Sunday 1 September 2013

Hello CUDA -- Part 2

A hello world program is a often the first program which starts off programming in that language. However, CUDA involves the GPU and checking the GPU status with a CUDA C code is similar to a hello world program. CUDA installations come along with sample programs which check for the GPU. In CUDA 5.5 installation in Ubuntu 12.04, such a program can be found at, /usr/local/cuda-5.5/samples/1_Utilities/deviceQuery.cpp.

Here we look into a simple variant of such a program,

//devicequery.cu
//Compile with => nvcc devicequery.cu -o devicequery
//Run with ./devicequery


#include <stdio.h>
 
// Print device properties
void printDevProp(cudaDeviceProp devProp)
{
    printf("Major revision number:         %d\n",  devProp.major);
    printf("Minor revision number:         %d\n",  devProp.minor);
    printf("Name:                          %s\n",  devProp.name);
    printf("Total global memory:           %u\n",  devProp.totalGlobalMem);
    printf("Total shared memory per block: %u\n",  devProp.sharedMemPerBlock);
    printf("Total registers per block:     %d\n",  devProp.regsPerBlock);
    printf("Warp size:                     %d\n",  devProp.warpSize);
    printf("Maximum memory pitch:          %u\n",  devProp.memPitch);
    printf("Maximum threads per block:     %d\n",  devProp.maxThreadsPerBlock);
    for (int i = 0; i < 3; ++i)
    printf("Maximum dimension %d of block:  %d\n", i, devProp.maxThreadsDim[i]);
    for (int i = 0; i < 3; ++i)
    printf("Maximum dimension %d of grid:   %d\n", i, devProp.maxGridSize[i]);
    printf("Clock rate:                    %d\n",  devProp.clockRate);
    printf("Total constant memory:         %u\n",  devProp.totalConstMem);
    printf("Texture alignment:             %u\n",  devProp.textureAlignment);
    printf("Concurrent copy and execution: %s\n",  (devProp.deviceOverlap ? "Yes" : "No"));
    printf("Number of multiprocessors:     %d\n",  devProp.multiProcessorCount);
    printf("Kernel execution timeout:      %s\n",  (devProp.kernelExecTimeoutEnabled ? "Yes" : "No"));
    return;
}
 
int main()
{
    // Number of CUDA devices
    int devCount;
    cudaGetDeviceCount(&devCount);
    printf("CUDA Device Query...\n");
    printf("There are %d CUDA devices.\n", devCount);
 
    // Iterate through devices
    for (int i = 0; i < devCount; ++i)
    {
        // Get device properties
        printf("\nCUDA Device #%d\n", i);
        cudaDeviceProp devProp;
        cudaGetDeviceProperties(&devProp, i);
        printDevProp(devProp);
    }
 
    printf("\nPress any key to exit...");
    char c;
    scanf("%c", &c);

    return 0;
}

On running this program will 'query' the GPU and provide with result as;






























REFERENCES

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