Re: [PATCH v3 0/4] Add support for a DRM tool like PMU

[Arnaldo Carvalho de Melo <acme@kernel.org>]

On Wed, Apr 30, 2025 at 08:21:59AM -0700, Ian Rogers wrote:
> On Thu, Apr 3, 2025 at 1:24 PM Ian Rogers <irogers@google.com> wrote:
> >
> > DRM clients expose information through usage stats as documented in
> > Documentation/gpu/drm-usage-stats.rst (available online at
> > https://docs.kernel.org/gpu/drm-usage-stats.html). Add a tool like
> > PMU, similar to the hwmon PMU, that exposes DRM information.

Looks useful, I'll try to review and test tomorrow, but most probably
Friday, as tomorrow is labour day in this part of the world.

- Arnaldo
 
> I'm reminded by Brendan Gregg's new blog:
> https://www.brendangregg.com/blog/2025-05-01/doom-gpu-flame-graphs.html
> that this is still outstanding. The patches also reduce some directory
> scanning for the hwmon "PMU", they are in Google's tree:
> https://github.com/googleprodkernel/linux-perf/blob/google_tools_master/tools/perf/util/drm_pmu.c
> 
> Thanks,
> Ian
> 
> > v3: Minor tweak to the test so the skip (exit 2) doesn't trigger the
> >     trap cleanup.
> >
> > v2: Add support to only scan hwmon and drm PMUs if the event or PMU
> > wildcard can match. Add a test as requested by Namhyung. Add file
> > comments.
> >
> > v1:
> > https://lore.kernel.org/lkml/20250211071727.364389-1-irogers@google.com/
> >
> > Ian Rogers (4):
> >   perf parse-events: Avoid scanning PMUs that can't contain events
> >   perf parse-events: Avoid scanning PMUs that can't match a wildcard
> >   perf drm_pmu: Add a tool like PMU to expose DRM information
> >   perf tests: Add a DRM PMU test
> >
> >  tools/perf/tests/shell/drm_pmu.sh |  78 ++++
> >  tools/perf/util/Build             |   1 +
> >  tools/perf/util/drm_pmu.c         | 689 ++++++++++++++++++++++++++++++
> >  tools/perf/util/drm_pmu.h         |  39 ++
> >  tools/perf/util/evsel.c           |   9 +
> >  tools/perf/util/parse-events.c    |  30 +-
> >  tools/perf/util/pmu.c             |  15 +
> >  tools/perf/util/pmu.h             |   4 +-
> >  tools/perf/util/pmus.c            | 101 ++++-
> >  tools/perf/util/pmus.h            |   2 +
> >  10 files changed, 952 insertions(+), 16 deletions(-)
> >  create mode 100755 tools/perf/tests/shell/drm_pmu.sh
> >  create mode 100644 tools/perf/util/drm_pmu.c
> >  create mode 100644 tools/perf/util/drm_pmu.h
> >
> > --
> > 2.49.0.504.g3bcea36a83-goog
> >