Advantages And Disadvantages Of Multiprocessing

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Multiprocessing, in computing, a mode of operation in which two or more processors in a computer simultaneously process two or more different portions of the same program (set of instructions). Multiprocessing is typically carried out by two or more microprocessors, each of which is in effect a central processing unit (CPU) on a single tiny chip. Supercomputers typically combine thousands of such microprocessors to interpret and execute instructions.

The primary advantage of a multiprocessor computer is speed, and thus the ability to manage larger amounts of information. Because each processor in such a system is assigned to perform a specific function, it can perform its task, pass the instruction set on to the next processor, and begin working on a new set of instructions. For example, different processors may be used to manage memory storage, data communications, or arithmetic functions. Or a larger processor might utilize “slave” processors to conduct miscellaneous housekeeping duties, such as memory management.

A program running on any of the CPUs sees a normal (usually paged) virtual address space. The only unusual property this system has is that the CPU can write some value into a memory word and then read the word back and get a different value (because another CPU has changed it). When organized correctly, this property forms the basis of interprocessor communication: one CPU writes some data into memory and another one reads the data out. For the most part, multiprocessor operating systems are just regular operating systems. They handle system calls, do memory management, provide a file system, and manage I/O devices. Nevertheless, there are some areas in which they have unique features. These include process synchronization, resource management, and