perf tool pmuevents: About arm64 a76 JSON

[John Garry]

Hi,

I noticed that the JSON to support a76 pmu events was added recently.

May I ask why we add explicit support for the common architectural and 
microarch events (event id 0x0-0x3f), when they would be already 
available from the kernel pmuv3 driver?

The ampere emag jsons do similar. Others don't.

The only advantage I see is that we have an event description, but I am 
sure how useful that is.

Cheers,
John