linux-kernel - Re: [PATCH v2 0/4] Enable display of partial and empty SVE predicates from Arm SPE data

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Date:   Mon, 20 Mar 2023 19:29:09 -0300
From:   Arnaldo Carvalho de Melo <acme@...nel.org>
To:     Ian Rogers <irogers@...gle.com>
Cc:     James Clark <james.clark@....com>,
        linux-perf-users@...r.kernel.org, Anshuman.Khandual@....com,
        Peter Zijlstra <peterz@...radead.org>,
        Ingo Molnar <mingo@...hat.com>,
        Mark Rutland <mark.rutland@....com>,
        Alexander Shishkin <alexander.shishkin@...ux.intel.com>,
        Jiri Olsa <jolsa@...nel.org>,
        Namhyung Kim <namhyung@...nel.org>,
        Adrian Hunter <adrian.hunter@...el.com>,
        John Garry <john.g.garry@...cle.com>,
        Will Deacon <will@...nel.org>,
        Mike Leach <mike.leach@...aro.org>,
        Leo Yan <leo.yan@...aro.org>, linux-kernel@...r.kernel.org,
        linux-arm-kernel@...ts.infradead.org
Subject: Re: [PATCH v2 0/4] Enable display of partial and empty SVE
 predicates from Arm SPE data

Em Mon, Mar 20, 2023 at 10:50:59AM -0700, Ian Rogers escreveu:
> On Mon, Mar 20, 2023 at 8:15 AM James Clark <james.clark@....com> wrote:
> >
> > Changes since v1:
> >  * Rebase onto perf/core because it no longer applied cleanly
> >
> > ------------
> >
> > Hi,
> >
> > I'm submitting this on behalf of German who moved on to work on other
> > things in Arm before he could finish it off.
> >
> > The predicate information is available on SPE samples from
> > Armv8.3 (FEAT_SPEv1p1), this could be useful info for profiling SVE
> > code as partial and empty predicates indicate that the full vector
> > width isn't being used. There is a good example in the last commit
> > message.
> >
> > Though currently, there isn't a suitable field to store the info
> > on Perf samples, so this change also adds a new SIMD field.
> > This field could be used by other architectures, but currently there
> > is only one bit reserved to identify SVE. It's only added to
> > struct perf_sample on the userspace side, and isn't part of the kernel
> > ABI, so it doesn't survive a perf inject. Although this is the
> > same behavior for some other fields like branch flags, so I don't
> > think it should be an issue to do something similar here. Perhaps in
> > the future we could make sure everything that is synthesised from
> > auxtrace data also makes it back into the new Perf inject file without
> > being lost.
> 
> Series:
> Acked-by: Ian Rogers <irogers@...gle.com>

Thanks, applied.

- Arnaldo

 
> Thanks,
> Ian
> 
> > German Gomez (4):
> >   perf event: Add simd_flags field to perf_sample
> >   perf arm-spe: Refactor arm-spe to support operation packet type
> >   perf arm-spe: Add SVE flags to the SPE samples
> >   perf report: Add 'simd' sort field
> >
> >  tools/perf/Documentation/perf-report.txt      |  1 +
> >  .../util/arm-spe-decoder/arm-spe-decoder.c    | 30 ++++++++++--
> >  .../util/arm-spe-decoder/arm-spe-decoder.h    | 47 +++++++++++++++----
> >  tools/perf/util/arm-spe.c                     | 28 +++++++++--
> >  tools/perf/util/hist.c                        |  1 +
> >  tools/perf/util/hist.h                        |  1 +
> >  tools/perf/util/sample.h                      | 13 +++++
> >  tools/perf/util/sort.c                        | 47 +++++++++++++++++++
> >  tools/perf/util/sort.h                        |  2 +
> >  9 files changed, 152 insertions(+), 18 deletions(-)
> >
> >
> > base-commit: 96d541699e5c50b1bc2d50c83cd7145994d5f071
> > --
> > 2.34.1
> >

-- 

- Arnaldo