scholarly journals Approximation Algorithms for Multiprocessor Energy-Efficient Scheduling of Periodic Real-Time Tasks with Uncertain Task Execution Time

Author(s):  
Jian-Jia Chen ◽  
Chuan-Yue Yang ◽  
Hsueh-I Lu ◽  
Tei-Wei Kuo
2014 ◽  
Vol 889-890 ◽  
pp. 1257-1261
Author(s):  
Yan Hong Bai ◽  
Cong Liu

RTWT (Real-Time Windows Target) and xPC Target are two developing environments based on Matlab/RTW for hardware-in-loop real-time simulation and rapid control prototype. Some error messages which lead to program stop often occur in their practical applications, such as CPU overload, buffer too small, and so on. In this paper, performance of the two simulation environments were studied by analyzing their working mechanism and conducting a lot of experiments, including signal data logging capability, sampling period and system stability. And the reasons which cause error running messages were analyzed. The following conclusions have been drawn. For RTWT data logging capability is not limited by buffer size because the data in buffer are saved to file in real-time during operating. While for xPC Target data logging capability is not limited by buffer size because the data in buffer are uploaded to the host computer and stored in file at the end of run. As long as the sampling period is slightly larger than the task execution time, xPC Target can run stably. RTWT can run stably only when the sampling period is far larger than the task execution time. The proposed conclusions can provide reference for selection between RTWT and xPC Target and their application.


Energies ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 4508
Author(s):  
Xin Li ◽  
Liangyuan Wang ◽  
Jemal H. Abawajy ◽  
Xiaolin Qin ◽  
Giovanni Pau ◽  
...  

Efficient big data analysis is critical to support applications or services in Internet of Things (IoT) system, especially for the time-intensive services. Hence, the data center may host heterogeneous big data analysis tasks for multiple IoT systems. It is a challenging problem since the data centers usually need to schedule a large number of periodic or online tasks in a short time. In this paper, we investigate the heterogeneous task scheduling problem to reduce the global task execution time, which is also an efficient method to reduce energy consumption for data centers. We establish the task execution for heterogeneous tasks respectively based on the data locality feature, which also indicate the relationship among the tasks, data blocks and servers. We propose a heterogeneous task scheduling algorithm with data migration. The core idea of the algorithm is to maximize the efficiency by comparing the cost between remote task execution and data migration, which could improve the data locality and reduce task execution time. We conduct extensive simulations and the experimental results show that our algorithm has better performance than the traditional methods, and data migration actually works to reduce th overall task execution time. The algorithm also shows acceptable fairness for the heterogeneous tasks.


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