     35 pthread_cond_wait,end_thread
     20 read(libpthread.so.0),read(unistd.h:35)
     18 pthread_cond_wait,os_event_wait_low
      3 select(libc.so.6),os_thread_sleep
      3 pthread_cond_wait,MYSQL_LOG::wait_for_update
      1 select(libc.so.6),handle_connections_sockets
      1 do_sigwait(libpthread.so.0),sigwait(libpthread.so.0)
      1 btr_search_guess_on_hash,btr_cur_search_to_nth_level
      1 btr_cur_search_to_nth_level,btr_estimate_n_rows_in_range
