cuda-samples/Samples/vectorAddMMAP/vectorAddMMAP.cpp
2019-10-23 19:00:39 +05:30

326 lines
10 KiB
C++

/* 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.
*/
/* Vector addition: C = A + B.
*
* This sample replaces the device allocation in the vectorAddDrvsample with
* cuMemMap-ed allocations. This sample demonstrates that the cuMemMap api
* allows the user to specify the physical properties of their memory while
* retaining the contiguos nature of their access, thus not requiring a change
* in their program structure.
*
*/
// Includes
#include <cuda.h>
#include <stdio.h>
#include <string.h>
#include <cstring>
#include <iostream>
// includes, project
#include <helper_cuda_drvapi.h>
#include <helper_functions.h>
// includes, CUDA
#include <builtin_types.h>
#include "multidevicealloc_memmap.hpp"
using namespace std;
// Variables
CUdevice cuDevice;
CUcontext cuContext;
CUmodule cuModule;
CUfunction vecAdd_kernel;
float *h_A;
float *h_B;
float *h_C;
CUdeviceptr d_A;
CUdeviceptr d_B;
CUdeviceptr d_C;
size_t allocationSize = 0;
// Functions
int CleanupNoFailure();
void RandomInit(float *, int);
bool findModulePath(const char *, string &, char **, string &);
// define input ptx file for different platforms
#if defined(_WIN64) || defined(__LP64__)
#define PTX_FILE "vectorAdd_kernel64.ptx"
#else
#define PTX_FILE "vectorAdd_kernel32.ptx"
#endif
// collect all of the devices whose memory can be mapped from cuDevice.
vector<CUdevice> getBackingDevices(CUdevice cuDevice) {
int num_devices;
checkCudaErrors(cuDeviceGetCount(&num_devices));
vector<CUdevice> backingDevices;
backingDevices.push_back(cuDevice);
for (int dev = 0; dev < num_devices; dev++) {
int capable = 0;
int attributeVal = 0;
// The mapping device is already in the backingDevices vector
if (dev == cuDevice) {
continue;
}
// Only peer capable devices can map each others memory
checkCudaErrors(cuDeviceCanAccessPeer(&capable, cuDevice, dev));
if (!capable) {
continue;
}
// The device needs to support virtual address management for the required
// apis to work
checkCudaErrors(cuDeviceGetAttribute(
&attributeVal, CU_DEVICE_ATTRIBUTE_VIRTUAL_ADDRESS_MANAGEMENT_SUPPORTED,
cuDevice));
if (attributeVal == 0) {
continue;
}
backingDevices.push_back(dev);
}
return backingDevices;
}
// Host code
int main(int argc, char **argv) {
printf("Vector Addition (Driver API)\n");
int N = 50000;
size_t size = N * sizeof(float);
int attributeVal = 0;
// Initialize
checkCudaErrors(cuInit(0));
cuDevice = findCudaDeviceDRV(argc, (const char **)argv);
// Check that the selected device supports virtual address management
checkCudaErrors(cuDeviceGetAttribute(
&attributeVal, CU_DEVICE_ATTRIBUTE_VIRTUAL_ADDRESS_MANAGEMENT_SUPPORTED,
cuDevice));
printf("Device %d VIRTUAL ADDRESS MANAGEMENT SUPPORTED = %d.\n", cuDevice,
attributeVal);
if (attributeVal == 0) {
printf("Device %d doesn't support VIRTUAL ADDRESS MANAGEMENT.\n", cuDevice);
exit(EXIT_WAIVED);
}
// The vector addition happens on cuDevice, so the allocations need to be
// mapped there.
vector<CUdevice> mappingDevices;
mappingDevices.push_back(cuDevice);
// Collect devices accessible by the mapping device (cuDevice) into the
// backingDevices vector.
vector<CUdevice> backingDevices = getBackingDevices(cuDevice);
// Create context
checkCudaErrors(cuCtxCreate(&cuContext, 0, cuDevice));
// first search for the module path before we load the results
string module_path, ptx_source;
if (!findModulePath(PTX_FILE, module_path, argv, ptx_source)) {
if (!findModulePath("vectorAdd_kernel.cubin", module_path, argv,
ptx_source)) {
printf("> findModulePath could not find <vectorAdd> ptx or cubin\n");
exit(EXIT_FAILURE);
}
} else {
printf("> initCUDA loading module: <%s>\n", module_path.c_str());
}
// Create module from binary file (PTX or CUBIN)
if (module_path.rfind("ptx") != string::npos) {
// in this branch we use compilation with parameters
const unsigned int jitNumOptions = 3;
CUjit_option *jitOptions = new CUjit_option[jitNumOptions];
void **jitOptVals = new void *[jitNumOptions];
// set up size of compilation log buffer
jitOptions[0] = CU_JIT_INFO_LOG_BUFFER_SIZE_BYTES;
int jitLogBufferSize = 1024;
jitOptVals[0] = (void *)(size_t)jitLogBufferSize;
// set up pointer to the compilation log buffer
jitOptions[1] = CU_JIT_INFO_LOG_BUFFER;
char *jitLogBuffer = new char[jitLogBufferSize];
jitOptVals[1] = jitLogBuffer;
// set up pointer to set the Maximum # of registers for a particular kernel
jitOptions[2] = CU_JIT_MAX_REGISTERS;
int jitRegCount = 32;
jitOptVals[2] = (void *)(size_t)jitRegCount;
checkCudaErrors(cuModuleLoadDataEx(&cuModule, ptx_source.c_str(),
jitNumOptions, jitOptions,
(void **)jitOptVals));
printf("> PTX JIT log:\n%s\n", jitLogBuffer);
} else {
checkCudaErrors(cuModuleLoad(&cuModule, module_path.c_str()));
}
// Get function handle from module
checkCudaErrors(
cuModuleGetFunction(&vecAdd_kernel, cuModule, "VecAdd_kernel"));
// Allocate input vectors h_A and h_B in host memory
h_A = (float *)malloc(size);
h_B = (float *)malloc(size);
h_C = (float *)malloc(size);
// Initialize input vectors
RandomInit(h_A, N);
RandomInit(h_B, N);
// Allocate vectors in device memory
// note that a call to cuCtxEnablePeerAccess is not needed even though
// the backing devices and mapping device are not the same.
// This is because the cuMemSetAccess call explicitly specifies
// the cross device mapping.
// cuMemSetAccess is still subject to the constraints of cuDeviceCanAccessPeer
// for cross device mappings (hence why we checked cuDeviceCanAccessPeer
// earlier).
checkCudaErrors(simpleMallocMultiDeviceMmap(&d_A, &allocationSize, size,
backingDevices, mappingDevices));
checkCudaErrors(simpleMallocMultiDeviceMmap(&d_B, NULL, size, backingDevices,
mappingDevices));
checkCudaErrors(simpleMallocMultiDeviceMmap(&d_C, NULL, size, backingDevices,
mappingDevices));
// Copy vectors from host memory to device memory
checkCudaErrors(cuMemcpyHtoD(d_A, h_A, size));
checkCudaErrors(cuMemcpyHtoD(d_B, h_B, size));
// This is the new CUDA 4.0 API for Kernel Parameter Passing and Kernel Launch
// (simpler method)
// Grid/Block configuration
int threadsPerBlock = 256;
int blocksPerGrid = (N + threadsPerBlock - 1) / threadsPerBlock;
void *args[] = {&d_A, &d_B, &d_C, &N};
// Launch the CUDA kernel
checkCudaErrors(cuLaunchKernel(vecAdd_kernel, blocksPerGrid, 1, 1,
threadsPerBlock, 1, 1, 0, NULL, args, NULL));
// Copy result from device memory to host memory
// h_C contains the result in host memory
checkCudaErrors(cuMemcpyDtoH(h_C, d_C, size));
// Verify result
int i;
for (i = 0; i < N; ++i) {
float sum = h_A[i] + h_B[i];
if (fabs(h_C[i] - sum) > 1e-7f) {
break;
}
}
CleanupNoFailure();
printf("%s\n", (i == N) ? "Result = PASS" : "Result = FAIL");
exit((i == N) ? EXIT_SUCCESS : EXIT_FAILURE);
}
int CleanupNoFailure() {
// Free device memory
checkCudaErrors(simpleFreeMultiDeviceMmap(d_A, allocationSize));
checkCudaErrors(simpleFreeMultiDeviceMmap(d_B, allocationSize));
checkCudaErrors(simpleFreeMultiDeviceMmap(d_C, allocationSize));
// Free host memory
if (h_A) {
free(h_A);
}
if (h_B) {
free(h_B);
}
if (h_C) {
free(h_C);
}
checkCudaErrors(cuCtxDestroy(cuContext));
return EXIT_SUCCESS;
}
// Allocates an array with random float entries.
void RandomInit(float *data, int n) {
for (int i = 0; i < n; ++i) {
data[i] = rand() / (float)RAND_MAX;
}
}
bool inline findModulePath(const char *module_file, string &module_path,
char **argv, string &ptx_source) {
char *actual_path = sdkFindFilePath(module_file, argv[0]);
if (actual_path) {
module_path = actual_path;
} else {
printf("> findModulePath file not found: <%s> \n", module_file);
return false;
}
if (module_path.empty()) {
printf("> findModulePath could not find file: <%s> \n", module_file);
return false;
} else {
printf("> findModulePath found file at <%s>\n", module_path.c_str());
if (module_path.rfind(".ptx") != string::npos) {
FILE *fp = fopen(module_path.c_str(), "rb");
fseek(fp, 0, SEEK_END);
int file_size = ftell(fp);
char *buf = new char[file_size + 1];
fseek(fp, 0, SEEK_SET);
fread(buf, sizeof(char), file_size, fp);
fclose(fp);
buf[file_size] = '\0';
ptx_source = buf;
delete[] buf;
}
return true;
}
}