2019 IEEE Real-Time Systems Symposium (RTSS)最新文献_第2页

Timely Fine-Grained Interference-Sensitive Run-Time Adaptation of Time-Triggered Schedules 时间触发调度的及时细粒度干扰敏感运行时自适应

2019 IEEE Real-Time Systems Symposium (RTSS) Pub Date : 2019-12-01 DOI: 10.1109/RTSS46320.2019.00030

Stefanos Skalistis, A. Kritikakou

{"title":"Timely Fine-Grained Interference-Sensitive Run-Time Adaptation of Time-Triggered Schedules","authors":"Stefanos Skalistis, A. Kritikakou","doi":"10.1109/RTSS46320.2019.00030","DOIUrl":"https://doi.org/10.1109/RTSS46320.2019.00030","url":null,"abstract":"In time-critical systems, run-time adaptation is required to improve the performance of time-triggered execution, derived based on Worst-Case Execution Time (WCET) of tasks. By improving performance, the systems can provide higher Quality-of-Service, in safety-critical systems, or execute other best-effort applications, in mixed-critical systems. To achieve this goal, we propose a parallel interference-sensitive run-time adaptation mechanism that enables a fine-grained synchronisation among cores. Since the run-time adaptation of offline solutions can potentially violate the timing guarantees, we present the Response-Time Analysis (RTA) of the proposed mechanism showing that the system execution is free of timing-anomalies. The RTA takes into account the timing behavior of the proposed mechanism and its associated WCET. To support our contribution, we evaluate the behavior and the scalability of the proposed approach for different application types and execution configurations on the 8-core Texas Instruments TMS320C6678 platform. The obtained results show significant performance improvement compared to state-of-the-art centralized approaches.","PeriodicalId":102892,"journal":{"name":"2019 IEEE Real-Time Systems Symposium (RTSS)","volume":"165 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122437224","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 10

Work-in-Progress: ARTIC: An Adaptive Real-Time Imprecise Computation Pipeline for Audio Analysis 正在进行的工作:ARTIC:音频分析的自适应实时不精确计算管道

2019 IEEE Real-Time Systems Symposium (RTSS) Pub Date : 2019-12-01 DOI: 10.1109/RTSS46320.2019.00071

Michael Yantosca, A. Cheng

{"title":"Work-in-Progress: ARTIC: An Adaptive Real-Time Imprecise Computation Pipeline for Audio Analysis","authors":"Michael Yantosca, A. Cheng","doi":"10.1109/RTSS46320.2019.00071","DOIUrl":"https://doi.org/10.1109/RTSS46320.2019.00071","url":null,"abstract":"One of the more complex issues facing natural language processing (NLP) is how to deal with overlapped speech, i.e., when two or more speakers interfere with or talk over each other, and the more general case of co-channel speech, i.e., when two or more speakers are present in an audio stream regardless of interference. Frequently, one speaker is selected as a primary speaker for the purpose of analysis with other speakers relegated to the category of interfering speakers. Despite the breadth of research into overlapped speech detection, few endeavors have been made into preserving the speech of so-called interfering speakers. A compelling case can be made for a more comprehensive analysis of co-channel speech in the fields of computational linguistics, accessibility automation, and entertainment, particularly under real-time constraints. Currently available open-source audio libraries, while technically capable of supporting such research endeavors, are cumbersome to work with. To this end, the work introduces the Adaptive Real-Time Imprecise Computation (ARTIC) pipeline for audio analysis, a simple but flexible approach to stream processing that tracks computation times and deadlines for the various pipeline stages and affords the user the ability to specify automatic precision reductions to avoid projected deadline misses as well as automatic precision increases to combat underutilization. A proof of concept is tested with the intent to build upon this groundwork for a more comprehensive project having the goal of multi-speaker interference detection and eventually speaker separation.","PeriodicalId":102892,"journal":{"name":"2019 IEEE Real-Time Systems Symposium (RTSS)","volume":"52 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117194202","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

K2: Work-Constraining Scheduling of NVMe-Attached Storage K2: nvme存储的工作约束调度

2019 IEEE Real-Time Systems Symposium (RTSS) Pub Date : 2019-12-01 DOI: 10.1109/RTSS46320.2019.00016

Till Miemietz, H. Weisbach, M. Roitzsch, Hermann Härtig

{"title":"K2: Work-Constraining Scheduling of NVMe-Attached Storage","authors":"Till Miemietz, H. Weisbach, M. Roitzsch, Hermann Härtig","doi":"10.1109/RTSS46320.2019.00016","DOIUrl":"https://doi.org/10.1109/RTSS46320.2019.00016","url":null,"abstract":"For data-driven cyber-physical systems, timely access to storage is an important building block of real-time guarantees. At the same time, storage technology undergoes continued technological advancements. The introduction of NVMe fundamentally changes the interface to the drive by exposing request parallelism available at the flash package level to the storage stack, allowing to extract higher throughput and lower latencies from the drive. The resulting architectural changes within the operating system render many historical designs and results obsolete, requiring a fresh look at the I/O scheduling landscape. In this paper, we conduct a comprehensive survey of the existing NVMe-compatible I/O schedulers in Linux regarding their suitability for real-time applications. We find all schedulers severely lacking in terms of performance isolation and tail latencies. Therefore, we propose K2, a new I/O scheduler specifically designed to reduce latency at the 99.9th percentile, while maintaining the throughput gains promised by NVMe. By limiting the length of NVMe device queues, K2 reduces read latencies up to 10x and write latencies up to 6.8x, while penalizing throughput for non-real-time background load by at most 2.7x.","PeriodicalId":102892,"journal":{"name":"2019 IEEE Real-Time Systems Symposium (RTSS)","volume":"174 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115791982","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 4

[Copyright notice] (版权)

2019 IEEE Real-Time Systems Symposium (RTSS) Pub Date : 2019-12-01 DOI: 10.1109/rtss46320.2019.00003

引用次数: 0

Work-in-Progress: Validation of Probabilistic Timing Models of a Periodic Task with Interference - A Case Study 正在进行的工作:具有干扰的周期性任务的概率时序模型的验证-一个案例研究

2019 IEEE Real-Time Systems Symposium (RTSS) Pub Date : 2019-12-01 DOI: 10.1109/RTSS46320.2019.00055

A. Friebe, A. Papadopoulos, T. Nolte

{"title":"Work-in-Progress: Validation of Probabilistic Timing Models of a Periodic Task with Interference - A Case Study","authors":"A. Friebe, A. Papadopoulos, T. Nolte","doi":"10.1109/RTSS46320.2019.00055","DOIUrl":"https://doi.org/10.1109/RTSS46320.2019.00055","url":null,"abstract":"Probabilistic timing analysis techniques have been proposed for real-time systems to remedy the problems that deterministic estimates of the task's Worst-Case Execution Time and Worst-Case Response-Time can be both intractable and overly pessimistic. Often, assumptions are made that a task's response time and execution time probability distributions are independent of the other tasks. This assumption may not hold in real systems. In this paper, we analyze the timing behavior of a simple periodic task on a Raspberry Pi model 3 running Arch Linux ARM. In particular, we observe and analyze the distributions of wake-up latencies and execution times for the sequential jobs released by a simple periodic task. We observe that the timing behavior of jobs is affected by release events during the job's execution time, and of other processes running in between subsequent jobs of the periodic task. Using a data consistency approach we investigate whether it is reasonable to model the timing distribution of jobs affected by release events and intermediate processes as translations of the empirical timing distribution of non-affected jobs. According to the analysis, this paper shows that a translated distribution model of non-affected jobs is invalid for the execution time distribution of jobs affected by intermediate processes. Regarding the wake-up latency distribution with intermediate processes, a translated distribution model is improbable, but cannot be completely ruled out.","PeriodicalId":102892,"journal":{"name":"2019 IEEE Real-Time Systems Symposium (RTSS)","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129274730","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

Work-in-Progress: Real-Time Reactors in C 正在进行的工作:C语言中的实时反应器

2019 IEEE Real-Time Systems Symposium (RTSS) Pub Date : 2019-12-01 DOI: 10.1109/RTSS46320.2019.00067

Marten Lohstroh, Edward A. Lee

引用次数: 1

An Efficient Utilization-Based Test for Scheduling Hard Real-Time Sporadic DAG Task Systems on Multiprocessors 基于高效利用率的多处理器硬实时零散DAG任务系统调度测试

2019 IEEE Real-Time Systems Symposium (RTSS) Pub Date : 2019-12-01 DOI: 10.1109/RTSS46320.2019.00026

Zheng Dong, Cong Liu

{"title":"An Efficient Utilization-Based Test for Scheduling Hard Real-Time Sporadic DAG Task Systems on Multiprocessors","authors":"Zheng Dong, Cong Liu","doi":"10.1109/RTSS46320.2019.00026","DOIUrl":"https://doi.org/10.1109/RTSS46320.2019.00026","url":null,"abstract":"The scheduling and schedulability analysis of real-time directed acyclic graph (DAG) task systems have received much recent attention. The DAG model can accurately represent intra-task parallelism and precedence constraints existing in many application domains. Existing techniques show that analyzing the DAG model is fundamentally more challenging compared to the ordinary sporadic task model, due to the complex intra-DAG precedence constraints which may cause rather pessimistic schedulability loss. However, such increased loss is counter-intuitive because the DAG structure shall better exploit the hardware parallelism provided by the multiprocessor platform. Our key observation is that the intra-DAG precedence constraints, if not carefully considered by the scheduling algorithm, may cause unpredictable execution behaviors of sub-tasks in a DAG and thus pessimistic analysis. In this paper, we present a set of novel scheduling and analysis techniques for better supporting hard real-time sporadic DAG tasks on multiprocessors, through smartly defining and analyzing the execution order of subtasks in each DAG. Combined with a new DAG-specific interval analysis framework, the proposed subtask ordering technique leads to a highly efficient utilization-based schedulability test. Importantly, the developed test becomes identical to the classical density test designed for the sporadic task model, if each DAG in the system has an out-degree of one (i.e., only containing a chain of subtasks). Experiments show the efficiency of the developed test, which improves schedulability upon existing utilization-based tests by over 60% on average and is often able to guarantee schedulability with little utilization loss.","PeriodicalId":102892,"journal":{"name":"2019 IEEE Real-Time Systems Symposium (RTSS)","volume":"102 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122237119","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 5

Optimal Scheduling for Active Cell Balancing 主动单元均衡的最优调度

2019 IEEE Real-Time Systems Symposium (RTSS) Pub Date : 2019-12-01 DOI: 10.1109/RTSS46320.2019.00021

Debayan Roy, Swaminathan Narayanaswamy, Alma Pröbstl, S. Chakraborty

{"title":"Optimal Scheduling for Active Cell Balancing","authors":"Debayan Roy, Swaminathan Narayanaswamy, Alma Pröbstl, S. Chakraborty","doi":"10.1109/RTSS46320.2019.00021","DOIUrl":"https://doi.org/10.1109/RTSS46320.2019.00021","url":null,"abstract":"Active cell balancing is performed to minimize the variation in the charge levels of the individual cells in a high-power battery pack, to improve its usable capacity. The process of charge equalization is carried out by scheduling pairs of cells to transfer charge over a hardware circuit. Improving the time for charge equalization has been studied in the power electronics and the electronic design automation domains. However, these approaches have focused on the electronics issues and used heuristics to determine the charge transfer schedule. Hence, no optimality results on charge equalization times are known. We, for the first time, take a real-time systems approach and propose an optimal scheduling framework for active cell balancing. The proposed framework employs a hybrid optimization technique consisting of two sequential stages. In the first stage, we solve a mixed-integer linear programming problem to identify the time-optimal set of charge transfers required to achieve charge equalization. In the second stage, we construct a conflict graph based on the obtained charge transfers, to which we apply the minimum vertex coloring algorithm to synthesize the minimum length schedule. Results show that our proposed framework can reduce the charge equalization time by more than 50% (e.g., from 11 h to 5h). Hence, this has real benefits, e.g., in the context of charging electric vehicles. While task and message scheduling problems have been extensively studied in the real-time systems literature, the scheduling problem we study here, has not been addressed before.","PeriodicalId":102892,"journal":{"name":"2019 IEEE Real-Time Systems Symposium (RTSS)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116836341","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Work-in-Progress: Combining Two Security Methods to Detect Versatile Integrity Attacks in Cyber-Physical Systems 研究进展:结合两种安全方法检测网络物理系统中多种完整性攻击

2019 IEEE Real-Time Systems Symposium (RTSS) Pub Date : 2019-12-01 DOI: 10.1109/RTSS46320.2019.00073

Victor M. Lopez Rodriguez, A. Cheng, B. Doan

引用次数: 3

Work-in-Progress: Leveraging the Selfless Driving Model to Reduce Vehicular Network Congestion 研究进展:利用无私驾驶模式减少车辆网络拥塞

2019 IEEE Real-Time Systems Symposium (RTSS) Pub Date : 2019-12-01 DOI: 10.1109/RTSS46320.2019.00061

Guangli Dai, Pavan Kumar Paluri, T. Carmichael, A. Cheng, R. Miikkulainen

{"title":"Work-in-Progress: Leveraging the Selfless Driving Model to Reduce Vehicular Network Congestion","authors":"Guangli Dai, Pavan Kumar Paluri, T. Carmichael, A. Cheng, R. Miikkulainen","doi":"10.1109/RTSS46320.2019.00061","DOIUrl":"https://doi.org/10.1109/RTSS46320.2019.00061","url":null,"abstract":"With increasing traffic in urban areas, it is crucial to examine strategies to reduce traffic network congestion. Popular navigation policies currently tend to select the fastest path available for each vehicle. However, a top-down approach to navigation, which considers the traffic network as a whole, offers several speedup possibilities. Minimizing the average travel time of all vehicles in the network with respect to their separate travel deadlines improves traffic throughput. Because such a strategy does not guarantee an optimal navigation route for individual vehicles, we refer to it as a \"selfless\" policy and based on this observation we propose the Selfless Traffic Routing (STR) model. Hence, we propose a test bed based on Simulation of Urban MObility (SUMO) that can evaluate the performance of a traffic routing policy based on the average travel time of all vehicle agents in a given traffic grid. Continuously calculating optimal actions for multiple agents in real-time is computationally complex. We therefore introduce a value-based reinforcement learning strategy to achieve the benefits offered by a selfless traffic routing model. We explore how this approach can potentially achieve an optimal balance between action quality and the real-time performance of each decision.","PeriodicalId":102892,"journal":{"name":"2019 IEEE Real-Time Systems Symposium (RTSS)","volume":"40 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126518780","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2