Re: [PATCH v2] perf list: Add PMU pai_ext event description for IBM z16

[Arnaldo Carvalho de Melo <acme@kernel.org>]

Em Tue, Nov 15, 2022 at 09:58:22AM +0100, Thomas Richter escreveu:
> On 11/14/22 17:06, Arnaldo Carvalho de Melo wrote:
> > Em Fri, Nov 11, 2022 at 02:54:02PM +0100, Thomas Richter escreveu:
> >> Add the event description for the IBM z16 pai_ext PMU released with
> >> commit c432fefe8e62 ("s390/pai: Add support for PAI Extension 1 NNPA counters")

> >> The document SA22-7832-13 "z/Architecture Principles of Operation",
> >> published May, 2022, contains the description of the Processor
> >> Activity Instrumentation Facility and the NNPA counter set., See
> >> Pages 5-113 to 5-116.

> >> Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>

> >> --- /dev/null
> >> +++ b/tools/perf/pmu-events/arch/s390/cf_z16/pai_ext.json
> >> @@ -0,0 +1,198 @@
> >> +[
> >> +	{
> >> +		"Unit": "PAI-EXT",
> >> +		"EventCode": "6144",
> >> +		"EventName": "NNPA_ALL",
> >> +		"BriefDescription": "NNPA ALL",
> >> +		"PublicDescription": "Sum of all non zero NNPA counters"
> >> +	},

> > Since the Brief description mentions NNPA, shouldn't the Public
> > Description expand on this "NNPA" acronym?, something like:

> > Oops, can't expand on that since there isn't a link to that SA22-7832-13
> > document.

> > Googling for it...

> > https://www-40.ibm.com/servers/resourcelink/svc03100.nsf/pages/zResourceLinkUrl?OpenDocument&url=http://www.ibm.com/servers/resourcelink/lib03010.nsf/0/B9DE5F05A9D57819852571C500428F9A/$file/SA22-7832-13.pdf

> > Ok, requires registration.

> > I wonder what is the value of these descriptions then :-\

> > I miss Ingo jumping into these discussions :-)
 
> I added Andreas Krebbel to the discussion, he knows more than I on this counters.
 
> NNPA stands for Neural Networks Processing Assist. This is a new feature in 
> the IBM z16. Here is a quote from Document SG2489-51 IBM z16 (3931) Technical Guide:
 
> <START-OF-QUOTE>
>   "The new IBM z16 microprocessor chip, also called the IBM Telum processor, integrates a
>    new AI accelerator. This innovation brings incredible value to applications and workloads that
>    are running on IBM Z platform.
>    Customers can benefit from the integrated AI accelerator by adding AI operations that are
>    used to perform fraud prevention and fraud detection, customer behavior predictions, and
>    supply chain operations. All of these operations are done in real time and fully integrated in
>    transactional workloads. As a result, valuable insights are gained from their data instantly.
> 
>    ...
>    The AI accelerator is driven by the new Neural Networks Processing Assist (NNPA)
>    instruction.
>    NNPA is a new nonprivileged Complex Instruction Set Computer (CISC) memory-to-memory
>    instruction that operates on tensor objects that are in user program’s memory. AI functions
>    and macros are abstracted by NNPA."
> <END-OF-QUOTE>
> 
> This intension of this patch is to give a small hint on what these NNPA counters are
> supposed to count and operate on. A full explanation is given in the document
> SA22-7832-13 "z/Architecture Principles of Operation", Chapter 26, pp 26-1 to 26-115.
> 
> If you think this small description is not worth it, then we can drop the patch.

So perhaps:

+	{
+		"Unit": "PAI-EXT",
+		"EventCode": "6144",
+		"EventName": "NNPA_ALL",
+		"BriefDescription": "NNPA ALL",
+		"PublicDescription": "Sum of all non zero NNPA (Neural Networks Processing Assist) counters"
+	},

?

- Arnaldo