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Apply consistent code formatting across the repo. Add clang-format and pre-commit hooks.

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This commit is contained in:
Rob Armstrong
2025-03-27 10:30:07 -07:00
parent 2cd58fbc9a
commit ceab6e8bcc
782 changed files with 107230 additions and 106548 deletions
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587
Samples/0_Introduction/simpleStreams/simpleStreams.cu
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@@ -44,141 +44,137 @@
*
* Elapsed times are averaged over nreps repetitions (10 by default).
*
*/
*/
const char *sSDKsample = "simpleStreams";
const char *sEventSyncMethod[] = {"cudaEventDefault", "cudaEventBlockingSync",
"cudaEventDisableTiming", NULL};
const char *sEventSyncMethod[] = {"cudaEventDefault", "cudaEventBlockingSync", "cudaEventDisableTiming", NULL};
const char *sDeviceSyncMethod[] = {
"cudaDeviceScheduleAuto", "cudaDeviceScheduleSpin",
"cudaDeviceScheduleYield", "INVALID",
"cudaDeviceScheduleBlockingSync", NULL};
const char *sDeviceSyncMethod[] = {"cudaDeviceScheduleAuto",
"cudaDeviceScheduleSpin",
"cudaDeviceScheduleYield",
"INVALID",
"cudaDeviceScheduleBlockingSync",
NULL};
// System includes
#include <stdio.h>
#include <assert.h>
#include <stdio.h>
// CUDA runtime
#include <cuda_runtime.h>
// helper functions and utilities to work with CUDA
#include <helper_functions.h>
#include <helper_cuda.h>
#include <helper_functions.h>
#ifndef WIN32
#include <sys/mman.h> // for mmap() / munmap()
#include <sys/mman.h> // for mmap() / munmap()
#endif
// Macro to aligned up to the memory size in question
#define MEMORY_ALIGNMENT 4096
#define MEMORY_ALIGNMENT 4096
#define ALIGN_UP(x, size) (((size_t)x + (size - 1)) & (~(size - 1)))
__global__ void init_array(int *g_data, int *factor, int num_iterations) {
int idx = blockIdx.x * blockDim.x + threadIdx.x;
__global__ void init_array(int *g_data, int *factor, int num_iterations)
{
int idx = blockIdx.x * blockDim.x + threadIdx.x;
for (int i = 0; i < num_iterations; i++) {
g_data[idx] += *factor; // non-coalesced on purpose, to burn time
}
}
bool correct_data(int *a, const int n, const int c) {
for (int i = 0; i < n; i++) {
if (a[i] != c) {
printf("%d: %d %d\n", i, a[i], c);
return false;
for (int i = 0; i < num_iterations; i++) {
g_data[idx] += *factor; // non-coalesced on purpose, to burn time
}
}
return true;
}
inline void AllocateHostMemory(bool bPinGenericMemory, int **pp_a,
int **ppAligned_a, int nbytes) {
bool correct_data(int *a, const int n, const int c)
{
for (int i = 0; i < n; i++) {
if (a[i] != c) {
printf("%d: %d %d\n", i, a[i], c);
return false;
}
}
return true;
}
inline void AllocateHostMemory(bool bPinGenericMemory, int **pp_a, int **ppAligned_a, int nbytes)
{
#if CUDART_VERSION >= 4000
#if !defined(__arm__) && !defined(__aarch64__)
if (bPinGenericMemory) {
if (bPinGenericMemory) {
// allocate a generic page-aligned chunk of system memory
#ifdef WIN32
printf(
"> VirtualAlloc() allocating %4.2f Mbytes of (generic page-aligned "
"system memory)\n",
(float)nbytes / 1048576.0f);
*pp_a = (int *)VirtualAlloc(NULL, (nbytes + MEMORY_ALIGNMENT),
MEM_RESERVE | MEM_COMMIT, PAGE_READWRITE);
printf("> VirtualAlloc() allocating %4.2f Mbytes of (generic page-aligned "
"system memory)\n",
(float)nbytes / 1048576.0f);
*pp_a = (int *)VirtualAlloc(NULL, (nbytes + MEMORY_ALIGNMENT), MEM_RESERVE | MEM_COMMIT, PAGE_READWRITE);
#else
printf(
"> mmap() allocating %4.2f Mbytes (generic page-aligned system "
"memory)\n",
(float)nbytes / 1048576.0f);
*pp_a = (int *)mmap(NULL, (nbytes + MEMORY_ALIGNMENT),
PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANON, -1, 0);
printf("> mmap() allocating %4.2f Mbytes (generic page-aligned system "
"memory)\n",
(float)nbytes / 1048576.0f);
*pp_a = (int *)mmap(NULL, (nbytes + MEMORY_ALIGNMENT), PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANON, -1, 0);
#endif
*ppAligned_a = (int *)ALIGN_UP(*pp_a, MEMORY_ALIGNMENT);
*ppAligned_a = (int *)ALIGN_UP(*pp_a, MEMORY_ALIGNMENT);
printf(
"> cudaHostRegister() registering %4.2f Mbytes of generic allocated "
"system memory\n",
(float)nbytes / 1048576.0f);
// pin allocate memory
checkCudaErrors(
cudaHostRegister(*ppAligned_a, nbytes, cudaHostRegisterMapped));
} else
printf("> cudaHostRegister() registering %4.2f Mbytes of generic allocated "
"system memory\n",
(float)nbytes / 1048576.0f);
// pin allocate memory
checkCudaErrors(cudaHostRegister(*ppAligned_a, nbytes, cudaHostRegisterMapped));
}
else
#endif
#endif
{
printf("> cudaMallocHost() allocating %4.2f Mbytes of system memory\n",
(float)nbytes / 1048576.0f);
// allocate host memory (pinned is required for achieve asynchronicity)
checkCudaErrors(cudaMallocHost((void **)pp_a, nbytes));
*ppAligned_a = *pp_a;
}
{
printf("> cudaMallocHost() allocating %4.2f Mbytes of system memory\n", (float)nbytes / 1048576.0f);
// allocate host memory (pinned is required for achieve asynchronicity)
checkCudaErrors(cudaMallocHost((void **)pp_a, nbytes));
*ppAligned_a = *pp_a;
}
}
inline void FreeHostMemory(bool bPinGenericMemory, int **pp_a,
int **ppAligned_a, int nbytes) {
inline void FreeHostMemory(bool bPinGenericMemory, int **pp_a, int **ppAligned_a, int nbytes)
{
#if CUDART_VERSION >= 4000
#if !defined(__arm__) && !defined(__aarch64__)
// CUDA 4.0 support pinning of generic host memory
if (bPinGenericMemory) {
// unpin and delete host memory
checkCudaErrors(cudaHostUnregister(*ppAligned_a));
// CUDA 4.0 support pinning of generic host memory
if (bPinGenericMemory) {
// unpin and delete host memory
checkCudaErrors(cudaHostUnregister(*ppAligned_a));
#ifdef WIN32
VirtualFree(*pp_a, 0, MEM_RELEASE);
VirtualFree(*pp_a, 0, MEM_RELEASE);
#else
munmap(*pp_a, nbytes);
munmap(*pp_a, nbytes);
#endif
} else
}
else
#endif
#endif
{
cudaFreeHost(*pp_a);
}
{
cudaFreeHost(*pp_a);
}
}
static const char *sSyncMethod[] = {
"0 (Automatic Blocking)",
"1 (Spin Blocking)",
"2 (Yield Blocking)",
"3 (Undefined Blocking Method)",
"4 (Blocking Sync Event) = low CPU utilization",
NULL};
static const char *sSyncMethod[] = {"0 (Automatic Blocking)",
"1 (Spin Blocking)",
"2 (Yield Blocking)",
"3 (Undefined Blocking Method)",
"4 (Blocking Sync Event) = low CPU utilization",
NULL};
void printHelp() {
printf("Usage: %s [options below]\n", sSDKsample);
printf("\t--sync_method=n for CPU/GPU synchronization\n");
printf("\t n=%s\n", sSyncMethod[0]);
printf("\t n=%s\n", sSyncMethod[1]);
printf("\t n=%s\n", sSyncMethod[2]);
printf("\t <Default> n=%s\n", sSyncMethod[4]);
printf(
"\t--use_generic_memory (default) use generic page-aligned for system "
"memory\n");
printf(
"\t--use_cuda_malloc_host (optional) use cudaMallocHost to allocate "
"system memory\n");
void printHelp()
{
printf("Usage: %s [options below]\n", sSDKsample);
printf("\t--sync_method=n for CPU/GPU synchronization\n");
printf("\t n=%s\n", sSyncMethod[0]);
printf("\t n=%s\n", sSyncMethod[1]);
printf("\t n=%s\n", sSyncMethod[2]);
printf("\t <Default> n=%s\n", sSyncMethod[4]);
printf("\t--use_generic_memory (default) use generic page-aligned for system "
"memory\n");
printf("\t--use_cuda_malloc_host (optional) use cudaMallocHost to allocate "
"system memory\n");
}
#if defined(__APPLE__) || defined(MACOSX)
@@ -187,259 +183,240 @@ void printHelp() {
#define DEFAULT_PINNED_GENERIC_MEMORY true
#endif
int main(int argc, char **argv) {
int cuda_device = 0;
int nstreams = 4; // number of streams for CUDA calls
int nreps = 10; // number of times each experiment is repeated
int n = 16 * 1024 * 1024; // number of ints in the data set
int nbytes = n * sizeof(int); // number of data bytes
dim3 threads, blocks; // kernel launch configuration
float elapsed_time, time_memcpy, time_kernel; // timing variables
float scale_factor = 1.0f;
int main(int argc, char **argv)
{
int cuda_device = 0;
int nstreams = 4; // number of streams for CUDA calls
int nreps = 10; // number of times each experiment is repeated
int n = 16 * 1024 * 1024; // number of ints in the data set
int nbytes = n * sizeof(int); // number of data bytes
dim3 threads, blocks; // kernel launch configuration
float elapsed_time, time_memcpy, time_kernel; // timing variables
float scale_factor = 1.0f;
// allocate generic memory and pin it laster instead of using cudaHostAlloc()
// allocate generic memory and pin it laster instead of using cudaHostAlloc()
bool bPinGenericMemory =
DEFAULT_PINNED_GENERIC_MEMORY; // we want this to be the default behavior
int device_sync_method =
cudaDeviceBlockingSync; // by default we use BlockingSync
bool bPinGenericMemory = DEFAULT_PINNED_GENERIC_MEMORY; // we want this to be the default behavior
int device_sync_method = cudaDeviceBlockingSync; // by default we use BlockingSync
int niterations; // number of iterations for the loop inside the kernel
int niterations; // number of iterations for the loop inside the kernel
printf("[ %s ]\n\n", sSDKsample);
printf("[ %s ]\n\n", sSDKsample);
if (checkCmdLineFlag(argc, (const char **)argv, "help")) {
printHelp();
return EXIT_SUCCESS;
}
if ((device_sync_method = getCmdLineArgumentInt(argc, (const char **)argv,
"sync_method")) >= 0) {
if (device_sync_method == 0 || device_sync_method == 1 ||
device_sync_method == 2 || device_sync_method == 4) {
printf("Device synchronization method set to = %s\n",
sSyncMethod[device_sync_method]);
printf("Setting reps to 100 to demonstrate steady state\n");
nreps = 100;
} else {
printf("Invalid command line option sync_method=\"%d\"\n",
device_sync_method);
return EXIT_FAILURE;
if (checkCmdLineFlag(argc, (const char **)argv, "help")) {
printHelp();
return EXIT_SUCCESS;
}
} else {
printHelp();
return EXIT_SUCCESS;
}
if (checkCmdLineFlag(argc, (const char **)argv, "use_generic_memory")) {
if ((device_sync_method = getCmdLineArgumentInt(argc, (const char **)argv, "sync_method")) >= 0) {
if (device_sync_method == 0 || device_sync_method == 1 || device_sync_method == 2 || device_sync_method == 4) {
printf("Device synchronization method set to = %s\n", sSyncMethod[device_sync_method]);
printf("Setting reps to 100 to demonstrate steady state\n");
nreps = 100;
}
else {
printf("Invalid command line option sync_method=\"%d\"\n", device_sync_method);
return EXIT_FAILURE;
}
}
else {
printHelp();
return EXIT_SUCCESS;
}
if (checkCmdLineFlag(argc, (const char **)argv, "use_generic_memory")) {
#if defined(__APPLE__) || defined(MACOSX)
bPinGenericMemory = false; // Generic Pinning of System Paged memory not
// currently supported on Mac OSX
bPinGenericMemory = false; // Generic Pinning of System Paged memory not
// currently supported on Mac OSX
#else
bPinGenericMemory = true;
bPinGenericMemory = true;
#endif
}
if (checkCmdLineFlag(argc, (const char **)argv, "use_cuda_malloc_host")) {
bPinGenericMemory = false;
}
printf("\n> ");
cuda_device = findCudaDevice(argc, (const char **)argv);
// check the compute capability of the device
int num_devices = 0;
checkCudaErrors(cudaGetDeviceCount(&num_devices));
if (0 == num_devices) {
printf(
"your system does not have a CUDA capable device, waiving test...\n");
return EXIT_WAIVED;
}
// check if the command-line chosen device ID is within range, exit if not
if (cuda_device >= num_devices) {
printf(
"cuda_device=%d is invalid, must choose device ID between 0 and %d\n",
cuda_device, num_devices - 1);
return EXIT_FAILURE;
}
checkCudaErrors(cudaSetDevice(cuda_device));
// Checking for compute capabilities
cudaDeviceProp deviceProp;
checkCudaErrors(cudaGetDeviceProperties(&deviceProp, cuda_device));
niterations = 5;
// Check if GPU can map host memory (Generic Method), if not then we override
// bPinGenericMemory to be false
if (bPinGenericMemory) {
printf("Device: <%s> canMapHostMemory: %s\n", deviceProp.name,
deviceProp.canMapHostMemory ? "Yes" : "No");
if (deviceProp.canMapHostMemory == 0) {
printf(
"Using cudaMallocHost, CUDA device does not support mapping of "
"generic host memory\n");
bPinGenericMemory = false;
}
}
// Anything that is less than 32 Cores will have scaled down workload
scale_factor =
max((32.0f / (_ConvertSMVer2Cores(deviceProp.major, deviceProp.minor) *
(float)deviceProp.multiProcessorCount)),
1.0f);
n = (int)rint((float)n / scale_factor);
if (checkCmdLineFlag(argc, (const char **)argv, "use_cuda_malloc_host")) {
bPinGenericMemory = false;
}
printf("> CUDA Capable: SM %d.%d hardware\n", deviceProp.major,
deviceProp.minor);
printf("> %d Multiprocessor(s) x %d (Cores/Multiprocessor) = %d (Cores)\n",
deviceProp.multiProcessorCount,
_ConvertSMVer2Cores(deviceProp.major, deviceProp.minor),
_ConvertSMVer2Cores(deviceProp.major, deviceProp.minor) *
deviceProp.multiProcessorCount);
printf("\n> ");
cuda_device = findCudaDevice(argc, (const char **)argv);
printf("> scale_factor = %1.4f\n", 1.0f / scale_factor);
printf("> array_size = %d\n\n", n);
// check the compute capability of the device
int num_devices = 0;
checkCudaErrors(cudaGetDeviceCount(&num_devices));
// enable use of blocking sync, to reduce CPU usage
printf("> Using CPU/GPU Device Synchronization method (%s)\n",
sDeviceSyncMethod[device_sync_method]);
checkCudaErrors(cudaSetDeviceFlags(
device_sync_method | (bPinGenericMemory ? cudaDeviceMapHost : 0)));
if (0 == num_devices) {
printf("your system does not have a CUDA capable device, waiving test...\n");
return EXIT_WAIVED;
}
// allocate host memory
int c = 5; // value to which the array will be initialized
int *h_a = 0; // pointer to the array data in host memory
int *hAligned_a = 0; // pointer to the array data in host memory (aligned to
// MEMORY_ALIGNMENT)
// check if the command-line chosen device ID is within range, exit if not
if (cuda_device >= num_devices) {
printf("cuda_device=%d is invalid, must choose device ID between 0 and %d\n", cuda_device, num_devices - 1);
return EXIT_FAILURE;
}
// Allocate Host memory (could be using cudaMallocHost or VirtualAlloc/mmap if
// using the new CUDA 4.0 features
AllocateHostMemory(bPinGenericMemory, &h_a, &hAligned_a, nbytes);
checkCudaErrors(cudaSetDevice(cuda_device));
// allocate device memory
int *d_a = 0,
*d_c = 0; // pointers to data and init value in the device memory
checkCudaErrors(cudaMalloc((void **)&d_a, nbytes));
checkCudaErrors(cudaMemset(d_a, 0x0, nbytes));
checkCudaErrors(cudaMalloc((void **)&d_c, sizeof(int)));
checkCudaErrors(cudaMemcpy(d_c, &c, sizeof(int), cudaMemcpyHostToDevice));
// Checking for compute capabilities
cudaDeviceProp deviceProp;
checkCudaErrors(cudaGetDeviceProperties(&deviceProp, cuda_device));
printf("\nStarting Test\n");
niterations = 5;
// allocate and initialize an array of stream handles
cudaStream_t *streams =
(cudaStream_t *)malloc(nstreams * sizeof(cudaStream_t));
// Check if GPU can map host memory (Generic Method), if not then we override
// bPinGenericMemory to be false
if (bPinGenericMemory) {
printf("Device: <%s> canMapHostMemory: %s\n", deviceProp.name, deviceProp.canMapHostMemory ? "Yes" : "No");
for (int i = 0; i < nstreams; i++) {
checkCudaErrors(cudaStreamCreate(&(streams[i])));
}
if (deviceProp.canMapHostMemory == 0) {
printf("Using cudaMallocHost, CUDA device does not support mapping of "
"generic host memory\n");
bPinGenericMemory = false;
}
}
// create CUDA event handles
// use blocking sync
cudaEvent_t start_event, stop_event;
int eventflags =
((device_sync_method == cudaDeviceBlockingSync) ? cudaEventBlockingSync
: cudaEventDefault);
// Anything that is less than 32 Cores will have scaled down workload
scale_factor =
max((32.0f / (_ConvertSMVer2Cores(deviceProp.major, deviceProp.minor) * (float)deviceProp.multiProcessorCount)),
1.0f);
n = (int)rint((float)n / scale_factor);
checkCudaErrors(cudaEventCreateWithFlags(&start_event, eventflags));
checkCudaErrors(cudaEventCreateWithFlags(&stop_event, eventflags));
printf("> CUDA Capable: SM %d.%d hardware\n", deviceProp.major, deviceProp.minor);
printf("> %d Multiprocessor(s) x %d (Cores/Multiprocessor) = %d (Cores)\n",
deviceProp.multiProcessorCount,
_ConvertSMVer2Cores(deviceProp.major, deviceProp.minor),
_ConvertSMVer2Cores(deviceProp.major, deviceProp.minor) * deviceProp.multiProcessorCount);
// time memcopy from device
checkCudaErrors(cudaEventRecord(start_event, 0)); // record in stream-0, to
// ensure that all previous
// CUDA calls have
// completed
checkCudaErrors(cudaMemcpyAsync(hAligned_a, d_a, nbytes,
cudaMemcpyDeviceToHost, streams[0]));
checkCudaErrors(cudaEventRecord(stop_event, 0));
checkCudaErrors(cudaEventSynchronize(
stop_event)); // block until the event is actually recorded
checkCudaErrors(cudaEventElapsedTime(&time_memcpy, start_event, stop_event));
printf("memcopy:\t%.2f\n", time_memcpy);
printf("> scale_factor = %1.4f\n", 1.0f / scale_factor);
printf("> array_size = %d\n\n", n);
// time kernel
threads = dim3(512, 1);
blocks = dim3(n / threads.x, 1);
checkCudaErrors(cudaEventRecord(start_event, 0));
init_array<<<blocks, threads, 0, streams[0]>>>(d_a, d_c, niterations);
checkCudaErrors(cudaEventRecord(stop_event, 0));
checkCudaErrors(cudaEventSynchronize(stop_event));
checkCudaErrors(cudaEventElapsedTime(&time_kernel, start_event, stop_event));
printf("kernel:\t\t%.2f\n", time_kernel);
// enable use of blocking sync, to reduce CPU usage
printf("> Using CPU/GPU Device Synchronization method (%s)\n", sDeviceSyncMethod[device_sync_method]);
checkCudaErrors(cudaSetDeviceFlags(device_sync_method | (bPinGenericMemory ? cudaDeviceMapHost : 0)));
//////////////////////////////////////////////////////////////////////
// time non-streamed execution for reference
threads = dim3(512, 1);
blocks = dim3(n / threads.x, 1);
checkCudaErrors(cudaEventRecord(start_event, 0));
// allocate host memory
int c = 5; // value to which the array will be initialized
int *h_a = 0; // pointer to the array data in host memory
int *hAligned_a = 0; // pointer to the array data in host memory (aligned to
// MEMORY_ALIGNMENT)
for (int k = 0; k < nreps; k++) {
init_array<<<blocks, threads>>>(d_a, d_c, niterations);
checkCudaErrors(
cudaMemcpy(hAligned_a, d_a, nbytes, cudaMemcpyDeviceToHost));
}
// Allocate Host memory (could be using cudaMallocHost or VirtualAlloc/mmap if
// using the new CUDA 4.0 features
AllocateHostMemory(bPinGenericMemory, &h_a, &hAligned_a, nbytes);
checkCudaErrors(cudaEventRecord(stop_event, 0));
checkCudaErrors(cudaEventSynchronize(stop_event));
checkCudaErrors(cudaEventElapsedTime(&elapsed_time, start_event, stop_event));
printf("non-streamed:\t%.2f\n", elapsed_time / nreps);
// allocate device memory
int *d_a = 0,
*d_c = 0; // pointers to data and init value in the device memory
checkCudaErrors(cudaMalloc((void **)&d_a, nbytes));
checkCudaErrors(cudaMemset(d_a, 0x0, nbytes));
checkCudaErrors(cudaMalloc((void **)&d_c, sizeof(int)));
checkCudaErrors(cudaMemcpy(d_c, &c, sizeof(int), cudaMemcpyHostToDevice));
//////////////////////////////////////////////////////////////////////
// time execution with nstreams streams
threads = dim3(512, 1);
blocks = dim3(n / (nstreams * threads.x), 1);
memset(hAligned_a, 255,
nbytes); // set host memory bits to all 1s, for testing correctness
checkCudaErrors(cudaMemset(
d_a, 0, nbytes)); // set device memory to all 0s, for testing correctness
checkCudaErrors(cudaEventRecord(start_event, 0));
printf("\nStarting Test\n");
// allocate and initialize an array of stream handles
cudaStream_t *streams = (cudaStream_t *)malloc(nstreams * sizeof(cudaStream_t));
for (int k = 0; k < nreps; k++) {
// asynchronously launch nstreams kernels, each operating on its own portion
// of data
for (int i = 0; i < nstreams; i++) {
init_array<<<blocks, threads, 0, streams[i]>>>(d_a + i * n / nstreams,
d_c, niterations);
checkCudaErrors(cudaStreamCreate(&(streams[i])));
}
// asynchronously launch nstreams memcopies. Note that memcopy in stream x
// will only
// commence executing when all previous CUDA calls in stream x have
// completed
// create CUDA event handles
// use blocking sync
cudaEvent_t start_event, stop_event;
int eventflags = ((device_sync_method == cudaDeviceBlockingSync) ? cudaEventBlockingSync : cudaEventDefault);
checkCudaErrors(cudaEventCreateWithFlags(&start_event, eventflags));
checkCudaErrors(cudaEventCreateWithFlags(&stop_event, eventflags));
// time memcopy from device
checkCudaErrors(cudaEventRecord(start_event, 0)); // record in stream-0, to
// ensure that all previous
// CUDA calls have
// completed
checkCudaErrors(cudaMemcpyAsync(hAligned_a, d_a, nbytes, cudaMemcpyDeviceToHost, streams[0]));
checkCudaErrors(cudaEventRecord(stop_event, 0));
checkCudaErrors(cudaEventSynchronize(stop_event)); // block until the event is actually recorded
checkCudaErrors(cudaEventElapsedTime(&time_memcpy, start_event, stop_event));
printf("memcopy:\t%.2f\n", time_memcpy);
// time kernel
threads = dim3(512, 1);
blocks = dim3(n / threads.x, 1);
checkCudaErrors(cudaEventRecord(start_event, 0));
init_array<<<blocks, threads, 0, streams[0]>>>(d_a, d_c, niterations);
checkCudaErrors(cudaEventRecord(stop_event, 0));
checkCudaErrors(cudaEventSynchronize(stop_event));
checkCudaErrors(cudaEventElapsedTime(&time_kernel, start_event, stop_event));
printf("kernel:\t\t%.2f\n", time_kernel);
//////////////////////////////////////////////////////////////////////
// time non-streamed execution for reference
threads = dim3(512, 1);
blocks = dim3(n / threads.x, 1);
checkCudaErrors(cudaEventRecord(start_event, 0));
for (int k = 0; k < nreps; k++) {
init_array<<<blocks, threads>>>(d_a, d_c, niterations);
checkCudaErrors(cudaMemcpy(hAligned_a, d_a, nbytes, cudaMemcpyDeviceToHost));
}
checkCudaErrors(cudaEventRecord(stop_event, 0));
checkCudaErrors(cudaEventSynchronize(stop_event));
checkCudaErrors(cudaEventElapsedTime(&elapsed_time, start_event, stop_event));
printf("non-streamed:\t%.2f\n", elapsed_time / nreps);
//////////////////////////////////////////////////////////////////////
// time execution with nstreams streams
threads = dim3(512, 1);
blocks = dim3(n / (nstreams * threads.x), 1);
memset(hAligned_a, 255,
nbytes); // set host memory bits to all 1s, for testing correctness
checkCudaErrors(cudaMemset(d_a, 0, nbytes)); // set device memory to all 0s, for testing correctness
checkCudaErrors(cudaEventRecord(start_event, 0));
for (int k = 0; k < nreps; k++) {
// asynchronously launch nstreams kernels, each operating on its own portion
// of data
for (int i = 0; i < nstreams; i++) {
init_array<<<blocks, threads, 0, streams[i]>>>(d_a + i * n / nstreams, d_c, niterations);
}
// asynchronously launch nstreams memcopies. Note that memcopy in stream x
// will only
// commence executing when all previous CUDA calls in stream x have
// completed
for (int i = 0; i < nstreams; i++) {
checkCudaErrors(cudaMemcpyAsync(hAligned_a + i * n / nstreams,
d_a + i * n / nstreams,
nbytes / nstreams,
cudaMemcpyDeviceToHost,
streams[i]));
}
}
checkCudaErrors(cudaEventRecord(stop_event, 0));
checkCudaErrors(cudaEventSynchronize(stop_event));
checkCudaErrors(cudaEventElapsedTime(&elapsed_time, start_event, stop_event));
printf("%d streams:\t%.2f\n", nstreams, elapsed_time / nreps);
// check whether the output is correct
printf("-------------------------------\n");
bool bResults = correct_data(hAligned_a, n, c * nreps * niterations);
// release resources
for (int i = 0; i < nstreams; i++) {
checkCudaErrors(cudaMemcpyAsync(hAligned_a + i * n / nstreams,
d_a + i * n / nstreams, nbytes / nstreams,
cudaMemcpyDeviceToHost, streams[i]));
checkCudaErrors(cudaStreamDestroy(streams[i]));
}
}
checkCudaErrors(cudaEventRecord(stop_event, 0));
checkCudaErrors(cudaEventSynchronize(stop_event));
checkCudaErrors(cudaEventElapsedTime(&elapsed_time, start_event, stop_event));
printf("%d streams:\t%.2f\n", nstreams, elapsed_time / nreps);
checkCudaErrors(cudaEventDestroy(start_event));
checkCudaErrors(cudaEventDestroy(stop_event));
// check whether the output is correct
printf("-------------------------------\n");
bool bResults = correct_data(hAligned_a, n, c * nreps * niterations);
// Free cudaMallocHost or Generic Host allocated memory (from CUDA 4.0)
FreeHostMemory(bPinGenericMemory, &h_a, &hAligned_a, nbytes);
// release resources
for (int i = 0; i < nstreams; i++) {
checkCudaErrors(cudaStreamDestroy(streams[i]));
}
checkCudaErrors(cudaFree(d_a));
checkCudaErrors(cudaFree(d_c));
checkCudaErrors(cudaEventDestroy(start_event));
checkCudaErrors(cudaEventDestroy(stop_event));
// Free cudaMallocHost or Generic Host allocated memory (from CUDA 4.0)
FreeHostMemory(bPinGenericMemory, &h_a, &hAligned_a, nbytes);
checkCudaErrors(cudaFree(d_a));
checkCudaErrors(cudaFree(d_c));
return bResults ? EXIT_SUCCESS : EXIT_FAILURE;
return bResults ? EXIT_SUCCESS : EXIT_FAILURE;
}