使用perf报告解释perf.data文件的输出

Question

我的C ++应用程序正在消耗大量CPU周期。因此，我已经使用了Linux Profiler对我的应用程序进行了调查

。 。

# To display the perf.data header info, please use --header/--header-only options.
#
#
# Total Lost Samples: 0
#
# Samples: 43K of event 'cpu-clock:uhH'
# Event count (approx.): 10966500000
#
# Overhead  Command          Shared Object              Symbol                                                                                                                                                                              
# ........  ...............  .........................  ....................................................................................................................................................................................
#

59.19%  ZManager  libc-2.23.so        [.] __mcount_internal
14.15%  ZManager  libc-2.23.so        [.] _mcount
 1.41%  ZManager  ZManager            [.] std::vector<unsigned int, std::allocator<unsigned int> >::~vector
 1.17%  ZManager  ZManager            [.] std::vector<unsigned int, std::allocator<unsigned int> >::size
 1.16%  ZManager  ZManager            [.] std::vector<unsigned int, std::allocator<unsigned int> >::vector
 0.46%  ZManager  ZManager            [.] std::_Vector_base<unsigned int, std::allocator<unsigned int> >::_Vector_impl::_Vector_impl
 0.45%  ZManager  ZManager            [.] std::__copy_move_a2<false, __gnu_cxx::__normal_iterator<unsigned int const*, std::vector<unsigned int, std::allocator<unsigned int> > >, unsigned int*>
 0.40%  ZManager  libpthread-2.23.so         [.] pthread_mutex_lock
 0.39%  ZManager  ZManager            [.] std::__miter_base<__gnu_cxx::__normal_iterator<unsigned int const*, std::vector<unsigned int, std::allocator<unsigned int> > > >
 0.38%  ZManager  libc-2.23.so               [.] _int_malloc
 0.36%  ZManager  ZManager            [.] std::__niter_base<__gnu_cxx::__normal_iterator<unsigned int const*, std::vector<unsigned int, std::allocator<unsigned int> > > >
 0.34%  ZManager  ZManager            [.] std::allocator<unsigned int>::allocator
 0.34%  ZManager  ZManager            [.] std::allocator<unsigned int>::~allocator

从上面可以明显看出，大多数CPU是由LIBC中的某些指令所消耗的（我的程序正在调用），

这显示出

59.19%  ZManager  libc-2.23.so        [.] __mcount_internal
14.15%  ZManager  libc-2.23.so        [.] _mcount

显示什么__ mcount_internal和_mcount方法？