Hi all,
It is known that Arm introduced Activity Monitor Extension from v8.4-A. AMU supports system reg and utility bus access.
My wonder is why AMU were introduced when PMU already exists. From a hardware perspective, they just do the same (to count events).
An arm white paper Power and Performance Management using Arm SCMI Specification says AMU is used to provide a performance feedback to the OS kernel.
Why does the OS not just take the PMU results to get the performance information?
Thnaks in advance.