CODEWITHSUNDEEP
c++cuda
Tdt
Tdt

Reputation: 3

Cuda (warpSize is negative)

I have Nvidia geforce 310M and when i write this code 

int main()
{
    int dev;
    cudaDeviceProp prop;
    cudaGetDevice(&dev);
    cudaGetDeviceProperties(&prop,dev);
    cout << "Device name " << prop.name << endl;
    cout << "warp size  = " << prop.warpSize << endl;
    cout << "mutiprocesosrs = " << prop.multiProcessorCount << endl;
    return 0;
}

it writes : 

Device name ♀
warp size  = -2144521342
mutiprocesosrs = 0
Press any key to continue . . .

and every time i run this program it produces different warp size. how can i fix that ?

(p.s. I'm using visual studio 2010)

Upvotes: 0

Views: 576

Answers (2)

Michael Haidl
Michael Haidl

Reputation: 5492

With this code you can check if, something with your cuda setup is wrong. (Taken from the cuda deviceQuery sample)

    if (cudaGetDeviceCount((int*)&_deviceCount) != cudaSuccess) 
    {
        printf("ERROR: CUDA Driver and Runtime version may be mismatched.\n");
        return false;
    }

    // This function call returns 0 if there are no CUDA capable devices.
    if (_deviceCount == 0)
    {
        printf("ERROR: There is no device supporting CUDA!\n");
        return false;
    }

    _deviceProperties = SAVE_ALLOCATE(cudaDeviceProp, _deviceCount * sizeof(cudaDeviceProp));

    for (unsigned int dev = 0; dev < _deviceCount; ++dev) 
    {
        cudaGetDeviceProperties(&_deviceProperties[dev], dev);

        printf("\nDevice %d: \"%s\"\n", dev, _deviceProperties[dev].name);

    #if CUDART_VERSION >= 2020
        // Console log
        cudaDriverGetVersion(&_driverVersion);
        printf("  CUDA Driver Version:                           %d.%d\n",              _driverVersion/1000, _driverVersion%100);
        cudaRuntimeGetVersion(&_runtimeVersion);
        printf("  CUDA Runtime Version:                          %d.%d\n",              _runtimeVersion/1000, _runtimeVersion%100);
    #endif
        printf("  CUDA Capability revision number:               %d.%d\n",              

_deviceProperties[dev].major,_deviceProperties[dev].minor);
}

you sould see if something is wrong ;)

Upvotes: 1

Kerrek SB
Kerrek SB

Reputation: 477690

Check first of all whether the function calls succeed!

cudaDeviceProp prop;
int dev;

if (cudaGetDevice(&dev) != cudaSuccess)
{
  /* error */
  abort();
}

if (cudaGetDeviceProperties(&prop, dev) != cudaSuccess)
{
  /* error */
  abort();
}

I made a little macro I use for calling all CUDA functions which takes care of the checking and throws a custom exception:

#define CUDACALL(F, ARGS...) do { e = F(ARGS); if (e != cudaSuccess) throw cudaException(#F, e); } while (false)

With this, I just say,

try
{
   int dev;
   cudaDeviceProp prop;
   CUDACALL(cudaGetDevice, &dev);
   CUDACALL(cudaGetDeviceProperties, &prop, dev);
   // ...
}
catch (cudeException const & e)
{
  std::cerr << "Cuda error: " << e.what() << "\n";
}

The exception class is defined as follows:

struct cudaException : public std::exception
{
  cudaException(const std::string & str, cudaError_t err) : s(str), e(err) { }

  ~cudaException() throw() { }

  virtual const char * what() const throw()
  {
    const std::string r = s + ": \"" + cudaGetErrorString(e) + "\" (" + (char)(e + '0') + ')';
    return r.c_str();
  }
private:
  std::string s;
  cudaError_t e;
};

Upvotes: 3

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