What: /sys/bus/event_source/devices/<pmu>
Date: 2014/02/24
Contact:	Linux kernel mailing list <linux-kernel@vger.kernel.org>
Description:	Performance Monitoring Unit (<pmu>)

		Each <pmu> directory, for a PMU device, is a name
		optionally followed by an underscore and then either a
		decimal or hexadecimal number. For example, cpu is a
		PMU name without a suffix as is intel_bts,
		uncore_imc_0 is a PMU name with a 0 numeric suffix,
		ddr_pmu_87e1b0000000 is a PMU name with a hex
		suffix. The hex suffix must be more than two
		characters long to avoid ambiguity with PMUs like the
		S390 cpum_cf.

		Tools can treat PMUs with the same name that differ by
		suffix as instances of the same PMU for the sake of,
		for example, opening an event. For example, the PMUs
		uncore_imc_free_running_0 and
		uncore_imc_free_running_1 have an event data_read;
		opening the data_read event on a PMU specified as
		uncore_imc_free_running should be treated as opening
		the data_read event on PMU uncore_imc_free_running_0
		and PMU uncore_imc_free_running_1.