Communication between kernel and kernel module

Hi, Is there any way to call a function defined in a kernel module from within the kernel proper? Here's what I'm trying to do: I'm trying to keep track of when and for how long a process is being executed on the processor, i.e. I need to know when context switches occur. There is a function called context_switch() in linux/kernel/sched/core.c that is called whenever a context switch happens. I would like to call a function in a kernel module I've written from within context_switch() and pass some data to it. I've seen how to communicate between user space and kernel space, such as using a file in /dev or using system calls, but not how to communicate within the kernel itself. Regards, Drew