مقدمه. ۴

معیارهای کارایی.. ۴

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معیارهای کارایی.. ۶

محاسبه چهار معیار کارایی مطرح شده. ۷

بهینه کردن معیار های کارایی مطرح شده. ۹

ارزیابی های تجربی.. ۹

نتیجه گیری.. ۹

ویژگی های . ۱۰

ادامه کار. ۱۰

Performance Optimization Based on

Analytical Modeling in a Real-Time System

with Constrained Time/Utility Functions

Performance Optimization Based onAnalytical Modeling in a Real-Time Systemwith Constrained Time/Utility Functions

Abstract— We consider a single-processor firm real-time (FRT) system with exponential inter-arrival and execution times for jobs with relative deadlines following a general distribution. The scheduling policy of the system is first-come first-served (FCFS) and the capacity of the system is arbitrary. This system is subject to an arbitrary shaped time/utility function (TUF) which determines the accrued utility of each job according to its completion time. It is considered that the system power consumption at different working states is predetermined for each processor speed. We have proposed an exact analytical method for the calculation of specific performance and power-related measures of the system. The resulting analytical formulations for the performance measures which are functions of the processor speed and system capacity are then optimized through appropriate selection of the former parameter using derivatives and the latter parameter employing numerical search methods. Some experimental results are presented for different unimodal TUFs in systems with deterministic and exponential relative deadlines. For the latter distribution, the results are compared against similar results obtained through simulation for the non-preemptive earliest-deadline-first (NP-EDF) scheduling policy. The comparisons show that FCFS is superior to NP-EDF for some measures and TUFs.