perf test: Add a basic offcpu profiling test

  $ sudo ./perf test -v offcpu
   88: perf record offcpu profiling tests                              :
  --- start ---
  test child forked, pid 685966
  Basic off-cpu test
  Basic off-cpu test [Success]
  test child finished with 0
  ---- end ----
  perf record offcpu profiling tests: Ok

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
1 file changed