Skip to main content

Multilevel queue Scheduling in operating system-computer world

 

Multilevel queue Scheduling in operating system


Multilevel queue Scheduling 

Multilevel queue Scheduling algorithms has been created for situation in which processes are easily classified into different groups. A common division is made between foreground processes and background processes. In this scheduling algorithm, process in the ready queue can be divided into different classes where each class has its own scheduling needs. In other word we can say that a multilevel queue scheduling algorithm partition the ready queue into several separate queue. The process are permanently assigned to one queue, generally based on some property of the process, such as memory size, process priority, or process type. Each queue it's own scheduling algorithm. For example, a common process division is a foreground process and background process. The foreground queue is scheduled by an RR algorithm, while the background queue is scheduled by an FCFS algorithm. The process scheduler is alternately select jobs from each queue and assign them to the CPU based on the algorithm assigned to the queue. 

Order of priority

  1. System process queue
  2. Interactive process queue
  3. Batch process queue 
  4. Each queue has absolute priority over lower-priority queues.


Comments

Post a Comment

Popular posts from this blog

Single partition allocation, Multiple-partition allocation and Fixed Equal-size partitions in operating system-computer world

  Single partition allocation, Multiple-partition allocation and Fixed Equal-size partitions in operating system Single partition allocation In this scheme operating system is residing in law memory and user process are executing in higher memory. Advantages It is simple  It is easy to understand and use Disadvantages User job is limited to the size of available memory. It leads to poor Utilization of processor and memory. Multiple-partition allocation  It is the simplest method for allocating  memory is divided memory into several fixed size partitions. Fixed Equal-size partitions It divides the main memory Into equal number of fixed sized partitions, operating system occupies some fixed portion and remaining portion of main memory is available for user processes. Advantages It supports multi programming. A process whose size is less then or equal to the partitions size can be loaded into any available partition. Disadvantages If a program is big to fit in...
Post a Comment
Read more

Memory in computer (primary, secondary and cache memory)-computer world

  Memory : A memory just like a human brain.It is used to store data and instructions. Computer memory is the storage space in the computer, where data is to be processed and instruction  required processing are stored. Computer memory is classified into following types : 1. Cache memory : Cache memory is a very high speed semiconductor memory which can speed up the CPU. It act as buffer(small storage are ) Between the CPU and main memory. We can say that it is a high speed memory between CPU and RAM and it is used temporary store very active data and instruction during processing.  2. Primary memory : Primary holds only that data and instruction on which the computer is currently working. Data holds by primary memory is lost when power is switched of. Primary is not fast as resisters. Primary is divided into two subcategory's : 1. RAM(Random access memory) : Random access memory is a form of computer memory that can be read and change in any any order typically ...
Post a Comment
Read more

Definition of computer cables and types of cables

Definition of computer cables and types of cables Definition  of computer cables : A cable is one or more wires which are covered in plastic that transmitter power or data between devices and computers. A cables is also known as cord, connector or plug. Data cables provides communication between devices for example DVD and HDMI, USB cables and Cat 5. A power cable is used for supply the power and electricity. Types of cables : There are many types of cables used in computer science some of them are given below : Coaxial cable Twisted cable Optical cable Coaxial cable :   It is consist of a central copper wire surrounded  by a copper mess.  Coaxial cables are used for transmitting data at high rate. Coaxial tables are used by telephone companies to transmit data because cables handle  up to 40000 telephone calls simultaneously. Coaxial  cables group of specially wrapped and insulated wires.   Twisted pair cab...
Post a Comment
Read more