performancecounter - Configuring the PMU to read Perfomance Counters

I am using Linux 4.19.2 (ubuntu 16.04) on an intel i7-3770 CPU. I have used tools like perf for performance monitoring. I want to write a basic piece of code to read performance counters without using any such tools.

I came across the rdpmc instruction. Before using it, I am having trouble with configuring the registers to count a particular event. I checked some forums like https://software.intel.com/en-us/forums/software-tuning-performance-optimization-platform-monitoring/topic/745751 but this didn't help.
What exactly is meant by configuring the PMU here? And how would one do it?

I want to read from kernel code itself, so there's no issue of privileges. What is the easiest way to do it?

Also, is rdpmc the least overhead way to this?