Re: [PATCH v1] perf arm: Workaround ARM PMUs cpu maps having offline cpus

From: Ian Rogers
Date: Mon Jun 10 2024 - 13:33:44 EST


On Mon, Jun 10, 2024 at 6:30 AM Leo Yan <leo.yan@xxxxxxx> wrote:
[snip]
> I did a test for this patch, it works well for me.
>
> Tested-by: Leo Yan <leo.yan@xxxxxxx>
>
> Just a nitpick and I think it is not an issue caused by this patch.
> After hotplug off one CPU and then if specify the CPU with option '-C',
> the 'perf stat' command still continues to run. This is inconsistent
> with the 'perf record' which exits with failures immediately.
>
> Maybe consider to send an extra patch to address this issue?

As you say, this doesn't relate to the problem fixed here. I don't
have a problem with the command line behavior change but I think my
getting shouted at budget is fairly well exhausted. How about we trade
issues, if the following get fixed:

Renaming of the cycles event in arm_dsu_pmu.c - I'd say this is a top
priority issue right now.
Fixing ARM hybrid default perf stat (it is crazy we can accept this
being broken), opening events on both BIG.little PMUs as done here:
https://lore.kernel.org/lkml/20240510053705.2462258-4-irogers@xxxxxxxxxx/

I'll address this.

Thanks,
Ian