Documentation/admin-guide/perf/hns3-pmu.rst

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Documentation/admin-guide/perf/hns3-pmu.rst
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HNS3 Performance Monitoring Unit (PMU)
======================================

HNS3(HiSilicon network system 3) Performance Monitoring Unit (PMU) is an
End Point device to collect performance statistics of HiSilicon SoC NIC.
On Hip09, each SICL(Super I/O cluster) has one PMU device.

HNS3 PMU supports collection of performance statistics such as bandwidth,
latency, packet rate and interrupt rate.

Each HNS3 PMU supports 8 hardware events.

HNS3 PMU driver
===============

The HNS3 PMU driver registers a perf PMU with the name of its sicl id.::

  /sys/bus/event_source/devices/hns3_pmu_sicl_<sicl_id>

PMU driver provides description of available events, filter modes, format,
identifier and cpumask in sysfs.

The "events" directory describes the event code of all supported events
shown in perf list.

The "filtermode" directory describes the supported filter modes of each
event.

The "format" directory describes all formats of the config (events) and
config1 (filter options) fields of the perf_event_attr structure.

The "identifier" file shows version of PMU hardware device.

The "bdf_min" and "bdf_max" files show the supported bdf range of each
pmu device.

The "hw_clk_freq" file shows the hardware clock frequency of each pmu
device.

Example usage of checking event code and subevent code::

  $# cat /sys/bus/event_source/devices/hns3_pmu_sicl_0/events/dly_tx_normal_to_mac_time
  config=0x00204
  $# cat /sys/bus/event_source/devices/hns3_pmu_sicl_0/events/dly_tx_normal_to_mac_packet_num
  config=0x10204

Each performance statistic has a pair of events to get two values to
calculate real performance data in userspace.

The bits 0~15 of config (here 0x0204) are the true hardware event code. If
two events have same value of bits 0~15 of config, that means they are
event pair. And the bit 16 of config indicates getting counter 0 or
counter 1 of hardware event.

After getting two values of event pair in userspace, the formula of
computation to calculate real performance data is:::

  counter 0 / counter 1

Example usage of checking supported filter mode::

  $# cat /sys/bus/event_source/devices/hns3_pmu_sicl_0/filtermode/bw_ssu_rpu_byte_num
  filter mode supported: global/port/port-tc/func/func-queue/

Example usage of perf::

  $# perf list
  hns3_pmu_sicl_0/bw_ssu_rpu_byte_num/ [kernel PMU event]
  hns3_pmu_sicl_0/bw_ssu_rpu_time/     [kernel PMU event]

Annotation

Implementation Notes