Real-Time in Embedded Linux Systems
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Copy on Write Based File Systems Performance Analysis and Implementation
Copy On Write Based File Systems Performance Analysis And Implementation Sakis Kasampalis Kongens Lyngby 2010 IMM-MSC-2010-63 Technical University of Denmark Department Of Informatics Building 321, DK-2800 Kongens Lyngby, Denmark Phone +45 45253351, Fax +45 45882673 [email protected] www.imm.dtu.dk Abstract In this work I am focusing on Copy On Write based file systems. Copy On Write is used on modern file systems for providing (1) metadata and data consistency using transactional semantics, (2) cheap and instant backups using snapshots and clones. This thesis is divided into two main parts. The first part focuses on the design and performance of Copy On Write based file systems. Recent efforts aiming at creating a Copy On Write based file system are ZFS, Btrfs, ext3cow, Hammer, and LLFS. My work focuses only on ZFS and Btrfs, since they support the most advanced features. The main goals of ZFS and Btrfs are to offer a scalable, fault tolerant, and easy to administrate file system. I evaluate the performance and scalability of ZFS and Btrfs. The evaluation includes studying their design and testing their performance and scalability against a set of recommended file system benchmarks. Most computers are already based on multi-core and multiple processor architec- tures. Because of that, the need for using concurrent programming models has increased. Transactions can be very helpful for supporting concurrent program- ming models, which ensure that system updates are consistent. Unfortunately, the majority of operating systems and file systems either do not support trans- actions at all, or they simply do not expose them to the users. -
The Linux Kernel Module Programming Guide
The Linux Kernel Module Programming Guide Peter Jay Salzman Michael Burian Ori Pomerantz Copyright © 2001 Peter Jay Salzman 2007−05−18 ver 2.6.4 The Linux Kernel Module Programming Guide is a free book; you may reproduce and/or modify it under the terms of the Open Software License, version 1.1. You can obtain a copy of this license at http://opensource.org/licenses/osl.php. This book is distributed in the hope it will be useful, but without any warranty, without even the implied warranty of merchantability or fitness for a particular purpose. The author encourages wide distribution of this book for personal or commercial use, provided the above copyright notice remains intact and the method adheres to the provisions of the Open Software License. In summary, you may copy and distribute this book free of charge or for a profit. No explicit permission is required from the author for reproduction of this book in any medium, physical or electronic. Derivative works and translations of this document must be placed under the Open Software License, and the original copyright notice must remain intact. If you have contributed new material to this book, you must make the material and source code available for your revisions. Please make revisions and updates available directly to the document maintainer, Peter Jay Salzman <[email protected]>. This will allow for the merging of updates and provide consistent revisions to the Linux community. If you publish or distribute this book commercially, donations, royalties, and/or printed copies are greatly appreciated by the author and the Linux Documentation Project (LDP). -
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. -
Huawei Announces EROFS Linux File-System, Might Eventually Be Used
ARTICLES & REVIEWS NEWS ARCHIVE FORUMS PREMIUM CATEGORIES Custom Search Search Latest Linux News Huawei Announces EROFS Linux File-System, Might Huawei Announces EROFS Linux File- Eventually Be Used By Android Devices System, Might Eventually Be Used By Android Devices Written by Michael Larabel in Linux Storage on 31 May 2018 at 09:00 AM EDT. 3 Comments Mesa 18.0.5 Is The Last Planned Release In Huawei's Gao Xiang has announced the EROFS open-source Linux file-system The Series intended for Android devices, but still at its very early stages of AMD K8 Support Stripped Out Of Coreboot development. NVIDIA’s Next Generation Mainstream GPU Will At Least Be Detailed In August EROFS is the company's new approach for a read-only file-system that would work well for Android devices. EROFS is short for the Extendable Read-Only GNOME 3 Might Be Too Resource Hungry To File-System and they began developing it with being unsatisfied with other read-only file- Ever Run Nicely On The Raspberry Pi system alternatives. XWayland Gets Patch To Automatically Use EGLStreams For NVIDIA Support When EROFS is designed to offer better performance than other read-only alternatives while still Needed focusing upon saving storage space. As part of EROFS is also a compression mode pursuing BPFILTER Landing For Linux 4.18 For a different design approach than other file-systems: the compression numbers shared in Eventually Better Firewall / Packet Filtering today's announcement on both server hardware and a Kirin 970 are compelling for being in AMDGPU Patches Prepping JPEG Support For the early stages of development. -
Oracle® Linux 7 Monitoring and Tuning the System
Oracle® Linux 7 Monitoring and Tuning the System F32306-03 October 2020 Oracle Legal Notices Copyright © 2020, Oracle and/or its affiliates. This software and related documentation are provided under a license agreement containing restrictions on use and disclosure and are protected by intellectual property laws. Except as expressly permitted in your license agreement or allowed by law, you may not use, copy, reproduce, translate, broadcast, modify, license, transmit, distribute, exhibit, perform, publish, or display any part, in any form, or by any means. Reverse engineering, disassembly, or decompilation of this software, unless required by law for interoperability, is prohibited. The information contained herein is subject to change without notice and is not warranted to be error-free. If you find any errors, please report them to us in writing. If this is software or related documentation that is delivered to the U.S. Government or anyone licensing it on behalf of the U.S. Government, then the following notice is applicable: U.S. GOVERNMENT END USERS: Oracle programs (including any operating system, integrated software, any programs embedded, installed or activated on delivered hardware, and modifications of such programs) and Oracle computer documentation or other Oracle data delivered to or accessed by U.S. Government end users are "commercial computer software" or "commercial computer software documentation" pursuant to the applicable Federal Acquisition Regulation and agency-specific supplemental regulations. As such, the use, reproduction, duplication, release, display, disclosure, modification, preparation of derivative works, and/or adaptation of i) Oracle programs (including any operating system, integrated software, any programs embedded, installed or activated on delivered hardware, and modifications of such programs), ii) Oracle computer documentation and/or iii) other Oracle data, is subject to the rights and limitations specified in the license contained in the applicable contract. -
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. -
An Introduction to Linux IPC
An introduction to Linux IPC Michael Kerrisk © 2013 linux.conf.au 2013 http://man7.org/ Canberra, Australia [email protected] 2013-01-30 http://lwn.net/ [email protected] man7 .org 1 Goal ● Limited time! ● Get a flavor of main IPC methods man7 .org 2 Me ● Programming on UNIX & Linux since 1987 ● Linux man-pages maintainer ● http://www.kernel.org/doc/man-pages/ ● Kernel + glibc API ● Author of: Further info: http://man7.org/tlpi/ man7 .org 3 You ● Can read a bit of C ● Have a passing familiarity with common syscalls ● fork(), open(), read(), write() man7 .org 4 There’s a lot of IPC ● Pipes ● Shared memory mappings ● FIFOs ● File vs Anonymous ● Cross-memory attach ● Pseudoterminals ● proc_vm_readv() / proc_vm_writev() ● Sockets ● Signals ● Stream vs Datagram (vs Seq. packet) ● Standard, Realtime ● UNIX vs Internet domain ● Eventfd ● POSIX message queues ● Futexes ● POSIX shared memory ● Record locks ● ● POSIX semaphores File locks ● ● Named, Unnamed Mutexes ● System V message queues ● Condition variables ● System V shared memory ● Barriers ● ● System V semaphores Read-write locks man7 .org 5 It helps to classify ● Pipes ● Shared memory mappings ● FIFOs ● File vs Anonymous ● Cross-memory attach ● Pseudoterminals ● proc_vm_readv() / proc_vm_writev() ● Sockets ● Signals ● Stream vs Datagram (vs Seq. packet) ● Standard, Realtime ● UNIX vs Internet domain ● Eventfd ● POSIX message queues ● Futexes ● POSIX shared memory ● Record locks ● ● POSIX semaphores File locks ● ● Named, Unnamed Mutexes ● System V message queues ● Condition variables ● System V shared memory ● Barriers ● ● System V semaphores Read-write locks man7 .org 6 It helps to classify ● Pipes ● Shared memory mappings ● FIFOs ● File vs Anonymous ● Cross-memoryn attach ● Pseudoterminals tio a ● proc_vm_readv() / proc_vm_writev() ● Sockets ic n ● Signals ● Stream vs Datagram (vs uSeq. -
Linux and Free Software: What and Why?
Linux and Free Software: What and Why? (Qué son Linux y el Software libre y cómo beneficia su uso a las empresas para lograr productividad económica y ventajas técnicas?) JugoJugo CreativoCreativo Michael Kerrisk UniversidadUniversidad dede SantanderSantander UDESUDES © 2012 Bucaramanga,Bucaramanga, ColombiaColombia [email protected] 77 JuneJune 20122012 http://man7.org/ man7.org 1 Who am I? ● Programmer, educator, and writer ● UNIX since 1987; Linux since late 1990s ● Linux man-pages maintainer since 2004 ● Author of a book on Linux programming man7.org 2 Overview ● What is Linux? ● How are Linux and Free Software created? ● History ● Where is Linux used today? ● What is Free Software? ● Source code; Software licensing ● Importance and advantages of Free Software and Software Freedom ● Concluding remarks man7.org 3 ● What is Linux? ● How are Linux and Free Software created? ● History ● Where is Linux used today? ● What is Free Software? ● Source code; Software licensing ● Importance and advantages of Free Software and Software Freedom ● Concluding remarks man7.org 4 What is Linux? ● An operating system (sistema operativo) ● (Operating System = OS) ● Examples of other operating systems: ● Windows ● Mac OS X Penguins are the Linux mascot man7.org 5 But, what's an operating system? ● Two definitions: ● Kernel ● Kernel + package of common programs man7.org 6 OS Definition 1: Kernel ● Computer scientists' definition: ● Operating System = Kernel (núcleo) ● Kernel = fundamental program on which all other programs depend man7.org 7 Programs can live -
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. -
ZFS 2018 and Onward
SEE TEXT ONLY 2018 and Onward BY ALLAN JUDE 2018 is going to be a big year for ZFS RAID-Z Expansion not only FreeBSD, but for OpenZFS • 2018Q4 as well. OpenZFS is the collaboration of developers from IllumOS, FreeBSD, The ability to add an additional disk to an existing RAID-Z VDEV to grow its size with- Linux, Mac OS X, many industry ven- out changing its redundancy level. For dors, and a number of other projects example, a RAID-Z2 consisting of 6 disks to maintain and advance the open- could be expanded to contain 7 disks, source version of Sun’s ZFS filesystem. increasing the available space. This is accomplished by reflowing the data across Improved Pool Import the disks, so as to not change an individual • 2018Q1 block’s offset from the start of the VDEV. The new disk will appear as a new column on the A new patch set changes the way pools are right, and the data will be relocated to main- imported, such that they depend less on con- tain the offset within the VDEV. Similar to figuration data from the system. Instead, the reflowing a paragraph by making it wider, possibly outdated configuration from the sys- without changing the order of the words. In tem is used to find the pool, and partially open the end this means all of the new space shows it read-only. Then the correct on-disk configura- up at the end of the disk, without any frag- tion is loaded. This reduces the number of mentation. -
Z/OS Distributed File Service Zseries File System Implementation Z/OS V1R13
Front cover z/OS Distributed File Service zSeries File System Implementation z/OS V1R13 Defining and installing a zSeries file system Performing backup and recovery, sysplex sharing Migrating from HFS to zFS Paul Rogers Robert Hering ibm.com/redbooks International Technical Support Organization z/OS Distributed File Service zSeries File System Implementation z/OS V1R13 October 2012 SG24-6580-05 Note: Before using this information and the product it supports, read the information in “Notices” on page xiii. Sixth Edition (October 2012) This edition applies to version 1 release 13 modification 0 of IBM z/OS (product number 5694-A01) and to all subsequent releases and modifications until otherwise indicated in new editions. © Copyright International Business Machines Corporation 2010, 2012. All rights reserved. Note to U.S. Government Users Restricted Rights -- Use, duplication or disclosure restricted by GSA ADP Schedule Contract with IBM Corp. Contents Notices . xiii Trademarks . xiv Preface . .xv The team who wrote this book . .xv Now you can become a published author, too! . xvi Comments welcome. xvi Stay connected to IBM Redbooks . xvi Chapter 1. zFS file systems . 1 1.1 zSeries File System introduction. 2 1.2 Application programming interfaces . 2 1.3 zFS physical file system . 3 1.4 zFS colony address space . 4 1.5 zFS supports z/OS UNIX ACLs. 4 1.6 zFS file system aggregates. 5 1.6.1 Compatibility mode aggregates. 5 1.6.2 Multifile system aggregates. 6 1.7 Metadata cache. 7 1.8 zFS file system clones . 7 1.8.1 Backup file system . 8 1.9 zFS log files.