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Unformatted text preview: 1 Operating System 1st Exam. for 2005 Fall Semester Date: 10-18-2006, Time: 09:10 a.m.- 10:40 a.m. Name: Student ID: Dept: There are 10 problems in this examination. The weights for each (sub)problem is indicated. Please do all of them. 1. [Basic Concepts] These are 10(a-j) true or false problems. If your answer is false please give the true statement with respect to the original false one. (a) (4%) [Introduction] Interrupt-driven I/O is fine for moving small amounts of data but can produce high overhead when used for bulk data movement such as disk I/O. To solve this problem, direct memory access (DMA) is used. After setting up buffers, pointers, and counters for the I/O device, the device controller transfers each small amount of data directly to or from its own buffer storage to memory, with intervention by the CPU. (b) (4%) [Introduction] The multiprogramming system in use today are two types: asymmetric multiprogramming (ASMP) and symmetric multiprogramming (SMP). In ASMP, a master processor controls the system; other processors either look to the master for instruction or have predefined tasks. On the other hand, SMP means that all proces- sors are peers; no master-slave relationship exists between processors. 2 (c) (4%) [System Structures] System calls provide an interface to the services made available by an operating system. The run-time support system (a set of functions built into libraries included with a compiler) for most programming languages provides a system-call interface that serves as the link to system calls made available by the operating sys- tem. The system-call interface intercepts function calls in the API and invokes the necessary system call within the operating system....
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