When does trashing occur in Operating System?

• Thrashing occurs when your system begins to devote more time to paging rather than computing. Thrashing causes serious performance issues.
• The operating system keeps track of CPU usage at all times. If the CPU is underutilised, the operating system increases the degree of multiprogramming by introducing more processes to the system. A global page replacement technique is currently in use.
• So, if the operating system adds new processes, this algorithm will swap in and out some pages. As a result, CPU consumption has increased. OS added new processes to the system in order to boost CPU utilisation. However, after a while, page faults begin to occur, lowering CPU utilisation. 
• The operating system creates extra processes, resulting in an increase in page faults and a fall in CPU utilisation.

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