3 how a vm system uses main memory as a cache at any

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Unformatted text preview: works fairly well on a variety of machines. On lightly loaded processors, it consistently gets accurate results on most machines, even for computations with long durations. Only the newer version of Linux incurs a sufficiently high timer interrupt overhead to seriously affect the measurement accuracy. For this system, compensating for this overhead greatly improves the measurement accuracy. On heavily loaded machines, getting accurate measurements becomes difficult as execution times become longer. Most systems have some maximum execution time beyond which the measurement accuracy becomes very poor. The exact value of this threshold is highly system dependent, but typically ranges between 10 and 200 milliseconds. 9.5 Time-of-Day Measurements Our use of the IA32 cycle counter provides high-precision timing measurements, but it has the drawback that it only works on IA32 systems. It would be good to have a more portable solution. We have seen that the library functions times and clock are implemented using interval counters and hence are not very accurate. Another possibility is to use the libr...
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This note was uploaded on 09/02/2010 for the course ELECTRICAL 360 taught by Professor Schultz during the Spring '10 term at BYU.

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