Messages in this thread | | | Date | Thu, 10 Sep 2015 16:00:30 +0900 | From | Namhyung Kim <> | Subject | Re: [PATCH 5/5] perf tools: Enhance parsing events tracepoint error output |
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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
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