Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1221959

Re: [PATCH 5/5] perf tools: Enhance parsing events tracepoint error output

Show all headers | View raw

On Mon, Sep 07, 2015 at 10:38:07AM +0200, Jiri Olsa wrote:
> Enhancing parsing events tracepoint error output. Adding
> more verbose output when the tracepoint is not found or
> the tracing event path cannot be access.
> 
>   $ sudo perf record -e sched:sched_krava ls
>   event syntax error: 'sched:sched_krava'
>                        \___ unknown tracepoint
> 
>   Error:  File /sys/kernel/debug/tracing//tracing/events/sched/sched_krava not found.
>   Hint:   Perhaps this kernel misses some CONFIG_ setting to enable this feature?.
> 
>   Run 'perf list' for a list of valid events
>   ...
> 
>   $ perf record -e sched:sched_krava ls
>   event syntax error: 'sched:sched_krava'
>                        \___ can't access trace events
> 
>   Error:  No permissions to read /sys/kernel/debug/tracing//tracing/events/sched/sched_krava
>   Hint:   Try 'sudo mount -o remount,mode=755 /sys/kernel/debug'

What about tracefs?  On my system, tracefs is mounted on
/sys/kernel/debug/tracing thus I cannot access trace events after
remounting debugfs with mode=755.

Also, IIRC tracepoint events adds PERF_SAMPLE_RAW bit automatically,
and it requires perf_event_paranoid being -1 for non-root user, right?

Thanks,
Namhyung
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Back to linux.kernel | Previous | Next — Next in thread | Find similar | Unroll thread

Thread

Re: [PATCH 5/5] perf tools: Enhance parsing events tracepoint error  output Namhyung Kim <namhyung@kernel.org> - 2015-09-10 09:10 +0200
  Re: [PATCH 5/5] perf tools: Enhance parsing events tracepoint error  output Jiri Olsa <jolsa@redhat.com> - 2015-09-10 10:10 +0200
    Re: [PATCH 5/5] perf tools: Enhance parsing events tracepoint error  output Namhyung Kim <namhyung@kernel.org> - 2015-09-11 18:20 +0200
      Re: [PATCH 5/5] perf tools: Enhance parsing events tracepoint error  output Jiri Olsa <jolsa@redhat.com> - 2015-09-11 18:20 +0200
        Re: [PATCH 5/5] perf tools: Enhance parsing events tracepoint error output Raphaël Beamonte <raphael.beamonte@gmail.com> - 2015-09-11 20:00 +0200
          Re: [PATCH 5/5] perf tools: Enhance parsing events tracepoint error  output Arnaldo Carvalho de Melo <acme@kernel.org> - 2015-09-11 21:00 +0200
            Re: [PATCH 5/5] perf tools: Enhance parsing events tracepoint error output Raphaël Beamonte <raphael.beamonte@gmail.com> - 2015-09-11 22:00 +0200
              Re: [PATCH 5/5] perf tools: Enhance parsing events tracepoint error  output Arnaldo Carvalho de Melo <arnaldo.melo@gmail.com> - 2015-09-11 22:30 +0200
                Re: [PATCH 5/5] perf tools: Enhance parsing events tracepoint error output Raphaël Beamonte <raphael.beamonte@gmail.com> - 2015-09-12 00:10 +0200
    Re: [PATCH 5/5] perf tools: Enhance parsing events tracepoint error  output Arnaldo Carvalho de Melo <acme@kernel.org> - 2015-09-14 23:00 +0200

csiph-web