path: root/Documentation/ABI
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authorCody P Schafer <dev@codyps.com>2014-09-30 23:03:19 -0700
committerArnaldo Carvalho de Melo <acme@redhat.com>2014-10-15 15:54:40 -0300
commited90a4466340e51699139ea83dbe0f4536360e6d (patch)
treed1c02068c3dda6b2a37944b36ffebb2507392d3b /Documentation/ABI
parent1e378ebd117d1828b9d5dbe0538887478fcb9d84 (diff)
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>
Diffstat (limited to 'Documentation/ABI')
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.

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