Hello_world example---warning and incomplete output

Accelerated Computing CUDA CUDA Programming and Performance
1

I am using the “HelloWorld” example on “Google Code Archive - Long-term storage for Google Code Project Hosting.”.

But when compiling it I got a warning and there are some problems about the output, I don’t know how to fix it. Can anyone help me? I am very appreciated about it .

In Terminal:

LINtekiiMac:Hello_world linyu$ nvcc hello_world.cu -o hello_world
util/cuPrintf.cu: In function ‘int outputPrintfData(char*, char*)’:
util/cuPrintf.cu:607: warning: format not a string literal and no format arguments
util/cuPrintf.cu:607: warning: format not a string literal and no format arguments
LINtekiiMac:Hello_world linyu$ ./hello_world
Hello, world from the host!

I don’t know why i didn’t get the output of “hello, world from the device!”

2

I’m not sure why you’re getting that error.

Also note that Appendix B.17 of the CUDA 5.5 C Programming Guide has a more up to date example that demonstrates how to use the newer printf() facility.

The code winds up looking like this:

#include <stdio.h>

#if defined(__CUDA_ARCH__) && (__CUDA_ARCH__ < 200)
#error printf is only supported on devices of compute capability 2.0 and higher, please compile with -arch=sm_20 or higher
#endif

__global__ void device_greetings()
{
  printf("Hello, world from the device!\n");
}

int main(void)
{
  // greet from the host
  printf("Hello, world from the host!\n");

  // launch a kernel with a single thread to greet from the device
  device_greetings<<<1,1>>>();

  cudaDeviceSynchronize();

  return 0;
}

Compile with this:

nvcc -m 32 -arch sm_20 hello.cu -o hello