[PATCH v2 3/4] perf Documentation: sysfs events/ interfaces

From: Sukadev Bhattiprolu
Date: Wed Sep 24 2014 - 15:25:50 EST


From: Cody P Schafer <cody@xxxxxxxxxxxxxxxxxx>

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.

CC: Sukadev Bhattiprolu <sukadev@xxxxxxxxxxxxxxxxxx>
CC: Haren Myneni <hbabu@xxxxxxxxxx>
CC: Cody P Schafer <dev@xxxxxxxxxx>
Signed-off-by: Cody P Schafer <cody@xxxxxxxxxxxxxxxxxx>
---
.../testing/sysfs-bus-event_source-devices-events | 60 ++++++++++++++++++++++
1 file changed, 60 insertions(+)

diff --git a/Documentation/ABI/testing/sysfs-bus-event_source-devices-events b/Documentation/ABI/testing/sysfs-bus-event_source-devices-events
index 7b40a3c..a5226f0 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@xxxxxxxxxxxxxxx>
+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@xxxxxxxxxxxxxxx>
+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@xxxxxxxxxxxxxxx>
+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.
--
1.8.3.1

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/