Re: [PATCH v7 00/27] Legacy hardware/cache events as json

[James Clark]

On 05/10/2025 7:24 pm, Ian Rogers wrote:
> Mirroring similar work for software events in commit 6e9fa4131abb
> ("perf parse-events: Remove non-json software events"). These changes
> migrate the legacy hardware and cache events to json.  With no hard
> coded legacy hardware or cache events the wild card, case
> insensitivity, etc. is consistent for events. This does, however, mean
> events like cycles will wild card against all PMUs. A change doing the
> same was originally posted and merged from:
> https://lore.kernel.org/r/20240416061533.921723-10-irogers@xxxxxxxxxx
> and reverted by Linus in commit 4f1b067359ac ("Revert "perf
> parse-events: Prefer sysfs/JSON hardware events over legacy"") due to
> his dislike for the cycles behavior on ARM with perf record. Earlier
> patches in this series make perf record event opening failures
> non-fatal and hide the cycles event's failure to open on ARM in perf
> record, so it is expected the behavior will now be transparent in perf
> record on ARM. perf stat with a cycles event will wildcard open the
> event on all PMUs, however, with default events the cycles event will
> only be opened on core PMUs.

Hi Ian,

The previous issues seem to be fixed, I don't see any Perf test 
regressions or issues when there is an uncore PMU with a cycles event.

Tested-by: James Clark <james.clark@xxxxxxxxxx>