Each PRU has a CYCLE register which counts the number of cycles since the PRU was enabled. They also have a STALL register that counts how many times the PRU stalled fetching an instruction.
I’ve have some notes[1] about them in the PRU Cookbook.
It may not be exactly what you want, but, for quick measurements, I tend to toggle a bit on R30 and use an oscilloscope connected to the corresponding pin.