Operating System Interview Question and Answers
|31.||Why thread is called as a lightweight process?|
|It is called light weight process to emphasize the fact that a thread is like a process but is more efficient and uses fewer resources( n hence “lighter”)and they also share the address space.|
|32.||What are operating system services?|
|33.||What is a process?|
|A program in execution is called a process. Or it may also be called a unit of work. A process needs some system resources as CPU time, memory, files, and i/o devices to accomplish the task. Each process is represented in the operating system by a process control block or task control block (PCB).Processes are of two types
Operating system processes
|34.||What are the different job scheduling in operating systems?|
|Scheduling is the activity of the deciding when process will receive the resources they request.
FCFS ---> FCSFS stands for First Come First Served. In FCFS the job that has been waiting the longest is served next.
Round Robin Scheduling--->Round Robin scheduling is a scheduling method where each process gets a small quantity of time to run and then it is preempted and the next process gets to run. This is called time-sharing and gives the effect of all the processes running at the same time
Shortest Job First ---> The Shortest job First scheduling algorithm is a nonpreemptive scheduling algorithm that chooses the job that will execute the shortest amount of time.
Priority Scheduling--->Priority scheduling is a scheduling method where at all times the highest priority process is assigned the resource.
|35.||What is dual-mode operation?|
|In order to protect the operating systems and the system programs from the malfunctioning programs the two mode operations were evolved