2022 IEEE Real-Time Systems Symposium (RTSS)最新文献_第2页

Multi-mode on Multi-core: Making the best of both worlds with Omni 多核多模式:利用Omni实现两全其美

2022 IEEE Real-Time Systems Symposium (RTSS) Pub Date : 2022-12-01 DOI: 10.1109/RTSS55097.2022.00020

Robert Gifford, L. T. Phan

{"title":"Multi-mode on Multi-core: Making the best of both worlds with Omni","authors":"Robert Gifford, L. T. Phan","doi":"10.1109/RTSS55097.2022.00020","DOIUrl":"https://doi.org/10.1109/RTSS55097.2022.00020","url":null,"abstract":"When scheduling multi-mode real-time systems on multi-core platforms, a key question is how to dynamically adjust shared resources, such as cache and memory bandwidth, when resource demands change, without jeopardizing schedulability during mode changes. This paper presents Omni, a first end-to-end solution to this problem. Omni consists of a novel multi-mode resource allocation algorithm and a resource-aware schedulability test that supports general mode-change semantics as well as dynamic cache and bandwidth resource allocation. Omni's resource allocation leverages the platform's concurrency and the diversity of the tasks' demands to minimize overload during mode transitions; it does so by intelligently co-distributing tasks and resources across cores. Omni's schedulability test ensures predictable mode transitions, and it takes into account mode-change effects on the resource demands on different cores, so as to best match their dynamic needs using the available resources. We have implemented a prototype of Omni, and we have evaluated it using randomly generated multi-mode systems with several real-world benchmarks as the workload. Our results show that Omni has low overhead, and that it is substantially more effective in improving schedulability than the state of the art.","PeriodicalId":202402,"journal":{"name":"2022 IEEE Real-Time Systems Symposium (RTSS)","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126981489","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

Making Powerful Enemies on NVIDIA GPUs 在NVIDIA gpu上制造强大的敌人

2022 IEEE Real-Time Systems Symposium (RTSS) Pub Date : 2022-12-01 DOI: 10.1109/RTSS55097.2022.00040

Tyler Yandrofski, Jingyuan Chen, Nathan Otterness, James H. Anderson, F. D. Smith

{"title":"Making Powerful Enemies on NVIDIA GPUs","authors":"Tyler Yandrofski, Jingyuan Chen, Nathan Otterness, James H. Anderson, F. D. Smith","doi":"10.1109/RTSS55097.2022.00040","DOIUrl":"https://doi.org/10.1109/RTSS55097.2022.00040","url":null,"abstract":"Graphics Processing Units (GPUs) are widely used in safety-critical real-time systems such as autonomous vehicles due to their high performance on artificial intelligence (AI) work-loads. As the computing power of recent GPUs keeps growing, it becomes increasingly possible to allow multiple independent programs to access the GPU concurrently. This complicates timing analysis, as contention for shared GPU resources renders execution times less predictable and worst-case execution times (WCETs) difficult to estimate. This paper provides a method for producing enemy programs that intentionally contend for GPU resources in order to enable more confident measurement-based WCET estimations. This paper provides an experiment-driven method to design effective enemy programs for several different interference channels—specific shared resources within the GPU through which concurrent computations may impact others' execution times. The method is flexible and can be applied to different GPU sharing mechanisms. The enemies are evaluated against a large number of real GPU applications, and the results indicate that these enemies cause higher slowdowns for GPU tasks than other baseline resource-stressing methods.","PeriodicalId":202402,"journal":{"name":"2022 IEEE Real-Time Systems Symposium (RTSS)","volume":"213 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117315376","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

Analytical Approximations in Probabilistic Analysis of Real-Time Systems 实时系统概率分析中的解析近似

2022 IEEE Real-Time Systems Symposium (RTSS) Pub Date : 2022-12-01 DOI: 10.1109/RTSS55097.2022.00023

Filip Marković, T. Nolte, A. Papadopoulos

{"title":"Analytical Approximations in Probabilistic Analysis of Real-Time Systems","authors":"Filip Marković, T. Nolte, A. Papadopoulos","doi":"10.1109/RTSS55097.2022.00023","DOIUrl":"https://doi.org/10.1109/RTSS55097.2022.00023","url":null,"abstract":"Probabilistic timing and schedulability analysis of real-time systems is constrained by the problem of often intractable exact computations. The intractability problem is present whenever there is a large number of entities to be analysed, e.g., jobs, tasks, etc. In the last few years, the analytical approximations for deadline-miss probability emerged as an important solution in the above problem domain. In this paper, we explore analytical solutions for two major problems that are present in the probabilistic analysis of real-time systems. First, for a safe approximation of the entire probability distributions (e.g., of the accumulated execution workloads) we show how the Berry-Esseen theorem can be used. Second, we propose an approximation built on the Berry-Esseen theorem for efficient computation of the quantile functions of probability execution distributions. We also show the asymptotic bounds on the execution distribution of the fixed-priority preemptive tasks. In the evaluation, we investigate the complexity and accuracy of the proposed methods as the number of analysed jobs and tasks increases. The methods are compared with the circular convolution approach. We also investigate the memory footprint comparison between the proposed Berry-Esseen-based solutions and the circular convolution.. The contributions and results presented in this paper complement the state-of-the-art in accurate and efficient probabilistic analysis of real-time systems.","PeriodicalId":202402,"journal":{"name":"2022 IEEE Real-Time Systems Symposium (RTSS)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128920487","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

CAESAR: Coherence-Aided Elective and Seamless Alternative Routing via on-chip FPGA CAESAR:基于片上FPGA的相干辅助选择和无缝替代路由

2022 IEEE Real-Time Systems Symposium (RTSS) Pub Date : 2022-12-01 DOI: 10.1109/RTSS55097.2022.00038

Shahin Roozkhosh, Denis Hoornaert, R. Mancuso

{"title":"CAESAR: Coherence-Aided Elective and Seamless Alternative Routing via on-chip FPGA","authors":"Shahin Roozkhosh, Denis Hoornaert, R. Mancuso","doi":"10.1109/RTSS55097.2022.00038","DOIUrl":"https://doi.org/10.1109/RTSS55097.2022.00038","url":null,"abstract":"Prompted by the ever-growing demand for high-performance System-on-Chip (SoC) and the plateauing of CPU frequencies, the SoC design landscape is shifting. In a quest to offer programmable specialization, the adoption of tightly-coupled FPGAs co-located with traditional compute clusters has been embraced by major vendors. This $mathbf{CPU}+mathbf{FPGA}$ architectural paradigm opens the door to novel hardware/software co-design opportunities. The key principle is that CPU-originated memory traffic can be re-routed through the FPGA for analysis and management purposes. Albeit promising, the side-effect of this approach is that time-critical operations—such as cache-line refills—are fulfilled by moving data over slower interconnects meant for I/O traffic. In this article, we introduce a novel principle named Cache Coherence Backstabbing to precisely tackle these shortcomings. The technique leverages the ability to include the FGPA in the same coherence domain as the core processing elements. Importantly, this enables Coherence-Aided Elective and Seamless Alternative Routing (CAESAR), i.e., seamless inspection and routing of memory transactions, especially cache-line refills, through the FPGA. CAESAR allows the definition of new memory programming paradigms. We discuss the intrinsic potentials of the approach and evaluate it with a full-stack prototype implementation on a commercial platform. Our experiments show an improvement of up to 29% in read bandwidth, 23% in latency, and 13% in pragmatic workloads over the state of the art. Furthermore, we showcase the first in-coherence-domain run-time profiler design as a use-case of the CAESAR approach.","PeriodicalId":202402,"journal":{"name":"2022 IEEE Real-Time Systems Symposium (RTSS)","volume":"67 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126910778","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: 3

Response Time Analysis for Prioritized DAG Task with Mutually Exclusive Vertices 具有互斥顶点的优先DAG任务响应时间分析

2022 IEEE Real-Time Systems Symposium (RTSS) Pub Date : 2022-12-01 DOI: 10.1109/RTSS55097.2022.00046

Ran Bi, Qingqiang He, Jinghao Sun, Zhenyu Sun, Zhishan Guo, Nan Guan, Guozhen Tan

{"title":"Response Time Analysis for Prioritized DAG Task with Mutually Exclusive Vertices","authors":"Ran Bi, Qingqiang He, Jinghao Sun, Zhenyu Sun, Zhishan Guo, Nan Guan, Guozhen Tan","doi":"10.1109/RTSS55097.2022.00046","DOIUrl":"https://doi.org/10.1109/RTSS55097.2022.00046","url":null,"abstract":"Directed acyclic graph (DAG) becomes a popular model for modern real-time embedded software. It is really a challenge to bound the worst-case response time (WCRT) of DAG task. Parallelism, dependencies and mutual exclusion become three of the most critical properties of real-time parallel tasks. Recent work applied prioritizing techniques to reduce DAG task's WCRT bound, which has well studied the first two properties, i.e., parallelism and dependencies, but leaves the mutually exclusive property as an open problem. This paper focuses on all the three properties of real-time parallel software, and investigates how to estimate the WCRT of the DAG task model with mutually exclusive vertices and under prioritized list scheduling algorithms. We derive a reasonable WCRT bound for such a complicated DAG task, and prove that the corresponding WCRT bound computation problem is strongly NP-hard. It means that there are no pseudo-polynomial time algorithms to compute the WCRT bound. For the prioritized DAG with a constant number of mutual exclusive vertices, we develop a dynamic programming algorithm that is able to estimate the WCRT bound within pseudo-polynomial time. Experiments are conducted to evaluate the performance of our analysis method implemented with different priority assignment policies against the state-of-the-art.","PeriodicalId":202402,"journal":{"name":"2022 IEEE Real-Time Systems Symposium (RTSS)","volume":"59 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127451717","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

Work-in-Progress: Real-Time On-board Processing for Cloud Detection in FACSAT-2 Multispectral Satellite Imagery 正在进行的工作:FACSAT-2多光谱卫星图像中云检测的实时机载处理

2022 IEEE Real-Time Systems Symposium (RTSS) Pub Date : 2022-12-01 DOI: 10.1109/RTSS55097.2022.00051

Javier E. Mendez Gomez, A. Cheng

{"title":"Work-in-Progress: Real-Time On-board Processing for Cloud Detection in FACSAT-2 Multispectral Satellite Imagery","authors":"Javier E. Mendez Gomez, A. Cheng","doi":"10.1109/RTSS55097.2022.00051","DOIUrl":"https://doi.org/10.1109/RTSS55097.2022.00051","url":null,"abstract":"There are several optical sensors available that can be integrated into a small satellite for the remote recording of different places on Earth. Colombia in its FACSAT-2 satellite mission has selected a multispectral optical sensor of medium resolution for this task. However, the associated data processing model does not allow the generation of useful products for end users, given the effects that phenomena such as the presence of clouds could cause in 8-band multispectral images captured by FACSAT-2. Therefore, this work proposes the possibility of establishing a real-time system for on-board processing of the data recorded by the satellite optical sensor, taking advantage of the processing resources offered by the embedded computer system in charge of integrating the payloads to the satellite bus and initiating the development of software applications based on artificial intelligence techniques, so that together they can meet the need for autonomously estimating the percentage of cloud coverage in multispectral images prior to the storage and download process, while complying with the restrictions imposed on this type of systems with respect to the time variable.","PeriodicalId":202402,"journal":{"name":"2022 IEEE Real-Time Systems Symposium (RTSS)","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129075900","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

In-ConcReTeS: Interactive Consistency meets Distributed Real-Time Systems, Again! 混凝土:交互一致性满足分布式实时系统，再次!

2022 IEEE Real-Time Systems Symposium (RTSS) Pub Date : 2022-12-01 DOI: 10.1109/RTSS55097.2022.00027

A. Gujarati, Ningfeng Yang, Björn B. Brandenburg

{"title":"In-ConcReTeS: Interactive Consistency meets Distributed Real-Time Systems, Again!","authors":"A. Gujarati, Ningfeng Yang, Björn B. Brandenburg","doi":"10.1109/RTSS55097.2022.00027","DOIUrl":"https://doi.org/10.1109/RTSS55097.2022.00027","url":null,"abstract":"The problem of replica coordination is fundamental to building Byzantine fault-tolerant (BFT) distributed systems. Seminal BFT architectures for safety-critical real-time systems from the eighties and nineties relied on custom processors and networks, and are hence not readily usable today. Modern-day deployments on cloud platforms do not “scale down” to embedded platforms and are not designed around timeliness. Recent work on real-time BFT protocols focuses on simulations and reliability analyses. In short, there exist no easily programmable BFT libraries that can be conveniently retrofitted onto real-time applications with deadlines and that perform well on embedded platforms. We propose In-ConcReTeS, a BFT key-value store designed for building highly reliable control applications on commodity embedded platforms. At its core, In-ConcReTeS is a real-time friendly redesign and an efficient implementation of a BFT protocol used by seminal fault-tolerant architectures. We evaluated In-ConcReTeS using an inverted pendulum simulation and an automotive benchmark on a cluster of four Raspberry Pis connected over Ethernet. Our results show that, unlike Redis and etcd, In-ConcReTeS can repeatedly synchronize hundreds of key-value pairs, while tolerating faults, every tens of milliseconds.","PeriodicalId":202402,"journal":{"name":"2022 IEEE Real-Time Systems Symposium (RTSS)","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122334407","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: Measuring Security Protection in Real-time Embedded Firmware 正在进行的工作:测量实时嵌入式固件中的安全保护

2022 IEEE Real-Time Systems Symposium (RTSS) Pub Date : 2022-12-01 DOI: 10.1109/RTSS55097.2022.00050

Yuhao Wu, Yujie Wang, Shixuan Zhai, Zihan Li, Ao Li, Jinwen Wang, Ning Zhang

引用次数: 0

Work-in-Progress: A Holistic Approach to WCRT Analysis for Multicore Systems 正在进行的工作:多核系统WCRT分析的整体方法

2022 IEEE Real-Time Systems Symposium (RTSS) Pub Date : 2022-12-01 DOI: 10.1109/RTSS55097.2022.00054

Jatin Arora, Syed Aftab Rashid, Cláudio Maia, Geoffrey Nelissen, E. Tovar

引用次数: 0

Critical Instant for Probabilistic Timing Guarantees: Refuted and Revisited 概率时间保证的临界瞬间:反驳和重新审视

2022 IEEE Real-Time Systems Symposium (RTSS) Pub Date : 2022-12-01 DOI: 10.1109/RTSS55097.2022.00022

Kuan-Hsun Chen, Mario Gunzel, Georg von der Bruggen, Jian-Jia Chen

{"title":"Critical Instant for Probabilistic Timing Guarantees: Refuted and Revisited","authors":"Kuan-Hsun Chen, Mario Gunzel, Georg von der Bruggen, Jian-Jia Chen","doi":"10.1109/RTSS55097.2022.00022","DOIUrl":"https://doi.org/10.1109/RTSS55097.2022.00022","url":null,"abstract":"In soft real-time systems, tasks may occasionally miss their deadlines. This possibility has triggered research on probabilistic timing analysis for the execution time of a single program and probabilistic response time analysis of concurrently executed tasks. Under fixed-priority preemptive uniprocessor scheduling, it was shown that the classical critical instant theorem (for deriving the worst-case schedulability or response time) by Liu and Layland (in JACM 1973) can be applied to analyze the worst-case deadline failure probability (WCDFP) and the worst-case response time exceedance probability (WCRTEP). In this work, we present a counterexample for this result, showing that the WCDFP and WCRTEP derived by the classical critical instant theorem is unsound. We further provide two sound methods: one is to account for one additional carry-in job of a higher-priority task and another is to sample and inflate the execution time of certain jobs without adding one additional carry-in job. We show that these two methods do not dominate each other and, in the evaluation, apply them to two well-known approaches based on direct convolution and Chernoff bounds.","PeriodicalId":202402,"journal":{"name":"2022 IEEE Real-Time Systems Symposium (RTSS)","volume":"119 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132381593","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: 7