• J
    tools lib api fs: Store tracing mountpoint for better error message · dc240c5d
    Jiri Olsa 提交于
    Storing the actual tracing path mountpoint to display correct
    error message hint ('Hint:' line). The error hint rediscovers
    mountpoints, but it could be different from what we actually
    used in tracing path.
    
    Before we'd display debugfs mount even though tracefs was used:
      $ 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/events/sched/sched_krava
      Hint:   Try 'sudo mount -o remount,mode=755 /sys/kernel/debug'
      ...
    
    After this change, correct mountpoint is displayed:
      $ 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/events/sched/sched_krava
      Hint:   Try 'sudo mount -o remount,mode=755 /sys/kernel/debug/tracing'
      ...
    Signed-off-by: NJiri Olsa <jolsa@kernel.org>
    Cc: David Ahern <dsahern@gmail.com>
    Cc: Matt Fleming <matt@codeblueprint.co.uk>
    Cc: Namhyung Kim <namhyung@kernel.org>
    Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
    Cc: Raphael Beamonte <raphael.beamonte@gmail.com>
    Link: http://lkml.kernel.org/r/1442674027-19427-1-git-send-email-jolsa@kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
    dc240c5d
tracing_path.c 2.9 KB