Re: [PATCH v2 0/4] Perf tool: Enable Arm arch timer counter and arm-spe's timestamp

From: Arnaldo Carvalho de Melo
Date: Thu Aug 13 2020 - 09:05:33 EST


Em Thu, Aug 13, 2020 at 01:08:02PM +0100, John Garry escreveu:
> On 13/08/2020 12:18, Will Deacon wrote:
> > [ Adding John, as I only just realised he wasn't on CC and we were talking
> > about him! ]
> >
> > On Thu, Aug 13, 2020 at 10:59:01AM +0100, Will Deacon wrote:
> > > On Wed, Aug 12, 2020 at 03:53:34PM -0300, Arnaldo Carvalho de Melo wrote:
> > > > Em Wed, Aug 12, 2020 at 10:06:53AM -0600, Mathieu Poirier escreveu:
> > > > > The ARM SPE perf tools code is orphan and I don't have the cycles to
> > > > > pick it up. Leo has spent a lot of time in that code and as such I
> > > > > suggest that he starts maintaining it, probably following the same
> > > > > kind of arrangement you and I have for coresight.
> > > >
> > > > Thats ok with me, I think we should reflect that on the MAINTAINERS
> > > > file, right?
> > > >
> > > > We have this already:
> > > >
> > > > PERFORMANCE EVENTS SUBSYSTEM ARM64 PMU EVENTS
> > > > R: John Garry <john.garry@xxxxxxxxxx>
> > > > R: Will Deacon <will@xxxxxxxxxx>
> > > > L: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx (moderated for non-subscribers)
> > > > S: Supported
> > > > F: tools/perf/pmu-events/arch/arm64/
> > > >
> > > > I think we should have entries for CoreSight and ARM SPE, one listing
> > > > you as the maintainer and the other listing Leo, right?
> > >
> > > Fine by me. I'll continue to maintain the in-kernel SPE driver, but I'd love
> > > to see somebody step up to looking after the userspace code. It's seriously
> > > unloved on arm64 :(
> > >
> > > I'd even be happy to see one or two M: entries added for
> > > tools/perf/pmu-events/arch/arm64/. I realistically don't have the time to
> > > take that on, but I'd be thrilled if any/all of John, Mathieu and Leo were
> > > to be listed there if they are willing to do so and can spare the time to
> > > look after it. Even just silly things like making sure the thing
> > > cross-compiles have been broken in the recent past, so it's not necessarily
> > > about handling huge amounts of incoming patches.
> > >
> > > In other words, rather than slice up the arm64 parts of the perf tool, I'd
> > > argue in favour of a joint maintainership model for all the arm64 bits, if
> > > we have a few willing volunteers.
>
> Right, it makes sense not to chop up too much, so happy to see "PERFORMANCE
> EVENTS SUBSYSTEM ARM64 PMU EVENTS" expanded in terms of scope and
> membership.

Discuss this as long as you need and then send me a patch for the
MAINTAINERS file with your conclusion.

Great to see this happening,

- Arnaldo