Browse Definitions :
Definition

context switch

Contributor(s): Stan Gibilisco

A context switch is a procedure that a computer's CPU (central processing unit) follows to change from one task (or process) to another while ensuring that the tasks do not conflict. Effective context switching is critical if a computer is to provide user-friendly multitasking.

In a CPU, the term "context" refers to the data in the registers and program counter at a specific moment in time. A register holds the current CPU instruction. A program counter, also known as an instruction address register, is a small amount of fast memory that holds the address of the instruction to be executed immediately after the current one.

A context switch can be performed entirely in hardware (physical media). Older CPUs, such as those in the x86 series, do it that way. However, most modern CPUs perform context switches by means of software (programming). A modern CPU can perform hundreds of context switches per second. Therefore, the user gets the impression that the computer is performing multiple tasks in a parallel fashion, when the CPU actually alternates or rotates between or among the tasks at a high rate of speed.

 

Continue reading about context switching:

OSDev.org offers a concise explanation of how context switching works.

This was last updated in April 2012

Start the conversation

Send me notifications when other members comment.

Please create a username to comment.

-ADS BY GOOGLE

File Extensions and File Formats

SearchCompliance

  • Whistleblower Protection Act

    The Whistleblower Protection Act of 1989 is a law that protects federal government employees in the United States from ...

  • smart contract

    A smart contract, also known as a cryptocontract, is a computer program that directly controls the transfer of digital currencies...

  • risk map (risk heat map)

    A risk map, also known as a risk heat map, is a data visualization tool for communicating specific risks an organization faces. A...

SearchSecurity

  • challenge-response authentication

    In information security, challenge-response authentication is a type of authentication protocol where one entity presents a ...

  • Secure Shell (SSH)

    SSH, also known as Secure Shell or Secure Socket Shell, is a network protocol that gives users, particularly system ...

  • honeypot (computing)

    A honeypot is a network-attached system set up as a decoy to lure cyberattackers and to detect, deflect or study hacking attempts...

SearchHealthIT

SearchDisasterRecovery

  • virtual disaster recovery

    Virtual disaster recovery is a type of DR that typically involves replication and allows a user to fail over to virtualized ...

  • tabletop exercise (TTX)

    A tabletop exercise (TTX) is a disaster preparedness activity that takes participants through the process of dealing with a ...

  • risk mitigation

    Risk mitigation is a strategy to prepare for and lessen the effects of threats faced by a data center.

SearchStorage

  • exbibyte (EiB)

    An exbibyte (EiB) is a unit used to measure data capacity.

  • zebibyte (ZiB)

    A zebibyte (ZiB) is a unit used to measure computing and storage capacity.

  • tiered storage

    Tiered storage is a way to assign different categories of data to various types of storage media with the objective of reducing ...

Close