Generation and Optimization of Real-Time Code for Embedded Multiprocess and Multiprocessor Systems

嵌入式多进程和多处理器系统实时代码的生成和优化

• 批准号: 200265263
• 负责人: Professor Dr. Heiko Falk
• 金额: --
• 依托单位: Institut für Eingebettete Systeme E-13
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2011
• 资助国家: 德国
• 起止时间: 2010-12-31 至 2017-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/200265263?language=en
• 关键词: Generation; Optimization; Real; Time; Code

Many embedded systems are safety-critical real-time systems that have to meet stringent deadlines. During the design of such systems, their behavior is specified at a high abstraction level. Compilers translate these specifications into executable implementations. For single-cores and single processes, compilers have recently been extended to support real-time properties during this translation. For multiprocess- and multiprocessor-systems, compilers currently lack such a support.In the course of this project, we have proposed a couple of novel analyses to bound the interference between several processes and processors. In preemptive multiprocess-systems, the runtime of preempted tasks can grow due to cache evictions by a preempting task. We thus have designed a novel cache analysis to estimate these additional cache misses. For multiprocessor-systems, we came up with an analysis of TDMA-based buses that precisely estimates the timing of accesses to shared memory by individual processors. Overall, the first unified Worst-Case Execution Time (WCET) analysis framework for TDMA-based multiprocessors has been published.Furthermore, first compiler optimizations to reduce interferences in multiprocess-/multiprocessor-systems have been proposed by us. A first technique eliminates cache-related interferences between tasks in mixed-criticality systems. A second combined optimization considers both scheduling and memory allocation in multiprocessor-systems with heterogeneous local and shared memories.The first phase of this project focused on the WCET of single components of an entire system. This is, however, unsatisfying since in particular Worst-Case Response Times (WCRTs) and schedulability of an entire system are not considered. This aspect thus is the focus of the second project phase. Our overall goal is to improve schedulability of combined multiprocess- and multiprocessor-systems using compiler optimizations. For this purpose, we first of all investigate a formal model allowing the WCRT-oriented analysis and optimization of multiprocess-/multiprocessor-systems at compiler level.On top of this model, novel WCRT-oriented optimizations will be developed which improve schedulability of an entire system under consideration of deadlines for individual tasks. These optimizations will first be developed individually for multiprocess- and multiprocessor-systems. After that, these individual optimizations will be extended towards combined, cooperative approaches. Under consideration of the whole systems's schedulability, Pareto-optimal solutions for combined multiprocess-/multiprocessor-systems shall be found.

许多嵌入式系统是必须按照严格的截止日期进行安全关键的实时系统。在此类系统的设计过程中，它们的行为在高抽象水平上指定。编译器将这些规格转换为可执行的实现。对于单核和单个过程，最近已经扩展了编译器以支持此翻译过程中的实时属性。对于多进程和多处理器系统，编译器目前缺乏这样的支持。在该项目的过程中，我们提出了一些新颖的分析，以绑定几个过程和处理器之间的干扰。在先发制人的多进程系统中，由于抢先任务的缓存驱逐，预先抢先任务的运行时间可能会增加。因此，我们设计了一种新颖的缓存分析，以估计这些其他缓存失误。对于多处理器系统，我们提出了对基于TDMA的总线的分析，该总线精确地估算了单个处理器对共享内存的访问时间。总体而言，已经发布了第一个基于TDMA的多处理器的统一最坏情况执行时间（WCET）分析框架。FURTHERMORE，我们提出了第一个减少多处理 - /多处理器系统干扰的编译器优化。第一种技术消除了混合批判性系统中任务之间的与缓存相关的干扰。第二个组合优化考虑了与多处理器系统中的调度和内存分配，具有异质的本地和共享记忆。该项目的第一阶段侧重于整个系统的单个组件的WCET。但是，这是不令人满意的，因为不考虑不考虑整个系统的最坏情况响应时间（WCRT）。因此，这方面是第二个项目阶段的重点。我们的总体目标是使用编译器优化提高组合多处理和多处理器系统的计划。为此，我们首先研究了一个正式的模型，允许以WCRT为导向的分析和优化编译器级别的多处理 - /多处理器系统。在该模型的顶部，将开发出新的面向WCRT的优化，从而提高了整个系统的计划。这些优化将首先针对多进程和多处理器系统单独开发。之后，这些个人优化将扩展到合并合作的方法。在考虑整个系统的可调度性方面，应找到用于组合多处理 - /多处理器系统的帕累托最佳解决方案。

项目成果

Cache-Aware Instruction SPM Allocation for Hard Real-Time Systems

• DOI: 10.1145/2906363.2906369
• 发表时间: 2016-05
• 期刊: Proceedings of the 19th International Workshop on Software and Compilers for Embedded Systems
• 作者: Arno Luppold;C. Kittsteiner;H. Falk

Practical Challenges of ILP-based SPM Allocation Optimizations

• DOI: 10.1145/2906363.2906371
• 发表时间: 2016-05
• 期刊: Proceedings of the 19th International Workshop on Software and Compilers for Embedded Systems
• 作者: Dominic Oehlert;Arno Luppold;H. Falk

Bus-Aware Static Instruction SPM Allocation for Multicore Hard Real-Time Systems

多核硬实时系统的总线感知静态指令 SPM 分配

• DOI: 10.4230/lipics.ecrts.2017.1
• 发表时间: 2017
• 作者: Dominic Oehlert;Arno Luppold;Heiko Falk
• 通讯作者: Heiko Falk

Code Optimization of Periodic Preemptive Hard Real-Time Multitasking Systems

周期性抢占式硬实时多任务系统的代码优化

• DOI: 10.1109/isorc.2015.8
• 发表时间: 2015
• 期刊: 2015 IEEE 18th International Symposium on Real-Time Distributed Computing
• 作者: Arno Luppold;Heiko Falk
• 通讯作者: Heiko Falk

Schedulability Aware WCET-Optimization of Periodic Preemptive Hard Real-Time Multitasking Systems

可调度性感知 WCET-周期性抢占式硬实时多任务系统的优化

• DOI: 10.1145/2764967.2771930
• 发表时间: 2015
• 期刊: Proceedings of the 18th International Workshop on Software and Compilers for Embedded Systems
• 作者: Arno Luppold;Heiko Falk
• 通讯作者: Heiko Falk