A process of comparing the actual performance of a machine with the intended performance, and the adjusting the machine to reduce and eventually eliminate the difference between the actual and intended performance is called（） A: open loop control B: feedback C: combining control D: integral proce

What does the FREQ column show when running the tprof option? （） A: Total amount of Ticks used by all users B: Total amount of Ticks used by all processes C: Total amount of Ticks used by a specific user D: Total amount of Ticks used by a specific type of proce