Segmentation Violation while using cuMemcpyHtoD

Accelerated Computing CUDA CUDA Programming and Performance
1

Hi All,

I was trying to use driver API transfer some data from host to device.
I am using redhat enterprise edition 5 and "GeForce 8800 GT
Major revision number: 1
Minor revision number: 1
Total amount of global memory: 536150016 bytes
Number of multiprocessors: 14
Number of cores: 112
Total amount of constant memory: 65536 bytes
Total amount of shared memory per block: 16384 bytes
Total number of registers available per block: 8192
Warp size: 32
Maximum number of threads per block: 512
Maximum sizes of each dimension of a block: 512 x 512 x 64
Maximum sizes of each dimension of a grid: 65535 x 65535 x 1
Maximum memory pitch: 262144 bytes
Texture alignment: 256 bytes
Clock rate: 1.51 GHz
Concurrent copy and execution: Yes

when i run the matrixMulDrv from cuda sdk it says test passed.

And when i try to run the below given code it gives me Segmentation fault.

Is this becoz i am doing something wrong or is it becoz i am not including any lib or is it driver problem???

Help Needed

Advance Thanks,

Tom

the driver info::

Title: NVIDIA Accelerated Graphics Driver Set for Linux-x86
Version: 169.12
Description: The NVIDIA Accelerated Graphics Driver Set for Linux-x86
provides accelerated 2D and 3D support for Linux-x86
using NVIDIA GPUs.
Keywords: OpenGL XFree86 NVIDIA
Author: NVIDIA Corporation Linux Development Team (linux-bugs ‘at’ nvidia.com)
Maintained-by: NVIDIA Corporation Linux Development Team (linux-bugs ‘at’ nvidia.com)
Original-site: http://www.nvidia.com
Platform: Linux
Copying-policy: NVIDIA Software License

#include <stdint.h>
#include <fcntl.h>
#include <sys/types.h>
#include <unistd.h>
#include <string.h>
#include <stdlib.h>
#include <stdio.h>
#include <cuda.h>
#include <cutil.h>
#include <cutil_inline.h>
#include <cufft.h>

int runTest(int argc, char** argv);

int main(int argc, char **argv)
{

 runTest(argc, argv);
 return 0;

}

int runTest(int argc, char **argv)
{

int cDevices;
int hcuDevice = 0;
CUresult status;
char szName[256];
CUdevprop devProps;
int* h_data ;






  status = cuInit(0);
  if ( CUDA_SUCCESS != status )
  {
      return 1;
  }

  status = cuDeviceGetCount( &cDevices );
  if ( CUDA_SUCCESS != status )
  {
      return 1;
  }

  if ( cDevices == 0 )
  {
      return 1;
  }

  status = cuDeviceGet( &hcuDevice, 0 );

  if ( CUDA_SUCCESS != status )
  {
      return 1;

if ( CUDA_SUCCESS == cuDeviceGetProperties( &devProps, hcuDevice ) )
{
printf(“\tsharedMemPerBlock: %d\n”, devProps.sharedMemPerBlock );
printf(“\tconstantMemory : %d\n”, devProps.totalConstantMemory );
printf(“\tregsPerBlock : %d\n”, devProps.regsPerBlock );
printf(“\tclockRate : %d\n”, devProps.clockRate );
}

  CUcontext  hcuContext  = 0;
  CUdevprop hcuDevprops;


  status = cuCtxCreate( &hcuContext, 0, hcuDevice );
  if ( CUDA_SUCCESS != status )
  {
      fprintf( stderr, "cuCtxCreate failed %d\n",status);
  }

  if ( CUDA_SUCCESS != cuDeviceGetProperties( &hcuDevprops, hcuDevice ) )
  {
      fprintf(stderr,"cuDeviceGetProperties failed!\n");
  }

  if((h_data=(int*)malloc(200000))==NULL)
      printf("ERROR FROM MALLOC\n");

  memset(h_data,0,20000);



 CUdeviceptr hcuarray;


 int mem_size=200000;


 cuMemAlloc(&hcuarray,mem_size);


 cutilDrvSafeCallNoSync(cuMemcpyHtoD(hcuarray,&h_data,200000));

 while(1)
 {
 }
 return 0;

}

2

Your memset is a bit overly enthusiastic. ;)

In general, when you segfault, run the program in a debugger and see where it crashes. It may not be where you think it is.

3

!!!!

4

Memset was an R&d accident.

If you try the size data to copy to device to 1000 .it will work.

If you increase to 10000 , it will work some time and it will give violation some time.

if you increase to 200000 ,it always give segmentation violation.

when you run this in GDB the error comes from cudaLIB

thanks,

Tom