Operating Systems: Concurrent and Distributed Software Design

5.9. Memory management in system design

Is memory management hardware always needed in a computer system? If the system is very small and simple and needs to be very cheap, such as a low-end handheld device, a memory management unit may not be justifiable; it consumes space on the CPU, power during its operation and memory space for its translation tables.

An alternative to hardware MMU systems is sometimes to use a safe language or execution environment such as the Java Virtual Machine to enforce protection between applications. Such systems rely on the type safety of the language in which an application is written to prevent it from achieving arbitrary access to system resources. We will see some examples of these systems in Chapter 26.

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