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: Cody P Schafer <dev@codyps.com>
Signed-off-by: Sukadev 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: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 60 insertions, 0 deletions

diff --git a/Documentation/ABI/testing/sysfs-bus-event_source-devices-events b/Documentation/ABI/testing/sysfs-bus-event_source-devices-events
index 7b40a3cbc26a..a5226f094159 100644
--- a/Documentation/ABI/testing/sysfs-bus-event_source-devices-events
+++ b/Documentation/ABI/testing/sysfs-bus-event_source-devices-events
@@ -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.