perf record: Propagate exit status of a command line workload

perf record: Propagate exit status of a command line workload

Currently perf record doesn't propagate the exit status of a workload
given by the command line.  But sometimes it'd useful if it's
propagated so that a monitoring script can handle errors
appropriately.

To do that, it moves most of logic out of the exit handlers and run
them directly in the __cmd_record().  The only thing needs to be done
in the handler is propagating terminating signal so that the shell can
terminate its loop properly when Ctrl-C was pressed.  Also it cleaned
up the resource management code in record__exit().

With this change, perf record returns the child exit status in case of
normal termination and send signal to itself when terminated by signal.

Example run of Stephane's case:

  $ perf record true && echo yes || echo no
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.013 MB perf.data (~589 samples) ]
  yes

  $ perf record false && echo yes || echo no
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.013 MB perf.data (~589 samples) ]
  no

Jiri's case (error in parent):

  $ perf record -m 10G true && echo yes || echo no
  rounding mmap pages size to 17179869184 bytes (4194304 pages)
  failed to mmap with 12 (Cannot allocate memory)
  no

  $ ulimit -n 6
  $ perf record sleep 1 && echo yes || echo no
  failed to create 'go' pipe: Too many open files
  Couldn't run the workload!
  no

And Peter's case (interrupted by signal):

  $ while :; do perf record sleep 1; done
  ^C[ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.014 MB perf.data (~593 samples) ]

Reported-by: Stephane Eranian <eranian@google.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Stephane Eranian <eranian@google.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Ingo Molnar <mingo@kernel.org>
Link: http://lkml.kernel.org/r/1399855645-25815-1-git-send-email-namhyung@kernel.org
Signed-off-by: Jiri Olsa <jolsa@kernel.org>