CODEWITHSUNDEEP
cudagpgpugpunsight
TripleS
TripleS

Reputation: 1246

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

I'm using nsight 2.2, Toolkit 4.2, latest nvidia driver, I'm using couple GPUs 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?

Update

Initially, my debug command line is as follows:

# 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.

Upvotes: 6

Views: 4844

Answers (4)

Joon
Joon

Reputation: 21

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.

Upvotes: 2

Zahid
Zahid

Reputation: 81

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.

Upvotes: 0

Roger Dahl
Roger Dahl

Reputation: 15724

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).

Upvotes: 6

Roger Dahl
Roger Dahl

Reputation: 15724

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.

Upvotes: 0

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