Re: [PATCH 0/6] perf jevents: Add NVIDIA Tegra410 uncore PMU events and metrics

[Ian Rogers]

On Tue, Oct 20, 2026 at 12:15 PM Arnaldo Carvalho de Melo
<acme@xxxxxxxxxx> wrote:
>
> On Mon, Oct 19, 2026 at 06:23:16PM +0100, James Clark wrote:
> > On 19/10/2026 17:42, Besar Wicaksono wrote:
> > > Add event aliases and derived metrics for the NVIDIA Tegra410 uncore
> > > PMUs.
>
> > Reviewed-by: James Clark <james.clark@xxxxxxxxxx>
>
> Thanks, applied to perf-tools-next, for v7.4.

Hi Arnaldo,

can we not take these in v7.4 as there is unaddressed feedback:
https://lore.kernel.org/linux-perf-users/CAP-5=fWucvdYefDOL3Vn=O=YUPEXE+tngDDfPLv-T5i3WkCJVA@xxxxxxxxxxxxxx/

The specific problem is that the NVidia PMUs have adopted a convention
not supported by the perf tool of 'pmu_name_<socket>_rc_<num>'. rc
stands for root complex. What ends up happening is that aggregation is
broken as the json is claiming that pmu_name is the PMU's name while
the suffix perf_pmus code thinks pmu_name_<socket>_rc is the pmu name.
They've wrangled support via the json by claiming these are sys
events.

We can either:
1) support a new suffix convention of <num>_rc_<num>
2) push back and ask the driver writers to name their PMU correctly as
defined in the ABI:
https://web.git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/ABI/testing/sysfs-bus-event_source-devices

If we do (1) then it would be nice if the support for that could be
contained in this patch series. In any case these events don't belong
in sys.

Thanks,
Ian

> - Arnaldo