[PATCH v2 0/9] perf: Add NVIDIA Tegra410 uncore PMU events and metrics

[Ian Rogers]

On Fri, Oct 30, 2026 at 10:49 AM Besar Wicaksono <bwicaksono at nvidia.com> wrote:
>
> Add event aliases and derived metrics for the NVIDIA Tegra410 uncore
> PMUs, and fix perf's aggregation of PMU instances that are numbered in
> more than one parts in their name.
>
> The series covers the UCF, PCIe, PCIe target, CPU memory latency, and
> chip-to-chip interconnect PMUs. It provides symbolic names for the raw
> event encodings and metrics for bandwidth, frequency, and average read
> latency.
>
> The PCIe and PCIe target PMUs are named nvidia_pcie_pmu_<socket>_rc_<rc>
> and nvidia_pcie_tgt_pmu_<socket>_rc_<rc>. Their json Unit uses the
> existing comma-separated form ("nvidia_pcie_pmu_,rc_"), but perf only
> merged instances that differ in the trailing number, so these events and
> metrics gave one result per socket and were reported incorrectly (e.g.
> with --metric-only), as discussed in v1. Patches 6-9 fix this:
>
> - Patch 6 adds a check of the cpumasks of all merged PMU instances to the
>   zero-count skip in perf stat, so a socket that counts nothing shows 0
>   instead of having its row hidden.
> - Patch 7 merges PMU instances that match the same comma-separated json
>   Unit. This also applies to the HiSilicon hisi_sccl PMUs, which use the
>   same json form; not tested on HiSilicon hardware.
> - Patch 8 labels a merged uncore counter after all of its PMUs, e.g.
>   nvidia_pcie_pmu_*_rc_*/cycles/ or nvidia_ucf_pmu/cycles/, instead of
>   after the first instance, such as nvidia_pcie_pmu_0_rc_0/cycles/.
>   Output with --no-aggr is unchanged.
> - Patch 9 describes these PMU names in the ABI document.
>
> Changes in v2:
> - Move the uncore JSON out of the sys directory and remove the
>   "Compat" fields. Thanks to Ian Rogers for the feedback.
> - Drop "perf jevents: Process model files before sys subdirectories",
>   which this series no longer needs.
> - Add UCF SLC and memory bandwidth metrics from all sources to local
>   CMEM (read, write and read+write) and from local sources to local
>   CMEM and to remote memory, PCIe bandwidth metrics to local
>   destinations, and read+write bandwidth metrics for UCF SLC, UCF
>   memory and PCIe. Thanks to Chun-Tse Shao for the suggestion.
> - Add patches 6-9 to fix the PCIe instance aggregation. Thanks to Ian
>   Rogers and Chun-Tse Shao for the pointers.
>
> v1: https://lore.kernel.org/all/20261019164241.403644-1-bwicaksono@nvidia.com/

Why don't we look to fix code in drivers/perf? This series introduces
PMU instances, overloads the meaning of aliases, and a bunch of other
silly complexity due to poor reviews and maintenance of drivers/perf -
specifically by not pointing out the ABI issues. Isn't this a
straightforward, whoops we did a bad suffix and here's the patch to
rename our PMU in the driver? Throwing more complexity at the problem
doesn't feel like the right fix.

Thanks,
Ian

> Besar Wicaksono (9):
>   perf jevents: Add support for NVIDIA Tegra410 UCF PMU aliasing
>   perf jevents: Add support for NVIDIA Tegra410 PCIE PMU aliasing
>   perf jevents: Add support for NVIDIA Tegra410 PCIE-TGT PMU aliasing
>   perf jevents: Add support for NVIDIA Tegra410 CPU Memory Latency PMU
>     aliasing
>   perf jevents: Add support for NVIDIA Tegra410 C2C PMU aliasing
>   perf stat: Check merged PMU instance's cpumasks when skipping zero
>     counts
>   perf pmu: Merge PMU instances that match the same comma-separated json
>     Unit
>   perf evsel: Name a merged uncore counter after all of its PMUs
>   perf Documentation: Describe PMU names numbered in more than one place
>
>  .../testing/sysfs-bus-event_source-devices    |  14 +
>  .../arm64/nvidia/t410/uncore-cpu_mem.json     |  43 +
>  .../arm64/nvidia/t410/uncore-nvclink.json     |  67 ++
>  .../arm64/nvidia/t410/uncore-nvdlink.json     |  43 +
>  .../arm64/nvidia/t410/uncore-nvlink_c2c.json  | 115 +++
>  .../arch/arm64/nvidia/t410/uncore-pcie.json   | 249 ++++++
>  .../arm64/nvidia/t410/uncore-pcie_tgt.json    |  83 ++
>  .../arch/arm64/nvidia/t410/uncore-ucf.json    | 764 ++++++++++++++++++
>  tools/perf/tests/pmu.c                        | 134 +++
>  tools/perf/util/evlist.c                      |   2 +-
>  tools/perf/util/evsel.c                       |  83 +-
>  tools/perf/util/evsel.h                       |   2 +-
>  tools/perf/util/parse-events.c                |   2 +-
>  tools/perf/util/pmu.c                         |  65 ++
>  tools/perf/util/pmu.h                         |   9 +
>  tools/perf/util/pmus.c                        |  47 ++
>  tools/perf/util/pmus.h                        |   1 +
>  tools/perf/util/stat-display.c                |  20 +
>  18 files changed, 1737 insertions(+), 6 deletions(-)
>  create mode 100644 tools/perf/pmu-events/arch/arm64/nvidia/t410/uncore-cpu_mem.json
>  create mode 100644 tools/perf/pmu-events/arch/arm64/nvidia/t410/uncore-nvclink.json
>  create mode 100644 tools/perf/pmu-events/arch/arm64/nvidia/t410/uncore-nvdlink.json
>  create mode 100644 tools/perf/pmu-events/arch/arm64/nvidia/t410/uncore-nvlink_c2c.json
>  create mode 100644 tools/perf/pmu-events/arch/arm64/nvidia/t410/uncore-pcie.json
>  create mode 100644 tools/perf/pmu-events/arch/arm64/nvidia/t410/uncore-pcie_tgt.json
>  create mode 100644 tools/perf/pmu-events/arch/arm64/nvidia/t410/uncore-ucf.json
>
> --
> 2.43.0
>