Groups Created for CUDA Programs
The take home point for group creation when debugging CUDA programs is that CUDA threads are placed in the same share group as are their host Linux processes. Because CUDA threads and the host process are all in the same share group, you can create pending or sliding breakpoints on source lines and functions in the GPU code before the code is loaded onto the GPU. This organization allows support for a unified Source view display, where the breakpoint and source line information of the code running on the GPU is unified with the code running on the host CPU.
How groups are created when debugging CUDA programs
More on the unified Source view display