Final answer:
Interleaving prevents a long process from blocking other processes by allowing the CPU to switch to other tasks during I/O operations, maximizing CPU efficiency and fairness in processing time allocation.
Step-by-step explanation:
The CPU is switched to execute another process rather than remaining idle during I/O time. Interleaving also prevents a long process from blocking other processes. This technique is a part of CPU scheduling in operating systems, which allows for more efficient utilization of the CPU. When a process is executing an input/output (I/O) operation, it does not require the CPU, and thus the CPU can be used to carry out other tasks.
By switching the CPU to another process, the operating system maximizes CPU usage and avoids wasteful downtime. This is crucial for keeping the system responsive and efficient, especially in a multiuser or multitasking environment where multiple processes may need to run concurrently. Without interleaving, processes that perform lengthy computations could monopolize the CPU, causing significant delays for other processes. This mechanism ensures that all active processes receive a fair share of the CPU's time.