[RFC 0/6] perf tools: Add perf_evlist errno

[Jiri Olsa]

hi,
Andi reported wrong error message for :S modifier
on kernel without event ID ioctl support.

The reason was that the ioctl failed, but the error was
printed like the mmap would:

    $ perf.old record -e '{cycles,cache-misses}:S' ls
    failed to mmap with 25 (Inappropriate ioctl for device)
    ls: Terminated

I experimentally added sort of 'libc errno' interface for
perf_evlist to be able to get proper error message, like:

    $ perf record -e '{cycles,cache-misses}:S' ls
    Cannot read event group on this kernel.
    Please consider kernel update (v3.12+).
    ls: Terminated

I'm not sure about this approach. Maybe it'd be better be more
global..? So before throwing this out, sending it as RFC ;-)

thanks for ideas,
jirka

Signed-off-by: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Corey Ashford <cjashfor@xxxxxxxxxxxxxxxxxx>
Cc: Frederic Weisbecker <fweisbec@xxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Paul Mackerras <paulus@xxxxxxxxx>
Cc: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Cc: David Ahern <dsahern@xxxxxxxxx>
Cc: Andi Kleen <andi@xxxxxxxxxxxxxx>
---
Jiri Olsa (6):
      perf tools: Add perf_evlist error string interface
      perf tools: Add PERF_EVLIST__ERRNO_MMAP internal error
      perf tools: Add PERF_EVLIST__ERRNO_OPEN internal error
      perf tools: Add PERF_EVLIST__ERRNO_IOCTL_ID_GROUP internal error
      perf tools: Add PERF_EVLIST__ERRNO_NEWTP internal error
      perf tools: Use perf_evlist__strerror in kvm/record/top/trace commands

 tools/perf/builtin-kvm.c    |   2 +-
 tools/perf/builtin-record.c |  13 +------
 tools/perf/builtin-top.c    |   3 +-
 tools/perf/builtin-trace.c  |  34 ++++++++---------
 tools/perf/util/evlist.c    | 205 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++---------------------------------
 tools/perf/util/evlist.h    |  23 +++++++++++-
 6 files changed, 181 insertions(+), 99 deletions(-)
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