Re: [PATCH 6/6][v3] perf: Document the ABI of perf sysfs entries

[Jiri Olsa <jolsa@redhat.com>]

On Wed, Jan 16, 2013 at 10:58:16AM -0800, Sukadev Bhattiprolu wrote:
> Jiri Olsa [jolsa@redhat.com] wrote:
> | On Tue, Jan 15, 2013 at 03:57:59PM -0300, Arnaldo Carvalho de Melo wrote:
> | > Em Wed, Jan 09, 2013 at 05:07:03PM -0800, Sukadev Bhattiprolu escreveu:
> | > > [PATCH 6/6][v3] perf: Document the ABI of perf sysfs entries
> | > > 
> | > > This patchset addes two new sets of files to sysfs:
> | > > 
> | > > 	- generic and POWER-specific perf events in /sys/devices/cpu/events/
> | > > 	- perf event config format in /sys/devices/cpu/format/event
> | > > 
> | > > Document the format of these files which would become part of the ABI.
> | > > 
> | > > Changelog[v3]:
> | > > 	[Greg KH] Include ABI documentation.
> | > 
> | > Jiri, can I have your ack on this one too?
> | 
> | hm, we already already 'format' definition but in testing section
> | (and we are missing 'events' definition there.. my bad)
> 
> I see that file now ! I have removed that documentation from my patch.
> | 
> | anyway, after reading Documentation/ABI/README looks like we
> | should go for 'testing' section with this as well.. stable
> | seems scary at this point ;-)
> 
> Agree.
> 
> Here is the updated patch.
> ---
> 
> This patchset addes two new sets of files to sysfs for POWER architecture.
> 
> 	- perf event config format in /sys/devices/cpu/format/event
> 	- generic and POWER-specific perf events in /sys/devices/cpu/events/
> 
> The format of the first file is already documented in:
> 
> 	Documentation/ABI/testing/sysfs-bus-event_source-devices-format
> 
> Document the format of the second set of files '/sys/devices/cpu/events/*'
> which would also become part of the ABI.
> 
> Changelog[v3.1]:
> 	(small changes to this one patch).
> 	[Jiri Olsa]: Remove the documentation for the 'config format' file
> 	as it is already documented.
> 	[Jiri Olsa]: Move the documentation of 'events' also to 'testing/'
> 
> Changelog[v3]:
> 	[Greg KH] Include ABI documentation.
> 
> Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
> ---
>  .../testing/sysfs-bus-event_source-devices-events  |   58 ++++++++++++++++++++
>  1 files changed, 58 insertions(+), 0 deletions(-)
>  delete mode 100644 Documentation/ABI/stable/sysfs-devices-cpu-events
>  create mode 100644 Documentation/ABI/testing/sysfs-bus-event_source-devices-events
> 
> diff --git a/Documentation/ABI/stable/sysfs-devices-cpu-events b/Documentation/ABI/stable/sysfs-devices-cpu-events
> deleted file mode 100644
> index e69de29..0000000
> diff --git a/Documentation/ABI/testing/sysfs-bus-event_source-devices-events b/Documentation/ABI/testing/sysfs-bus-event_source-devices-events
> new file mode 100644
> index 0000000..2c4081e
> --- /dev/null
> +++ b/Documentation/ABI/testing/sysfs-bus-event_source-devices-events
> @@ -0,0 +1,58 @@
> +What:		/sys/devices/cpu/events/
> +		/sys/devices/cpu/events/branch-misses
> +		/sys/devices/cpu/events/cache-references
> +		/sys/devices/cpu/events/cache-misses
> +		/sys/devices/cpu/events/stalled-cycles-frontend
> +		/sys/devices/cpu/events/branch-instructions
> +		/sys/devices/cpu/events/stalled-cycles-backend
> +		/sys/devices/cpu/events/instructions
> +		/sys/devices/cpu/events/cpu-cycles
> +
> +Date:		2012/01/NN
> +
> +Contact:	Linux kernel mailing list <linux-kernel@vger.kernel.org>
> +
> +Description:	Generic performance monitoring events
> +
> +		A collection of performance monitoring events that may be
> +		supported by many/most CPUs. These events can be monitored
> +		using the 'perf(1)' tool.
> +
> +		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".

Maybe it'd worth to mention, that it does not need to be just 'event',
but anything from /sys/bus/event_source/devices/<dev>/format directory,
like

		The can be multiple terms like 'event=0xNNNN' specified
		and separated with comma. All available terms are located
		in /sys/bus/event_source/devices/<dev>/format file.

Please feel free to rephrase or use proper English ;-)

otherwise it's ok,
jirka