Perf-top doesn't work on Fedora Asahi Remix

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1

Hi. perf top doesn’t work on Fedora Asahi although it does on Arch Asahi. Any way to fix this?

Thanks.

2

On systems with heterogeneous CPUs you need to specify the counters manually.

sudo perf top -e apple_firestorm_pmu/cycles/ -e apple_icestorm_pmu/cycles/

It’s a bit awkward but it is what it is. You can also specify just cycles which I think will give you the sum total:

sudo perf top -e cycles

Though of course the meaning of a “cycle” is not the same when you have several CPU types, so this usage is questionable from a data quality standpoint since it will depend on what CPU types each process is scheduled on.

I’m not entirely sure why just sudo perf top doesn’t work though.

3

Hmm… actually, I think something is broken with the PMUs again. I’m only getting events for firestorm, not icestorm, on this t6000. I’ll look into it.

4

This is a userspace regression - perf 6.5 and later is completely broken on big.LITTLE systems. Bisected the first commit that broke everything to 5ea8f2ccffb and the first commit that started the current broken behavior to 82fe2e45cdb00.

Edit: reported here: [REGRESSION] Perf (userspace) broken on big.LITTLE systems since v6.5

5

Nice, thanks for figuring this out!