Correctness Tools For Petascale Computing
DOWNLOAD
Download Correctness Tools For Petascale Computing PDF/ePub or read online books in Mobi eBooks. Click Download or Read Online button to get Correctness Tools For Petascale Computing book now. This website allows unlimited access to, at the time of writing, more than 1.5 million titles, including hundreds of thousands of titles in various foreign languages. If the content not found or just blank you must refresh this page
Correctness Tools For Petascale Computing
DOWNLOAD
Author :
language : en
Publisher:
Release Date : 2014
Correctness Tools For Petascale Computing written by and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2014 with categories.
Final Report
DOWNLOAD
Author :
language : en
Publisher:
Release Date : 2014
Final Report written by and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2014 with categories.
In the course of developing parallel programs for leadership computing systems, subtle programming errors often arise that are extremely difficult to diagnose without tools. To meet this challenge, University of Maryland, the University of Wisconsin--Madison, and Rice University worked to develop lightweight tools to help code developers pinpoint a variety of program correctness errors that plague parallel scientific codes. The aim of this project was to develop software tools that help diagnose program errors including memory leaks, memory access errors, round-off errors, and data races. Research at Rice University focused on developing algorithms and data structures to support efficient monitoring of multithreaded programs for memory access errors and data races. This is a final report about research and development work at Rice University as part of this project.
Petascale Computing
DOWNLOAD
Author : David A. Bader
language : en
Publisher: CRC Press
Release Date : 2007-12-22
Petascale Computing written by David A. Bader and has been published by CRC Press this book supported file pdf, txt, epub, kindle and other format this book has been release on 2007-12-22 with Computers categories.
Although the highly anticipated petascale computers of the near future will perform at an order of magnitude faster than today's quickest supercomputer, the scaling up of algorithms and applications for this class of computers remains a tough challenge. From scalable algorithm design for massive concurrency toperformance analyses and scientific vis
Petascale Computing Enabling Technologies Project Final Report
DOWNLOAD
Author :
language : en
Publisher:
Release Date : 2010
Petascale Computing Enabling Technologies Project Final Report written by and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2010 with categories.
The Petascale Computing Enabling Technologies (PCET) project addressed challenges arising from current trends in computer architecture that will lead to large-scale systems with many more nodes, each of which uses multicore chips. These factors will soon lead to systems that have over one million processors. Also, the use of multicore chips will lead to less memory and less memory bandwidth per core. We need fundamentally new algorithmic approaches to cope with these memory constraints and the huge number of processors. Further, correct, efficient code development is difficult even with the number of processors in current systems; more processors will only make it harder. The goal of PCET was to overcome these challenges by developing the computer science and mathematical underpinnings needed to realize the full potential of our future large-scale systems. Our research results will significantly increase the scientific output obtained from LLNL large-scale computing resources by improving application scientist productivity and system utilization. Our successes include scalable mathematical algorithms that adapt to these emerging architecture trends and through code correctness and performance methodologies that automate critical aspects of application development as well as the foundations for application-level fault tolerance techniques. PCET's scope encompassed several research thrusts in computer science and mathematics: code correctness and performance methodologies, scalable mathematics algorithms appropriate for multicore systems, and application-level fault tolerance techniques. Due to funding limitations, we focused primarily on the first three thrusts although our work also lays the foundation for the needed advances in fault tolerance. In the area of scalable mathematics algorithms, our preliminary work established that OpenMP performance of the AMG linear solver benchmark and important individual kernels on Atlas did not match the predictions of our simple initial model. Our investigations demonstrated that a poor default memory allocation mechanism degraded performance. We developed a prototype NUMA library to provide generic mechanisms to overcome these issues, resulting in significantly improved OpenMP performance. After additional testing, we will make this library available to all users, providing a simple means to improve threading on LLNL's production Linux platforms. We also made progress on developing new scalable algorithms that target multicore nodes. We designed and implemented a new AMG interpolation operator with improved convergence properties for very low complexity coarsening schemes. This implementation will also soon be available to LLNL's application teams as part of the hypre library. We presented results for both topics in an invited plenary talk entitled 'Efficient Sparse Linear Solvers for Multi-Core Architectures' at the 2009 HPCMP Institutes Annual Meeting/CREATE Annual All-Hands Meeting. The interpolation work was summarized in a talk entitled 'Improving Interpolation for Aggressive Coarsening' at the 14th Copper Mountain Conference on Multigrid Methods and in a research paper that will appear in Numerical Linear Algebra with Applications. In the area of code correctness, we significantly extended our behavior equivalence class identification mechanism. Specifically, we not only demonstrated it works well at very large scales but we also added the ability to classify MPI tasks not only by function call traces, but also by specific call sites (source code line numbers) being executed by tasks. More importantly, we developed a new technique to determine relative logical execution progress of tasks in the equivalence classes by combining static analysis with our original dynamic approach. We applied this technique to a correctness issue that arose at 4096 tasks during the development of the new AMG interpolation operator discussed above. This scale isat the limit of effectiveness of production tools, but our technique quickly located the erroneous source code, demonstrating the power of understanding relationships between behavioral equivalence classes. This work is the subject of a paper recently accepted to SC09, as well as a presentation entitled 'Providing Order to Extreme Scale Debugging Chaos' given at the ParaDyn Week annual conference in College Park, MD. In addition to this theoretical extension, we have made significant progress in developing a front end for this tool set, and the front-end is now available on several of LLNL's largescale computing resources. In addition, we explored mechanisms to identify exact locations of erroneous MPI usage in application source code. In this work, we developed a new model that led to a highly efficient algorithm for detecting deadlock during dynamic software testing. This work was the subject of a well-received paper at ICS 2009 [4].
Lightweight And Statistical Techniques For Petascale Debugging
DOWNLOAD
Author :
language : en
Publisher:
Release Date : 2011
Lightweight And Statistical Techniques For Petascale Debugging written by and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2011 with categories.
Petascale platforms with O(105) and O(106) processing cores are driving advancements in a wide range of scientific disciplines. These large systems create unprecedented application development challenges. Scalable correctness tools are critical to shorten the time-to-solution on these systems. Currently, many DOE application developers use primitive manual debugging based on printf or traditional debuggers such as TotalView or DDT. This paradigm breaks down beyond a few thousand cores, yet bugs often arise above that scale. Programmers must reproduce problems in smaller runs to analyze them with traditional tools, or else perform repeated runs at scale using only primitive techniques. Even when traditional tools run at scale, the approach wastes substantial effort and computation cycles. Continued scientific progress demands new paradigms for debugging large-scale applications. The Correctness on Petascale Systems (CoPS) project is developing a revolutionary debugging scheme that will reduce the debugging problem to a scale that human developers can comprehend. The scheme can provide precise diagnoses of the root causes of failure, including suggestions of the location and the type of errors down to the level of code regions or even a single execution point. Our fundamentally new strategy combines and expands three relatively new complementary debugging approaches. The Stack Trace Analysis Tool (STAT), a 2011 R & D 100 Award Winner, identifies behavior equivalence classes in MPI jobs and highlights behavior when elements of the class demonstrate divergent behavior, often the first indicator of an error. The Cooperative Bug Isolation (CBI) project has developed statistical techniques for isolating programming errors in widely deployed code that we will adapt to large-scale parallel applications. Finally, we are developing a new approach to parallelizing expensive correctness analyses, such as analysis of memory usage in the Memgrind tool. In the first two years of the project, we have successfully extended STAT to determine the relative progress of different MPI processes. We have shown that the STAT, which is now included in the debugging tools distributed by Cray with their large-scale systems, substantially reduces the scale at which traditional debugging techniques are applied. We have extended CBI to large-scale systems and developed new compiler based analyses that reduce its instrumentation overhead. Our results demonstrate that CBI can identify the source of errors in large-scale applications. Finally, we have developed MPIecho, a new technique that will reduce the time required to perform key correctness analyses, such as the detection of writes to unallocated memory. Overall, our research results are the foundations for new debugging paradigms that will improve application scientist productivity by reducing the time to determine which package or module contains the root cause of a problem that arises at all scales of our high end systems. While we have made substantial progress in the first two years of CoPS research, significant work remains. While STAT provides scalable debugging assistance for incorrect application runs, we could apply its techniques to assertions in order to observe deviations from expected behavior. Further, we must continue to refine STAT's techniques to represent behavioral equivalence classes efficiently as we expect systems with millions of threads in the next year. We are exploring new CBI techniques that can assess the likelihood that execution deviations from past behavior are the source of erroneous execution. Finally, we must develop usable correctness analyses that apply the MPIecho parallelization strategy in order to locate coding errors. We expect to make substantial progress on these directions in the next year but anticipate that significant work will remain to provide usable, scalable debugging paradigms.
Parallel Computing
DOWNLOAD
Author : Barbara Chapman
language : en
Publisher: IOS Press
Release Date : 2010
Parallel Computing written by Barbara Chapman and has been published by IOS Press this book supported file pdf, txt, epub, kindle and other format this book has been release on 2010 with Computers categories.
From Multicores and GPUs to Petascale. Parallel computing technologies have brought dramatic changes to mainstream computing the majority of todays PCs, laptops and even notebooks incorporate multiprocessor chips with up to four processors. Standard components are increasingly combined with GPUs Graphics Processing Unit, originally designed for high-speed graphics processing, and FPGAs Free Programmable Gate Array to build parallel computers with a wide spectrum of high-speed processing functions. The scale of this powerful hardware is limited only by factors such as energy consumption and thermal control. However, in addition to"
Contemporary High Performance Computing
DOWNLOAD
Author : Jeffrey S. Vetter
language : en
Publisher: CRC Press
Release Date : 2017-11-23
Contemporary High Performance Computing written by Jeffrey S. Vetter and has been published by CRC Press this book supported file pdf, txt, epub, kindle and other format this book has been release on 2017-11-23 with Computers categories.
Contemporary High Performance Computing: From Petascale toward Exascale focuses on the ecosystems surrounding the world’s leading centers for high performance computing (HPC). It covers many of the important factors involved in each ecosystem: computer architectures, software, applications, facilities, and sponsors. The first part of the book examines significant trends in HPC systems, including computer architectures, applications, performance, and software. It discusses the growth from terascale to petascale computing and the influence of the TOP500 and Green500 lists. The second part of the book provides a comprehensive overview of 18 HPC ecosystems from around the world. Each chapter in this section describes programmatic motivation for HPC and their important applications; a flagship HPC system overview covering computer architecture, system software, programming systems, storage, visualization, and analytics support; and an overview of their data center/facility. The last part of the book addresses the role of clouds and grids in HPC, including chapters on the Magellan, FutureGrid, and LLGrid projects. With contributions from top researchers directly involved in designing, deploying, and using these supercomputing systems, this book captures a global picture of the state of the art in HPC.
Tools For High Performance Computing 2013
DOWNLOAD
Author : Andreas Knüpfer
language : en
Publisher: Springer
Release Date : 2014-10-06
Tools For High Performance Computing 2013 written by Andreas Knüpfer and has been published by Springer this book supported file pdf, txt, epub, kindle and other format this book has been release on 2014-10-06 with Computers categories.
Current advances in High Performance Computing (HPC) increasingly impact efficient software development workflows. Programmers for HPC applications need to consider trends such as increased core counts, multiple levels of parallelism, reduced memory per core, and I/O system challenges in order to derive well performing and highly scalable codes. At the same time, the increasing complexity adds further sources of program defects. While novel programming paradigms and advanced system libraries provide solutions for some of these challenges, appropriate supporting tools are indispensable. Such tools aid application developers in debugging, performance analysis, or code optimization and therefore make a major contribution to the development of robust and efficient parallel software. This book introduces a selection of the tools presented and discussed at the 7th International Parallel Tools Workshop, held in Dresden, Germany, September 3-4, 2013.
Quantum Monte Carlo Endstation For Petascale Computing
DOWNLOAD
Author :
language : en
Publisher:
Release Date : 2011
Quantum Monte Carlo Endstation For Petascale Computing written by and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2011 with categories.
NCSU research group has been focused on accomplising the key goals of this initiative: establishing new generation of quantum Monte Carlo (QMC) computational tools as a part of Endstation petaflop initiative for use at the DOE ORNL computational facilities and for use by computational electronic structure community at large; carrying out high accuracy quantum Monte Carlo demonstration projects in application of these tools to the forefront electronic structure problems in molecular and solid systems; expanding the impact of QMC methods and approaches; explaining and enhancing the impact of these advanced computational approaches. In particular, we have developed quantum Monte Carlo code (QWalk, www.qwalk.org) which was significantly expanded and optimized using funds from this support and at present became an actively used tool in the petascale regime by ORNL researchers and beyond. These developments have been built upon efforts undertaken by the PI's group and collaborators over the period of the last decade. The code was optimized and tested extensively on a number of parallel architectures including petaflop ORNL Jaguar machine. We have developed and redesigned a number of code modules such as evaluation of wave functions and orbitals, calculations of pfaffians and introduction of backflow coordinates together with overall organization of the code and random walker distribution over multicore architectures. We have addressed several bottlenecks such as load balancing and verified efficiency and accuracy of the calculations with the other groups of the Endstation team. The QWalk package contains about 50,000 lines of high quality object-oriented C++ and includes also interfaces to data files from other conventional electronic structure codes such as Gamess, Gaussian, Crystal and others. This grant supported PI for one month during summers, a full-time postdoc and partially three graduate students over the period of the grant duration, it has resulted in 13 published papers, 15 invited talks and lectures nationally and internationally. My former graduate student and postdoc Dr. Michal Bajdich, who was supported byt this grant, is currently a postdoc with ORNL in the group of Dr. F. Reboredo and Dr. P. Kent and is using the developed tools in a number of DOE projects. The QWalk package has become a truly important research tool used by the electronic structure community and has attracted several new developers in other research groups. Our tools use several types of correlated wavefunction approaches, variational, diffusion and reptation methods, large-scale optimization methods for wavefunctions and enables to calculate energy differences such as cohesion, electronic gaps, but also densities and other properties, using multiple runs one can obtain equations of state for given structures and beyond. Our codes use efficient numerical and Monte Carlo strategies (high accuracy numerical orbitals, multi-reference wave functions, highly accurate correlation factors, pairing orbitals, force biased and correlated sampling Monte Carlo), are robustly parallelized and enable to run on tens of thousands cores very efficiently. Our demonstration applications were focused on the challenging research problems in several fields of materials science such as transition metal solids. We note that our study of FeO solid was the first QMC calculation of transition metal oxides at high pressures.
Euro Par 2011 Parallel Processing Workshops
DOWNLOAD
Author : Michael Alexander
language : en
Publisher: Springer
Release Date : 2012-04-14
Euro Par 2011 Parallel Processing Workshops written by Michael Alexander and has been published by Springer this book supported file pdf, txt, epub, kindle and other format this book has been release on 2012-04-14 with Computers categories.
This book constitutes thoroughly refereed post-conference proceedings of the workshops of the 17th International Conference on Parallel Computing, Euro-Par 2011, held in Bordeaux, France, in August 2011. The papers of these 12 workshops CCPI, CGWS, HeteroPar, HiBB, HPCVirt, HPPC, HPSS HPCF, PROPER, CCPI, and VHPC focus on promotion and advancement of all aspects of parallel and distributed computing.