Commit ed90a446 authored by Cody P Schafer's avatar Cody P Schafer Committed by Arnaldo Carvalho de Melo
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perf Documentation: sysfs events/ interfaces 



Add documentation for the <event>, <event>.scale, and <event>.unit
files in sysfs.

	<event>.scale and <event>.unit were undocumented.
	<event> was previously documented only for specific powerpc pmu events.

Signed-off-by: default avatarCody P Schafer <dev@codyps.com>
Signed-off-by: default avatarSukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com>
Cc: Cody P Schafer <dev@codyps.com>
Cc: Haren Myneni <hbabu@us.ibm.com>
Cc: Haren Myneni <hbabu@us.ibm.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Michael Ellerman <michaele@au1.ibm.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: linuxppc-dev@lists.ozlabs.org
Link: http://lkml.kernel.org/r/1412143402-26061-4-git-send-email-sukadev@linux.vnet.ibm.com


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent 1e378ebd

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

+60 −0
Original line number Diff line number Diff line
@@ -599,3 +599,63 @@ Description: POWER-systems specific performance monitoring events 
		Further, multiple terms like 'event=0xNNNN' can be specified

		and separated with comma. All available terms are defined in

		the /sys/bus/event_source/devices/<dev>/format file.



What: /sys/bus/event_source/devices/<pmu>/events/<event>

Date: 2014/02/24

Contact:	Linux kernel mailing list <linux-kernel@vger.kernel.org>

Description:	Per-pmu performance monitoring events specific to the running system



		Each file (except for some of those with a '.' in them, '.unit'

		and '.scale') in the 'events' directory describes a single

		performance monitoring event supported by the <pmu>. The name

		of the file is the name of the event.



		File contents:



			<term>[=<value>][,<term>[=<value>]]...



		Where <term> is one of the terms listed under

		/sys/bus/event_source/devices/<pmu>/format/ and <value> is

		a number is base-16 format with a '0x' prefix (lowercase only).

		If a <term> is specified alone (without an assigned value), it

		is implied that 0x1 is assigned to that <term>.



		Examples (each of these lines would be in a seperate file):



			event=0x2abc

			event=0x423,inv,cmask=0x3

			domain=0x1,offset=0x8,starting_index=0xffff



		Each of the assignments indicates a value to be assigned to a

		particular set of bits (as defined by the format file

		corresponding to the <term>) in the perf_event structure passed

		to the perf_open syscall.



What: /sys/bus/event_source/devices/<pmu>/events/<event>.unit

Date: 2014/02/24

Contact:	Linux kernel mailing list <linux-kernel@vger.kernel.org>

Description:	Perf event units



		A string specifying the English plural numerical unit that <event>

		(once multiplied by <event>.scale) represents.



		Example:



			Joules



What: /sys/bus/event_source/devices/<pmu>/events/<event>.scale

Date: 2014/02/24

Contact:	Linux kernel mailing list <linux-kernel@vger.kernel.org>

Description:	Perf event scaling factors



		A string representing a floating point value expressed in

		scientific notation to be multiplied by the event count

		recieved from the kernel to match the unit specified in the

		<event>.unit file.



		Example:



			2.3283064365386962890625e-10



		This is provided to avoid performing floating point arithmetic

		in the kernel.

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