Default [Q] Android Kernel - identification of scheduling algorithm part of code

I want to identify the algorithm, signals and processes pertaining to the incoming/outgoing calls and the mobile data usage scheduling which is done by the android kernel.

How do we identify these particular parts of the code among so many lines of code(related to the scheduling)?

Can someone please help me out with this?(Any answer in the form of ER Diagram/Schema would be helpful and be appreciated)