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 majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
