There are three steps:
1. Add includes/ .h files
2. create a cuda context
3. query the memory on the device

Below is an example of the code required to get the amount of free and total global memory on a cuda device:

#include <iostream> // to output to the console
#include <cuda.h> // to get memory on the device
#include <cuda_runtime.h> // to get device count
int main( int argc, char** argv)
{
	//get device count
	int deviceCount = 0;
    cudaError_t error_id = cudaGetDeviceCount(&deviceCount);
	if(deviceCount == 0)
	{
		cout << "Error no cuda devices";
		return 1;
	}

	//get the first cuda device
	CUdevice cudaDevice;
	CUresult result = cuDeviceGet(&cudaDevice, 0);
	if(result!= CUDA_SUCCESS)
	{
		cout << "Error fetching cuda device";
		return 1;
	}

	//create cuda context
	CUcontext cudaContext;
	result = cuCtxCreate(&cudaContext, CU_CTX_SCHED_AUTO, cudaDevice);
	if(result != CUDA_SUCCESS)
	{
		cout << "Error creating cuda context";
		return 1;
	}

	//get the amount of free memory on the graphics card
	size_t free;
	size_t total;
	result = cuMemGetInfo(&free, &total);

	cout << "free memory: " << free / 1024 / 1024 << "mb, total memory: " << total / 1024 / 1024 << "mb" << endl;
	char c;
	cin >> c;

	return 0;
}

Gotchas
if you get compile error “unresolved external symbol _cuMemGetInfo”
you need to update the project properties to link the cuda.lib file. To do this:
1. right click on project->properties->configuration->Linker.
2. in the additional dependencies field add cuda.lib

See screenshot below:

References
Nvidia toolkit doc on cuMemGetInfo

Tags: CUDA, Programming

Posted in CUDA Programming by stevenmarkford No Comments Yet