How to do Parallel programming using JOGL

I need Information about parallel execution of JOGL Code on GPU .How can i Achieve parallelism using JOGL? and How to calculate the time required to run and execute the program using CPU and GPU? Any Suggestion is  appreciable.

OpenGL in general doesn't give an explicit control on how it parallelizes the operations.

If I were you, I would look at JOCL:
http://jogamp.org/jocl/www/

Another option is the compute shader stage:
https://www.khronos.org/opengl/wiki/Compute_Shader