cuda-samples/Samples/7_libNVVM/uvmlite/uvmlite.c
2023-06-29 19:33:40 +00:00

324 lines
11 KiB
C

// Copyright (c) 2014-2023, 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.
#include <assert.h>
#include <builtin_types.h>
#include <cuda.h>
#include <math.h>
#include <nvvm.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/stat.h>
#define ERROR_IF(expr) \
if (expr) { \
fprintf(stderr, "Failed check at %s:%d\n", __FILE__, __LINE__); \
exit(EXIT_FAILURE); \
}
// If 'err' is non-zero, emit an error message and exit.
#define checkCudaErrors(err) __checkCudaErrors(err, __FILE__, __LINE__)
static void __checkCudaErrors(CUresult err, const char *filename, int line) {
assert(filename);
if (CUDA_SUCCESS != err) {
const char *ename = NULL;
const CUresult res = cuGetErrorName(err, &ename);
fprintf(stderr,
"CUDA API Error %04d: \"%s\" from file <%s>, "
"line %i.\n",
err, ((CUDA_SUCCESS == res) ? ename : "Unknown"), filename, line);
exit(err);
}
}
// Compile the NVVM IR into PTX.
static char *generatePTX(const char *ll, size_t size, const char *filename,
int devMajor, int devMinor) {
assert(ll && filename);
// Create a program instance for libNVVM.
nvvmProgram program;
nvvmResult result = nvvmCreateProgram(&program);
if (result != NVVM_SUCCESS) {
fprintf(stderr, "nvvmCreateProgram: Failed\n");
exit(EXIT_FAILURE);
}
// Add the NVVM IR as a module to our libNVVM program.
result = nvvmAddModuleToProgram(program, ll, size, filename);
if (result != NVVM_SUCCESS) {
fprintf(stderr, "nvvmAddModuleToProgram: Failed\n");
exit(EXIT_FAILURE);
}
// Dynamically construct the compute capability.
char arch[32] = {0};
snprintf(arch, sizeof(arch) - 1, "-arch=compute_%d%d", devMajor, devMinor);
// Compile the IR into PTX.
const char *options[] = {arch};
result = nvvmCompileProgram(program, 1, options);
if (result != NVVM_SUCCESS) {
char *Msg = NULL;
size_t LogSize;
fprintf(stderr, "nvvmCompileProgram: Failed\n");
nvvmGetProgramLogSize(program, &LogSize);
Msg = (char *)malloc(LogSize);
nvvmGetProgramLog(program, Msg);
fprintf(stderr, "%s\n", Msg);
free(Msg);
exit(EXIT_FAILURE);
}
size_t ptxSize = 0;
result = nvvmGetCompiledResultSize(program, &ptxSize);
if (result != NVVM_SUCCESS) {
fprintf(stderr, "nvvmGetCompiledResultSize: Failed\n");
exit(EXIT_FAILURE);
}
char *ptx = malloc(ptxSize);
assert(ptx);
result = nvvmGetCompiledResult(program, ptx);
if (result != NVVM_SUCCESS) {
fprintf(stderr, "nvvmGetCompiledResult: Failed\n");
free(ptx);
exit(EXIT_FAILURE);
}
result = nvvmDestroyProgram(&program);
if (result != NVVM_SUCCESS) {
fprintf(stderr, "nvvmDestroyProgram: Failed\n");
free(ptx);
exit(EXIT_FAILURE);
}
return ptx;
}
static char *loadProgramSource(const char *filename, size_t *size) {
assert(filename && size);
*size = 0;
char *source = NULL;
FILE *fh = fopen(filename, "rb");
if (fh) {
struct stat statbuf;
stat(filename, &statbuf);
source = (char *)malloc(statbuf.st_size + 1);
if (source) {
fread(source, statbuf.st_size, 1, fh);
source[statbuf.st_size] = 0;
*size = statbuf.st_size + 1;
}
} else {
fprintf(stderr, "Error reading file %s\n", filename);
exit(EXIT_FAILURE);
}
return source;
}
// Return the device compute capability in major and minor.
static CUdevice cudaDeviceInit(int *major, int *minor) {
assert(major && minor);
// Count the number of CUDA compute capable devices..
CUresult err = cuInit(0);
int deviceCount = 0;
if (CUDA_SUCCESS == err)
checkCudaErrors(cuDeviceGetCount(&deviceCount));
if (deviceCount == 0) {
fprintf(stderr, "cudaDeviceInit error: no devices supporting CUDA\n");
exit(EXIT_FAILURE);
}
// Get the first device discovered (device 0) and print its name.
CUdevice cuDevice = 0;
checkCudaErrors(cuDeviceGet(&cuDevice, 0));
char name[128] = {0};
checkCudaErrors(cuDeviceGetName(name, sizeof(name), cuDevice));
printf("Using CUDA Device [0]: %s\n", name);
// Get and test the compute capability.
checkCudaErrors(cuDeviceGetAttribute(
major, CU_DEVICE_ATTRIBUTE_COMPUTE_CAPABILITY_MAJOR, cuDevice));
checkCudaErrors(cuDeviceGetAttribute(
minor, CU_DEVICE_ATTRIBUTE_COMPUTE_CAPABILITY_MINOR, cuDevice));
printf("compute capability = %d.%d\n", *major, *minor);
if (*major < 5) {
fprintf(stderr, "Device 0 is not sm_50 or later\n");
exit(EXIT_FAILURE);
}
// Check if managed memory is supported.
int supportsUvm = 0;
checkCudaErrors(cuDeviceGetAttribute(
&supportsUvm, CU_DEVICE_ATTRIBUTE_MANAGED_MEMORY, cuDevice));
if (!supportsUvm) {
printf("This device does not support managed memory.");
exit(EXIT_SUCCESS);
}
// Check if unified addressing is supported (host and device share same
// the address space).
int supportsUva = 0;
checkCudaErrors(cuDeviceGetAttribute(
&supportsUva, CU_DEVICE_ATTRIBUTE_UNIFIED_ADDRESSING, cuDevice));
if (!supportsUva) {
printf("This device does not support a unified address space.");
exit(EXIT_SUCCESS);
}
return cuDevice;
}
static CUresult buildKernel(CUcontext *phContext, CUdevice *phDevice,
CUmodule *phModule, CUfunction *phKernel) {
assert(phContext && phDevice && phModule && phKernel);
// Initialize CUDA and obtain the device's compute capability.
int major = 0, minor = 0;
*phDevice = cudaDeviceInit(&major, &minor);
// Create a context on the device.
checkCudaErrors(cuCtxCreate(phContext, 0, *phDevice));
// Get the NVVM IR from file.
size_t size = 0;
const char *filename = "uvmlite64.ll";
char *ll = loadProgramSource(filename, &size);
fprintf(stdout, "NVVM IR ll file loaded\n");
// Use libNVVM to generate PTX.
char *ptx = generatePTX(ll, size, filename, major, minor);
fprintf(stdout, "PTX generated:\n");
fprintf(stdout, "%s\n", ptx);
// Load module from PTX.
checkCudaErrors(cuModuleLoadDataEx(phModule, ptx, 0, NULL, NULL));
// Locate the kernel entry point.
checkCudaErrors(cuModuleGetFunction(phKernel, *phModule, "test_kernel"));
free(ll);
free(ptx);
return CUDA_SUCCESS;
}
int main(void) {
const unsigned int nThreads = 1;
const unsigned int nBlocks = 1;
// Pointers to the variables in the managed memory.
// See uvmlite64.ll for their definition.
CUdeviceptr devp_xxx, devp_yyy;
size_t size_xxx, size_yyy;
int *p_xxx, *p_yyy;
// Initialize the device and get a handle to the kernel
CUcontext hContext = 0;
CUdevice hDevice = 0;
CUmodule hModule = 0;
CUfunction hKernel = 0;
checkCudaErrors(buildKernel(&hContext, &hDevice, &hModule, &hKernel));
// Whether or not a device supports unified addressing may be queried by
// calling cuDeviceGetAttribute() with the deivce attribute
// CU_DEVICE_ATTRIBUTE_UNIFIED_ADDRESSING.
{
int attrVal;
checkCudaErrors(cuDeviceGetAttribute(
&attrVal, CU_DEVICE_ATTRIBUTE_UNIFIED_ADDRESSING, hDevice));
ERROR_IF(attrVal != 1);
}
// Get the address of the variable xxx, yyy in the managed memory.
checkCudaErrors(cuModuleGetGlobal(&devp_xxx, &size_xxx, hModule, "xxx"));
checkCudaErrors(cuModuleGetGlobal(&devp_yyy, &size_yyy, hModule, "yyy"));
// Whether or not the pointer points to managed memory may be queried by
// calling cuPointerGetAttribute() with the pointer attribute
// CU_POINTER_ATTRIBUTE_IS_MANAGED.
{
unsigned int attrVal;
checkCudaErrors(cuPointerGetAttribute(
&attrVal, CU_POINTER_ATTRIBUTE_IS_MANAGED, devp_xxx));
ERROR_IF(attrVal != 1);
checkCudaErrors(cuPointerGetAttribute(
&attrVal, CU_POINTER_ATTRIBUTE_IS_MANAGED, devp_yyy));
ERROR_IF(attrVal != 1);
}
// Since CUdeviceptr is opaque, it is safe to use cuPointerGetAttribute to get
// the host pointers.
{
void *host_ptr_xxx, *host_ptr_yyy;
checkCudaErrors(cuPointerGetAttribute(
&host_ptr_xxx, CU_POINTER_ATTRIBUTE_HOST_POINTER, devp_xxx));
checkCudaErrors(cuPointerGetAttribute(
&host_ptr_yyy, CU_POINTER_ATTRIBUTE_HOST_POINTER, devp_yyy));
p_xxx = (int *)host_ptr_xxx;
p_yyy = (int *)host_ptr_yyy;
}
printf("The initial value of xxx initialized by the device = %d\n", *p_xxx);
printf("The initial value of yyy initialized by the device = %d\n", *p_yyy);
ERROR_IF(*p_xxx != 10);
ERROR_IF(*p_yyy != 100);
// The host adds 1 and 11 to xxx and yyy.
*p_xxx += 1;
*p_yyy += 11;
printf("The host added 1 and 11 to xxx and yyy.\n");
// Launch the kernel with the following parameters.
{
void *params[] = {(void *)&devp_xxx};
checkCudaErrors(cuLaunchKernel(hKernel, nBlocks, 1, 1, nThreads, 1, 1, 0,
NULL, params, NULL));
}
checkCudaErrors(cuCtxSynchronize());
printf("kernel added 20 and 30 to xxx and yyy, respectively.\n");
printf("The final value checked in the host: xxx = %d, yyy = %d\n", *p_xxx,
*p_yyy);
if (hModule) {
checkCudaErrors(cuModuleUnload(hModule));
hModule = 0;
}
if (hContext) {
checkCudaErrors(cuCtxDestroy(hContext));
hContext = 0;
}
return 0;
}