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All-Reduce
Collective operations are building blocks for interaction patterns, that are often used in SPMD algorithms in the parallel programming context. Hence, there is an interest in efficient realizations of these operations. A realization of the collective operations is provided by the Message Passing Interface The Message Passing Interface (MPI) standard, chapter 7.3.1. Mathematics and Computer Science Division, . (MPI). Definitions In all asymptotic runtime functions, we denote the latency , the communication cost per word |
Hypercube (communication Pattern)
d-dimensional hypercube is a network topology for parallel computers with 2^d processing elements. The topology allows for an efficient implementation of some basic communication primitives such as Broadcast, All- Reduce, and Prefix sum. The processing elements are numbered 0 through 2^d - 1. Each processing element is adjacent to processing elements whose numbers differ in one and only one bit. The algorithms described in this page utilize this structure efficiently. Algorithm outline Most of the communication primitives presented in this article share a common template. Initially, each processing element possesses one message that must reach every other processing element during the course of the algorithm. The following pseudo code sketches the communication steps necessary. Hereby, Initialization, Operation, and Output are placeholders that depend on the given communication primitive (see next section). Input: message m. Output: depends on Initialization, Operation and Outpu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Barrier (computer Science)
In parallel computing, a barrier is a type of synchronization method. A barrier for a group of threads or processes in the source code means any thread/process must stop at this point and cannot proceed until all other threads/processes reach this barrier. Many collective routines and directive-based parallel languages impose implicit barriers. For example, a parallel ''do'' loop in Fortran with OpenMP will not be allowed to continue on any thread until the last iteration is completed. This is in case the program relies on the result of the loop immediately after its completion. In message passing, any global communication (such as reduction or scatter) may imply a barrier. In concurrent computing, a barrier may be in a ''raised'' or ''lowered state''. The term latch is sometimes used to refer to a barrier that starts in the raised state and cannot be re-raised once it is in the lowered state. The term count-down latch is sometimes used to refer to a latch that is automatically ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parallel Computing
Parallel computing is a type of computation in which many calculations or processes are carried out simultaneously. Large problems can often be divided into smaller ones, which can then be solved at the same time. There are several different forms of parallel computing: bit-level, instruction-level, data, and task parallelism. Parallelism has long been employed in high-performance computing, but has gained broader interest due to the physical constraints preventing frequency scaling.S.V. Adve ''et al.'' (November 2008)"Parallel Computing Research at Illinois: The UPCRC Agenda" (PDF). Parallel@Illinois, University of Illinois at Urbana-Champaign. "The main techniques for these performance benefits—increased clock frequency and smarter but increasingly complex architectures—are now hitting the so-called power wall. The computer industry has accepted that future performance increases must largely come from increasing the number of processors (or cores) on a die, rather tha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Network Topology
Network topology is the arrangement of the elements ( links, nodes, etc.) of a communication network. Network topology can be used to define or describe the arrangement of various types of telecommunication networks, including command and control radio networks, industrial fieldbusses and computer networks. Network topology is the topological structure of a network and may be depicted physically or logically. It is an application of graph theory wherein communicating devices are modeled as nodes and the connections between the devices are modeled as links or lines between the nodes. Physical topology is the placement of the various components of a network (e.g., device location and cable installation), while logical topology illustrates how data flows within a network. Distances between nodes, physical interconnections, transmission rates, or signal types may differ between two different networks, yet their logical topologies may be identical. A network’s physical topology ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Grid Network
Elex Media Komputindo is a publishing company in Indonesia which publishes books, comics, magazines, novels and other print media. Established on January 15, 1985, Elex Media Komputindo is a subsidiary of Kompas Gramedia Group. Elex is headquartered in Tanah Abang, Central Jakarta. Elex Media Komputindo is known as the pioneer of manga publishing in Indonesia, and is now one of the largest comic publishers in Indonesia. History Established in 1985, Elex Media initially published various electronic and computer-themed books. The founder of Kompas, Jakob Oetama, was interested in the potential of manga during his visit to Japan in the late 1980s. In 1991, Elex Media plunged into the manga publishing industry with the publication of Kyoko Mizuki's ''Candy Candy'' manga, originally published by Kodansha. Other manga like '' Kungfu Boy'', ''Doraemon'', and '' Dragon Ball'' began to follow. The decision of the New Order government to allow the establishment of private television ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fat Tree
The fat tree network is a universal network for provably efficient communication. It was invented by Charles E. Leiserson of the Massachusetts Institute of Technology in 1985. k-ary n-trees, the type of fat-trees commonly used in most high-performance networks, were initially formalized in 1997. In a tree data structure, every branch has the same thickness, regardless of their place in the hierarchy—they are all "skinny" (''skinny'' in this context means low- bandwidth). In a fat tree, branches nearer the top of the hierarchy are "fatter" (thicker) than branches further down the hierarchy. In a telecommunications network, the branches are data links; the varied thickness (bandwidth) of the data links allows for more efficient and technology-specific use. Mesh and hypercube topologies have communication requirements that follow a rigid algorithm, and cannot be tailored to specific packaging technologies. Applications in supercomputers Supercomputers that use a fat tree netwo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scatter
{{disambiguation ...
Scatter may refer to: * Scattering, in physics, the study of collisions * Statistical dispersion or scatter * Scatter (modeling), a substance used in the building of dioramas and model railways * Scatter, in computer programming, a parameter in network broadcasting * Scatter (band), a Scottish improvisational music collective See also * Scatter plot, a type of diagram * Scattered (other) Scattered may refer to: Music * Scattered (album), ''Scattered'' (album), a 2010 album by The Handsome Family * Scattered (The Kinks song), "Scattered" (The Kinks song), 1993 * "Scattered", a song by Ace Young * "Scattered", a song by Lauren Jaure ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gather
Gather, gatherer, or gathering may refer to: Anthropology and sociology *Hunter-gatherer, a person or a society whose subsistence depends on hunting and gathering of wild foods * Intensive gathering, the practice of cultivating wild plants as a step toward domestication *Harvesting crops Craftwork * Gather (sewing), an area where fabric is folded or bunched together with thread or yarn * Gather (knitting), a generic term for one of several knitting techniques to draw stitches closer together *Gathering (bookbinding), a number of sheets of paper folded and sewn or glued as a group into a bookbinding Gathering *Gathering, any type of party or meeting, including: ** Bee (gathering), an old term which describes a group of people coming together for a task **Salon (gathering), a party associated with French and Italian intellectuals * Global gathering, a music festival in the United Kingdom * Rainbow Gathering * Ricochet Gathering, a music event in the United States * Tribal Gathering, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SPMD
In computing, single program, multiple data (SPMD) is a technique employed to achieve parallelism; it is a subcategory of MIMD. Tasks are split up and run simultaneously on multiple processors with different input in order to obtain results faster. SPMD is the most common style of parallel programming. It is also a prerequisite for research concepts such as active messages and distributed shared memory. SPMD vs SIMD In SPMD, multiple autonomous processors simultaneously execute the same program at independent points, rather than in the lockstep that SIMD or SIMT imposes on different data. With SPMD, tasks can be executed on general purpose CPUs; SIMD requires vector processors to manipulate data streams. Note that the two are not mutually exclusive. Distributed memory SPMD usually refers to message passing programming on distributed memory computer architectures. A distributed memory computer consists of a collection of independent computers, called nodes. Each node starts ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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