perf evlist: Handle -EINVAL for sample_freq > max_sample_rate in strerror_open()
authorArnaldo Carvalho de Melo <acme@redhat.com>
Thu, 18 Feb 2016 16:34:09 +0000 (13:34 -0300)
committerArnaldo Carvalho de Melo <acme@redhat.com>
Fri, 19 Feb 2016 22:12:42 +0000 (19:12 -0300)
commitd9aade7fd27a604bbffd363e6a68416ef51bab88
treeceb9bc0f19f42307604df6fcde5927eccf39d4af
parent85723885feb823b4fc352b727ece0b6d00306c4d
perf evlist: Handle -EINVAL for sample_freq > max_sample_rate in strerror_open()

When running the "code reading" test we get:

  # perf test -v "code reading" 2>&1 | tail -5
  Parsing event 'cycles:u'
  perf_evlist__open failed
  test child finished with -1
  ---- end ----
  Test object code reading: FAILED!
  #

And with -vv we get the errno value, -22, i.e. -EINVAL, but we can do
better and handle the case at hand, with this patch it becomes:

  # perf test -v "code reading" 2>&1 | tail -7
  perf_evlist__open() failed!
  Error: Invalid argument.
  Hint:  Check /proc/sys/kernel/perf_event_max_sample_rate.
  Hint:  The current value is 1000 and 4000 is being requested.
  test child finished with -1
  ---- end ----
  Test object code reading: FAILED!
  #

Next patch will make this 'perf test' entry to use perf_evlist__strerror()

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Steven Noonan <steven@uplinklabs.net>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-i31ai6kfefn75eapejjokfhc@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
tools/perf/util/evlist.c