本文選題：實(shí)時系統(tǒng) + 節(jié)能調(diào)度��； 參考：《國防科學(xué)技術(shù)大學(xué)》2012年博士論文

【摘要】：現(xiàn)實(shí)世界的實(shí)際需求促進(jìn)了實(shí)時系統(tǒng)的產(chǎn)生和發(fā)展，隨著電子技術(shù)和計算機(jī)技術(shù)的飛速發(fā)展，實(shí)時系統(tǒng)的應(yīng)用范圍也在不斷擴(kuò)大。這些領(lǐng)域的發(fā)展迫切需要提供性能更強(qiáng)大、操作更靈活、效能比更高的微處理器系統(tǒng)，以滿足實(shí)時應(yīng)用越來越復(fù)雜化、智能化的需求。 隨著VLSI技術(shù)的迅猛發(fā)展與應(yīng)用需求的不斷提高，芯片制造商正在推出多核芯片和片上多處理器系統(tǒng)，多核和多處理器平臺已經(jīng)變得更加普遍，受到了嵌入式實(shí)時領(lǐng)域越來越多的關(guān)注。但是，處理器的高性能會帶來高能耗。而能耗是很多嵌入式實(shí)時系統(tǒng)首要考慮的因素，特別是無線移動和便攜式計算設(shè)備。為了滿足嵌入式實(shí)時應(yīng)用的進(jìn)一步發(fā)展，節(jié)能實(shí)時調(diào)度技術(shù)研究已經(jīng)成為當(dāng)前學(xué)術(shù)和工業(yè)界共同關(guān)注的前沿領(lǐng)域和熱門課題之一，并且隨著“綠色計算”需求的提出，變得越來越重要。 本文針對多核/多處理器實(shí)時系統(tǒng)中的能耗問題，由多處理器系統(tǒng)到多核處理器系統(tǒng)，由偶發(fā)任務(wù)模型到一般任務(wù)模型，由理想DVFS處理器模型到實(shí)際DVFS處理器多維限制模型，從以下四個方面展開研究： 1.本文提出一種多處理器系統(tǒng)中偶發(fā)任務(wù)節(jié)能實(shí)時調(diào)度算法。從多處理器偶發(fā)任務(wù)在線節(jié)能實(shí)時調(diào)度問題出發(fā)，提出了基于偶發(fā)任務(wù)最優(yōu)實(shí)時調(diào)度LRE-TL的多處理器在線節(jié)能調(diào)度算法，通過LRE-TL與獨(dú)立DVFS和DPM技術(shù)相結(jié)合，，根據(jù)偶發(fā)任務(wù)動態(tài)釋放所導(dǎo)致負(fù)載不斷變化的情況，在每個TL面的初始時刻和偶發(fā)任務(wù)釋放時刻對所有活躍任務(wù)實(shí)現(xiàn)在線動態(tài)電壓和頻率調(diào)節(jié)。算法不僅可以保證偶發(fā)任務(wù)集的最優(yōu)可調(diào)度性，而且實(shí)驗(yàn)結(jié)果表明其始終優(yōu)于已有算法，尤其在在高負(fù)載情況下能耗節(jié)余達(dá)到30%。 2.本文提出多核系統(tǒng)中偶發(fā)任務(wù)在線節(jié)能實(shí)時調(diào)度算法。從偶發(fā)任務(wù)動態(tài)釋放問題出發(fā)，提出了一種基于TL流調(diào)度的多核在線節(jié)能實(shí)時調(diào)度算法TL-DVFS，利用LRE-TL算法實(shí)現(xiàn)任務(wù)調(diào)度，在每個TL面的初始時刻、偶發(fā)任務(wù)的釋放時刻進(jìn)行動態(tài)電壓頻率調(diào)節(jié)，能較好適應(yīng)因偶發(fā)任務(wù)的動態(tài)釋放而產(chǎn)生的動態(tài)負(fù)載變化。經(jīng)過系統(tǒng)的數(shù)學(xué)分析和仿真實(shí)驗(yàn)，結(jié)果表明TL-DVFS算法與現(xiàn)有方法相比，不僅保證了偶發(fā)任務(wù)集的最優(yōu)可調(diào)度性，而且實(shí)現(xiàn)了更多的能耗節(jié)余，尤其在高負(fù)載情況下節(jié)能效果更明顯。通過考慮任務(wù)實(shí)際執(zhí)行時間往往小于最壞情況執(zhí)行時間的情況，進(jìn)一步提出了一種基于動態(tài)松弛時間回收的節(jié)能實(shí)時調(diào)度算法DSREM，在每個TL面的提前完成時刻實(shí)現(xiàn)動態(tài)松弛時間回收，降低后續(xù)偶發(fā)任務(wù)的執(zhí)行頻率，實(shí)現(xiàn)更多的節(jié)能。實(shí)驗(yàn)結(jié)果表明，DSREM算法在任務(wù)集總負(fù)載超過某一個值之后，其節(jié)能效果始終優(yōu)于現(xiàn)有方法，尤其隨著總負(fù)載的增加，節(jié)能效果會更好。 3.本文提出一種基于Global EDF的多核系統(tǒng)一般任務(wù)在線節(jié)能實(shí)時調(diào)度算法。針對一般任務(wù)模型，提出了一種不基于先驗(yàn)知識，在同構(gòu)多核系統(tǒng)中基于GlobalEDF在線節(jié)能硬實(shí)時調(diào)度算法GEDF-OLEASA，通過引入速度調(diào)節(jié)因子，利用松弛時間，結(jié)合動態(tài)功耗管理和動態(tài)電壓/頻率調(diào)節(jié)技術(shù)，降低多核系統(tǒng)中任務(wù)的執(zhí)行速度，達(dá)到實(shí)時約束與能耗節(jié)余之間的合理折中。實(shí)驗(yàn)結(jié)果表明，該算法適用于不同類型的片上動態(tài)電壓/頻率調(diào)節(jié)技術(shù)，GEDF-OLEASA算法始終比GlobalEDF算法更節(jié)能，最多可節(jié)能15~20％，最少可節(jié)能5~10%。 4.本文提出一種開銷敏感的最優(yōu)節(jié)能實(shí)時調(diào)度算法。為解決原有最優(yōu)算法在實(shí)際開銷不可忽視條件下不再具有最優(yōu)性問題，提出開銷敏感的基于幀任務(wù)多處理器最優(yōu)節(jié)能實(shí)時調(diào)度算法。該算法根據(jù)關(guān)鍵速度來判斷系統(tǒng)負(fù)載情況，確定具有最低能耗值的活躍處理器個數(shù)，然后根據(jù)狀態(tài)切換開銷來確定最優(yōu)調(diào)度序列。該算法允許實(shí)時任務(wù)在任意處理器之間遷移，計算復(fù)雜度小，易于在實(shí)時操作系統(tǒng)中實(shí)現(xiàn)。系統(tǒng)的數(shù)學(xué)分析證明了該算法的最優(yōu)性。 本文通過對多處理器系統(tǒng)偶發(fā)任務(wù)模型、多核系統(tǒng)偶發(fā)任務(wù)模型、一般任務(wù)模型及實(shí)際處理器開銷模型的節(jié)能實(shí)時調(diào)度技術(shù)研究，對多核/多處理器實(shí)時系統(tǒng)的節(jié)能設(shè)計實(shí)現(xiàn)進(jìn)行了有益的探索。本文的理論分析、仿真實(shí)驗(yàn)和評價結(jié)果表明，上述節(jié)能實(shí)時調(diào)度技術(shù)是有效的，能夠有效解決多核/多處理器實(shí)時系統(tǒng)的能耗問題。
[Abstract]:Real world demand has promoted the production and development of real-time systems. With the rapid development of electronic technology and computer technology, the application scope of real-time systems is also expanding. The development of these fields is urgently needed to provide more powerful, more flexible, more efficient microprocessor systems to meet real-time applications. The more complex and intelligent the need.
With the rapid development of VLSI technology and the increasing demand for application, the chip manufacturers are introducing multi core chips and on chip multiprocessor systems. The multi-core and multiprocessor platforms have become more common. More and more attention has been paid to the embedded real-time field. However, the high performance of the processor will bring high energy consumption, and the energy consumption is much more. In order to meet the further development of embedded real-time applications, the research of real-time scheduling technology for energy saving has become one of the frontiers and hot topics of common concern in the academia and industry, and with the requirement of "green computing". Out, it's becoming more and more important.
In this paper, the problem of energy consumption in multi-core / multi processor real-time systems is studied from four aspects: from multi processor system to multi-core processor system, from the occasional task model to the general task model, from the ideal DVFS processor model to the actual DVFS processor multidimensional limit model.
1. this paper proposes an energy-efficient real-time scheduling algorithm for multi processor systems. Starting from the on-line energy-saving real-time scheduling problem of multi processor occasional tasks, a multi processor online energy saving scheduling algorithm based on the optimal real-time scheduling LRE-TL is proposed. By combining the LRE-TL with the independent DVFS and the DPM technology, this algorithm is based on the occasional task. In the case of the dynamic load changing, the dynamic voltage and frequency adjustment of all active tasks is realized at the initial time of each TL surface and the release time of the occasional task. The algorithm can not only guarantee the optimal schedulability of the occasional task set, but also the experimental results show that it is always superior to the existing algorithms, especially in the high negative. Energy savings reached 30%. under the load condition
2. this paper proposes a real-time scheduling algorithm for online energy saving in multi-core systems. Starting from the dynamic release of occasional missions, a multi-core online energy-saving real-time scheduling algorithm based on TL flow scheduling is proposed, which uses the LRE-TL algorithm to realize task scheduling. It is dynamic at the beginning of each TL plane and the release time of the occasional task. The voltage frequency regulation can better adapt to the dynamic load changes caused by the dynamic release of the occasional task. Through the system mathematical analysis and simulation experiments, the results show that the TL-DVFS algorithm not only guarantees the optimal schedulability of the occasional task set, but also has more energy savings, especially in the high load situation. The effect of energy saving is more obvious. By considering the fact that the actual execution time of the task is often less than the worst case execution time, a new energy saving real-time scheduling algorithm DSREM based on dynamic relaxation time recovery is proposed. The dynamic relaxation time recovery is realized at the time of advance completion of each TL surface, and the execution frequency of the subsequent incidental task is reduced. The experimental results show that, after the total load of the task set exceeds a certain value, the efficiency of the DSREM algorithm is always better than the existing method, especially with the increase of the total load, the efficiency of energy saving will be better.
3. this paper presents an online energy saving real-time scheduling algorithm for general task of multi-core systems based on Global EDF. For general task model, a hard real-time scheduling algorithm based on GlobalEDF online energy saving, without prior knowledge, is proposed in the isomorphic multi kernel system. By introducing the speed regulation factor, the relaxation time is used to combine the motion. State power management and dynamic voltage / frequency modulation techniques reduce the execution speed of tasks in multi-core systems and achieve a reasonable compromise between real time constraints and energy savings. The experimental results show that the algorithm is suitable for different types of on-chip dynamic voltage / frequency modulation techniques. The GEDF-OLEASA algorithm is always more energy-efficient than the GlobalEDF algorithm and is most available. Energy saving 15~20%, minimum energy saving 5~10%.
4. this paper proposes a cost sensitive and optimal energy saving real-time scheduling algorithm. In order to solve the problem that the original optimal algorithm no longer has the optimality problem under the condition that the actual cost can not be ignored, this algorithm proposes a cost sensitive real-time scheduling algorithm based on the frame task multi processor optimal energy saving. The number of active processors with the lowest energy consumption value, then the optimal scheduling sequence is determined according to the state switching overhead. The algorithm allows real-time tasks to migrate among any processors, the computational complexity is small, and it is easy to implement in the real-time operating system. The system's mathematical analysis proves the optimality of the algorithm.
In this paper, we study the multi processor system contingency model, the multi core system contingency model, the general task model and the real time processor cost model, and study the energy-saving real-time scheduling of the multi core / multi processor real-time system. The theoretical analysis, simulation experiment and evaluation result table of this paper are made. Obviously, the energy saving real-time scheduling technology is effective, and it can effectively solve the energy consumption problem of multi-core / multiprocessor real-time system.
【學(xué)位授予單位】：國防科學(xué)技術(shù)大學(xué)
【學(xué)位級別】：博士
【學(xué)位授予年份】：2012
【分類號】：TP332

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相關(guān)期刊論文 前3條

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本文編號：2076259