Table-based QoS control for embedded real-time systems
Table-based QoS control for embedded real-time systems
复制标题
嵌入式实时系统基于表的 QoS 控制
DOI：
10.1145/314403.314448
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发表时间：
1999
期刊：
影响因子：
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通讯作者：
Tatsukawa Kosuke
中科院分区：
文献类型：
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作者：
Sugawara Tomoyoshi;Tatsukawa Kosuke
本文提出了一种适用于嵌入式实时系统的新QoS控制方案。我们的计划重点是实时系统，在这些系统中，设备控制和多媒体处理都需要处理。这样的系统需要保持控制任务的正时约束，同时为多媒体处理任务提供最高的服务质量（QOS）。尽管提出了许多QoS控制方案并用于分布式多媒体系统，但它们不适合此类实时系统。他们的QoS控制策略无法准确地保持控制任务的时序约束。为了克服此问题，我们选择了一个方案，该方案使用一个描述所有任务资源要求的表。可以从表中计算到系统中的任务和总资源利用率的资源分配。使用我们的计划，可以实施任何QoS控制策略，例如公平共享政策或基于优先级的策略。换句话说，首次有可能在QoS控制上直接反映系统设计人员的意图。我们已经根据我们提出的方案实施了CPU时间QoS控制机制，并在μ-Itron Ver上进行了评估。基于3.0的实时操作系统。评估结果表明，QoS控制方案可以在超载状态下保持截止日期的较低和CPU利用率。结果还表明，QoS控制机制的开销足够小，可以支持多媒体和控制应用。
This paper proposes a new QoS control scheme that is suited for embedded real-time systems. Our scheme focused on real-time systems where both device control and multimedia processing are required. Such systems needs to keep timing constraints of control tasks while providing the highest possible quality of service(QoS) to multimedia processing tasks. Although many QoS control schemes are proposed and used in distributed multimedia systems, they are not suited for such real-time systems. Their QoS control policies cannot exactly keep the timing constraints of control tasks.To overcome this problem we chose a scheme which uses a table describing resource requirements of all tasks. Resource allocations for tasks and total resource utilization in a system can be calculated from the table. Using our scheme, any QoS control policies, such as a fair-share policy or a priority based policy, can be implemented. In other words, it has become possible for the first time to allow the intention of system designers to be directly reflected on QoS control.We have implemented a CPU time QoS control mechanism based on our proposed scheme and evaluated it on a μ-ITRON Ver. 3.0 based real-time OS. The evaluation results demonstrate that the QoS control scheme can keep deadline misses low and CPU utilization high under an overloaded state. The results also show that overhead of the QoS control mechanism is small enough to support both multimedia and control applications.