What:		/sys/bus/event_source/devices/<dev>/caps
Date:		May 2022
KernelVersion:	5.19
Contact:	Linux kernel mailing list <linux-kernel@vger.kernel.org>
Description:
		Attribute group to describe the capabilities exposed
		for a particular pmu. Each attribute of this group can
		expose information specific to a PMU, say pmu_name, so that
		userspace can understand some of the feature which the
		platform specific PMU supports.

		One of the example available capability in supported platform
		like Intel is pmu_name, which exposes underlying CPU name known
		to the PMU driver.

		Example output in powerpc:
		grep . /sys/bus/event_source/devices/cpu/caps/*
		/sys/bus/event_source/devices/cpu/caps/pmu_name:POWER9

		The "branch_counter_nr" in the supported platform exposes the
		maximum number of counters which can be shown in the u64 counters
		of PERF_SAMPLE_BRANCH_COUNTERS, while the "branch_counter_width"
		exposes the width of each counter. Both of them can be used by
		the perf tool to parse the logged counters in each branch.
