Debugging a CUDA kernel in Fortran


we are prgramming Fortran in our group and
want to write CUDA code.

But writing CUDA code and not being
able to use a Debugger to step through it
(pgdbg or totalview or … ) is not an option - for the
scientists around me.

Totalview would be usable, but the Portland Fortran compiler we have
does not include debugging information for the CUDA code.
“The Cuda kernel module was not compiled with -G” is the error

pgdbg does not allow me to step through the CUDA code.

I hope there is a solution to this problem.


Hi Otfried,

To debug CUDA Fortran, compile in emulation mode (-Mcuda=emu) and then run within PGDBG.

We are working on debugging on the device, but this support wont be available till later this year.

  • Mat

Hi Mat,

that is good news :-)

Emulation mode is good enough for getting a better understanding
of how CUDA actually excutes the program and
debugging on the device anyway disturbs the real-time execution.