Question

Considering all the pieces of the operating system we have discussed, describe the steps the os takes when performing a context switch. assume that processes are waiting in the ready queue.

Answer 1

A context switch is a critical function of modern operating systems wherein the CPU transitions control between processes. It involves saving the state of the current process and restoring the state of the next process to be executed. The procedure ensures fair CPU time distribution and supports multi-tasking.

Step-by-step explanation:

Understanding the Context Switch Process in Operating Systems

When an operating system performs a context switch, it follows a series of steps to ensure the smooth transition of CPU control from one process to another. The process typically occurs when a running process needs to be switched out so another process can run. Here is an outline of the steps involved:

• The operating system signals a context switch, often because the executing process has reached the end of its time slice, is waiting for I/O, or a higher priority process needs to run.
• The current state of the processor, including program counter, registers, and other execution context, is saved into the process control block (PCB) of the current process.
• The PCB of the process to be switched to is loaded into the memory, restoring its execution context into the processor.
• The operating system updates the process state information in the process table to reflect the change.
• The CPU begins executing the new process, which now has control over the CPU.

This mechanism ensures that multiple processes receive CPU time appropriately, and is essential to the multi-tasking capabilities of modern operating systems.