Generation and Optimization of Real-Time Code for Embedded Multiprocess and Multiprocessor Systems (E = Mp2)

Fact Sheet

AcronymE = Mp2
NameGeneration and Optimization of Real-Time Code for Embedded Multiprocess and Multiprocessor Systems
(in German: Generierung und Optimierung von Echtzeitfähigem Code für Eingebettete Multiprozess- und Multiprozessor-Systeme)
Role of TUHHApplicant
Start Date01/02/2012
End Date30/09/2017
Funds DonorDeutsche Forschungsgemeinschaft (DFG)


During the design of safety-critical real-time systems like, e.g., airbag or flight attitude controllers, their behavior is specified at a high abstraction level. Compilers are an indispensible tool on the way from such a model-based specification to an actual implementation. For singlecore and singleprocess systems, compilers have recently been extended to support real-time properties already during compilation. For multiprocess and multiprocessor systems, compilers currently lack such a support despite of the increasing relevance of such parallel systems.

E = Mp2 aims to provide a software development environment for multiprocess and multiprocessor systems which produces efficient and optimized program code that provably meets real-time constraints. For this purpose, it has to be clarified how compiler and scheduler of an operating system need to cooperate. In addition, novel timing models supporting response times of processes and schedulability of entire systems need to be developed. Based on these timing models, novel compiler optimizations targeting on worst-case timing aspects and schedulability are designed.

In multiprocess systems, tasks can preempt each other and thus interfere. E = Mp2 develops compiler optimizations considering such context switches and scheduling strategies. In multiprocessor systems, different cores can access shared resources (e.g., buses or memories) at the same time and thus can cause additional interference. Therefore, this project works on compiler optimizations minimizing the worst-case timing of such systems by considering accesses to shared resources.

E = Mp2 Publications of the Embedded Systems Design Group

Title: Real-Time Task Scheduling on Island-Based Multi-Core Platforms.
Written by: Che-Wei Chang, Jian-Jia Chen, Tei-Wei Kuo and Heiko Falk
in: <em>IEEE Transactions on Parallel and Distributed Systems (TPDS)</em>. February (2015).
Volume: <strong>26</strong>. Number: (2),
on pages: 538-550
Publisher: IEEE:
ISBN: 10.1109/TPDS.2013.2297308
how published: 15-90 CCK+15 TPDS

Note: hfalk, ESD, emp2, tacle

Abstract: With the increasing number of cores in a computing system, how to coordinate the computing units and heterogeneous memory resources has soon become extremely critical for real-time systems. This paper explores the joint considerations of memory management and real-time task scheduling over island-based multi-core architecture, where the local memory module of an island offers shorter access time than the global memory module does. The objective of this work is to minimize the number of needed islands to successfully schedule real-time tasks. When the required amount of the local memory space is specified for each task, a scheduling algorithm is proposed to provide an asymptotic 29/9-approximation bound. When there is flexibility in determining the needed local memory space for each task, we propose an algorithm with an asymptotic 4-approximation bound to jointly manage memory resources and allocate computing cores. In addition to the worst-case approximation analysis, the proposed algorithms are also evaluated with 82 real-life benchmarks with the support of a worst-case execution time analyzer. Moreover, extensive evaluations are conducted to show the capability of the proposed approaches when being used with various computing cores and memory resources.