this paper presents a partially-automated solution for the definition of test oracles for validating Simulink models. Since these models are widely used for the design of embeddedsystems, their thorough validation is...
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ISBN:
(纸本)9781479908516
this paper presents a partially-automated solution for the definition of test oracles for validating Simulink models. Since these models are widely used for the design of embeddedsystems, their thorough validation is key. Errors and misunderstandings in these models may preclude the correctness and reliability of the final system: a manual, human-intensive validation activity is not enough, and automated solutions are fundamental to improve the current state of the art. the paper also presents Apolom, a prototype oracle generator, and the results of two experiments.
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...
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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...
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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.
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...
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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.
Processor partitioning and hierarchical scheduling have been widely used for composing hard real-timesystems on a shared hardware platform while preserving the timing requirements of the systems. Due to the safety cr...
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ISBN:
(纸本)9781479908509
Processor partitioning and hierarchical scheduling have been widely used for composing hard real-timesystems on a shared hardware platform while preserving the timing requirements of the systems. Due to the safety critical nature of hard real-timesystems, a conservative analysis is often used for deriving a sufficient partition size. Applying the exact same analysis for deriving the partition sizes for soft real-timesystems result in unnecessary processors overallocation and consequently waste of the CPU resource. In this paper, to address the problem of composing soft and hard real-timesystems on a resource constrained shared hardware, we present a multi-level adaptive hierarchical scheduling framework. In our framework, we adapt the processor partition sizes of soft real-timesystems according to their need at each time point by on-line monitoring their processor demand. Furthermore, we implement our adaptive framework in the Linux kernel and show the performance of our framework using a case study.
the Elastic Mixed-Criticality (E-MC) task model and an Early-Release EDF (ER-EDF) scheduling algorithm have been studied to address the service interruption problem for low-criticality tasks in uniprocessor systems. I...
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ISBN:
(纸本)9781479908509
the Elastic Mixed-Criticality (E-MC) task model and an Early-Release EDF (ER-EDF) scheduling algorithm have been studied to address the service interruption problem for low-criticality tasks in uniprocessor systems. In this paper, focusing on multicore systems, we first investigate the schedulability of E-MC tasks under partitioned-EDF (P-EDF) by considering various task-to-core mapping heuristics. then, with and without task migrations being considered, we study both global and local early-release schemes. Compared to the state-of-the-art Global EDF-VD scheduler, the superior performance of the proposed schemes in terms of improving the service levels of low-criticality tasks is confirmed through extensive simulations.
Withthe prevalence of virtualization technology, virtual machine networks (VMN) have been widely used in host network applications. To provide fault tolerance and non-stop features to network applications and preserv...
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ISBN:
(纸本)9781479961245
Withthe prevalence of virtualization technology, virtual machine networks (VMN) have been widely used in host network applications. To provide fault tolerance and non-stop features to network applications and preserve the network consistency among virtual machines (VM), the distributed snapshot technique of virtual machine networks regains the attention of academia. While existing approaches still suffer from long service interruption and performance degradation when taking snapshots. Especially the TCP back off problem, which is due to the inconsistence of the snapshot completion time among VMs, may lead to network packet loss and even crash the connections among virtual machines. In this paper, we present Sync Snap, a system that takes live distributed memory snapshots of virtual machine networks synchronously with only milliseconds of downtime and ensure all the VMs complete snapshots at almost the same time. An adaptive single-VM snapshot approach is proposed to accurately control the snapshot duration through dynamically adjusting the snapshot speed. Furthermore, a synchronization mechanism is designed to ensure that a global consistency state of VMN can be reached by controlling snapshot duration of each VM. We have implemented SyncSnap on QEMU/KVM and performed several experiments to evaluate its effectiveness and efficiency. the experimental results demonstrate that our approach can control the VM snapshot duration to a given value with only tens of milliseconds deviation and reduce TCP back off duration to hundreds milliseconds.
the proceedings contain 68 papers. the topics discussed include: reducing preemptions and migrations in real-time multiprocessor scheduling algorithms by releasing the fairness;mode transition for online scheduling of...
ISBN:
(纸本)9780769545028
the proceedings contain 68 papers. the topics discussed include: reducing preemptions and migrations in real-time multiprocessor scheduling algorithms by releasing the fairness;mode transition for online scheduling of adaptive real-timesystems on multiprocessors;utilization-controlled task consolidation for power optimization in multi-core real-timesystems;a reliability enhancement mechanism for high-assurance MLC flash-based storage systems;limiting worst-case end-to-end latency when traffic increases in a switched avionics network;design and implementation of on-chip adaptive router with predictor for regional congestion;HW resource componentizing for addressing the mega-complexity of cyber-physical systems;Virtual Lock: a smartphone application for personal surveillance using camera sensor networks;dynamic activation timing configuration for product line development;and stabilization of projected image for wearable walking support system using Pico-projector.
Phase change memory (PCM) has emerged as a promising candidate to replace DRAM in embeddedsystems. However, it can only sustain a limited number of write operations. To solve this issue, this paper proposes a novel a...
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ISBN:
(纸本)9781479908509
Phase change memory (PCM) has emerged as a promising candidate to replace DRAM in embeddedsystems. However, it can only sustain a limited number of write operations. To solve this issue, this paper proposes a novel and effective wear-leveling technique in software level to prolong the lifetime of PCM-based embeddedsystems. A polynomialtime algorithm, Multi-Space Wear Leveling Algorithm (MWL), is proposed to achieve effective wear-leveling. the experimental results show our technique can greatly extend the lifetime of PCM-based embeddedsystems compared withthe previous work. Compared withthe method without adopting wear-leveling, it introduces no more than 0.7% extra writes and 0.6% running overhead.
In modern embedded platforms, safety-critical functionalities that must be certified correct to very high levels of assurance may co-exist with less critical software that are not subject to certification requirements...
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ISBN:
(纸本)9781479908516
In modern embedded platforms, safety-critical functionalities that must be certified correct to very high levels of assurance may co-exist with less critical software that are not subject to certification requirements. One seeks to satisfy two, sometimes contradictory, goals upon such mixed-criticality platforms: (i) certify the safety-critical functionalities under very conservative assumptions, and (ii) achieve high resource utilization during run-time, when actual behavior does not live up to the pessimistic assumptions under which certification was made. this paper describes efforts at designing fixed-priority scheduling algorithms that balance these two requirements, when scheduling recurrent tasks that are triggered by external events of unknown exact frequency.
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