What Every Programmer Should Know About Memory
Total Page:16
File Type:pdf, Size:1020Kb
Load more
Recommended publications
-
Better Performance Through a Disk/Persistent-RAM Hybrid Design
The Conquest File System: Better Performance Through a Disk/Persistent-RAM Hybrid Design AN-I ANDY WANG Florida State University GEOFF KUENNING Harvey Mudd College PETER REIHER, GERALD POPEK University of California, Los Angeles ________________________________________________________________________ Modern file systems assume the use of disk, a system-wide performance bottleneck for over a decade. Current disk caching and RAM file systems either impose high overhead to access memory content or fail to provide mechanisms to achieve data persistence across reboots. The Conquest file system is based on the observation that memory is becoming inexpensive, which enables all file system services to be delivered from memory, except providing large storage capacity. Unlike caching, Conquest uses memory with battery backup as persistent storage, and provides specialized and separate data paths to memory and disk. Therefore, the memory data path contains no disk-related complexity. The disk data path consists of only optimizations for the specialized disk usage pattern. Compared to a memory-based file system, Conquest incurs little performance overhead. Compared to several disk-based file systems, Conquest achieves 1.3x to 19x faster memory performance, and 1.4x to 2.0x faster performance when exercising both memory and disk. Conquest realizes most of the benefits of persistent RAM at a fraction of the cost of a RAM-only solution. Conquest also demonstrates that disk-related optimizations impose high overheads for accessing memory content in a memory-rich environment. Categories and Subject Descriptors: D.4.2 [Operating Systems]: Storage Management—Storage Hierarchies; D.4.3 [Operating Systems]: File System Management—Access Methods and Directory Structures; D.4.8 [Operating Systems]: Performance—Measurements General Terms: Design, Experimentation, Measurement, and Performance Additional Key Words and Phrases: Persistent RAM, File Systems, Storage Management, and Performance Measurement ________________________________________________________________________ 1. -
Virtual Memory
Chapter 4 Virtual Memory Linux processes execute in a virtual environment that makes it appear as if each process had the entire address space of the CPU available to itself. This virtual address space extends from address 0 all the way to the maximum address. On a 32-bit platform, such as IA-32, the maximum address is 232 − 1or0xffffffff. On a 64-bit platform, such as IA-64, this is 264 − 1or0xffffffffffffffff. While it is obviously convenient for a process to be able to access such a huge ad- dress space, there are really three distinct, but equally important, reasons for using virtual memory. 1. Resource virtualization. On a system with virtual memory, a process does not have to concern itself with the details of how much physical memory is available or which physical memory locations are already in use by some other process. In other words, virtual memory takes a limited physical resource (physical memory) and turns it into an infinite, or at least an abundant, resource (virtual memory). 2. Information isolation. Because each process runs in its own address space, it is not possible for one process to read data that belongs to another process. This improves security because it reduces the risk of one process being able to spy on another pro- cess and, e.g., steal a password. 3. Fault isolation. Processes with their own virtual address spaces cannot overwrite each other’s memory. This greatly reduces the risk of a failure in one process trig- gering a failure in another process. That is, when a process crashes, the problem is generally limited to that process alone and does not cause the entire machine to go down. -
Red Hat Enterprise Linux 6 Developer Guide
Red Hat Enterprise Linux 6 Developer Guide An introduction to application development tools in Red Hat Enterprise Linux 6 Dave Brolley William Cohen Roland Grunberg Aldy Hernandez Karsten Hopp Jakub Jelinek Developer Guide Jeff Johnston Benjamin Kosnik Aleksander Kurtakov Chris Moller Phil Muldoon Andrew Overholt Charley Wang Kent Sebastian Red Hat Enterprise Linux 6 Developer Guide An introduction to application development tools in Red Hat Enterprise Linux 6 Edition 0 Author Dave Brolley [email protected] Author William Cohen [email protected] Author Roland Grunberg [email protected] Author Aldy Hernandez [email protected] Author Karsten Hopp [email protected] Author Jakub Jelinek [email protected] Author Jeff Johnston [email protected] Author Benjamin Kosnik [email protected] Author Aleksander Kurtakov [email protected] Author Chris Moller [email protected] Author Phil Muldoon [email protected] Author Andrew Overholt [email protected] Author Charley Wang [email protected] Author Kent Sebastian [email protected] Editor Don Domingo [email protected] Editor Jacquelynn East [email protected] Copyright © 2010 Red Hat, Inc. and others. The text of and illustrations in this document are licensed by Red Hat under a Creative Commons Attribution–Share Alike 3.0 Unported license ("CC-BY-SA"). An explanation of CC-BY-SA is available at http://creativecommons.org/licenses/by-sa/3.0/. In accordance with CC-BY-SA, if you distribute this document or an adaptation of it, you must provide the URL for the original version. Red Hat, as the licensor of this document, waives the right to enforce, and agrees not to assert, Section 4d of CC-BY-SA to the fullest extent permitted by applicable law. -
Exploring Weak Scalability for FEM Calculations on a GPU-Enhanced Cluster
Exploring weak scalability for FEM calculations on a GPU-enhanced cluster Dominik G¨oddeke a,∗,1, Robert Strzodka b,2, Jamaludin Mohd-Yusof c, Patrick McCormick c,3, Sven H.M. Buijssen a, Matthias Grajewski a and Stefan Turek a aInstitute of Applied Mathematics, University of Dortmund bStanford University, Max Planck Center cComputer, Computational and Statistical Sciences Division, Los Alamos National Laboratory Abstract The first part of this paper surveys co-processor approaches for commodity based clusters in general, not only with respect to raw performance, but also in view of their system integration and power consumption. We then extend previous work on a small GPU cluster by exploring the heterogeneous hardware approach for a large-scale system with up to 160 nodes. Starting with a conventional commodity based cluster we leverage the high bandwidth of graphics processing units (GPUs) to increase the overall system bandwidth that is the decisive performance factor in this scenario. Thus, even the addition of low-end, out of date GPUs leads to improvements in both performance- and power-related metrics. Key words: graphics processors, heterogeneous computing, parallel multigrid solvers, commodity based clusters, Finite Elements PACS: 02.70.-c (Computational Techniques (Mathematics)), 02.70.Dc (Finite Element Analysis), 07.05.Bx (Computer Hardware and Languages), 89.20.Ff (Computer Science and Technology) ∗ Corresponding author. Address: Vogelpothsweg 87, 44227 Dortmund, Germany. Email: [email protected], phone: (+49) 231 755-7218, fax: -5933 1 Supported by the German Science Foundation (DFG), project TU102/22-1 2 Supported by a Max Planck Center for Visual Computing and Communication fellowship 3 Partially supported by the U.S. -
Chapter 3. Booting Operating Systems
Chapter 3. Booting Operating Systems Abstract: Chapter 3 provides a complete coverage on operating systems booting. It explains the booting principle and the booting sequence of various kinds of bootable devices. These include booting from floppy disk, hard disk, CDROM and USB drives. Instead of writing a customized booter to boot up only MTX, it shows how to develop booter programs to boot up real operating systems, such as Linux, from a variety of bootable devices. In particular, it shows how to boot up generic Linux bzImage kernels with initial ramdisk support. It is shown that the hard disk and CDROM booters developed in this book are comparable to GRUB and isolinux in performance. In addition, it demonstrates the booter programs by sample systems. 3.1. Booting Booting, which is short for bootstrap, refers to the process of loading an operating system image into computer memory and starting up the operating system. As such, it is the first step to run an operating system. Despite its importance and widespread interests among computer users, the subject of booting is rarely discussed in operating system books. Information on booting are usually scattered and, in most cases, incomplete. A systematic treatment of the booting process has been lacking. The purpose of this chapter is to try to fill this void. In this chapter, we shall discuss the booting principle and show how to write booter programs to boot up real operating systems. As one might expect, the booting process is highly machine dependent. To be more specific, we shall only consider the booting process of Intel x86 based PCs. -
Red Hat Enterprise Linux 8 Security Hardening
Red Hat Enterprise Linux 8 Security hardening Securing Red Hat Enterprise Linux 8 Last Updated: 2021-09-06 Red Hat Enterprise Linux 8 Security hardening Securing Red Hat Enterprise Linux 8 Legal Notice Copyright © 2021 Red Hat, Inc. The text of and illustrations in this document are licensed by Red Hat under a Creative Commons Attribution–Share Alike 3.0 Unported license ("CC-BY-SA"). An explanation of CC-BY-SA is available at http://creativecommons.org/licenses/by-sa/3.0/ . In accordance with CC-BY-SA, if you distribute this document or an adaptation of it, you must provide the URL for the original version. Red Hat, as the licensor of this document, waives the right to enforce, and agrees not to assert, Section 4d of CC-BY-SA to the fullest extent permitted by applicable law. Red Hat, Red Hat Enterprise Linux, the Shadowman logo, the Red Hat logo, JBoss, OpenShift, Fedora, the Infinity logo, and RHCE are trademarks of Red Hat, Inc., registered in the United States and other countries. Linux ® is the registered trademark of Linus Torvalds in the United States and other countries. Java ® is a registered trademark of Oracle and/or its affiliates. XFS ® is a trademark of Silicon Graphics International Corp. or its subsidiaries in the United States and/or other countries. MySQL ® is a registered trademark of MySQL AB in the United States, the European Union and other countries. Node.js ® is an official trademark of Joyent. Red Hat is not formally related to or endorsed by the official Joyent Node.js open source or commercial project. -
ELF1 7D Virtual Memory
ELF1 7D Virtual Memory Young W. Lim 2021-07-06 Tue Young W. Lim ELF1 7D Virtual Memory 2021-07-06 Tue 1 / 77 Outline 1 Based on 2 Virtual memory Virtual Memory in Operating System Physical, Logical, Virtual Addresses Kernal Addresses Kernel Logical Address Kernel Virtual Address User Virtual Address User Space Young W. Lim ELF1 7D Virtual Memory 2021-07-06 Tue 2 / 77 Based on "Study of ELF loading and relocs", 1999 http://netwinder.osuosl.org/users/p/patb/public_html/elf_ relocs.html I, the copyright holder of this work, hereby publish it under the following licenses: GNU head Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.2 or any later version published by the Free Software Foundation; with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A copy of the license is included in the section entitled GNU Free Documentation License. CC BY SA This file is licensed under the Creative Commons Attribution ShareAlike 3.0 Unported License. In short: you are free to share and make derivative works of the file under the conditions that you appropriately attribute it, and that you distribute it only under a license compatible with this one. Young W. Lim ELF1 7D Virtual Memory 2021-07-06 Tue 3 / 77 Compling 32-bit program on 64-bit gcc gcc -v gcc -m32 t.c sudo apt-get install gcc-multilib sudo apt-get install g++-multilib gcc-multilib g++-multilib gcc -m32 objdump -m i386 Young W. -
Secure Foundations: Why RHEL Isn't Just Another Linux
Secure Foundations: Why RHEL isn’t just another Linux distribution Lucy Kerner Principal Technical Product Marketing Manager - Security, Red Hat May 3, 2017 ONLY TWO OPERATING SYSTEMS MATTER WORLDWIDE SERVER OPERATING ENVIRONMENT NEW LICENSE SHIPMENTS AND PAID SUBSCRIPTIONS 2008-2019 (000) Why does the OS matter? “Vulnerabilities, patch management, and their exploitation are still the root cause of most breaches.” - Gartner, September 2016 [http://www.gartner.com/doc/3438517/time-align-vulnerability-manageme nt-priorities] There are lots of OS’s out there…. TRADITIONAL LIGHTWEIGHT ABSTRACTION 15 Years of Making Open Source Enterprise-Ready PARTICIPATE We participate in and create STABILIZE community-powered upstream projects. We commercialize these platforms together with a rich ecosystem of services and certifications. INTEGRATE We integrate upstream projects, fostering open Containers community platforms. Secure Virtualization Software IBM Power Control Groups Defined Cluster File IBM Z Series Automated Security Real-Time Networking Red Hat Systems Audits Kernel Enterprise Virtualization Software Linux is Born Defined Storage ‘02 ‘03 ‘05 ‘07 ‘10 ‘11 ‘12 ‘13 ‘15 ‘17 Top Corporate Maintainer of the Linux Kernel CORPORATE SIGNOFFS SINCE KERNEL 3.19 Source: Linux Kernel Development (The Linux Foundation, August 2016) What security do I get with Red Hat Enterprise Linux? Security Technologies in Red Hat Enterprise Linux Identity Crypto SELinux Management OpenSCAP Auditd IdM/SSSD VALUE OF A RED HAT SUBSCRIPTION CUSTOMER GLOBAL AUTOMATED PRODUCT EXPERTISE PORTAL TECHNICAL SERVICES SECURITY SUPPORT CERTIFICATIONS COMMUNITIES CONTINUOUS ASSURANCES LIFE-CYCLE FEEDBACK PROMISE PRODUCT SECURITY MISSION Red Hat Product Security's mission is to help protect customers from meaningful security concerns and manage vulnerabilities in open source software. -
View Annual Report
2013 ANNUAL REPORT ON FORM 10-K Dear Stockholders: In 2013, we made significant progress in bringing AMD closer to our mission of becoming the world’s leading designer and integrator of innovative, tailored technology solutions that empower people to push the boundaries of what is possible. Throughout the year, we achieved many goals the Company set going into 2013 despite broader PC industry challenges. Transformation and Progress: Profitability and Acceleration of Our Business Our strategic three-phase plan to transform AMD began with resetting and restructuring our business to lay the foundation for the acceleration of our growth. By the end of 2013, we successfully implemented phase one and phase two of our turnaround plan to create a more efficient and sustainable business model in the following ways: • Reducing our operating expenses more than 30 percent from the first quarter of 2012 to the fourth quarter of 2013. • Generating more than 30 percent of our net revenues in the second half of 2013 from our semi-custom and embedded businesses, both high-growth focus areas for AMD. • Exiting the year with cash balances, including marketable securities, of $1.2 billion, above our optimal cash balance target of $1.1 billion, and establishing an incremental secured revolving line of credit up to $500 million. • Returning to profitability and free cash flow in the second half of the year. I’m very pleased to report that AMD has also made steady progress on phase three of our plan: to transform our business into a high-growth market competitor. Our business transformation is being propelled by an increasingly diversified product portfolio and a focus on driving to 50 percent of AMD revenue from five high-growth markets by the end of 2015: semi-custom solutions, ultra-low power client PC, embedded, dense server, and professional graphics. -
Catalyst™ Software Suite Version 9.5 Release Notes
Catalyst™ Software Suite Version 9.5 Release Notes This release note provides information on the latest posting of AMD’s industry leading software suite, Catalyst™. This particular software suite updates both the AMD Display Driver, and the Catalyst™ Control Center. This unified driver has been further enhanced to provide the highest level of power, performance, and reliability. The AMD Catalyst™ software suite is the ultimate in performance and stability. For exclusive Catalyst™ updates follow Catalyst Maker on Twitter. This release note provides information on the following: z Web Content z AMD Product Support z Operating Systems Supported z New Features z Performance Improvements z Resolved Issues for the Windows Vista Operating System z Resolved Issues for the Windows XP Operating System z Resolved Issues for the Windows 7 Operating System z Known Issues Under the Windows Vista Operating System z Known Issues Under the Windows XP Operating System z Known Issues Under the Windows 7 Operating System z Installing the Catalyst™ Vista Software Driver z Catalyst™ Crew Driver Feedback ATI Catalyst™ Release Note Version 9.5 1 Web Content The Catalyst™ Software Suite 9.5 contains the following: z Radeon™ display driver 8.612 z HydraVision™ for both Windows XP and Vista z HydraVision™ Basic Edition (Windows XP only) z WDM Driver Install Bundle z Southbridge/IXP Driver z Catalyst™ Control Center Version 8.612 Caution: The Catalyst™ software driver and the Catalyst™ Control Center can be downloaded independently of each other. However, for maximum stability and performance AMD recommends that both components be updated from the same Catalyst™ release. -
Lewis University Dr. James Girard Summer Undergraduate Research Program 2021 Faculty Mentor - Project Application
Lewis University Dr. James Girard Summer Undergraduate Research Program 2021 Faculty Mentor - Project Application Exploring the Use of High-level Parallel Abstractions and Parallel Computing for Functional and Gate-Level Simulation Acceleration Dr. Lucien Ngalamou Department of Engineering, Computing and Mathematical Sciences Abstract System-on-Chip (SoC) complexity growth has multiplied non-stop, and time-to- market pressure has driven demand for innovation in simulation performance. Logic simulation is the primary method to verify the correctness of such systems. Logic simulation is used heavily to verify the functional correctness of a design for a broad range of abstraction levels. In mainstream industry verification methodologies, typical setups coordinate the validation e↵ort of a complex digital system by distributing logic simulation tasks among vast server farms for months at a time. Yet, the performance of logic simulation is not sufficient to satisfy the demand, leading to incomplete validation processes, escaped functional bugs, and continuous pressure on the EDA1 industry to develop faster simulation solutions. In this research, we will explore a solution that uses high-level parallel abstractions and parallel computing to boost the performance of logic simulation. 1Electronic Design Automation 1 1 Project Description 1.1 Introduction and Background SoC complexity is increasing rapidly, driven by demands in the mobile market, and in- creasingly by the fast-growth of assisted- and autonomous-driving applications. SoC teams utilize many verification technologies to address their complexity and time-to-market chal- lenges; however, logic simulation continues to be the foundation for all verification flows, and continues to account for more than 90% [10] of all verification workloads. -
Virtualization: Comparision of Windows and Linux
VIRTUALIZATION: COMPARISION OF WINDOWS AND LINUX Ms. Pooja Sharma Lecturer (I.T) PCE, Jaipur Email:[email protected] Charnaksh Jain IV yr (I.T) PCE, Jaipur [email protected] Abstract Full-Virtualization, Para-Virtualization, hyper- visior(Hyper-V), Guest Operating System, Host Virtualization as a concept is not new; computational Operating System. environment virtualization has been around since the first mainframe systems. But recently, the term 1. Introduction "virtualization" has become ubiquitous, representing any type of process obfuscation where a process is Virtualization provides a set of tools for increasing somehow removed from its physical operating flexibility and lowering costs, things that are environment. Because of this ambiguity, important in every enterprise and Information virtualization can almost be applied to any and all Technology organization. Virtualization solutions are parts of an IT infrastructure. For example, mobile becoming increasingly available and rich in features. device emulators are a form of virtualization because the hardware platform normally required to run the Since virtualization can provide significant benefits mobile operating system has been emulated, to your organization in multiple areas, you should be removing the OS binding from the hardware it was establishing pilots, developing expertise and putting written for. But this is just one example of one type virtualization technology to work now. of virtualization; there are many definitions of the In essence, virtualization increases flexibility by term "virtualization" floating around in the current decoupling an operating system and the services and lexicon, and all (or at least most) of them are correct, applications supported by that system from a specific which can be quite confusing.