Linux Power Management Architecture
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Enea® Linux 4.0 Release Information
Enea® Linux 4.0 Release Information 4.0-docupdate1 Enea® Linux 4.0 Release Information Enea® Linux 4.0 Release Information Copyright Copyright © Enea Software AB 2014. This User Documentation consists of confidential information and is protected by Trade Secret Law. This notice of copyright does not indicate any actual or intended publication of this information. Except to the extent expressly stipulated in any software license agreement covering this User Documentation and/or corresponding software, no part of this User Documentation may be reproduced, transmitted, stored in a retrieval system, or translated, in any form or by any means, without the prior written permission of Enea Software AB. However, permission to print copies for personal use is hereby granted. Disclaimer The information in this User Documentation is subject to change without notice, and unless stipulated in any software license agreement covering this User Documentation and/or corresponding software, should not be construed as a commitment of Enea Software AB. Trademarks Enea®, Enea OSE®, and Polyhedra® are the registered trademarks of Enea AB and its subsidiaries. Enea OSE®ck, Enea OSE® Epsilon, Enea® Element, Enea® Optima, Enea® Linux, Enea® LINX, Enea® LWRT, Enea® Accelerator, Polyhedra® Flash DBMS, Polyhedra® Lite, Enea® dSPEED, Accelerating Network Convergence™, Device Software Optimized™, and Embedded for Leaders™ are unregistered trademarks of Enea AB or its subsidiaries. Any other company, product or service names mentioned in this document are the registered or unregistered trade- marks of their respective owner. Acknowledgements and Open Source License Conditions Information is found in the Release Information manual. © Enea Software AB 2014 4.0-docupdate1 ii Enea® Linux 4.0 Release Information Table of Contents 1 - About This Release ..................................................................................................... -
Low Level Tracing for Latency Analysis
Low Level Tracing for Latency Analysis From Baremetal to Hardware Tracing Blocks Suchakrapani Datt Sharma & Thomas Bertauld Oct 12, 2016 École Polytechnique de Montréal Laboratoire DORSAL whoami Suchakra ● PhD student, Computer Engineering (Prof Michel Dagenais) DORSAL Lab, École Polytechnique de Montréal – UdeM ● Works on debugging, tracing and trace aggregation (LTTng, eBPF), hardware tracing and VMs. ● Loves poutine, samosas and bikes POLYTECHNIQUE MONTREAL – Suchakrapani Datt Sharma whoami Thomas ● MSc student, Computer Engineering (Prof Michel Dagenais) DORSAL Lab, École Polytechnique de Montréal – UdeM ● Worked on embedded systems tracing, baremetal systems, trace analysis and now in financial-tech domain ● Loves computer games POLYTECHNIQUE MONTREAL – Suchakrapani Datt Sharma Agenda Latency ● Introduction ● Tools and techniques Hardware Tracing ● Intel Processor Trace ● ARM CoreSight ● Hardware trace based analysis Baremetal Tracing ● Heterogeneous system challenges ● Low level traces with barectf POLYTECHNIQUE MONTREAL – Suchakrapani Datt Sharma Latency POLYTECHNIQUE MONTREAL – Suchakrapani Datt Sharma SS ncy Super Complex Stuff Late S POLYTECHNIQUE MONTREAL – Suchakrapani Datt Sharma SS S POLYTECHNIQUE MONTREAL – Suchakrapani Datt Sharma SS S Hardware Interrupt POLYTECHNIQUE MONTREAL – Suchakrapani Datt Sharma Delay between interrupt and do_IRQ() SS S Hardware Interrupt Interrupt Handler POLYTECHNIQUE MONTREAL – Suchakrapani Datt Sharma Delay between interrupt and Interrupt do_IRQ() Handler Delay SS S Hardware Interrupt Interrupt -
Linux Kernel and Driver Development Training Slides
Linux Kernel and Driver Development Training Linux Kernel and Driver Development Training © Copyright 2004-2021, Bootlin. Creative Commons BY-SA 3.0 license. Latest update: October 9, 2021. Document updates and sources: https://bootlin.com/doc/training/linux-kernel Corrections, suggestions, contributions and translations are welcome! embedded Linux and kernel engineering Send them to [email protected] - Kernel, drivers and embedded Linux - Development, consulting, training and support - https://bootlin.com 1/470 Rights to copy © Copyright 2004-2021, Bootlin License: Creative Commons Attribution - Share Alike 3.0 https://creativecommons.org/licenses/by-sa/3.0/legalcode You are free: I to copy, distribute, display, and perform the work I to make derivative works I to make commercial use of the work Under the following conditions: I Attribution. You must give the original author credit. I Share Alike. If you alter, transform, or build upon this work, you may distribute the resulting work only under a license identical to this one. I For any reuse or distribution, you must make clear to others the license terms of this work. I Any of these conditions can be waived if you get permission from the copyright holder. Your fair use and other rights are in no way affected by the above. Document sources: https://github.com/bootlin/training-materials/ - Kernel, drivers and embedded Linux - Development, consulting, training and support - https://bootlin.com 2/470 Hyperlinks in the document There are many hyperlinks in the document I Regular hyperlinks: https://kernel.org/ I Kernel documentation links: dev-tools/kasan I Links to kernel source files and directories: drivers/input/ include/linux/fb.h I Links to the declarations, definitions and instances of kernel symbols (functions, types, data, structures): platform_get_irq() GFP_KERNEL struct file_operations - Kernel, drivers and embedded Linux - Development, consulting, training and support - https://bootlin.com 3/470 Company at a glance I Engineering company created in 2004, named ”Free Electrons” until Feb. -
Fixing USB Autosuspend Serge Y
Fixing USB Autosuspend Serge Y. Stroobandt Copyright 2015–2017, licensed under Creative Commons BY-NC-SA Problem The Linux kernel automatically suspends USB de- vices when there is driver support and the devices are not in use.1 This saves quite a bit of power. How- ever, some USB devices are not compatible with USB autosuspend and will misbehave at some point. Af- fected devices are most commonly USB mice and keyboards.2 Personally,I had only one Microsoft™ Wheel Mouse Optical affected, despitewning o other mod- els of the same brand. In essence, this is not really a USB hardware problem, but perhaps more a Lin- ux problem. The actual fault lies with a misinterpretation of the eXtensible Host Controller Interface (xHCI) specification. This issueviousl pre y did not exist with the older Enhanced Host Controller Interface (EHCI) specification. A «Sharp» explanation is available online.3 The Linux kernel patch for this problem will probably one day automatically trickle in downstream and onto my affectedubuntu X LTS 14.04 system. Nonetheless, with a crashing computer mouse at hand, things cannot wait. However, patching my current 3.13.0-35-generic x86_64 kernel is out of the question! We will rather grab this opportunity to learn a bit about writing rules for udev , the device manager for the Linux kernel. I am writing “for the Linux kernel”, because udev executes entirely in user space. Identify the device First, one needs to properly identify the affected USBvice de by its vendor and product ID. Run the following command and look for the device description. -
Enlightening the I/O Path: a Holistic Approach for Application Performance
Enlightening the I/O Path: A Holistic Approach for Application Performance Sangwook Kim, Apposha and Sungkyunkwan University; Hwanju Kim, Sungkyunkwan University and Dell EMC; Joonwon Lee and Jinkyu Jeong, Sungkyunkwan University https://www.usenix.org/conference/fast17/technical-sessions/presentation/kim-sangwook This paper is included in the Proceedings of the 15th USENIX Conference on File and Storage Technologies (FAST ’17). February 27–March 2, 2017 • Santa Clara, CA, USA ISBN 978-1-931971-36-2 Open access to the Proceedings of the 15th USENIX Conference on File and Storage Technologies is sponsored by USENIX. Enlightening the I/O Path: A Holistic Approach for Application Performance Sangwook Kim†§, Hwanju Kim§,∗ Joonwon Lee§, Jinkyu Jeong§ †Apposha, §Sungkyunkwan University [email protected], [email protected], [email protected], [email protected] Abstract main reason for this form of structuring is to reduce re- quest handling latency by taking off the internal activ- In data-intensive applications, such as databases and key- ities from the critical path of request execution. How- value stores, reducing the request handling latency is im- ever, background tasks are still interfering foreground portant for providing better data services. In such appli- tasks since they inherently share the I/O path in a stor- cations, I/O-intensive background tasks, such as check- age stack. For example, background checkpointing in pointing, are the major culprit in worsening the latency relational database has known to hinder delivering low due to the contention in shared I/O stack and storage. and predictable transaction latency, but the database and To minimize the contention, properly prioritizing I/Os operating system (OS) communities have no reasonable is crucial but the effectiveness of existing approaches is solution despite their collaborative efforts [12]. -
Oracle Solaris 11 Express What's
ORACLE SOLARIS 11 EXPRESS 2010.11 | WHAT’S NEW ORACLE SOLARIS 11 EXPRESS 2010.11 WHAT’S NEW Oracle Solaris is the industry leading operating system for the enterprise. Oracle Solaris 11 Express 2010.11 raises the bar on the innovation introduced in Oracle Solaris 10, with a unique feature set NEW FEATURE HIGHLIGHTS that few other operating systems can offer. Oracle Solaris 11 Express 2010.11 has been tested and • Oracle Solaris 10 Zones for business optimized for Oracle hardware and software, and is an integral part of Oracle's combined hardware investment protection and software portfolio. • Built-in network virtualization and resource Oracle Solaris 11 Express 2010.11 provides customers with the latest access to Oracle Solaris 11 management for enhanced server workload technology, allowing developers, architects and administrators to test and deploy within an consolidation enterprise environments and greatly simplify their day to day operations. Oracle Solaris 11 Express 2010.11 has the reliability, availability, and serviceability that you'd expect from a leading • Greatly reduced planned and unplanned downtime with new package management tools enterprise operating system. with safe system upgrade With new features such as network based package management tools to greatly decrease planned • New optimizations and features designed to system downtime and provide for a completely safe system upgrade, built-in network virtualization deliver proven scalability and reliability as an and resource control management for an unprecedented level of flexibility for application integrated component of Oracle's Exadata and consolidation, and on-disk ZFS encryption to provide the highest levels of security in your data Exalogic systems center, Oracle Solaris 11 Express 2010.11 is the most exciting release of the Oracle Solaris platform to date. -
Powerkap - a Tool for Improving Energy Transparency for Software Developers on GNU/Linux (X86) Platforms
Project Report Department of Computing Imperial College of Science, Technology and Medicine PowerKap - A tool for Improving Energy Transparency for Software Developers on GNU/Linux (x86) platforms Author: Supervisor: Krish De Souza Dr. Anandha Gopalan Submitted in partial fulfilment of the requirements for the M.Eng Computing 4 of Imperial College London Contents 1 Introduction 6 1.1 Motivation . .6 1.2 Objectives . .7 1.3 Achievements . .7 2 Background 9 2.1 The relationship between power and energy. .9 2.2 Power controls on x86 platforms . .9 2.3 Improving software for power efficiency . 10 2.3.1 Algorithm . 10 2.3.2 Multithreading . 10 2.3.3 Vectorisation . 10 2.3.4 Improper sleep loops . 12 2.3.5 OS Timers . 13 2.3.6 Context aware programming . 13 2.4 Current methods of monitoring energy. 14 2.4.1 Out of Band Energy Monitor . 14 2.4.2 In-Band Energy Monitor . 14 2.4.2.1 Powertop . 15 2.4.2.2 Turbostat . 16 2.5 Related Work . 16 2.5.1 ENTRA 2012-2015 . 16 2.5.1.1 Common Assertion Language . 16 2.5.1.2 Compiler Optimisation and Power Trade-offs . 18 2.5.1.3 Superoptimization . 18 2.5.1.4 Thermal trade-off . 20 2.5.2 eProf . 20 2.5.2.1 Asynchronous vs Synchronous . 20 2.5.2.2 Profiling implementation . 21 2.5.3 Energy Formal Definitions . 21 2.5.3.1 Java Based Energy Formalism . 22 2.5.3.2 Energy Application Model . 22 2.5.4 Impact of language, Compiler, Optimisations . -
Yocto Project and Embedded OS
Yocto Project and Jeffrey Osier-Mixon Embedded OS •What is the Yocto Project and why is it important? •Working with an open source collaborative project & community Kevin McGrath •Yocto Project concepts in a nutshell: environment, metadata, tools • Using Yocto cross-compiler • Running kernel via qemu th • Module installation, virtio, etc. July 28 2015 • Lessons learned, capabilities 11:00 PDT (GMT -7) 1 Yocto Project and Embedded OS Our guests Jeffrey Osier-Mixon: Jeff "Jefro" Osier-Mixon works for Intel Corporation in Intel's Open Source Technology Center, where his current role is community manager for the Yocto Project.. Jefro also works as a community architect and consultant for a number of open source projects and speaks regularly at open source conferences worldwide. He has been deeply involved with open source since the early 1990s. Kevin McGrath : Instructor at Oregon State University. I primarily teach the operating systems sequence and the senior capstone project sequence, but have taught architecture, assembly programming, introductory programming classes, and just about anything else that needs someone to teach it. While my background is in network security and high performance computing (computational physics), today I mostly live in the embedded space, leading to the “ECE wannabe” title in my department. Oleg Verge (Moderator): Technical Program Manager Intel Higher Education, System Engineer MCSE,CCNA, VCP Intel® IoT Developer Kit v1.0 Hardware components = + + Helpful Linux* tools (GCC tool chain, perf, oProfile, Software image + etc.), required drivers (Wi-Fi*, Bluetooth®, etc.), useful = API libraries, and daemons like LighttPD and Node.js. + Intel XDK Support for various IDEs = + + + For C/C++ For java, For Arduino* For Visual + node.js.,html5 sketches Programming Cloud services = Intel IoT Analytics includes capabilities for data collection, + storage, visualization, and analysis of sensor data. -
Rootfs Made Easy with Buildroot
Kernel Recipes 2013 Rootfs made easy with Buildroot How kernel developers can finally solve the rootfs problem. Thomas Petazzoni Bootlin [email protected] - Kernel, drivers and embedded Linux - Development, consulting, training and support - https://bootlin.com 1/1 Thomas Petazzoni I CTO and embedded Linux engineer at Bootlin I Embedded Linux development: kernel and driver development, system integration, boot time and power consumption optimization, consulting, etc. I Embedded Linux training, Linux driver development training and Android system development training, with materials freely available under a Creative Commons license. I We're hiring! I http://bootlin.com I Contributing the kernel support for the new Armada 370 and Armada XP ARM SoCs from Marvell (widely used in NAS devices). I Major contributor to Buildroot, an open-source, simple and fast embedded Linux build system I Living in Toulouse, south west of France - Kernel, drivers and embedded Linux - Development, consulting, training and support - https://bootlin.com 2/1 Doing kernel development is awesome, but... - Kernel, drivers and embedded Linux - Development, consulting, training and support - https://bootlin.com 3/1 A kernel without a root filesystem is kind of useless input: ImExPS/2 Generic Explorer Mouse as /devices/fpga:07/serio1/input/input1 Root-NFS: no NFS server address VFS: Unable to mount root fs via NFS, trying floppy. VFS: Cannot open root device "(null)" or unknown-block(2,0) Please append a correct "root=" boot option; here are the available partitions: Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(2,0) - Kernel, drivers and embedded Linux - Development, consulting, training and support - https://bootlin.com 4/1 Solutions often used by kernel dev I A complete Linux distribution + Readily available - Large (can hardly be used as an initramfs) - Not available for all architectures - Not easy to customize. -
SUSE Linux Enterprise Server 12 SP4 System Analysis and Tuning Guide System Analysis and Tuning Guide SUSE Linux Enterprise Server 12 SP4
SUSE Linux Enterprise Server 12 SP4 System Analysis and Tuning Guide System Analysis and Tuning Guide SUSE Linux Enterprise Server 12 SP4 An administrator's guide for problem detection, resolution and optimization. Find how to inspect and optimize your system by means of monitoring tools and how to eciently manage resources. Also contains an overview of common problems and solutions and of additional help and documentation resources. Publication Date: September 24, 2021 SUSE LLC 1800 South Novell Place Provo, UT 84606 USA https://documentation.suse.com Copyright © 2006– 2021 SUSE LLC and contributors. All rights reserved. Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.2 or (at your option) version 1.3; with the Invariant Section being this copyright notice and license. A copy of the license version 1.2 is included in the section entitled “GNU Free Documentation License”. For SUSE trademarks, see https://www.suse.com/company/legal/ . All other third-party trademarks are the property of their respective owners. Trademark symbols (®, ™ etc.) denote trademarks of SUSE and its aliates. Asterisks (*) denote third-party trademarks. All information found in this book has been compiled with utmost attention to detail. However, this does not guarantee complete accuracy. Neither SUSE LLC, its aliates, the authors nor the translators shall be held liable for possible errors or the consequences thereof. Contents About This Guide xii 1 Available Documentation xiii -
Microprocessor
Microprocessor A microprocessor is a computer processor that incorporates the functions of a central processing unit on a single integrated circuit (IC), or at most a few integrated circuits. The microprocessor is a multipurpose, clock driven, register based, digital-integrated circuit that accepts binary data as input, processes it according to instructions stored in its memory, and provides results as output. Microprocessors contain both combinational logic and sequential digital logic. Microprocessors operate on numbers and symbols represented in the binary numeral system. The integration of a whole CPU onto a single chip or on a few chips greatly reduced the cost of processing power, increasing efficiency. Integrated circuit processors are produced in large numbers by highly automated processes, resulting in a low per-unit cost. Single- chip processors increase reliability because there are many fewer electrical connections to fail. As microprocessor designs improve, the cost of manufacturing a chip (with smaller components built on a semiconductor chip the same size) generally stays the same. Before microprocessors, small computers had been built using racks of circuit boards with many medium- and small-scale integrated circuits. Microprocessors combined this into one or a few large-scale ICs. Continued increases in microprocessor capacity have since rendered other forms of computers almost completely obsolete (see history of computing hardware), with one or more microprocessors used in everything from the smallest embedded systems -
Controlling Processor C-State Usage in Linux
Controlling Processor C-State Usage in Linux A Dell technical white paper describing the use of C-states with Linux operating systems Stuart Hayes | Enterprise Linux Engineering Controlling Processor C-State Usage in Linux THIS DOCUMENT IS FOR INFORMATIONAL PURPOSES ONLY, AND MAY CONTAIN TYPOGRAPHICAL ERRORS AND TECHNICAL INACCURACIES. THE CONTENT IS PROVIDED AS IS, WITHOUT EXPRESS OR IMPLIED WARRANTIES OF ANY KIND. © 2013 Dell Inc. All rights reserved. Reproduction of this material in any manner whatsoever without the express written permission of Dell Inc. is strictly forbidden. For more information, contact Dell. Dell, the DELL logo, and the DELL badge are trademarks of Dell Inc. Intel and Xeon are registered trademarks of Intel Corporation in the U.S. and other countries. Other trademarks and trade names may be used in this document to refer to either the entities claiming the marks and names or their products. Dell Inc. disclaims any proprietary interest in trademarks and trade names other than its own. November 2013 | Revision 1.1 Page ii Controlling Processor C-State Usage in Linux Contents Introduction ................................................................................................................ 4 Background ................................................................................................................. 4 Checking C-State Usage .................................................................................................. 4 Disabling C-States for Low Latency ...................................................................................