Documentation/ABI/testing/sysfs-bus-event_source-devices-caps

   1 What:           /sys/bus/event_source/devices/<dev>/caps
   2 Date:           May 2022
   3 KernelVersion:  5.19
   4 Contact:        Linux kernel mailing list <linux-kernel@vger.kernel.org>
   5 Description:
   6                 Attribute group to describe the capabilities exposed
   7                 for a particular pmu. Each attribute of this group can
   8                 expose information specific to a PMU, say pmu_name, so that
   9                 userspace can understand some of the feature which the
  10                 platform specific PMU supports.
  11
  12                 One of the example available capability in supported platform
  13                 like Intel is pmu_name, which exposes underlying CPU name known
  14                 to the PMU driver.
  15
  16                 Example output in powerpc:
  17                 grep . /sys/bus/event_source/devices/cpu/caps/*
  18                 /sys/bus/event_source/devices/cpu/caps/pmu_name:POWER9
  19
  20                 The "branch_counter_nr" in the supported platform exposes the
  21                 maximum number of counters which can be shown in the u64 counters
  22                 of PERF_SAMPLE_BRANCH_COUNTERS, while the "branch_counter_width"
  23                 exposes the width of each counter. Both of them can be used by
  24                 the perf tool to parse the logged counters in each branch.