Re: [PATCH 1/3] perf vendor events: For the Neoverse N2

[John Garry]

On 07/12/2021 12:13, Andrew Kilroy wrote:
> On 07/12/2021 09:57, John Garry wrote:
> > On 03/12/2021 12:35, Andrew Kilroy wrote:
> > > Updates the common and microarch json file to add counters
> > > available in the Neoverse N2 chip, but should also apply to other ArmV8
> > > and ArmV9 cpus.  Specified in ArmV8 architecture reference manual
> > >
> > > https://developer.arm.com/documentation/ddi0487/gb/?lang=en
> > >
> > > Some of the counters added to armv8-common-and-microarch.json are
> > > specified in the ArmV9 architecture reference manual supplement
> > > (issue A.a):
> > >
> > > https://developer.arm.com/documentation/ddi0608/aa
> > >
> > > The additional ArmV9 counters are
> > >
> > >    TRB_WRAP
> > >    TRCEXTOUT0
> > >    TRCEXTOUT1
> > >    TRCEXTOUT2
> > >    TRCEXTOUT3
> > >    CTI_TRIGOUT4
> > >    CTI_TRIGOUT5
> > >    CTI_TRIGOUT6
> > >    CTI_TRIGOUT7
> > >
> > > This patch also adds files in pmu-events/arch/arm64/arm/neoverse-n2 for
> > > perf list to output the counter names in categories.
> > >
> > > A subsequent patch renames armv8-common-and-microarch.json and
> > > armv8-recommended.json to reflect that counters for armv9 are being
> > > added.
> >
> > This commentary should be in a cover letter. Please do that.
> >
> > And did you consider just adding a armv9-common-and-microarch.json and
> > armv9-recommended.json instead of adding to and renaming the v8 version?
> > I know that it creates scattered definitions, but we already have that in
> > dividing the common and the recommended JSONs.
>
> I considered it, but I wasn't sure what was preferable.  I thought I'd 
> get some feedback.  Do you consider the separation important?  Any 
> particular reason?

At the moment I don't think that it's a big issue. I just thought it 
better to keep a structured and distinct file organisation by having 
separate files. v9 stuff is quite new, so we can wait for other input here.

Thanks,
John