Using Low-Power Processors in Smartphones Without Knowing Them
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Shared Memory Multiprocessors
Shared Memory Multiprocessors Logical design and software interactions 1 Shared Memory Multiprocessors Symmetric Multiprocessors (SMPs) • Symmetric access to all of main memory from any processor Dominate the server market • Building blocks for larger systems; arriving to desktop Attractive as throughput servers and for parallel programs • Fine-grain resource sharing • Uniform access via loads/stores • Automatic data movement and coherent replication in caches • Useful for operating system too Normal uniprocessor mechanisms to access data (reads and writes) • Key is extension of memory hierarchy to support multiple processors 2 Supporting Programming Models Message passing Programming models Compilation Multiprogramming or library Communication abstraction User/system boundary Shared address space Operating systems support Hardware/software boundary Communication hardware Physical communication medium • Address translation and protection in hardware (hardware SAS) • Message passing using shared memory buffers – can be very high performance since no OS involvement necessary • Focus here on supporting coherent shared address space 3 Natural Extensions of Memory System P1 Pn Switch P1 Pn (Interleaved) First-level $ $ $ Bus (Interleaved) Main memory Mem I/O devices (a) Shared cache (b) Bus-based shared memory P1 Pn P1 Pn $ $ $ $ Mem Mem Interconnection network Interconnection network Mem Mem (c) Dancehall (d) Distributed-memory 4 Caches and Cache Coherence Caches play key role in all cases • Reduce average data access time • Reduce bandwidth -
Introduction to Multi-Threading and Vectorization Matti Kortelainen Larsoft Workshop 2019 25 June 2019 Outline
Introduction to multi-threading and vectorization Matti Kortelainen LArSoft Workshop 2019 25 June 2019 Outline Broad introductory overview: • Why multithread? • What is a thread? • Some threading models – std::thread – OpenMP (fork-join) – Intel Threading Building Blocks (TBB) (tasks) • Race condition, critical region, mutual exclusion, deadlock • Vectorization (SIMD) 2 6/25/19 Matti Kortelainen | Introduction to multi-threading and vectorization Motivations for multithreading Image courtesy of K. Rupp 3 6/25/19 Matti Kortelainen | Introduction to multi-threading and vectorization Motivations for multithreading • One process on a node: speedups from parallelizing parts of the programs – Any problem can get speedup if the threads can cooperate on • same core (sharing L1 cache) • L2 cache (may be shared among small number of cores) • Fully loaded node: save memory and other resources – Threads can share objects -> N threads can use significantly less memory than N processes • If smallest chunk of data is so big that only one fits in memory at a time, is there any other option? 4 6/25/19 Matti Kortelainen | Introduction to multi-threading and vectorization What is a (software) thread? (in POSIX/Linux) • “Smallest sequence of programmed instructions that can be managed independently by a scheduler” [Wikipedia] • A thread has its own – Program counter – Registers – Stack – Thread-local memory (better to avoid in general) • Threads of a process share everything else, e.g. – Program code, constants – Heap memory – Network connections – File handles -
Detecting False Sharing Efficiently and Effectively
W&M ScholarWorks Arts & Sciences Articles Arts and Sciences 2016 Cheetah: Detecting False Sharing Efficiently andff E ectively Tongping Liu Univ Texas San Antonio, Dept Comp Sci, San Antonio, TX 78249 USA; Xu Liu Coll William & Mary, Dept Comp Sci, Williamsburg, VA 23185 USA Follow this and additional works at: https://scholarworks.wm.edu/aspubs Recommended Citation Liu, T., & Liu, X. (2016, March). Cheetah: Detecting false sharing efficiently and effectively. In 2016 IEEE/ ACM International Symposium on Code Generation and Optimization (CGO) (pp. 1-11). IEEE. This Article is brought to you for free and open access by the Arts and Sciences at W&M ScholarWorks. It has been accepted for inclusion in Arts & Sciences Articles by an authorized administrator of W&M ScholarWorks. For more information, please contact [email protected]. Cheetah: Detecting False Sharing Efficiently and Effectively Tongping Liu ∗ Xu Liu ∗ Department of Computer Science Department of Computer Science University of Texas at San Antonio College of William and Mary San Antonio, TX 78249 USA Williamsburg, VA 23185 USA [email protected] [email protected] Abstract 1. Introduction False sharing is a notorious performance problem that may Multicore processors are ubiquitous in the computing spec- occur in multithreaded programs when they are running on trum: from smart phones, personal desktops, to high-end ubiquitous multicore hardware. It can dramatically degrade servers. Multithreading is the de-facto programming model the performance by up to an order of magnitude, significantly to exploit the massive parallelism of modern multicore archi- hurting the scalability. Identifying false sharing in complex tectures. -
Decompose and Conquer: Addressing Evasive Errors in Systems on Chip
Decompose and Conquer: Addressing Evasive Errors in Systems on Chip by Doowon Lee A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy (Computer Science and Engineering) in the University of Michigan 2018 Doctoral Committee: Professor Valeria M. Bertacco, Chair Assistant Professor Reetuparna Das Professor Scott Mahlke Associate Professor Zhengya Zhang Doowon Lee [email protected] ORCID iD: 0000-0003-0046-7746 c Doowon Lee 2018 For my wife, Ghaeun ii ACKNOWLEDGMENTS I would like to express my deepest gratitude to my advisor, Professor Valeria Bertacco. She has affected me in many aspects. She is the most enthusiastic person I have ever met; she always inspires me to achieve more than I could imagine. She has offered an extraordinary research mentorship throughout my Ph.D. journey. She has been consistently available whenever I need her thoughtful advice and keen insight. Also, she has been very patient about my research endeavors, allowing me to navigate different research topics. Her guidance on writing and presentation has been helpful for me to become an outstanding professional after graduation. I also thank my dissertation committee members, Professors Scott Mahlke, Reetuparna Das, and Zhengya Zhang. Their comments on my research projects have been invaluable for me to improve this dissertation. In particular, in-depth discussions with them stimulate me to think out of the box, which in turn strengthens the impacts of the research proposed in the dissertation. Our research group members have helped enjoy a long journey to the degree at the University of Michigan. First of all, I am grateful to Professor Todd Austin for his advice on my research projects. -
A Design Methodology for Soft-Core Platforms on FPGA with SMP Linux
Muttillo et al. EURASIP Journal on Embedded Systems (2016) 2016:15 EURASIP Journal on DOI 10.1186/s13639-016-0051-9 Embedded Systems RESEARCH Open Access A design methodology for soft-core platforms on FPGA with SMP Linux, OpenMP support, and distributed hardware profiling system Vittoriano Muttillo1*, Giacomo Valente1, Fabio Federici1, Luigi Pomante1, Marco Faccio1,CarloTieri2 and Serenella Ferri2 Abstract In recent years, the use of multiprocessor systems has become increasingly common. Even in the embedded domain, the development of platforms based on multiprocessor systems or the porting of legacy single-core applications are frequent needs. However, such designs are often complicated, as embedded systems are characterized by numerous non-functional requirements and a tight hardware/software integration. This work proposes a methodology for the development and validation of an embedded multiprocessor system. Specifically, the proposed method assumes the use of a portable, open source API to support the parallelization and the possibility of prototyping the system on a field-programmable gate array. On this basis, the proposed flow allows an early exploration of the hardware configuration space, a preliminary estimate of performance, and the rapid development of a system able to satisfy the design specifications. An accurate assessment of the actual performance of the system is then enforced by the use of an hardware-based profiling subsystem. The proposed design flow is described, and a version specifically designed for LEON3 processor -
Improving Multiprocessor Performance with Coarse-Grain Coherence Tracking
Improving Multiprocessor Performance with Coarse-Grain Coherence Tracking Jason F. Cantin, Mikko H. Lipasti, and James E. Smith Department of Electrical and Computer Engineering University of Wisconsin, Madison {jcantin, mikko, jes}@ece.wisc.edu Abstract caused by broadcasts, high performance multiprocessor To maintain coherence in conventional shared-memory systems decouple the coherence mechanism from the data multiprocessor systems, processors first check other proc- transfer mechanism, allowing data to be moved directly essors’ caches before obtaining data from memory. This from a memory controller to a processor either over a coherence checking adds latency to memory requests and separate data network [1, 2, 3], or separate virtual chan- leads to large amounts of interconnect traffic in broadcast- nels [4]. This approach to dividing data transfer from based systems. Our results for a set of commercial, scien- coherence enforcement has significant performance poten- tific and multiprogrammed workloads show that on tial because the broadcast bottleneck can be sidestepped. average 67% (and up to 94%) of broadcasts are unneces- Many memory requests simply do not need to be broadcast sary. to the entire system, either because the data is not currently Coarse-Grain Coherence Tracking is a new technique shared, the request is an instruction fetch, the request that supplements a conventional coherence mechanism writes modified data back to memory, or the request is for and optimizes the performance of coherence enforcement. non-cacheable I/O data. The Coarse-Grain Coherence mechanism monitors the coherence status of large regions of memory, and uses that 1.1. Coarse-Grain Coherence Tracking information to avoid unnecessary broadcasts. -
Introduction to Ehealth and Informatics
Using Technology to Teach about Technology: Educational Offerings in mHealth and eHealth @ JHU Betty Jordan, DNSc, RNC Director, Baccalaureate Program Assistant Professor, Johns Hopkins University School of Nursing Edward Bunker, MPH, MS Associate (Instructor), JHU BSPH, Department of International Health Associate Director, Public Health Informatics Certificate Program Health Informatics Advisor, Jhpiego – an affiliate of Johns Hopkins Topics to Cover Brief Overview of the Global mHealth Initiative (GmI) Current course offerings in eHealth and mHealth Course offerings under discussion Experiences with Voice Thread Student service learning and mHealth student internships 2 Why mHealth? At the end of 2011, there were 6 billion mobile subscriptions Int. Telecom Union 2011 That’s almost 86% of the world’ s population 4.5 billion subscriptions are indeveloping the world alone mobiThinking 2012 in addition There are 4.2 billion texters worldwide That’s 5 times the (number of Facebook ) members 6.1 trillion texts sent worldwide each year Source: Tippett.org Mission: To improve global health by developing and advancing appropriate and effective uses of mobile information and communication technologies through innovative mHealth applications, evidence-based research, program evaluation, and advocacy. Vision: • Capitalize on engineering, IT and population-based research strengths • Develop and test novel solutions • Integrate active research into teaching and learning opportunities for students • Facilitate and expand collaborative networks across the Johns Hopkins University 5 6 Simple, Tangible Goals Drive innovation by fostering practical problem-solving − Interdisciplinary collaborations − “Grounded” in field reality − “Systems” construction − Strong emphasis on evaluation research Educate – understand the technology, the evidence, and the broader human systems Build capacity and global partnerships to test and scale mobile ICT where appropriate. -
HCI and Mhealth Wearable Tech: a Multidisciplinary Research Challenge
CHI 2020 Case Study CHI 2020, April 25–30, 2020, Honolulu, HI, USA HCI and mHealth Wearable Tech: A Multidisciplinary Research Challenge Abstract Lucretia Williams Amir Rahmani This paper explores the challenges of HCI work within University of California, Irvine University of California, Irvine multidisciplinary research projects across health Department of informatics School of Nursing sciences, social sciences, and engineering, through Irvine, CA, USA Irvine, CA, USA discussion of a specific case study research project [email protected] [email protected] focused on supporting under-resourced pregnant women. Capturing the perspectives of community- Gillian R. Hayes Nikil Dutt based health care workers (N=14) using wearable University of California, Irvine University of California, Irvine technology for servicing pregnant women provided Department of Informatics Department of Computer insight into considerations for technology for this Irvine, CA, USA Science specific population. Methods of inquiry included design [email protected] Irvine, CA, USA and development of a prototype wearable and mobile [email protected] system as well as self-report via a survey detailing their Yuqing Guo experience with the system and how it can possibly University of California, Irvine benefit their duties of monitoring their pregnant School of Nursing patients. The process outcomes of this work, however, Irvine, CA, USA provide broader insight into the challenges of [email protected] conducting this kind of interdisciplinary work that remain despite decades of effort and financial investment to support interdisciplinary research, particularly in health informatics and interactive Permission to make digital or hard copies of part or all of this work for technologies for health. -
Mhealth Basics: Introduction to Mobile Technology for Health Elearning
mHealth Basics: Introduction to Mobile Technology for Health eLearning Course Participant Study Group Preliminary Report January 12 – February 4, 2015 http://www.globalhealthlearning.org/community/89786 Background To enhance learners’ understanding of the main concepts in the mHealth Basics: Introduction to Mobile Technology for Health course and develop the basic skills needed to plan and implement digital health programs in the field, the K4Health Project facilitated an online, time-bound, cohort-based learning event in which learners were able to receive virtual technical assistance from digital health subject matter experts as well as learn from each other by discussing questions, challenges, and successes in working in the digital health field. The purpose of this study group was: • to help explore and think critically about course concepts as they move through the course material • to provide a virtual space for learners to connect with each other and with mHealth implementers from around the world • to elicit and share relevant, practical programmatic experiences related to mHealth The formal study group ran from January 12 – February 4, 2015. Prior to each day’s discussion, the study group facilitators, Trinity Zan of FHI 360 and Nandini Jayarajan of Johns Hopkins Center for Communication Programs (CCP), asked participants to read a session or sessions of the course, then respond to discussion questions posted to the online forum. Participants were encouraged to visit the online learning space to reflect on the discussion questions, ask questions, and share experiences related to their professional work, as well as how they have and/or plan to apply what they have learned from the course into their jobs. -
Mobile Technology-Based Services for Global Health and Wellness: Opportunities and Challenges”
“MOBILE TECHNOLOGY-BASED SERVICES FOR GLOBAL HEALTH AND WELLNESS: OPPORTUNITIES AND CHALLENGES” Summary of Main points from the OECD-HARVARD Global Health Institute Expert Consultation of 5-6 October 2016. This document reports on key issues emerging from the OECD Expert Consultation: “Mobile Technologies Based Services for Global Health and Wellness: Opportunities and Challenges (http://www.oecd.org/sti/ieconomy/mobile- technology-based-services-for-global-health.htm)”. The Consultation’s objectives were to further international dialogue on issues critical for the successful adoption of mobile-technology-based services for health and wellness with a special focus on privacy, security, quality assurance challenges and measurement needs for evidence-based policy-making. The Expert Consultation was held on 5-6 October, 2016 in Boston (US) at The Harvard Global Health Institute, in collaboration with Swedish Vinnova, Canada Health Infoway and the Global Coalition on Aging. Their financial support and that of participating member countries is gratefully acknowledged. This report was drafted by Elettra Ronchi (Senior Policy Analyst , Digital Economy and Policy Division, OECD), Liana Rosenkrantz Woskie (Assistant Director Harvard Global Health Institute Strategic Initiative on Quality, US ; London School of Informatics, UK) and Julia Adler Milstein (Associate Professor, University of California, San Francisco, US) based on inputs from workshop experts, the OECD Health Committee and the OECD Working Party on Security and Privacy in the Digital -
The Future of Health Is Mobile and Social
The Future of Health is Mobile and Social Jay M. Bernhardt, PhD, MPH Professor of Health Education and Behavior Director of the Center for Digital Health and Wellness College of Health and Human Performance and College of Public Health and Health Professions @jaybernhardt Starting Summer 2014 • Professor in the Moody College of Communication, University of Texas at Austin and Everett D. Collier Centennial Chair in Communication • Founding Director of a new “UT Center for Health Communication” • Expected joint appointments in the new Dell School of Medicine, UT College of Education, and UT-H School of Public Health - Austin Regional Campus • [email protected] @jaybernhardt Social Media Today and Tomorrow http://www.youtube.com/v/zxpa4dNVd3c @jaybernhardt Adult Gadget Ownership (2006-2013) http://www.pewinternet.org/Trend-Data-(Adults)/Device-Ownership.aspx @jaybernhardt Mobile Only Households @jaybernhardt Mobile Only Households • Hispanic adults (51%) more likely than non-Hispanic white adults (33%) or non-Hispanic black adults (39%) to be mobile only • Renters (54%) more mobile only than home owners (25%) • People in mobile-only households exhibit more risk behaviors – 5 or more drinks/day: 30% mobile 18% landlines – Smokers: 30% mobile 14% landlines – Get flu vaccine: 28% mobile 43% landlines • Take home message: Mobile-only households are significantly different from households with landlines Source: CDC NCHS Wireless Substitution Early Release of Estimates from the National Health Interview Survey, July – December 2012 @jaybernhardt Mobile Phone Activities (2010) @jaybernhardt Text Message Use (SMS) Continues to Increase • 9.8T SMS messages sent in 2012 • 80% of all US cell phone owners text • 92% of US smart phone owners text • US SMS users average 35 texts per day • 54% of “digital natives” prefer texting over talking vs. -
How 5G Technology Enables the Health Internet of Things Darrell M
July 2016 How 5G technology enables the health internet of things Darrell M. West INTRODUCTION magine a world where you can download an interactive 3-D video in a few seconds, a smart home anticipates your needs, and autonomous vehicles take you to your destination safely. This is the world of fifth-generation (5G) broadband technology. It promises speeds of more I 1 than 100 megabits per second, more data bandwidth, and fewer delays due to built-in computing intelligence that handles data very efficiently. This new era of 5G will bring together improved connectivity, cloud-based storage, and an array Darrell M. West is vice president and director of of connected devices and services. Extensive computing capability combined with virtual system Governance Studies and architecture will open up a mobile internet of things (IoT). Advanced digital networks will bring founding director of the Center for Technology together a system that connects billions of devices and sensors enabling advances in health care, Innovation at Brookings. His studies include education, resource management, transportation, agriculture, and many other areas. While much technology policy, of this work is underway today, we will see big strides soon at the 2018 Winter Olympics. Korean electronic government, 2 and mass media. mobile operators there will provide internet service at ultra-fast rates of 20GBs per second. Other developed countries expect to offer commercial 5G networks by 2020. With the number of digital devices expected to rise dramatically, much of the world will be connected around the clock.3 In this paper, I show how 5G differs from previous generations of advancement (3G and 4G), discuss emerging applications in health care, and demonstrate how these developments will enable new systems of care delivery.