Re: [PATCH RFC V2 0/4] perf/core: Add ability for an event to "pause" or "resume" AUX area tracing

[Adrian Hunter <adrian.hunter@intel.com>]

On 8/12/23 19:24, Adrian Hunter 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 circumstances
> 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.
> 
> 
> Changes in RFC V2:
> 
>       Use ->stop() / ->start() instead of ->pause_resume()
>       Move aux_start_paused bit into aux_output_cfg
>       Tighten up when Intel PT pause / resume is allowed
>       Add an example of how it might work for CoreSight

Any comments?

> 
> 
> Adrian Hunter (4):
>       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
>       coresight: Have a stab at support for pause / resume
> 
>  arch/x86/events/intel/pt.c                       | 63 ++++++++++++++++++++-
>  arch/x86/events/intel/pt.h                       |  4 ++
>  drivers/hwtracing/coresight/coresight-etm-perf.c | 29 ++++++++--
>  include/linux/perf_event.h                       | 15 +++++
>  include/uapi/linux/perf_event.h                  | 11 +++-
>  kernel/events/core.c                             | 72 +++++++++++++++++++++++-
>  kernel/events/internal.h                         |  1 +
>  tools/include/uapi/linux/perf_event.h            | 11 +++-
>  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 +
>  15 files changed, 255 insertions(+), 12 deletions(-)
> 
> 
> Regards
> Adrian