[PATCH] perf vendor events arm64: Remove uncountable events

[Ian Rogers]

On Sat, Jan 3, 2026 at 8:38 AM James Clark <james.clark at linaro.org> wrote:
>
>
>
> On 02/01/2026 3:29 pm, Ian Rogers wrote:
> > On Wed, Dec 31, 2025 at 4:13 AM James Clark <james.clark at linaro.org> wrote:
> >>
> >> These events are never countable by the PMU and are only intended to
> >> be used as external inputs to trace. Therefore showing them in 'perf
> >> list' is misleading so remove them.
> >
> > What does "trace" mean in this context?
> >
>
> CPU trace, Either ETE (Embedded Trace Extension) or ETM (Embedded Trace
> Macrocell). You can select PMU events as inputs to the trace block to
> make it do things like start and stop tracing.

Ah ok, trace immediately makes me think of `perf trace` currently.
Presumably there's no perf integration for ETE and ETM that somehow
use these event encodings? Looks not and the changes make sense to me.

Reviewed-by: Ian Rogers <irogers at google.com>

Thanks,
Ian

> > Thanks,
> > Ian
> >
> >> The generator script doesn't emit these events when used with the new
> >> telemetry-solution input files [1].
> >>
> >> 'perf list' should only show countable events because there are events
> >> that are sometimes implemented, sometimes countable and sometimes not,
> >> for example TRB_TRIG. If we always include any implemented events
> >> whether they are countable or not then it's not possible to tell whether
> >> they are usable in perf without going to the docs, defeating the point
> >> of 'perf list'.
> >>
> >> It's also not useful yet to display implemented events that are not
> >> countable (for help in using trace rather than perf stat), because
> >> PMU_OVFS and PMU_HOVFS are practically always implemented and TRB_TRIG
> >> is always implemented when there is TRBE.
> >>
> >> [1]: https://gitlab.arm.com/telemetry-solution/telemetry-solution/-/tree/main/data/pmu/cpu
> >>
> >> Signed-off-by: James Clark <james.clark at linaro.org>
> >> ---
> >>   tools/perf/pmu-events/arch/arm64/arm/cortex-a510/pmu.json  |  8 --------
> >>   tools/perf/pmu-events/arch/arm64/common-and-microarch.json | 12 ------------
> >>   tools/perf/pmu-events/arch/arm64/fujitsu/monaka/pmu.json   | 10 ----------
> >>   3 files changed, 30 deletions(-)
> >>
> >> diff --git a/tools/perf/pmu-events/arch/arm64/arm/cortex-a510/pmu.json b/tools/perf/pmu-events/arch/arm64/arm/cortex-a510/pmu.json
> >> deleted file mode 100644
> >> index d8b7b9f9e5fa..000000000000
> >> --- a/tools/perf/pmu-events/arch/arm64/arm/cortex-a510/pmu.json
> >> +++ /dev/null
> >> @@ -1,8 +0,0 @@
> >> -[
> >> -    {
> >> -        "ArchStdEvent": "PMU_OVFS"
> >> -    },
> >> -    {
> >> -        "ArchStdEvent": "PMU_HOVFS"
> >> -    }
> >> -]
> >> diff --git a/tools/perf/pmu-events/arch/arm64/common-and-microarch.json b/tools/perf/pmu-events/arch/arm64/common-and-microarch.json
> >> index 2416d9f8a83d..468cb085d879 100644
> >> --- a/tools/perf/pmu-events/arch/arm64/common-and-microarch.json
> >> +++ b/tools/perf/pmu-events/arch/arm64/common-and-microarch.json
> >> @@ -432,24 +432,12 @@
> >>           "EventName": "TRB_WRAP",
> >>           "BriefDescription": "Trace buffer current write pointer wrapped"
> >>       },
> >> -    {
> >> -        "PublicDescription": "PMU overflow, counters accessible to EL1 and EL0",
> >> -        "EventCode": "0x400D",
> >> -        "EventName": "PMU_OVFS",
> >> -        "BriefDescription": "PMU overflow, counters accessible to EL1 and EL0"
> >> -    },
> >>       {
> >>           "PublicDescription": "Trace buffer Trigger Event",
> >>           "EventCode": "0x400E",
> >>           "EventName": "TRB_TRIG",
> >>           "BriefDescription": "Trace buffer Trigger Event"
> >>       },
> >> -    {
> >> -        "PublicDescription": "PMU overflow, counters reserved for use by EL2",
> >> -        "EventCode": "0x400F",
> >> -        "EventName": "PMU_HOVFS",
> >> -        "BriefDescription": "PMU overflow, counters reserved for use by EL2"
> >> -    },
> >>       {
> >>           "PublicDescription": "PE Trace Unit external output 0",
> >>           "EventCode": "0x4010",
> >> diff --git a/tools/perf/pmu-events/arch/arm64/fujitsu/monaka/pmu.json b/tools/perf/pmu-events/arch/arm64/fujitsu/monaka/pmu.json
> >> deleted file mode 100644
> >> index 65bd6cdd0dd5..000000000000
> >> --- a/tools/perf/pmu-events/arch/arm64/fujitsu/monaka/pmu.json
> >> +++ /dev/null
> >> @@ -1,10 +0,0 @@
> >> -[
> >> -    {
> >> -        "ArchStdEvent": "PMU_OVFS",
> >> -        "BriefDescription": "This event counts the event generated each time one of the condition occurs described in Arm Architecture Reference Manual for A-profile architecture. This event is only for output to the trace unit."
> >> -    },
> >> -    {
> >> -        "ArchStdEvent": "PMU_HOVFS",
> >> -        "BriefDescription": "This event counts the event generated each time an event is counted by an event counter <n> and all of the condition occur described in Arm Architecture Reference Manual for A-profile architecture. This event is only for output to the trace unit."
> >> -    }
> >> -]
> >>
> >> ---
> >> base-commit: cbd41c6d4c26c161a2b0e70ad411d3885ff13507
> >> change-id: 20251230-james-perf-uncountable-events-28adfb93b73f
> >>
> >> Best regards,
> >> --
> >> James Clark <james.clark at linaro.org>
> >>
>