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References: <20231123121851.10826-1-adrian.hunter@intel.com>
In-Reply-To: <20231123121851.10826-1-adrian.hunter@intel.com>
From:   Ian Rogers <irogers@google.com>
Date:   Tue, 28 Nov 2023 11:52:49 -0800
Message-ID: <CAP-5=fXXrfOyNKrP8xu8+c5Wq1L=YgiEGuv6qC5XP5m+8ie9_w@mail.gmail.com>
Subject: Re: [PATCH RFC 0/3] perf/core: Add ability for an event to "pause" or
 "resume" AUX area tracing
To:     Adrian Hunter <adrian.hunter@intel.com>
Cc:     Peter Zijlstra <peterz@infradead.org>,
        Ingo Molnar <mingo@redhat.com>,
        Mark Rutland <mark.rutland@arm.com>,
        Alexander Shishkin <alexander.shishkin@linux.intel.com>,
        Heiko Carstens <hca@linux.ibm.com>,
        Thomas Richter <tmricht@linux.ibm.com>,
        Hendrik Brueckner <brueckner@linux.ibm.com>,
        Suzuki K Poulose <suzuki.poulose@arm.com>,
        Mike Leach <mike.leach@linaro.org>,
        James Clark <james.clark@arm.com>, coresight@lists.linaro.org,
        linux-arm-kernel@lists.infradead.org,
        Yicong Yang <yangyicong@hisilicon.com>,
        Jonathan Cameron <jonathan.cameron@huawei.com>,
        Will Deacon <will@kernel.org>,
        Arnaldo Carvalho de Melo <acme@kernel.org>,
        Jiri Olsa <jolsa@kernel.org>,
        Namhyung Kim <namhyung@kernel.org>,
        linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org
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On Thu, Nov 23, 2023 at 4:19=E2=80=AFAM Adrian Hunter <adrian.hunter@intel.=
com> wrote:
>
> Hi
>
> Hardware traces, such as instruction traces, can produce a vast amount of
> trace data, so being able to reduce tracing to more specific circumstance=
s
> can be useful.
>
> The ability to pause or resume tracing when another event happens, can do
> that.
>
> These patches add such a facilty and show how it would work for Intel
> Processor Trace.
>
> Maintainers of other AUX area tracing implementations are requested to
> consider if this is something they might employ and then whether or not
> the ABI would work for them.
>
> Changes to perf tools are not fleshed out yet.

This looks good to me but the perf tools parsing changes I'm not sure
on. It would be nice to have a test case, likely a shell test or
change to the intel-pt shell test, to show how they work.

Thanks,
Ian

> Adrian Hunter (3):
>       perf/core: Add aux_pause, aux_resume, aux_start_paused
>       perf/x86/intel/pt: Add support for pause_resume()
>       perf tools: Add support for AUX area pause_resume()
>
>  arch/x86/events/intel/pt.c                | 12 ++++++
>  include/linux/perf_event.h                |  9 +++++
>  include/uapi/linux/perf_event.h           | 13 ++++++-
>  kernel/events/core.c                      | 65 +++++++++++++++++++++++++=
++++--
>  kernel/events/internal.h                  |  1 +
>  tools/include/uapi/linux/perf_event.h     | 13 ++++++-
>  tools/perf/util/auxtrace.c                |  4 ++
>  tools/perf/util/evsel.c                   |  9 +++++
>  tools/perf/util/evsel_config.h            |  6 +++
>  tools/perf/util/parse-events.c            | 33 ++++++++++++++++
>  tools/perf/util/parse-events.h            |  3 ++
>  tools/perf/util/parse-events.l            |  3 ++
>  tools/perf/util/perf_event_attr_fprintf.c |  3 ++
>  13 files changed, 167 insertions(+), 7 deletions(-)
>
>
> Regards
> Adrian