3055q9ds - hardware directly? Explain exactly it works? The...

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Score:_______ Name:______________________________ ECE 3055 Quiz 9 - March 30, 2005 1. The ___ medium term scheduler _______ (see page 111) _______ in an Operating System may decide to reduce the degree of multiprogramming. 2. A compute bound process is running on a system with a large number of other processes. In which state would you expect it to spend most of it’s time. Why? It would spend most of its time in the ready state waiting for it’s turn to run since there are a large number of other processes running. 3. How can multiprogramming improve the utilization of a computer system even in a system with only one CPU? While a process is waiting on I/O another process can run. 4. In a modern multiprogramming OS, what would stop a program that attempts to access I/O
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Unformatted text preview: hardware directly? Explain exactly it works? The program would attempt to execute a privileged I/O instruction while the mode bit is set to user mode. This generates an error interrupt on the user program and does not even execute the I/O instruction. 5. For API calls to the OS, describe the two major approaches that can be used to physically support message exchanges between processes. (in terms of memory mapping and message buffers and not the identity of the processes or messages involved) Shared memory – the processes have a message buffer in a shared global data area Message Passing – the OS copies the message from the sending process and passes it to the receiving process. (See page 74 and chapter 3 slides)...
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This note was uploaded on 11/10/2009 for the course ECE 3055 taught by Professor Staff during the Fall '08 term at Georgia Institute of Technology.

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