[PATCH 0/2] perf: add documentation for sysfs interfaces

STALE4617d

3 messages, 1 author, 2014-03-06 · open the first message on its own page

[PATCH 0/2] perf: add documentation for sysfs interfaces

From: Cody P Schafer <hidden>
Date: 2014-03-06 00:45:20

Documents <pmu>/event/<event>{,.scale,.units} and then removes the redundant
POWER docs.

Slightly restricts <event> names to avoid API funkyness when we add new
<event>.????? files ('.' forbidden in event names).

The contact is currently lkml, it would be very useful to have a perf
development list to put here instead (acme, feel like making one?).

--

Cody P Schafer (2):
  perf Documentation: sysfs events/ interfaces
  perf Documentation: remove duplicated docs for powerpc cpu specific
    events

 .../testing/sysfs-bus-event_source-devices-events  | 92 +++++++++++-----------
 1 file changed, 47 insertions(+), 45 deletions(-)

-- 
1.9.0

[PATCH 2/2] perf Documentation: remove duplicated docs for powerpc cpu specific events

From: Cody P Schafer <hidden>
Date: 2014-03-06 00:46:51

Listing specific events doesn't actually help us at all here because:
 - these events actually vary between different ppc processors, they
   aren't garunteed to be present.
 - the documentation of the file contents is now duplicated by the
   docs for arbitrary event file contents.

Signed-off-by: Cody P Schafer <redacted>
---
 .../testing/sysfs-bus-event_source-devices-events  | 57 ----------------------
 1 file changed, 57 deletions(-)

diff --git a/Documentation/ABI/testing/sysfs-bus-event_source-devices-events b/Documentation/ABI/testing/sysfs-bus-event_source-devices-events
index 5393e1ed6..50c30a6 100644
--- a/Documentation/ABI/testing/sysfs-bus-event_source-devices-events
+++ b/Documentation/ABI/testing/sysfs-bus-event_source-devices-events

@@ -26,63 +26,6 @@ Description:	Generic performance monitoring events
 		"raw code" for the perf event identified by the file's
 		"basename".
 
-
-What: 		/sys/devices/cpu/events/PM_1PLUS_PPC_CMPL
-		/sys/devices/cpu/events/PM_BRU_FIN
-		/sys/devices/cpu/events/PM_BR_MPRED
-		/sys/devices/cpu/events/PM_CMPLU_STALL
-		/sys/devices/cpu/events/PM_CMPLU_STALL_BRU
-		/sys/devices/cpu/events/PM_CMPLU_STALL_DCACHE_MISS
-		/sys/devices/cpu/events/PM_CMPLU_STALL_DFU
-		/sys/devices/cpu/events/PM_CMPLU_STALL_DIV
-		/sys/devices/cpu/events/PM_CMPLU_STALL_ERAT_MISS
-		/sys/devices/cpu/events/PM_CMPLU_STALL_FXU
-		/sys/devices/cpu/events/PM_CMPLU_STALL_IFU
-		/sys/devices/cpu/events/PM_CMPLU_STALL_LSU
-		/sys/devices/cpu/events/PM_CMPLU_STALL_REJECT
-		/sys/devices/cpu/events/PM_CMPLU_STALL_SCALAR
-		/sys/devices/cpu/events/PM_CMPLU_STALL_SCALAR_LONG
-		/sys/devices/cpu/events/PM_CMPLU_STALL_STORE
-		/sys/devices/cpu/events/PM_CMPLU_STALL_THRD
-		/sys/devices/cpu/events/PM_CMPLU_STALL_VECTOR
-		/sys/devices/cpu/events/PM_CMPLU_STALL_VECTOR_LONG
-		/sys/devices/cpu/events/PM_CYC
-		/sys/devices/cpu/events/PM_GCT_NOSLOT_BR_MPRED
-		/sys/devices/cpu/events/PM_GCT_NOSLOT_BR_MPRED_IC_MISS
-		/sys/devices/cpu/events/PM_GCT_NOSLOT_CYC
-		/sys/devices/cpu/events/PM_GCT_NOSLOT_IC_MISS
-		/sys/devices/cpu/events/PM_GRP_CMPL
-		/sys/devices/cpu/events/PM_INST_CMPL
-		/sys/devices/cpu/events/PM_LD_MISS_L1
-		/sys/devices/cpu/events/PM_LD_REF_L1
-		/sys/devices/cpu/events/PM_RUN_CYC
-		/sys/devices/cpu/events/PM_RUN_INST_CMPL
-
-Date:		2013/01/08
-
-Contact:	Linux kernel mailing list <linux-kernel@vger.kernel.org>
-		Linux Powerpc mailing list <linuxppc-dev@ozlabs.org>
-
-Description:	POWER-systems specific performance monitoring events
-
-		A collection of performance monitoring events that may be
-		supported by the POWER CPU. These events can be monitored
-		using the 'perf(1)' tool.
-
-		These events may not be supported by other CPUs.
-
-		The contents of each file would look like:
-
-			event=0xNNNN
-
-		where 'N' is a hex digit and the number '0xNNNN' shows the
-		"raw code" for the perf event identified by the file's
-		"basename".
-
-		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>

-- 
1.9.0

[PATCH 1/2] perf Documentation: sysfs events/ interfaces

From: Cody P Schafer <hidden>
Date: 2014-03-06 00:47:46

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.

I've added a restriction that event names cannot contain '.' characters
so we can avoid breaking the API when we (inevitably) add more
'event.????' files.

Signed-off-by: Cody P Schafer <redacted>
---
 .../testing/sysfs-bus-event_source-devices-events  | 59 ++++++++++++++++++++++
 1 file changed, 59 insertions(+)

diff --git a/Documentation/ABI/testing/sysfs-bus-event_source-devices-events b/Documentation/ABI/testing/sysfs-bus-event_source-devices-events
index 3c1cc24..5393e1ed6 100644
--- a/Documentation/ABI/testing/sysfs-bus-event_source-devices-events
+++ b/Documentation/ABI/testing/sysfs-bus-event_source-devices-events

@@ -82,3 +82,62 @@ 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 (with a name not containing a '.') 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.

-- 
1.9.0

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