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.

许多嵌入式系统是安全关键的实时系统，必须满足严格的期限。在设计这样的系统时，它们的行为是在一个高抽象级别上指定的。编译器将这些规范转换为可执行的实现。对于单核和单进程，编译器最近已经扩展到在此转换期间支持实时属性。对于多进程和多处理器系统，编译器目前缺乏这样的支持。在这个项目的过程中，我们提出了一些新的分析，以约束多个进程和处理器之间的干扰。在抢占式多进程系统中，抢占任务的运行时间可能会由于抢占任务的缓存驱逐而增长。因此，我们设计了一种新的高速缓存分析，以估计这些额外的高速缓存未命中。对于多处理器系统，我们提出了一个基于TDMA的总线，精确地估计由各个处理器访问共享内存的时间分析。总体而言，第一个统一的最坏情况下的执行时间（WCET）的分析框架基于TDMA的多处理器已经出版。此外，第一编译优化，以减少干扰的多进程/多处理器系统已经提出了我们。第一种技术消除了混合关键度系统中任务之间的高速缓存相关干扰。第二个组合优化考虑调度和内存分配在多处理器系统与异构本地和共享memors.The第一阶段的项目集中在整个系统的单个组件的WCET。然而，这是不令人满意的，因为特别是最坏情况下的响应时间（WCRT）和整个系统的可扩展性没有被考虑。因此，这是项目第二阶段的重点。我们的总体目标是使用编译器优化来提高组合多进程和多处理器系统的可扩展性。为此，我们首先研究了一个形式化的模型，允许面向WCRT的多进程/多处理器系统的分析和优化在编译器级别上，在这个模型的顶部，新的面向WCRT的优化将开发提高可并行性的整个系统的最后期限下考虑个别任务。这些优化将首先针对多进程和多处理器系统单独开发。在此之后，这些单独的优化将扩展到组合，合作的方法。在考虑整个系统可并行性的前提下，寻求多进程/多处理机组合系统的帕累托最优解。

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