes, system
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
/* Using updated (v2) interfaces to cublas */
#include <cublas_v2.h>
#include <cuda_runtime.h>
#include <cusparse.h>
#include <cooperative_groups.h>
// Utilities and system includes
#include <helper_cuda.h> // helper function CUDA error checking and initialization
#include <helper_functions.h> // helper for shared functions common to CUDA Samples
namespace cg = cooperative_groups;
const char *sSDKname = "conjugateGradientCudaGraphs";
#ifndef WITH_GRAPH
#define WITH_GRAPH 1
#endif
/* genTridiag: generate a random tridiagonal symmetric matrix */
void genTridiag(int *I, int *J, float *val, int N, int nz) {
I[0] = 0, J[0] = 0, J[1] = 1;
val[0] = (float)rand() / RAND_MAX + 10.0f;
val[1] = (float)rand() / RAND_MAX;
int start;
for (int i = 1; i < N; i++) {
if (i > 1) {
I[i] = I[i - 1] + 3;
} else {
I[1] = 2;
}
start = (i - 1) * 3 + 2;
J[start] = i - 1;
J[start + 1] = i;
if (i < N - 1) {
J[start + 2] = i + 1;
}
val[start] = val[start - 1];
val[start + 1] = (float)rand() / RAND_MAX + 10.0f;
if (i < N - 1) {
val[start + 2] = (float)rand() / RAND_MAX;
}
}
I[N] = nz;
}
__global__ void initVectors(float *rhs, float *x, int N) {
size_t gid = blockIdx.x * blockDim.x + threadIdx.x;
for (size_t i = gid; i < N; i += gridDim.x * blockDim.x) {
rhs[i] = 1.0;
x[i] = 0.0;
}
}
__global__ void gpuDotProduct(float *vecA, float *vecB, float *result,
int size) {
cg::thread_block cta = cg::this_thread_block();
int gid = blockIdx.x * blockDim.x + threadIdx.x;
extern __shared__ double tmp[];
double temp_sum = 0.0;
for (int i = gid; i < size; i += gridDim.x * blockDim.x) {
temp_sum += (double)(vecA[i] * vecB[i]);
}
tmp[cta.thread_rank()] = temp_sum;
cg::sync(cta);
cg::thread_block_tile<32> tile32 = cg::tiled_partition<32>(cta);
double beta = temp_sum;
double temp;
for (int i = tile32.size() / 2; i > 0; i >>= 1) {
if (tile32.thread_rank() < i) {
temp = tmp[cta.thread_rank() + i];
beta += temp;
tmp[cta.thread_rank()] = beta;
}
cg::sync(tile32);
}
cg::sync(cta);
if (cta.thread_rank() == 0) {
beta = 0.0;
for (int i = 0; i < cta.size(); i += tile32.size()) {
beta += tmp[i];
}
atomicAdd(result, (float)beta);
}
}
__global__ void gpuSpMV(int *I, int *J, float *val, int nnz, int num_rows,
float alpha, float *inputVecX, float *outputVecY) {
size_t gid = blockIdx.x * blockDim.x + threadIdx.x;
for (size_t i = gid; i < num_rows; i += blockDim.x * gridDim.x) {
int row_elem = I[i];
int next_row_elem = I[i + 1];
int num_elems_this_row = next_row_elem - row_elem;
float output = 0.0;
for (int j = 0; j < num_elems_this_row; j++) {
output += alpha * val[row_elem + j] * inputVecX[J[row_elem + j]];
}
outputVecY[i] = output;
}
}
__global__ void r1_div_x(float *r1, float *r0, float *b) {
int gid = blockIdx.x * blockDim.x + threadIdx.x;
if (gid == 0) {
b[0] = r1[0] / r0[0];
}
}
__global__ void a_minus(float *a, float *na) {
int gid = blockIdx.x * blockDim.x + threadIdx.x;
if (gid == 0) {
na[0] = -(a[0]);
}
}
int main(int argc, char **argv) {
int N = 0, nz = 0, *I = NULL, *J = NULL;
float *val = NULL;
const float tol = 1e-5f;
const int max_iter = 10000;
float *x;
float *rhs;
float r1;
int *d_col, *d_row;
float *d_val, *d_x;
float *d_r, *d_p, *d_Ax;
int k;
float alpha, beta, alpham1;
cudaStream_t stream1, streamForGraph;
// This will pick the best possible CUDA capable device
cudaDeviceProp deviceProp;
int devID = findCudaDevice(argc, (const char **)argv);
if (devID < 0) {
printf("exiting...\n");
exit(EXIT_SUCCESS);
}
checkCudaErrors(cudaGetDeviceProperties(&deviceProp, devID));
// Statistics about the GPU device
printf(
"> GPU device has %d Multi-Processors, SM %d.%d compute capabilities\n\n",
deviceProp.multiProcessorCount, deviceProp.major, deviceProp.minor);
/* Generate a random tridiagonal symmetric matrix in CSR format */
N = 1048576;
nz = (N - 2) * 3 + 4;
I = (int *)malloc(sizeof(int) * (N + 1));
J = (int *)malloc(sizeof(int) * nz);
val = (float *)malloc(sizeof(float) * nz);
genTridiag(I, J, val, N, nz);
x = (float *)malloc(sizeof(float) * N);
rhs = (float *)malloc(sizeof(float) * N);
for (int i = 0; i < N; i++) {
rhs[i] = 1.0;
x[i] = 0.0;
}
/* Get handle to the CUBLAS context */
cublasHandle_t cublasHandle = 0;
cublasStatus_t cublasStatus;
cublasStatus = cublasCreate(&cublasHandle);
checkCudaErrors(cublasStatus);
/* Get handle to the CUSPARSE context */
cusparseHandle_t cusparseHandle = 0;
cusparseStatus_t cusparseStatus;
cusparseStatus = cusparseCreate(&cusparseHandle);
checkCudaErrors(cusparseStatus);
checkCudaErrors(cudaStreamCreate(&stream1));
checkCudaErrors(cudaMalloc((void **)&d_col, nz * sizeof(int)));
checkCudaErrors(cudaMalloc((void **)&d_row, (N + 1) * sizeof(int)));
checkCudaErrors(cudaMalloc((void **)&d_val, nz * sizeof(float)));
checkCudaErrors(cudaMalloc((void **)&d_x, N * sizeof(float)));
checkCudaErrors(cudaMalloc((void **)&d_r, N * sizeof(float)));
checkCudaErrors(cudaMalloc((void **)&d_p, N * sizeof(float)));
checkCudaErrors(cudaMalloc((void **)&d_Ax, N * sizeof(float)));
float *d_r1, *d_r0, *d_dot, *d_a, *d_na, *d_b;
checkCudaErrors(cudaMalloc((void **)&d_r1, sizeof(float)));
checkCudaErrors(cudaMalloc((void **)&d_r0, sizeof(float)));
checkCudaErrors(cudaMalloc((void **)&d_dot, sizeof(float)));
checkCudaErrors(cudaMalloc((void **)&d_a, sizeof(float)));
checkCudaErrors(cudaMalloc((void **)&d_na, sizeof(float)));
checkCudaErrors(cudaMalloc((void **)&d_b, sizeof(float)));
cusparseMatDescr_t descr = 0;
checkCudaErrors(cusparseCreateMatDescr(&descr));
checkCudaErrors(cusparseSetMatType(descr, CUSPARSE_MATRIX_TYPE_GENERAL));
checkCudaErrors(cusparseSetMatIndexBase(descr, CUSPARSE_INDEX_BASE_ZERO));
int numBlocks = 0, blockSize = 0, numBlocks2 = 0, blockSize2 = 0;
checkCudaErrors(
cudaOccupancyMaxPotentialBlockSize(&numBlocks, &blockSize, initVectors));
checkCudaErrors(cudaMemcpyAsync(d_col, J, nz * sizeof(int),
cudaMemcpyHostToDevice, stream1));
checkCudaErrors(cudaMemcpyAsync(d_row, I, (N + 1) * sizeof(int),
cudaMemcpyHostToDevice, stream1));
checkCudaErrors(cudaMemcpyAsync(d_val, val, nz * sizeof(float),
cudaMemcpyHostToDevice, stream1));
initVectors<<<numBlocks, blockSize, 0, stream1>>>(d_r, d_x, N);
checkCudaErrors(cudaOccupancyMaxPotentialBlockSize(&numBlocks2, &blockSize2,
gpuSpMV));
checkCudaErrors(cudaOccupancyMaxPotentialBlockSize(&numBlocks, &blockSize,
gpuDotProduct));
alpha = 1.0;
alpham1 = -1.0;
beta = 0.0;
checkCudaErrors(cusparseSetStream(cusparseHandle, stream1));
checkCudaErrors(
cusparseScsrmv(cusparseHandle, CUSPARSE_OPERATION_NON_TRANSPOSE, N, N, nz,
&alpha, descr, d_val, d_row, d_col, d_x, &beta, d_Ax));
checkCudaErrors(cublasSetStream(cublasHandle, stream1));
checkCudaErrors(cublasSaxpy(cublasHandle, N, &alpham1, d_Ax, 1, d_r, 1));
checkCudaErrors(
cublasSetPointerMode(cublasHandle, CUBLAS_POINTER_MODE_DEVICE));
checkCudaErrors(cublasSdot(cublasHandle, N, d_r, 1, d_r, 1, d_r1));
k = 1;
// First Iteration when k=1 starts
checkCudaErrors(cublasScopy(cublasHandle, N, d_r, 1, d_p, 1));
checkCudaErrors(
cusparseScsrmv(cusparseHandle, CUSPARSE_OPERATION_NON_TRANSPOSE, N, N, nz,
&alpha, descr, d_val, d_row, d_col, d_p, &beta, d_Ax));
checkCudaErrors(cublasSdot(cublasHandle, N, d_p, 1, d_Ax, 1, d_dot));
r1_div_x<<<1, 1, 0, stream1>>>(d_r1, d_dot, d_a);
checkCudaErrors(cublasSaxpy(cublasHandle, N, d_a, d_p, 1, d_x, 1));
a_minus<<<1, 1, 0, stream1>>>(d_a, d_na);
checkCudaErrors(cublasSaxpy(cublasHandle, N, d_na, d_Ax, 1, d_r, 1));
checkCudaErrors(cudaMemcpyAsync(d_r0, d_r1, sizeof(float),
cudaMemcpyDeviceToDevice, stream1));
checkCudaErrors(cublasSdot(cublasHandle, N, d_r, 1, d_r, 1, d_r1));
checkCudaErrors(cudaMemcpyAsync(&r1, d_r1, sizeof(float),
cudaMemcpyDeviceToHost, stream1));
checkCudaErrors(cudaStreamSynchronize(stream1));
printf("iteration = %3d, residual = %e\n", k, sqrt(r1));
// First Iteration when k=1 ends
k++;
#if WITH_GRAPH
cudaGraph_t initGraph;
checkCudaErrors(cudaStreamCreate(&streamForGraph));
checkCudaErrors(cublasSetStream(cublasHandle, stream1));
checkCudaErrors(cusparseSetStream(cusparseHandle, stream1));
checkCudaErrors(cudaStreamBeginCapture(stream1, cudaStreamCaptureModeGlobal));
r1_div_x<<<1, 1, 0, stream1>>>(d_r1, d_r0, d_b);
cublasSetPointerMode(cublasHandle, CUBLAS_POINTER_MODE_DEVICE);
checkCudaErrors(cublasSscal(cublasHandle, N, d_b, d_p, 1));
cublasSetPointerMode(cublasHandle, CUBLAS_POINTER_MODE_HOST);
checkCudaErrors(cublasSaxpy(cublasHandle, N, &alpha, d_r, 1, d_p, 1));
cublasSetPointerMode(cublasHandle, CUBLAS_POINTER_MODE_DEVICE);
#if 0 // Use cusparseScsrmv API when it is cuda graph compliant
checkCudaErrors(
cusparseSetPointerMode(cusparseHandle, CUSPARSE_POINTER_MODE_HOST));
checkCudaErrors(
cusparseScsrmv(cusparseHandle, CUSPARSE_OPERATION_NON_TRANSPOSE, N, N, nz,
&alpha, descr, d_val, d_row, d_col, d_p, &beta, d_Ax));
#else
gpuSpMV<<<numBlocks2, blockSize2, 0, stream1>>>(d_row, d_col, d_val, nz,
N, alpha, d_p, d_Ax);
#endif
checkCudaErrors(cudaMemsetAsync(d_dot, 0, sizeof(float), stream1));
// Use cublasSdot API when it is cuda graph compliant.
// checkCudaErrors(cublasSdot(cublasHandle, N, d_p, 1, d_Ax, 1, d_dot));
gpuDotProduct<<<numBlocks, blockSize, blockSize * sizeof(double), stream1>>>(
d_p, d_Ax, d_dot, N);
r1_div_x<<<1, 1, 0, stream1>>>(d_r1, d_dot, d_a);
checkCudaErrors(cublasSaxpy(cublasHandle, N, d_a, d_p, 1, d_x, 1));
a_minus<<<1, 1, 0, stream1>>>(d_a, d_na);
checkCudaErrors(cublasSaxpy(cublasHandle, N, d_na, d_Ax, 1, d_r, 1));
checkCudaErrors(cudaMemcpyAsync(d_r0, d_r1, sizeof(float),
cudaMemcpyDeviceToDevice, stream1));
checkCudaErrors(cudaMemsetAsync(d_r1, 0, sizeof(float), stream1));
// Use cublasSdot API when it is cuda graph compliant.
// checkCudaErrors(cublasSdot(cublasHandle, N, d_r, 1, d_r, 1, d_r1));
gpuDotProduct<<<numBlocks, blockSize, blockSize * sizeof(double), stream1>>>(
d_r, d_r, d_r1, N);
checkCudaErrors(cudaMemcpyAsync((float *)&r1, d_r1, sizeof(float),
cudaMemcpyDeviceToHost, stream1));
checkCudaErrors(cudaStreamEndCapture(stream1, &initGraph));
cudaGraphExec_t graphExec;
checkCudaErrors(cudaGraphInstantiate(&graphExec, initGraph, NULL, NULL, 0));
#endif
checkCudaErrors(cublasSetStream(cublasHandle, stream1));
checkCudaErrors(cusparseSetStream(cusparseHandle, stream1));
while (r1 > tol * tol && k <= max_iter) {
#if WITH_GRAPH
checkCudaErrors(cudaGraphLaunch(graphExec, streamForGraph));
checkCudaErrors(cudaStreamSynchronize(streamForGraph));
#else
r1_div_x<<<1, 1, 0, stream1>>>(d_r1, d_r0, d_b);
cublasSetPointerMode(cublasHandle, CUBLAS_POINTER_MODE_DEVICE);
checkCudaErrors(cublasSscal(cublasHandle, N, d_b, d_p, 1));
cublasSetPointerMode(cublasHandle, CUBLAS_POINTER_MODE_HOST);
checkCudaErrors(cublasSaxpy(cublasHandle, N, &alpha, d_r, 1, d_p, 1));
checkCudaErrors(cusparseScsrmv(
cusparseHandle, CUSPARSE_OPERATION_NON_TRANSPOSE, N, N, nz, &alpha,
descr, d_val, d_row, d_col, d_p, &beta, d_Ax));
cublasSetPointerMode(cublasHandle, CUBLAS_POINTER_MODE_DEVICE);
checkCudaErrors(cublasSdot(cublasHandle, N, d_p, 1, d_Ax, 1, d_dot));
r1_div_x<<<1, 1, 0, stream1>>>(d_r1, d_dot, d_a);
checkCudaErrors(cublasSaxpy(cublasHandle, N, d_a, d_p, 1, d_x, 1));
a_minus<<<1, 1, 0, stream1>>>(d_a, d_na);
checkCudaErrors(cublasSaxpy(cublasHandle, N, d_na, d_Ax, 1, d_r, 1));
checkCudaErrors(cudaMemcpyAsync(d_r0, d_r1, sizeof(float),
cudaMemcpyDeviceToDevice, stream1));
checkCudaErrors(cublasSdot(cublasHandle, N, d_r, 1, d_r, 1, d_r1));
checkCudaErrors(cudaMemcpyAsync((float *)&r1, d_r1, sizeof(float),
cudaMemcpyDeviceToHost, stream1));
checkCudaErrors(cudaStreamSynchronize(stream1));
#endif
printf("iteration = %3d, residual = %e\n", k, sqrt(r1));
k++;
}
#if WITH_GRAPH
checkCudaErrors(cudaMemcpyAsync(x, d_x, N * sizeof(float),
cudaMemcpyDeviceToHost, streamForGraph));
checkCudaErrors(cudaStreamSynchronize(streamForGraph));
#else
checkCudaErrors(cudaMemcpyAsync(x, d_x, N * sizeof(float),
cudaMemcpyDeviceToHost, stream1));
checkCudaErrors(cudaStreamSynchronize(stream1));
#endif
float rsum, diff, err = 0.0;
for (int i = 0; i < N; i++) {
rsum = 0.0;
for (int j = I[i]; j < I[i + 1]; j++) {
rsum += val[j] * x[J[j]];
}
diff = fabs(rsum - rhs[i]);
if (diff > err) {
err = diff;
}
}
#if WITH_GRAPH
checkCudaErrors(cudaGraphExecDestroy(graphExec));
checkCudaErrors(cudaGraphDestroy(initGraph));
checkCudaErrors(cudaStreamDestroy(streamForGraph));
#endif
checkCudaErrors(cudaStreamDestroy(stream1));
cusparseDestroy(cusparseHandle);
cublasDestroy(cublasHandle);
free(I);
free(J);
free(val);
free(x);
free(rhs);
cudaFree(d_col);
cudaFree(d_row);
cudaFree(d_val);
cudaFree(d_x);
cudaFree(d_r);
cudaFree(d_p);
cudaFree(d_Ax);
printf("Test Summary: Error amount = %f\n", err);
exit((k <= max_iter) ? 0 : 1);
}