Nsight skips (ignores) over break points in VS10 Cuda works fine, nsight consistently skips over several breakpoints

Question

I'm using nsight 2.2 , Toolkit 4.2 , latest nvidia driver , I'm using couple gpu's in my computer. Build customize 4.2. I have set "generate GPU ouput" on CUDA's project properties, nsight monitor is on (everything looks great).

I set several break points on my global - kernel function . nsight stops at the declaration of the function , but skips over several break points. it's just like nsight decide whether to hit a break point or skip over a break point. The funny thing is that nsight stops at for loops , but doesn't stop on simple assignment operations.

One more problem is that I can't set focus or add variables to the watch list , In this case (see attached screenshot)I can't resolve the value of variable : "posss" or "testDetctoinRate1" which are registers in this case. on the other hand , shared memory or block memory would insert automatically to the local's list.

Here is a screen shot of the kernel , before debugging

Here is a screen shot during debugging

I evoke my kernel function with following call:

checkCUDA<<<1, 32>>>(sumMat->rows,sumMat->cols , (UINT *)pGPUsumMat); 
cudaError = cudaGetLastError();
if(cudaError != cudaSuccess)
{
    printf("CUDA error: %s\n", cudaGetErrorString(cudaError));
    exit(-1);
}

kernel call works without an error.

Is there any option to forcing nsight stops at all breakpoints ? How can I add thread's registers to my watch list ?

Any help would be appreciated I can post my code on demand

Cheers

---

Initially , My debug command line is as followed:

Runtime API (NVCC Compilation Type is hybrid object or .c file)

set CUDAFE_FLAGS=--sdk_dir "c:\Program Files\Microsoft SDKs\Windows\v7.0A\" "C:\Program Files\NVIDIA GPU Computing Toolkit\CUDA\v4.2\bin\nvcc.exe" --use-local-env --cl-version 2010 -ccbin "C:\Program Files\Microsoft Visual Studio 10.0\VC\bin" -I"......\opencv\modules\gpu\src\opencv2\gpu\device" -I"......\opencv\modules\gpu\include\opencv2\gpu" -I"......\build\include\" -G --keep-dir "Debug" -maxrregcount=0 --machine 32 --compile -g -Xcompiler "/EHsc /nologo /Od /Zi /MDd " -o "Debug\%(Filename)%(Extension).obj" "%(FullPath)"

---

I changed on property page --> cuda --> host --> generate hosting debug information --> No

Now my command line doesn't contain the -g and -O letters , my command line is as followed:

Runtime API (NVCC Compilation Type is hybrid object or .c file)

set CUDAFE_FLAGS=--sdk_dir "c:\Program Files\Microsoft SDKs\Windows\v7.0A\" "C:\Program Files\NVIDIA GPU Computing Toolkit\CUDA\v4.2\bin\nvcc.exe" --use-local-env --cl-version 2010 -ccbin "C:\Program Files\Microsoft Visual Studio 10.0\VC\bin" -I"......\opencv\modules\gpu\src\opencv2\gpu\device" -I"......\opencv\modules\gpu\include\opencv2\gpu" -I"......\build\include\" -G --keep-dir "Debug" -maxrregcount=0 --machine 32 --compile -Xcompiler "/EHsc /nologo /Od /Zi /MDd " -o "Debug\%(Filename)%(Extension).obj" "%(FullPath)"

although, I do debug with -o , does it matter ? It doesn't make any change

Answer 1

Right click the .cu file in the Solution Explorer, then go to CUDA C/C++ | Device and set Generate GPU Debug Information to Yes (-G0).

Answer 2

Check whether "Enable CUDA Memory Checker" under Nsight is turned off or not. It may allow NSight to stop breakpoints of your CUDA kernel code on Debug mode of VS C++ 2010. At least, it works for me.

Answer 3

In the debug build, are you passing both the -O and the -g options to nvcc? If so, try removing the -O.

Background: This sounds like the kind of problem one gets when trying to debug code that has been optimized by the compiler. During optimization, the compiler changes the code in such a way that some lines of source no longer have any machine code instructions associated with them, making it impossible for the debugger to set breakpoints on those lines.

Answer 4

I have similar issue. Nsight is not stopping at any of the break points. But completes execution.

If i use -G0 as debug info option. It gives an error.

I am using nvidia 2.2.0.1225 with cuda 4.2 and cuda 5 tool kit. With 301.42 graphic driver.