How can we measure the CPU utilization of programs running on ARM processors, particularly the A15 series ? Are there some hardware counters that can be read ?
Utilization is a software concept, not something that really exists at the hardware level, especially when you factor in DVFS and things which change the number of cycles per second, so the approach to measure it generally depends on the operating system you are running.
On Linux/Android the "top" utility will give you a lot of information about utilization associated with a given process, or you can manually extract data from the "proc" virtual filesystem (which behaves the same as desktop Linux). ARM has a number of tools, such as DS-5 Streamline, which can tap into these data sources and visualize them for you. See:
ARM DS-5 Development Studio | ARM DS-5 Development Studio
For other operating systems this is a question best targeted at the OS vendor.
Cheers, Pete