Data being used in real-timesystems must be up-to-date to produce correct results. the use of outdated data can have catastrophic consequences since calculated control signals are based on stale data. Two distinct me...
详细信息
ISBN:
(纸本)9780769529752
Data being used in real-timesystems must be up-to-date to produce correct results. the use of outdated data can have catastrophic consequences since calculated control signals are based on stale data. Two distinct methods to update data exist: (i) dedicated tasks (DT) update data items, and (ii) on-demand (OD) updating being a conditioned part of the execution flow of tasks. On-demand updating has not been studied in terms of CPU utilization analysis for real-timesystems. this paper studies on-demand updating in terms of (i) imposed workload and compares the workload to Deferrable Scheduling (DS), and (ii) analytical formula for estimating workload to be used in CPU utilization based schedulability tests. It is found that on-demand updating uses less workload for updates compared to DS, which suggests on-demand updating should be used for resource constrained systems. However, using on-demand updating makes the execution times of updates unpredictable, which currently gives two possibilities (i) be pessimistic and assume all updates always execute or (ii) be less pessimistic but estimate the times between executions of updates. this paper devises a formula for such estimates and compares their result to approach (i). Evaluations show the formula can be useful for soft real-timesystems.
the use of cloud computing in different application areas is growing fast. More and more functions are being moved into the cloud in order to take advantage of cloud computing strengths such as scalability, resources ...
详细信息
ISBN:
(纸本)9781479966493
the use of cloud computing in different application areas is growing fast. More and more functions are being moved into the cloud in order to take advantage of cloud computing strengths such as scalability, resources on demand, and usage based cost models. However, most types of embeddedsystems are still in an early phase of cloud adoption, with a few exceptions found in e.g., data storage and user interfaces. In this paper we present a number of challenges and opportunities when introducing cloud computing into embeddedsystems. In particular, we look at embeddedsystems with requirements on timing predictability, i.e., real-timesystems. In the paper we conclude that it is possible to move a complete soft real-time system into the cloud. Moreover we see an upcoming development in cloud computing to potentially allow for hard real-timesystems to be moved to the cloud.
We present a high performance logging system for embedded UNIX and GNU/Linux applications. Compared to the standard UNIX and GNU/Linux logging method, syslog, our method has two orders of magnitude lower latency and a...
详细信息
ISBN:
(纸本)9781479908516
We present a high performance logging system for embedded UNIX and GNU/Linux applications. Compared to the standard UNIX and GNU/Linux logging method, syslog, our method has two orders of magnitude lower latency and an order of magnitude higher message throughput. this speed-up is mainly due to the use of a memory-mapped file as the means of interprocess communication, fewer memory copies and the batching of output messages in the logging daemon. In addition, our logging system also accepts syslog messages, providing compatibility with existing applications. Our logging system is in production use in the Cisco UCS Virtual Interface Card.
Modern real-timeembeddedsystems have increasingly penetrated our daily life and are also often constrained in terms of temperature and energy. In this paper, a thesis is defended that from a real-timesystems perspe...
详细信息
ISBN:
(纸本)9781479908516
Modern real-timeembeddedsystems have increasingly penetrated our daily life and are also often constrained in terms of temperature and energy. In this paper, a thesis is defended that from a real-timesystems perspective, thermally constrained dynamic power management approaches behave very similar to idealised dynamic voltage and frequency scaling. Hence, existing dynamic voltage and frequency scaling solutions proposed for periodic/sporadic task models can be applied to thermally constrained dynamic power management systems with moderate effort. this work presents the similarities along withthe distinctive elements between two approaches. Within the case study, the porting of a dynamic voltage and frequency scaling algorithm of the literature to thermally constrained dynamic power management system is demonstrated.
Modern processors often provide cache locking capability which can be applied statically and dynamically to manage cache in a predictable manner. the selection of instructions to be locked in the instruction cache (I-...
详细信息
ISBN:
(纸本)9780769537870
Modern processors often provide cache locking capability which can be applied statically and dynamically to manage cache in a predictable manner. the selection of instructions to be locked in the instruction cache (I-Cache) has dramatic influence on the performance of multi-task real-timeembeddedsystems. this paper focuses on using cache locking techniques on a shared I-Cache in a real-timeembedded system with multi-tasks to minimize its worst-case utilization (WCU) which is one of the most important criteria for designing real-timeembeddedsystems. We analyze the static and dynamic strategies to perform I-Cache locking and propose different algorithms which utilize the foreknowing information of the real-timeembeddedapplications. Experiments show that the proposed algorithms can reduce WCU further compared to previous techniques. Design suggestions on which strategy should be utilized under different situations are also induced from the experimental results.
Doubling the number of processing cores on a single processor chip with each technology generation has become conventional wisdom. While future manycore processors promise to offer much increased computational through...
详细信息
ISBN:
(纸本)9780769529752
Doubling the number of processing cores on a single processor chip with each technology generation has become conventional wisdom. While future manycore processors promise to offer much increased computational throughput under a given power envelope, sharing critical on-chip resources, such as caches and coreto-core interconnects, poses challenges to guaranteeing predictable performance to an application program. this paper focuses on the problem of sharing on-chip caching capacity among multiple programs scheduled together, especially at the L2 cache level. Specifically, two design aspects of a large shared L2 cache are considered: (1) non-uniform cache access latency and (2) cache contention. We observe that boththe aspects have to do with where, among many cache slices, a cache block is mapped to, and present an OS-based approach to managing the on-chip L2 cache memory by carefully mapping data to a cache at the page granularity. We show that a reasonable extension to the OS memory management subsystem and simple architectural support enable enforcing high-level policies to achieve application performance isolation and improve program performance predictability thereof.
Due to increasing demand for reconfigurability in embeddedsystems, real-time task scheduling is challenged by non-negligible reconfiguration overheads. We introduce the problem of real-time task scheduling under reco...
详细信息
ISBN:
(纸本)9781467382991
Due to increasing demand for reconfigurability in embeddedsystems, real-time task scheduling is challenged by non-negligible reconfiguration overheads. We introduce the problem of real-time task scheduling under reconfiguration overhead on heterogeneous reconfigurable systems while considering the data dependencies and data communication overhead. We introduce a novel graph representation which captures the delay overhead due to data dependencies and reconfiguration. We formulate the problem as a network flow problem and provide a mixed integer linear programming solution to minimize the completion time so called makespan. Results show that our proposed scheduling improves the makespan by 24.20% (on average) in comparison with maximum-transition-overhead scheduling.
Increasing demand for performance and further integration promotes the use of multi-and many-core systems - also in safety-critical embeddedsystems. In this domain, hardware platforms obviously have to support real-t...
详细信息
ISBN:
(纸本)9781479908516
Increasing demand for performance and further integration promotes the use of multi-and many-core systems - also in safety-critical embeddedsystems. In this domain, hardware platforms obviously have to support real-time, predictability constrained applications such as an anti-lock braking system. However, the on-going trend to integrate multiple functions with different criticalities (mixed critical) on a single platform calls for a paradigm shift. Mixed-critical systems require special attention with respect to functional (access protection) and non-functional (performance) isolation. An additional layer of protection and guaranteed service on the underlying infrastructure enables the efficient adoption of such architectures in safety-critical domains. In this paper, we present the IDAMe, a many-core platform which provides mechanisms to integrate applications of different criticalities on a single platform.
Integrating a Learning Management System withembeddedcomputing involves considering the communication between web-based applications and the embeddedsystems. the study proposes a model for SmartQuiz and Dynamic das...
详细信息
ISBN:
(纸本)9798350387568;9798350387575
Integrating a Learning Management System withembeddedcomputing involves considering the communication between web-based applications and the embeddedsystems. the study proposes a model for SmartQuiz and Dynamic dashboard embedded component within a Learning Management System with Blazor components and Biometric Sensor Integration. the objective relies on creating advanced learning platform upon enhancement of the security, having user-friendly experience for learners and educators, as well as real-time analytics. the proposed platforms will optimize the assessment process and improve data accuracy for a more efficient educational ecosystem.
Machine learning has attracted a lot of interest in the last few years as a solution to a variety of difficult challenges in many disciplines. An emerging area is that of embedded devices, where machine learning is de...
详细信息
ISBN:
(纸本)9798350332865
Machine learning has attracted a lot of interest in the last few years as a solution to a variety of difficult challenges in many disciplines. An emerging area is that of embedded devices, where machine learning is deployed to efficiently carry out tasks like data analysis, prediction, and decision-making in real-timeapplications. Challenges such as the necessity for fast and effective algorithms and the restricted resources available in embeddedsystems to cover the computational and storage demands need to be confronted to successfully integrate machine learning models into embeddedsystems. this work aims to provide an overview of the use of machine learning in embeddedsystems, including past and current solutions, and to present the challenges that need to be addressed. Future directions for the use of machine learning in embeddedsystems are also discussed.
暂无评论