Linux Schedulers
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Proceedings 2005
LAC2005 Proceedings 3rd International Linux Audio Conference April 21 – 24, 2005 ZKM | Zentrum fur¨ Kunst und Medientechnologie Karlsruhe, Germany Published by ZKM | Zentrum fur¨ Kunst und Medientechnologie Karlsruhe, Germany April, 2005 All copyright remains with the authors www.zkm.de/lac/2005 Content Preface ............................................ ............................5 Staff ............................................... ............................6 Thursday, April 21, 2005 – Lecture Hall 11:45 AM Peter Brinkmann MidiKinesis – MIDI controllers for (almost) any purpose . ....................9 01:30 PM Victor Lazzarini Extensions to the Csound Language: from User-Defined to Plugin Opcodes and Beyond ............................. .....................13 02:15 PM Albert Gr¨af Q: A Functional Programming Language for Multimedia Applications .........21 03:00 PM St´ephane Letz, Dominique Fober and Yann Orlarey jackdmp: Jack server for multi-processor machines . ......................29 03:45 PM John ffitch On The Design of Csound5 ............................... .....................37 04:30 PM Pau Arum´ıand Xavier Amatriain CLAM, an Object Oriented Framework for Audio and Music . .............43 Friday, April 22, 2005 – Lecture Hall 11:00 AM Ivica Ico Bukvic “Made in Linux” – The Next Step .......................... ..................51 11:45 AM Christoph Eckert Linux Audio Usability Issues .......................... ........................57 01:30 PM Marije Baalman Updates of the WONDER software interface for using Wave Field Synthesis . 69 02:15 PM Georg B¨onn Development of a Composer’s Sketchbook ................. ....................73 Saturday, April 23, 2005 – Lecture Hall 11:00 AM J¨urgen Reuter SoundPaint – Painting Music ........................... ......................79 11:45 AM Michael Sch¨uepp, Rene Widtmann, Rolf “Day” Koch and Klaus Buchheim System design for audio record and playback with a computer using FireWire . 87 01:30 PM John ffitch and Tom Natt Recording all Output from a Student Radio Station . -
Linux Scheduler Documentation
Linux Scheduler Documentation The kernel development community Jul 14, 2020 CONTENTS i ii CHAPTER ONE COMPLETIONS - “WAIT FOR COMPLETION”BARRIER APIS 1.1 Introduction: If you have one or more threads that must wait for some kernel activity to have reached a point or a specific state, completions can provide a race-free solution to this problem. Semantically they are somewhat like a pthread_barrier() and have similar use-cases. Completions are a code synchronization mechanism which is preferable to any misuse of locks/semaphores and busy-loops. Any time you think of using yield() or some quirky msleep(1) loop to allow something else to proceed, you probably want to look into using one of the wait_for_completion*() calls and complete() instead. The advantage of using completions is that they have a well defined, focused pur- pose which makes it very easy to see the intent of the code, but they also result in more efficient code as all threads can continue execution until the result isactually needed, and both the waiting and the signalling is highly efficient using low level scheduler sleep/wakeup facilities. Completions are built on top of the waitqueue and wakeup infrastructure of the Linux scheduler. The event the threads on the waitqueue are waiting for is reduced to a simple flag in ‘struct completion’, appropriately called “done”. As completions are scheduling related, the code can be found in ker- nel/sched/completion.c. 1.2 Usage: There are three main parts to using completions: • the initialization of the ‘struct completion’synchronization object • the waiting part through a call to one of the variants of wait_for_completion(), • the signaling side through a call to complete() or complete_all(). -
Embedded Systems
Sri Chandrasekharendra Saraswathi Viswa Maha Vidyalaya Department of Electronics and Communication Engineering STUDY MATERIAL for III rd Year VI th Semester Subject Name: EMBEDDED SYSTEMS Prepared by Dr.P.Venkatesan, Associate Professor, ECE, SCSVMV University Sri Chandrasekharendra Saraswathi Viswa Maha Vidyalaya Department of Electronics and Communication Engineering PRE-REQUISITE: Basic knowledge of Microprocessors, Microcontrollers & Digital System Design OBJECTIVES: The student should be made to – Learn the architecture and programming of ARM processor. Be familiar with the embedded computing platform design and analysis. Be exposed to the basic concepts and overview of real time Operating system. Learn the system design techniques and networks for embedded systems to industrial applications. Sri Chandrasekharendra Saraswathi Viswa Maha Vidyalaya Department of Electronics and Communication Engineering SYLLABUS UNIT – I INTRODUCTION TO EMBEDDED COMPUTING AND ARM PROCESSORS Complex systems and micro processors– Embedded system design process –Design example: Model train controller- Instruction sets preliminaries - ARM Processor – CPU: programming input and output- supervisor mode, exceptions and traps – Co- processors- Memory system mechanisms – CPU performance- CPU power consumption. UNIT – II EMBEDDED COMPUTING PLATFORM DESIGN The CPU Bus-Memory devices and systems–Designing with computing platforms – consumer electronics architecture – platform-level performance analysis - Components for embedded programs- Models of programs- -
1999 Nendo Supercompiler Te
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Advances in Mobile Cloud Computing and Big Data in the 5G Era Studies in Big Data
Studies in Big Data 22 Constandinos X. Mavromoustakis George Mastorakis Ciprian Dobre Editors Advances in Mobile Cloud Computing and Big Data in the 5G Era Studies in Big Data Volume 22 Series editor Janusz Kacprzyk, Polish Academy of Sciences, Warsaw, Poland e-mail: [email protected] About this Series The series “Studies in Big Data” (SBD) publishes new developments and advances in the various areas of Big Data-quickly and with a high quality. The intent is to cover the theory, research, development, and applications of Big Data, as embedded in the fields of engineering, computer science, physics, economics and life sciences. The books of the series refer to the analysis and understanding of large, complex, and/or distributed data sets generated from recent digital sources coming from sensors or other physical instruments as well as simulations, crowd sourcing, social networks or other internet transactions, such as emails or video click streams and other. The series contains monographs, lecture notes and edited volumes in Big Data spanning the areas of computational intelligence incl. neural networks, evolutionary computation, soft computing, fuzzy systems, as well as artificial intelligence, data mining, modern statistics and Operations research, as well as self-organizing systems. Of particular value to both the contributors and the readership are the short publication timeframe and the world-wide distribution, which enable both wide and rapid dissemination of research output. More information about this series at http://www.springer.com/series/11970 Constandinos X. Mavromoustakis George Mastorakis ⋅ Ciprian Dobre Editors Advances in Mobile Cloud Computing and Big Data in the 5G Era 123 Editors Constandinos X. -
On the Defectiveness of SCHED DEADLINE W.R.T. Tardiness and Afinities, and a Partial Fix Stephen Tang Luca Abeni James H
On the Defectiveness of SCHED_DEADLINE w.r.t. Tardiness and Afinities, and a Partial Fix Stephen Tang Luca Abeni James H. Anderson [email protected] {sytang,anderson}@cs.unc.edu Scuola Superiore Sant’Anna University of North Carolina at Chapel Hill Pisa, Italy Chapel Hill, USA ABSTRACT create new DL tasks until existing DL tasks reduce their bandwidth SCHED_DEADLINE (DL for short) is an Earliest-Deadline-First consumption. Note that preventing over-utilization is only a neces- sary condition for guaranteeing that tasks meet deadlines. (EDF) scheduler included in the Linux kernel. A question motivated Instead of guaranteeing that deadlines will be met, AC satisfes by DL is how EDF should be implemented in the presence of CPU afnities to maintain optimal bounded tardiness guarantees. Recent two goals [3]. The frst goal is to provide performance guarantees. works have shown that under arbitrary afnities, DL does not main- Specifcally, AC guarantees to each DL task that its long-run con- tain such guarantees. Such works have also shown that repairing sumption of CPU bandwidth remains within a bounded margin DL to maintain these guarantees would likely require an impractical of error from a requested rate. The second goal is to avoid the overhaul of the existing code. In this work, we show that for the starvation of lower-priority non-DL workloads. Specifcally, AC special case where afnities are semi-partitioned, DL can be modi- guarantees that some user-specifed amount of CPU bandwidth fed to maintain tardiness guarantees with minor changes. We also will remain for the execution of non-DL workloads. -
Inside the Linux 2.6 Completely Fair Scheduler
Inside the Linux 2.6 Completely Fair Scheduler http://www.ibm.com/developerworks/library/l-completely-fair-scheduler/ developerWorks Technical topics Linux Technical library Inside the Linux 2.6 Completely Fair Scheduler Providing fair access to CPUs since 2.6.23 The task scheduler is a key part of any operating system, and Linux® continues to evolve and innovate in this area. In kernel 2.6.23, the Completely Fair Scheduler (CFS) was introduced. This scheduler, instead of relying on run queues, uses a red-black tree implementation for task management. Explore the ideas behind CFS, its implementation, and advantages over the prior O(1) scheduler. M. Tim Jones is an embedded firmware architect and the author of Artificial Intelligence: A Systems Approach, GNU/Linux Application Programming (now in its second edition), AI Application Programming (in its second edition), and BSD Sockets Programming from a Multilanguage Perspective. His engineering background ranges from the development of kernels for geosynchronous spacecraft to embedded systems architecture and networking protocols development. Tim is a Consultant Engineer for Emulex Corp. in Longmont, Colorado. 15 December 2009 Also available in Japanese The Linux scheduler is an interesting study in competing pressures. On one side are the use models in which Linux is applied. Although Linux was originally developed as a desktop operating system experiment, you'll now find it on servers, tiny embedded devices, mainframes, and supercomputers. Not surprisingly, the scheduling loads for these domains differ. On the other side are the technological advances made in the platform, including architectures (multiprocessing, symmetric multithreading, non-uniform memory access [NUMA]) and virtualization. -
RTEMS C User Documentation Release 4.11.3 ©Copyright 2016, RTEMS Project (Built 15Th February 2018)
RTEMS C User Documentation Release 4.11.3 ©Copyright 2016, RTEMS Project (built 15th February 2018) CONTENTS I RTEMS C User’s Guide1 1 Preface 5 2 Overview 9 2.1 Introduction...................................... 10 2.2 Real-time Application Systems............................ 11 2.3 Real-time Executive.................................. 12 2.4 RTEMS Application Architecture........................... 13 2.5 RTEMS Internal Architecture............................. 14 2.6 User Customization and Extensibility......................... 15 2.7 Portability....................................... 16 2.8 Memory Requirements................................. 17 2.9 Audience........................................ 18 2.10 Conventions...................................... 19 2.11 Manual Organization................................. 20 3 Key Concepts 23 3.1 Introduction...................................... 24 3.2 Objects......................................... 25 3.2.1 Object Names................................. 25 3.2.2 Object IDs................................... 25 3.2.2.1 Thirty-Two Object ID Format.................... 25 3.2.2.2 Sixteen Bit Object ID Format.................... 26 3.2.3 Object ID Description............................. 26 3.3 Communication and Synchronization........................ 27 3.4 Time.......................................... 28 3.5 Memory Management................................. 29 4 RTEMS Data Types 31 4.1 Introduction...................................... 32 4.2 List of Data Types.................................. -
Thread Scheduling in Multi-Core Operating Systems Redha Gouicem
Thread Scheduling in Multi-core Operating Systems Redha Gouicem To cite this version: Redha Gouicem. Thread Scheduling in Multi-core Operating Systems. Computer Science [cs]. Sor- bonne Université, 2020. English. tel-02977242 HAL Id: tel-02977242 https://hal.archives-ouvertes.fr/tel-02977242 Submitted on 24 Oct 2020 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Ph.D thesis in Computer Science Thread Scheduling in Multi-core Operating Systems How to Understand, Improve and Fix your Scheduler Redha GOUICEM Sorbonne Université Laboratoire d’Informatique de Paris 6 Inria Whisper Team PH.D.DEFENSE: 23 October 2020, Paris, France JURYMEMBERS: Mr. Pascal Felber, Full Professor, Université de Neuchâtel Reviewer Mr. Vivien Quéma, Full Professor, Grenoble INP (ENSIMAG) Reviewer Mr. Rachid Guerraoui, Full Professor, École Polytechnique Fédérale de Lausanne Examiner Ms. Karine Heydemann, Associate Professor, Sorbonne Université Examiner Mr. Etienne Rivière, Full Professor, University of Louvain Examiner Mr. Gilles Muller, Senior Research Scientist, Inria Advisor Mr. Julien Sopena, Associate Professor, Sorbonne Université Advisor ABSTRACT In this thesis, we address the problem of schedulers for multi-core architectures from several perspectives: design (simplicity and correct- ness), performance improvement and the development of application- specific schedulers. -
Package Manager: the Core of a GNU/Linux Distribution
Package Manager: The Core of a GNU/Linux Distribution by Andrey Falko A Thesis submitted to the Faculty in partial fulfillment of the requirements for the BACHELOR OF ARTS Accepted Paul Shields, Thesis Adviser Allen Altman, Second Reader Christopher K. Callanan, Third Reader Mary B. Marcy, Provost and Vice President Simon’s Rock College Great Barrington, Massachusetts 2007 Abstract Package Manager: The Core of a GNU/Linux Distribution by Andrey Falko As GNU/Linux operating systems have been growing in popularity, their size has also been growing. To deal with this growth people created special programs to organize the software available for GNU/Linux users. These programs are called package managers. There exists a very wide variety of package managers, all offering their own benefits and deficiencies. This thesis explores all of the major aspects of package management in the GNU/Linux world. It covers what it is like to work without package managers, primitive package man- agement techniques, and modern package management schemes. The thesis presents the creation of a package manager called Vestigium. The creation of Vestigium is an attempt to automate the handling of file collisions between packages, provide a seamless interface for installing both binary packages and packages built from source, and to allow per package optimization capabilities. Some of the features Vestigium is built to have are lacking in current package managers. No current package manager contains all the features which Vestigium is built to have. Additionally, the thesis explains the problems that developers face in maintaining their respective package managers. i Acknowledgments I thank my thesis committee members, Paul Shields, Chris Callanan, and Allen Altman for being patient with my error-ridden drafts. -
Machine Learning for Load Balancing in the Linux Kernel Jingde Chen Subho S
Machine Learning for Load Balancing in the Linux Kernel Jingde Chen Subho S. Banerjee [email protected] [email protected] University of Illinois at Urbana-Champaign University of Illinois at Urbana-Champaign Zbigniew T. Kalbarczyk Ravishankar K. Iyer [email protected] [email protected] University of Illinois at Urbana-Champaign University of Illinois at Urbana-Champaign Abstract ACM Reference Format: The OS load balancing algorithm governs the performance Jingde Chen, Subho S. Banerjee, Zbigniew T. Kalbarczyk, and Rav- gains provided by a multiprocessor computer system. The ishankar K. Iyer. 2020. Machine Learning for Load Balancing in Linux’s Completely Fair Scheduler (CFS) scheduler tracks the Linux Kernel. In 11th ACM SIGOPS Asia-Pacific Workshop on Systems (APSys ’20), August 24–25, 2020, Tsukuba, Japan. ACM, New process loads by average CPU utilization to balance work- York, NY, USA, 8 pages. https://doi.org/10.1145/3409963.3410492 load between processor cores. That approach maximizes the utilization of processing time but overlooks the con- tention for lower-level hardware resources. In servers run- 1 Introduction ning compute-intensive workloads, an imbalanced need for The Linux scheduler, called the Completely Fair Scheduler limited computing resources hinders execution performance. (CFS) algorithm, enforces a fair scheduling policy that aims to This paper solves the above problem using a machine learn- allow all tasks to be executed with a fair quota of processing ing (ML)-based resource-aware load balancer. We describe time. CFS allocates CPU time appropriately among the avail- (1) low-overhead methods for collecting training data; (2) an able hardware threads to allow processes to make forward ML model based on a multi-layer perceptron model that imi- progress. -
Network Store: Exploring Slicing in Future 5G Networks
Network Store: Exploring Slicing in Future 5G Networks Navid Nikaein*, Eryk Schillerx, Romain Favraud*y, Kostas Katsalis\, Donatos Stavropoulos\, Islam Alyafawix, Zhongliang Zhaox, Torsten Braunx, and Thanasis Korakis\ *EURECOM, yDCNS xUniversity of Bern fi[email protected] [email protected] \University of Thessaly {kkatsalis,dostavro,korakis}@uth.gr ABSTRACT coupling between control and data planes, state-full design, In this paper, we present a revolutionary vision of 5G net- and dependency to dedicated hardware. The exploitation works, in which SDN programs wireless network functions, of cloud technologies, Software-Define Networking (SDN) and where Mobile Network Operators (MNO), Enterprises, and Network-Function Virtualization (NFV), can provide and Over-The-Top (OTT) third parties are provided with the necessary tools to break-down the vertical system or- NFV-ready Network Store. The proposed Network Store ganization, into a set of horizontal micro-service network serves as a digital distribution platform of programmable architectures. These can be used to combine relevant net- Virtualized Network Functions (VNFs) that enable 5G ap- work functions together, assign the target performance pa- plication use-cases. Currently existing application stores, rameters, and map them onto infrastructure resources. such as Apple's App Store for iOS applications, Google's In this paper, we present the design of a 5G-ready archi- Play Store for Android, or Ubuntu's Software Center, deliver tecture and a NFV-based Network Store that can serve as applications to user specific software platforms. Our vision a digital distribution platform for 5G application use-cases. is to provide a digital marketplace, gathering 5G enabling The goal of the Network Store is to provide programmable Network Applications and Network Functions, written to run pieces of code that on-the-fly reserve required resources, de- on top of commodity cloud infrastructures, connected to re- ploy and run the necessary software components, configure mote radio heads (RRH).