Result: Scheduling and Energy Savings for Small Scale Embedded FreeRTOS-based Real-Time Systems

Title:
Scheduling and Energy Savings for Small Scale Embedded FreeRTOS-based Real-Time Systems
Authors:
Gessé Oliveira, George Lima
Source:
Design Automation for Embedded Systems. 27:3-29
Publisher Information:
Research Square Platform LLC, 2022.
Publication Year:
2022
Subject Terms:
Dynamic priority scheduling, 0102 computer and information sciences, 02 engineering and technology, Fixed-priority pre-emptive scheduling, Multiprocessor Scheduling, 01 natural sciences, Hard Real-Time Systems, Parallel Computing and Performance Optimization, FOS: Mathematics, 0202 electrical engineering, electronic engineering, information engineering, Embedded system, Biology, Real-time operating system, Ecology, Performance Optimization, Rate-monotonic scheduling, Real-Time Scheduling in Embedded Systems, Mathematical optimization, Earliest deadline first scheduling, Reconfigurable Computing Systems and Design Methods, Computer science, Distributed computing, Programming language, Energy consumption, Fair-share scheduling, Operating system, Schedule, Hardware and Architecture, Implementation, FOS: Biological sciences, Computer Science, Physical Sciences, Embedded Systems, Scheduling Algorithms, Scheduling (production processes), Mathematics
Document Type:
Academic journal Article<br />Other literature type
ISSN:
1572-8080
0929-5585
DOI:
10.21203/rs.3.rs-1906556/v1
DOI:
10.1007/s10617-023-09267-7
DOI:
10.60692/7xwhs-h5k35
DOI:
10.60692/yg8rz-w3w57
Rights:
CC BY
Springer Nature TDM
Accession Number:
edsair.doi.dedup.....42c33a10a9d7606d0cc140f466a957a6
Database:
OpenAIRE

Further Information

Evaluating the effectiveness of system scheduling and energy savings in embedded real-time systems with low computing resources is the problem addressed in this paper. In such systems, the characteristics of the implemented scheduling policy play a relevant role in both schedulability and energy consumption. Ideally, the scheduling policy should provide higher schedulability bounds and low runtime overheads, allowing for better usage of available slack in the schedule for energy saving purposes. Due its low overhead and simple implementation, the usual scheduling policy employed in real-time embedded systems is based on fixed priority (FPS). Under this scheme, as the priority of all system tasks are assigned at design time, a simple priority vector suffices to indicate the current ready task to run. System schedulability, however, is usually lower than that provided by dynamic priority schedulers (DPS) according to which task priorities are assigned at runtime. Managing dynamic priority queues incurs higher overheads, though. Deciding whether DPS is a possible choice for such embedded requires careful evaluation. We evaluate two implementations of Earliest-Deadline First (EDF), a classical DPS, implemented in FreeRTOS running on an ARM-M4 architecture. EDF is compared against an optimal FPS, namely Rate-Monotonic scheduling (RMS). Further, two mechanisms for energy savings are described. They differ by the manner they compute the slack available in an EDF schedule, statically (SS-EDF) or dynamically (DS-EDF). These two approaches are experimentally evaluated. Results indicate that EDF can be effectively used for energy savings.