[root@sandy ~]# perf record -e task-clock:u -a usleep 1
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.482 MB perf.data (~21073 samples) ]
  [root@sandy ~]#

Before:

  [root@sandy ~]# perf evlist
  task-clock
  [root@sandy ~]#

After:

  [root@sandy ~]# perf evlist
  task-clock:u
  [root@sandy ~]#

Ditto for other tools.

Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-97ltkmj7v23kyhflltf6iz5n@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>