The Real-Time Linux Kernel: a Survey on PREEMPT RT
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Industrial Control Via Application Containers: Migrating from Bare-Metal to IAAS
Industrial Control via Application Containers: Migrating from Bare-Metal to IAAS Florian Hofer, Student Member, IEEE Martin A. Sehr Antonio Iannopollo, Member, IEEE Faculty of Computer Science Corporate Technology EECS Department Free University of Bolzano-Bozen Siemens Corporation University of California Bolzano, Italy Berkeley, CA 94704, USA Berkeley, CA 94720, USA fl[email protected] [email protected] [email protected] Ines Ugalde Alberto Sangiovanni-Vincentelli, Fellow, IEEE Barbara Russo Corporate Technology EECS Department Faculty of Computer Science Siemens Corporation University of California Free University of Bolzano-Bozen Berkeley, CA 94704, USA Berkeley, CA 94720, USA Bolzano, Italy [email protected] [email protected] [email protected] Abstract—We explore the challenges and opportunities of control design full authority over the environment in which shifting industrial control software from dedicated hardware to its software will run, it is not straightforward to determine bare-metal servers or cloud computing platforms using off the under what conditions the software can be executed on cloud shelf technologies. In particular, we demonstrate that executing time-critical applications on cloud platforms is viable based on computing platforms due to resource virtualization. Yet, we a series of dedicated latency tests targeting relevant real-time believe that the principles of Industry 4.0 present a unique configurations. opportunity to explore complementing traditional automation Index Terms—Industrial Control Systems, Real-Time, IAAS, components with a novel control architecture [3]. Containers, Determinism We believe that modern virtualization techniques such as application containerization [3]–[5] are essential for adequate I. INTRODUCTION utilization of cloud computing resources in industrial con- Emerging technologies such as the Internet of Things and trol systems. -
Microkernel Mechanisms for Improving the Trustworthiness of Commodity Hardware
Microkernel Mechanisms for Improving the Trustworthiness of Commodity Hardware Yanyan Shen Submitted in fulfilment of the requirements for the degree of Doctor of Philosophy School of Computer Science and Engineering Faculty of Engineering March 2019 Thesis/Dissertation Sheet Surname/Family Name : Shen Given Name/s : Yanyan Abbreviation for degree as give in the University calendar : PhD Faculty : Faculty of Engineering School : School of Computer Science and Engineering Microkernel Mechanisms for Improving the Trustworthiness of Commodity Thesis Title : Hardware Abstract 350 words maximum: (PLEASE TYPE) The thesis presents microkernel-based software-implemented mechanisms for improving the trustworthiness of computer systems based on commercial off-the-shelf (COTS) hardware that can malfunction when the hardware is impacted by transient hardware faults. The hardware anomalies, if undetected, can cause data corruptions, system crashes, and security vulnerabilities, significantly undermining system dependability. Specifically, we adopt the single event upset (SEU) fault model and address transient CPU or memory faults. We take advantage of the functional correctness and isolation guarantee provided by the formally verified seL4 microkernel and hardware redundancy provided by multicore processors, design the redundant co-execution (RCoE) architecture that replicates a whole software system (including the microkernel) onto different CPU cores, and implement two variants, loosely-coupled redundant co-execution (LC-RCoE) and closely-coupled redundant co-execution (CC-RCoE), for the ARM and x86 architectures. RCoE treats each replica of the software system as a state machine and ensures that the replicas start from the same initial state, observe consistent inputs, perform equivalent state transitions, and thus produce consistent outputs during error-free executions. -
Amazon's Antitrust Paradox
LINA M. KHAN Amazon’s Antitrust Paradox abstract. Amazon is the titan of twenty-first century commerce. In addition to being a re- tailer, it is now a marketing platform, a delivery and logistics network, a payment service, a credit lender, an auction house, a major book publisher, a producer of television and films, a fashion designer, a hardware manufacturer, and a leading host of cloud server space. Although Amazon has clocked staggering growth, it generates meager profits, choosing to price below-cost and ex- pand widely instead. Through this strategy, the company has positioned itself at the center of e- commerce and now serves as essential infrastructure for a host of other businesses that depend upon it. Elements of the firm’s structure and conduct pose anticompetitive concerns—yet it has escaped antitrust scrutiny. This Note argues that the current framework in antitrust—specifically its pegging competi- tion to “consumer welfare,” defined as short-term price effects—is unequipped to capture the ar- chitecture of market power in the modern economy. We cannot cognize the potential harms to competition posed by Amazon’s dominance if we measure competition primarily through price and output. Specifically, current doctrine underappreciates the risk of predatory pricing and how integration across distinct business lines may prove anticompetitive. These concerns are height- ened in the context of online platforms for two reasons. First, the economics of platform markets create incentives for a company to pursue growth over profits, a strategy that investors have re- warded. Under these conditions, predatory pricing becomes highly rational—even as existing doctrine treats it as irrational and therefore implausible. -
RTAI-Lab Tutorial: Scicoslab, Comedi, and Real-Time Control
RTAI-Lab tutorial: Scicoslab, Comedi, and real-time control Roberto Bucher 1 Simone Mannori Thomas Netter 2 May 24, 2010 Summary RTAI-Lab is a tool chain for real-time software and control system development. This tutorial shows how to install the various components: the RTAI real-time Linux kernel, the Comedi interface for control and measurement hardware, the Scicoslab GUI-based CACSD modeling software and associated RTAI-Lab blocks, and the xrtailab interactive oscilloscope. RTAI-Lab’s Scicos blocks are detailed and examples show how to develop elementary block diagrams, automatically generate real-time executables, and add custom elements. 1Main RTAI-Lab developer, person to contact for technical questions: roberto.bucher at supsi.ch, see page 46 Contents 1 Introduction 4 1.1 RTAI-Lab tool chain . .4 1.2 Commercial software . .4 2 Installation 5 2.1 Requirements . .5 2.1.1 Hardware requirements . .5 2.1.2 Software requirements . .6 2.2 Mesa library . .7 2.3 EFLTK library . .7 2.4 Linux kernel and RTAI patch . .7 2.5 Comedilib . .8 2.6 RTAI (1st pass) . .8 2.7 RTAI tests . .9 2.8 Comedi . .9 2.9 RTAI (2nd pass) . 10 2.10 ScicosLab . 11 2.11 RTAI-Lab add-ons to Scicoslab-4.4 . 11 2.12 User configuration for scicoslab-4.4 . 11 2.13 Load the modules . 11 3 Development with RTAI-Lab 13 3.1 Boot Linux-RTAI . 13 3.2 Start Scicos . 13 3.3 RTAI-Lib palette . 14 3.4 Real-time sinewave: step by step . 16 3.4.1 Create block diagram . -
Advanced Operating Systems #1
<Slides download> https://www.pf.is.s.u-tokyo.ac.jp/classes Advanced Operating Systems #2 Hiroyuki Chishiro Project Lecturer Department of Computer Science Graduate School of Information Science and Technology The University of Tokyo Room 007 Introduction of Myself • Name: Hiroyuki Chishiro • Project Lecturer at Kato Laboratory in December 2017 - Present. • Short Bibliography • Ph.D. at Keio University on March 2012 (Yamasaki Laboratory: Same as Prof. Kato). • JSPS Research Fellow (PD) in April 2012 – March 2014. • Research Associate at Keio University in April 2014 – March 2016. • Assistant Professor at Advanced Institute of Industrial Technology in April 2016 – November 2017. • Research Interests • Real-Time Systems • Operating Systems • Middleware • Trading Systems Course Plan • Multi-core Resource Management • Many-core Resource Management • GPU Resource Management • Virtual Machines • Distributed File Systems • High-performance Networking • Memory Management • Network on a Chip • Embedded Real-time OS • Device Drivers • Linux Kernel Schedule 1. 2018.9.28 Introduction + Linux Kernel (Kato) 2. 2018.10.5 Linux Kernel (Chishiro) 3. 2018.10.12 Linux Kernel (Kato) 4. 2018.10.19 Linux Kernel (Kato) 5. 2018.10.26 Linux Kernel (Kato) 6. 2018.11.2 Advanced Research (Chishiro) 7. 2018.11.9 Advanced Research (Chishiro) 8. 2018.11.16 (No Class) 9. 2018.11.23 (Holiday) 10. 2018.11.30 Advanced Research (Kato) 11. 2018.12.7 Advanced Research (Kato) 12. 2018.12.14 Advanced Research (Chishiro) 13. 2018.12.21 Linux Kernel 14. 2019.1.11 Linux Kernel 15. 2019.1.18 (No Class) 16. 2019.1.25 (No Class) Linux Kernel Introducing Synchronization /* The cases for Linux */ Acknowledgement: Prof. -
Process Scheduling Ii
PROCESS SCHEDULING II CS124 – Operating Systems Spring 2021, Lecture 12 2 Real-Time Systems • Increasingly common to have systems with real-time scheduling requirements • Real-time systems are driven by specific events • Often a periodic hardware timer interrupt • Can also be other events, e.g. detecting a wheel slipping, or an optical sensor triggering, or a proximity sensor reaching a threshold • Event latency is the amount of time between an event occurring, and when it is actually serviced • Usually, real-time systems must keep event latency below a minimum required threshold • e.g. antilock braking system has 3-5 ms to respond to wheel-slide • The real-time system must try to meet its deadlines, regardless of system load • Of course, may not always be possible… 3 Real-Time Systems (2) • Hard real-time systems require tasks to be serviced before their deadlines, otherwise the system has failed • e.g. robotic assembly lines, antilock braking systems • Soft real-time systems do not guarantee tasks will be serviced before their deadlines • Typically only guarantee that real-time tasks will be higher priority than other non-real-time tasks • e.g. media players • Within the operating system, two latencies affect the event latency of the system’s response: • Interrupt latency is the time between an interrupt occurring, and the interrupt service routine beginning to execute • Dispatch latency is the time the scheduler dispatcher takes to switch from one process to another 4 Interrupt Latency • Interrupt latency in context: Interrupt! Task -
What Is an Operating System III 2.1 Compnents II an Operating System
Page 1 of 6 What is an Operating System III 2.1 Compnents II An operating system (OS) is software that manages computer hardware and software resources and provides common services for computer programs. The operating system is an essential component of the system software in a computer system. Application programs usually require an operating system to function. Memory management Among other things, a multiprogramming operating system kernel must be responsible for managing all system memory which is currently in use by programs. This ensures that a program does not interfere with memory already in use by another program. Since programs time share, each program must have independent access to memory. Cooperative memory management, used by many early operating systems, assumes that all programs make voluntary use of the kernel's memory manager, and do not exceed their allocated memory. This system of memory management is almost never seen any more, since programs often contain bugs which can cause them to exceed their allocated memory. If a program fails, it may cause memory used by one or more other programs to be affected or overwritten. Malicious programs or viruses may purposefully alter another program's memory, or may affect the operation of the operating system itself. With cooperative memory management, it takes only one misbehaved program to crash the system. Memory protection enables the kernel to limit a process' access to the computer's memory. Various methods of memory protection exist, including memory segmentation and paging. All methods require some level of hardware support (such as the 80286 MMU), which doesn't exist in all computers. -
The Many Approaches to Real-Time and Safety Critical Linux Systems
Corporate Technology The Many Approaches to Real-Time and Safety-Critical Linux Open Source Summit Japan 2017 Prof. Dr. Wolfgang Mauerer Siemens AG, Corporate Research and Technologies Smart Embedded Systems Corporate Competence Centre Embedded Linux Copyright c 2017, Siemens AG. All rights reserved. Page 1 31. Mai 2017 W. Mauerer Siemens Corporate Technology Corporate Technology The Many Approaches to Real-Time and Safety-Critical Linux Open Source Summit Japan 2017 Prof. Dr. Wolfgang Mauerer, Ralf Ramsauer, Andreas Kolbl¨ Siemens AG, Corporate Research and Technologies Smart Embedded Systems Corporate Competence Centre Embedded Linux Copyright c 2017, Siemens AG. All rights reserved. Page 1 31. Mai 2017 W. Mauerer Siemens Corporate Technology Overview 1 Real-Time and Safety 2 Approaches to Real-Time Architectural Possibilities Practical Approaches 3 Approaches to Linux-Safety 4 Guidelines and Outlook Page 2 31. Mai 2017 W. Mauerer Siemens Corporate Technology Introduction & Overview About Siemens Corporate Technology: Corporate Competence Centre Embedded Linux Technical University of Applied Science Regensburg Theoretical Computer Science Head of Digitalisation Laboratory Target Audience Assumptions System Builders & Architects, Software Architects Linux Experience available Not necessarily RT-Linux and Safety-Critical Linux experts Page 3 31. Mai 2017 W. Mauerer Siemens Corporate Technology A journey through the worlds of real-time and safety Page 4 31. Mai 2017 W. Mauerer Siemens Corporate Technology Outline 1 Real-Time and Safety 2 Approaches to Real-Time Architectural Possibilities Practical Approaches 3 Approaches to Linux-Safety 4 Guidelines and Outlook Page 5 31. Mai 2017 W. Mauerer Siemens Corporate Technology Real-Time: What and Why? I Real Time Real Fast Deterministic responses to stimuli Caches, TLB, Lookahead Bounded latencies (not too late, not too Pipelines early) Optimise average case Repeatable results Optimise/quantify worst case Page 6 31. -
Linux Kernal II 9.1 Architecture
Page 1 of 7 Linux Kernal II 9.1 Architecture: The Linux kernel is a Unix-like operating system kernel used by a variety of operating systems based on it, which are usually in the form of Linux distributions. The Linux kernel is a prominent example of free and open source software. Programming language The Linux kernel is written in the version of the C programming language supported by GCC (which has introduced a number of extensions and changes to standard C), together with a number of short sections of code written in the assembly language (in GCC's "AT&T-style" syntax) of the target architecture. Because of the extensions to C it supports, GCC was for a long time the only compiler capable of correctly building the Linux kernel. Compiler compatibility GCC is the default compiler for the Linux kernel source. In 2004, Intel claimed to have modified the kernel so that its C compiler also was capable of compiling it. There was another such reported success in 2009 with a modified 2.6.22 version of the kernel. Since 2010, effort has been underway to build the Linux kernel with Clang, an alternative compiler for the C language; as of 12 April 2014, the official kernel could almost be compiled by Clang. The project dedicated to this effort is named LLVMLinxu after the LLVM compiler infrastructure upon which Clang is built. LLVMLinux does not aim to fork either the Linux kernel or the LLVM, therefore it is a meta-project composed of patches that are eventually submitted to the upstream projects. -
A Linux Kernel Scheduler Extension for Multi-Core Systems
A Linux Kernel Scheduler Extension For Multi-Core Systems Aleix Roca Nonell Master in Innovation and Research in Informatics (MIRI) specialized in High Performance Computing (HPC) Facultat d’informàtica de Barcelona (FIB) Universitat Politècnica de Catalunya Supervisor: Vicenç Beltran Querol Cosupervisor: Eduard Ayguadé Parra Presentation date: 25 October 2017 Abstract The Linux Kernel OS is a black box from the user-space point of view. In most cases, this is not a problem. However, for parallel high performance computing applications it can be a limitation. Such applications usually execute on top of a runtime system, itself executing on top of a general purpose kernel. Current runtime systems take care of getting the most of each system core by distributing work among the multiple CPUs of a machine but they are not aware of when one of their threads perform blocking calls (e.g. I/O operations). When such a blocking call happens, the processing core is stalled, leading to performance loss. In this thesis, it is presented the proof-of-concept of a Linux kernel extension denoted User Monitored Threads (UMT). The extension allows a user-space application to be notified of the blocking and unblocking of its threads, making it possible for a core to execute another worker thread while the other is blocked. An existing runtime system (namely Nanos6) is adapted, so that it takes advantage of the kernel extension. The whole prototype is tested on a synthetic benchmarks and an industry mock-up application. The analysis of the results shows, on the tested hardware and the appropriate conditions, a significant speedup improvement. -
Enabling Mobile Service Continuity Across Orchestrated Edge Networks
This is a postprint version of the following published document: Abdullaziz, O. I., Wang, L. C., Chundrigar, S. B. y Huang, K. L. (2019). Enabling Mobile Service Continuity across Orchestrated Edge Networks. IEEE Transactions on Network Science and Engineering, 7(3), pp. 1774-1787. DOI: https://doi.org/10.1109/TNSE.2019.2953129 © 2019 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works. Enabling Mobile Service Continuity across Orchestrated Edge Networks Osamah Ibrahiem Abdullaziz, Student Member, IEEE, Li-Chun Wang, Fellow, IEEE, Shahzoob Bilal Chundrigar and Kuei-Li Huang Abstract—Edge networking has become an important technology for providing low-latency services to end users. However, deploying an edge network does not guarantee continuous service for mobile users. Mobility can cause frequent interruptions and network delays as users leave the initial serving edge. In this paper, we propose a solution to provide transparent service continuity for mobile users in large-scale WiFi networks. The contribution of this work has three parts. First, we propose ARNAB architecture to achieve mobile service continuity. The term ARNAB means rabbit in Arabic, which represents an Architecture for Transparent Service Continuity via Double-tier Migration. The first tier migrates user connectivity, while the second tier migrates user containerized applications. ARNAB provides mobile services just like rabbits hop through the WiFi infrastructure. -
Building Embedded Linux Systems ,Roadmap.18084 Page Ii Wednesday, August 6, 2008 9:05 AM
Building Embedded Linux Systems ,roadmap.18084 Page ii Wednesday, August 6, 2008 9:05 AM Other Linux resources from O’Reilly Related titles Designing Embedded Programming Embedded Hardware Systems Linux Device Drivers Running Linux Linux in a Nutshell Understanding the Linux Linux Network Adminis- Kernel trator’s Guide Linux Books linux.oreilly.com is a complete catalog of O’Reilly’s books on Resource Center Linux and Unix and related technologies, including sample chapters and code examples. ONLamp.com is the premier site for the open source web plat- form: Linux, Apache, MySQL, and either Perl, Python, or PHP. Conferences O’Reilly brings diverse innovators together to nurture the ideas that spark revolutionary industries. We specialize in document- ing the latest tools and systems, translating the innovator’s knowledge into useful skills for those in the trenches. Visit con- ferences.oreilly.com for our upcoming events. Safari Bookshelf (safari.oreilly.com) is the premier online refer- ence library for programmers and IT professionals. Conduct searches across more than 1,000 books. Subscribers can zero in on answers to time-critical questions in a matter of seconds. Read the books on your Bookshelf from cover to cover or sim- ply flip to the page you need. Try it today for free. main.title Page iii Monday, May 19, 2008 11:21 AM SECOND EDITION Building Embedded Linux SystemsTomcat ™ The Definitive Guide Karim Yaghmour, JonJason Masters, Brittain Gilad and Ben-Yossef, Ian F. Darwin and Philippe Gerum Beijing • Cambridge • Farnham • Köln • Sebastopol • Taipei • Tokyo Building Embedded Linux Systems, Second Edition by Karim Yaghmour, Jon Masters, Gilad Ben-Yossef, and Philippe Gerum Copyright © 2008 Karim Yaghmour and Jon Masters.