即時多媒體工作之省電協同排程

Energy Efficient Real-Time Co-Scheduling of Multimedia DSP Jobs

陳健偉(Chien-Wei Chen)

指導教授 ： 郭大維

國立臺灣大學/電機資訊學院/資訊工程學研究所/碩士(2007年)

https://doi.org/10.6342/NTU.2007.02216

摘要

一方面為了節省成本，一方面為了滿足多媒體應用的需求，DSP 現已廣泛被使用於嵌入式系統之中。然而，DSP 上即時工作省電排程的相關研究為數不多。針對一個 DSP 上的週期性工作，像是 H.264 的解壓縮工作，本篇論文提出了一組基於滑動視窗的線上排程演算法，產生一序列的排程時間點與相對應的處理器速度。演算法的效果經由實作與模擬兩種方式作為評估，最多可達到 45% 的能源節省，而線上預測執行時間造成時限超出的情形最多亦不會超過 4%。

關鍵字

省電排程 ； 即時工作排程 ； 即時系統 ； 動態電壓調整排程 ； 能源消耗最小化 ； 雙核系統

並列摘要

While DSP's are now widely adopted in many embedded systems in the cost minimization and the resolving of computing needs of various multimedia applications, little work is done for energy-efficient real-time job scheduling over DSP's. As motivated by the needs, a set of sliding-window-based algorithms are proposed. A sequence of time points and their corresponding processor speeds is generated to run jobs of a periodic task on the DSP, such as that for the decoding of an H.264 stream. An online competitive DVS scheme for energy minimization with constrained buffer size consideration is proposed, and the capability of the scheme is evaluated by a series of experiments over real and synthesized traces. It was shown that roughly 45% energy saving was possible for many cases, and prediction errors were not significant enough to result in more than 4% in deadline missing.

並列關鍵字

Energy-efficient scheduling ； Real-time task scheduling ； Real-time systemsDVS scheduling ； Energy consumption minimization ； Dual-core systems

參考文獻

[1] T. A. Alenawy and H. Aydin. Energy-aware task allocation for rate monotonic scheduling. In Proceedings of the 11th IEEE Real-time and Embedded Technology and Applications Symposium (RTAS’05), pages 213–223, 2005.

[2] H. Aydin, R. Melhem, D. Moss′e, and P. Mej′ıa-Alvarez. Determining optimal processor speeds for periodic real-time tasks with different power characteristics. In Proceedings of

the IEEE EuroMicro Conference on Real-Time Systems, pages 225–232, 2001.

[3] H. Aydin, R. Melhem, D. Moss′e, and P. Mej′ıa-Alvarez. Dynamic and aggressive scheduling techniques for power-aware real-time systems. In Proceedings of the 22nd IEEE Real-Time

Systems Symposium, pages 95–105, 2001.