Skip to main content

CPU scheduling in operating system-computer world

  CPU scheduling in operating system

CPU scheduling :

 Whenever the CPU becomes idle, the operating system must select one of the processes. The selection process is carried by the short-term scheduler. The scheduler selects a process from the processes in memory that that are ready to execute and allocate the CPU to that process. The objective of time sharing is to skip the CPU among processes that user interact with each program while the program is in running position. As we discuss above the process scheduler selects an process for execution on the CPU. There will never more then one running process for a single processor system. If there are many processes, the process will have to wait until the CPU is free CPU Scheduling is basis of multi-programming operating system. In CPU scheduling many processes are kept in memory at a time. The CPU scheduler select a process from the many processes. The process scheduler scheduled different processes to be assigned to the CPU based on particular scheduling algorithm which we are going to discuss 
  1. First come, first served (FCFS)
  2. Shortest job first (SJF)
  3. Priority scheduling 
In complex operating system there are three types of schedulers 
Long term scheduler
  1. It is a job scheduler and it's speed is lesser then term scheduler.
  2. Short-term schedule. 
  3. It a CPU scheduler and it's speed is fastest among other two scheduler.
  4. Medium-term scheduler 
  5. It is a process swapping scheduler and it's speed is in between both short & long term scheduler.



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

Aggregation and Functional dependency in DBMS-computer world

  Aggregation and  Functional dependency in  DBMS Aggregation  In aggregation the relation between two entities is treated as a single entity. In aggregation relationship with its corresponding entity is aggregated into higher level entity . It is the process of compiling information on object, there by obstructing a higher level. On limitation of the ER model is that it can not Express relationship among relationships. The aggregation represent a relationship between a whole object and its component in other word we can say that using aggregation we can express relationship main relationships.  For example center entity offer the course entity act as a single entity in the relationship which is in a relationship with another entity visitor. In the real world if a visitor visits a coaching center they will never inquiry about the course or just about the center instead he will ask the inquiry about both. Functional dependency  Functional dependency play an ...
Post a Comment
Read more

Difference between HTML and DHTML-computer world

     Difference between HTML and DHTML  HTML is a markup language, while DHTML is a collection of Technology.  DHTML creates dynamic web page, whereas HTML create static web page.  DHTML allow including small animations and dynamic menus in web pages but HTML is not able to do so.   HTML used events, methods, properties to insulate dynamism in HTML pages.   HTML is used to describe the web page but DHTML is a collection of JavaScript and style sheet in an HTML page. HTML sites will be show upon client side Technologies, while  DHTML site will be fast enough upon client side Technologies as most of entries are checked on browser itself and not waste time rendering to server for mistake.  HTML creates a plain web page without any style and scripts called as HTML. Whereas,  DHTML creates a page with HTML, CSS,DOM And scripts called as DHTML.  HTML cannot any server side code but XHTML may contain server side code.  ...
Post a Comment
Read more