alt Hacker Newshttps://blog.bugsiki.dev/posts/apple-pmu/
> I quickly found out that Apple Instruments doesn’t support fetching more than 10 counters, sometimes 8, and sometimes less. I was constantly getting errors like '<SOME_COUNTER>' conflicts with a previously added event. The maximum that I could get is 10 counters. So, the first takeaway was that there is a limit to how many counters I can fetch, and another is that counters are, in some way, incompatible with each other. Why and how they’re incompatible is a good question.
Also: https://hmijailblog.blogspot.com/2015/09/using-intels-perfor...
Replies
saagarjha • yesterday at 2:44 PM
It’s a condemnation of how bad perf is if it loses to that.
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Your first example is a CPU limitation that Instruments doesn't model (does perf?), but is still mostly better than Intel chips that are limited to 4 dynamic counters (I think still? At least that's what I see in the Alder Lake's Golden Cove perfmon files...)
Your second example, is the complaint that Instruments doesn't have flamegraph visualization? That was true a decade ago when it was written, and is not true today. Or that Instrument's trace file format isn't documented?