![]() On processors with cycle times of 5 nano-seconds, There are a variety of problems that need to be addressed in order toĪccurately measure time intervals on various processors under various InĪddition, mhz is written in portable ANSI/C that can beĬompiled into an unknown sequence of instructions of unknown length. To measure the duration of a few instructions accurately. There are several problems with this simpleĪpproach, such as the lack of standard clocks with enough resolution Time the execution of a short number of instructions and divide by the Lmbench’s guiding philosophy can be describedĪs "accuracy, speed, portability, and simplicity." Each ofĪt first glance, determining the processor clock speed seems simple Used to develop the new timing methodologies for lmbench 2.0. Is part of the lmbench suite of micro-benchmarks and was On any specific compiler, operating system, or processor. It is used throughout lmbench 2.0Īnd can be used to measure the performance of other applications.Ĭlock speed in a platform independent fashion, which does not depend The system clock, and measures and accounts for both loop overhead and The benchmark to minimize run time while preserving accuracy,ĭetermines the necessary timing duration to get accurate results from Mhz utilizes lmbench 2.0 's new timing harness, which ![]() Mhz, much of the intellectual effort went into the design ofĮxpressions that minimize the opportunities for compiler and hardware ![]() Surprising effects on the experimental results. Unfortunately, repetitionĮnables many hardware and compiler optimizations that can have To minimize the loop overhead theĮxpression is repeated a hundred times. To run the benchmark long enough for timing to be accurate, mhzĮxecutes each expression in a loop. The performance tradeoffs of various optimization techniques. For example, a platform-independentĭatabase system optimizer may use the clock speed while calculating In large installations it is often easier toĮxperimentally determine the clock speed of a given machine than to Mhz can be used by anyone who wants or needs to know the processorĬlock speed. Greatest common divisor to determine the duration of a single Time of several different C expressions and finds the Mhz is a portable ANSI/C program that determines the processorĬlock speed in a platform independent way.
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