Parallel Programming
|
|
- Whitney Grant
- 6 years ago
- Views:
Transcription
1 Parallel Programming Lecture delivered by: Venkatanatha Sarma Y Assistant Professor MSRSAS-Bangalore 1
2 Session Objectives To understand the parallelization in terms of computational solutions. To understand the difference between designing an algorithm as a sequential solution and as a parallel solution To understand how to estimate Time and Space complexity for a given parallel algorithm To be aware of provisions for parallelism provided by a programming language 2
3 Introduction We have worked with sequential logic so far Today, multi core processors are common GPUs can also join in and help in computation Is it not a waste of resources if we do not use these idle computational elements? Can we make all algorithms work in parallel? What is the effect on data? 3
4 Which Algorithms Can Be Parallelized Not all algorithms can be parallelized Parallel logic requires different types of data Shared All execution blocks have access Private or Local Only one execution block has access Parallel logic also requires synchronization 4
5 Comparison of Two Algorithms Binary Search Divides problem space by half at each execution Quick Sort Requires access to complete problem space at all times Can be parallelized but complexity remains same Divides problem space at each iteration Finds location of pivot at each iteration Does not require access to all elements 5
6 Types of Data 6
7 Shared Data When executing a parallel program, there is a possibility that data can be shared among parallel Threads of execution The programmer or the language must ensure sanity of this data Such data is treated as a Critical Section Programming languages provide mechanisms to programmer such as semaphores (C) and Monitors (synchronized in Java) to deal with such sections of data 7
8 Private Data Data that is not shared Local information such as temporary variables Data available to all the threads as a copy of original data Loop invariant data that is not written to but is only read from Most variables that we use fall in to this category No need to worry about sanity of this set 8
9 Synchronization One thread has to finish before other starts its work Producer/Consumer problems All threads have to finish before continuing Parallelized blocks of logic arranged in sequence Merge Sort 9
10 Parallelization of Quick Sort 10
11 Recap Sorting of a list of numbers in ascending order Selection of Pivot Generating High List and Low List Recursively applying the algorithm on high list and low list 11
12 Example List: [4,11,14,17,22,63,65,79,89,95] Chosen Pivot: 79 High List: [89,95] Low List: [4,11,14,17,22,63,65] Execution FLow 12
13 Parallellization Method 1: Implement parallelization while sorting high list and low list Randomly choose a pivot from one of the threads and broadcast it to every thread Each process divides its unsorted list into two lists: Low List and High List based on the pivot Each process in the upper half of the process list sends its low list to a partner process in the lower half of the process list and receives a high list in return 13
14 Parallellization Now, one group of threads have high list, and the other threads have the low list. Thereafter, the threads can work on their high list and low list to split it in to high high list or high low list and low high list or low low list. After log P recursions, every thread has an unsorted list of values completely disjoint from the values held by the other processes. The largest value on process i will be smaller than the smallest value held by process i + 1. Each process can sort its list using sequential quicksort 14
15 Parallellization Execution FLow In Memory 15
16 Parallellization Issues in efficiency: Who chooses median? The data set is not distribited equally if load is not balanced Solution Do one iteration of quicksort Find local median and select the best median Data can now be evenly distributed 16
17 Parallellization Method 2: Hyper Quick Sort (Selecting median after linear Quicksort on local set) Apply quicksort in each thread Select median of medians and broadcast across threads Create low list and high list If Partner thread exists, swap with partner thread Repeat from step 1 Else Merge all lists, the complete list is sorted 17
18 Parallellization Execution FLow of Hyper Quick Sort 18
19 Parallellization Issues in efficiency: The data set can still not be distribited equally Communication overhead due to swapping and exchange of pivots Solution Do not swap! Have dataset relating to each thread moved to that thread in one go 19
20 Method 3: Parallel Sorting by Regular Sampling [PSRS](Selecting median from regularly sampled set) Apply quicksort in each thread Select possible median at every nth element in each thread Apply quicksort on gathered samples Select P-1 pivots from samples at regular intervals Broadcast pivots Each thread must partition its data in to P partitions Distribute ith partition of data to i th thread Merge data in every thread with local quick sort Parallellization 20
21 Parallellization Execution FLow of PSRS 21
22 OpenMP 22
23 OpenMP Checking for OpenMP installation dpkg --status <package> libgomp1 32 bit x86 installtion lib32gomp1 32 support on x64 installation lib64gomp1 64 support on x64 installation Check if compiler is installed dpkg --status gcc 23
24 Pre-Processor Directives #pragma omp pragmas_name [clauses] pragma omp Directive to preprocessor States that the code following is parallel code pragmas_name Directive indicating the type of block that follows clauses Optional attributes such as data specifications 24
25 Pre-Processor Directives #pragma omp pragmas_name [clauses] pragma omp Directive to preprocessor States that the code following is parallel code pragmas_name Directive indicating the type of block that follows clauses Optional attributes such as data specifications 25
26 #include "stdio.h" #include <omp.h> Simple Parallel Program int main(int argc, char *argv[]) { #pragma omp parallel { int NCPU,tid,NPR,NTHR; /* get the total number of CPUs/cores available for OpenMP */ NCPU = omp_get_num_procs(); /* get the current thread ID in the parallel region */ tid = omp_get_thread_num(); /* get the total number of threads available in this parallel region */ NPR = omp_get_num_threads(); /* get the total number of threads requested */ NTHR = omp_get_max_threads(); /* only execute this on the master thread! */ if (tid == 0) { printf("%i : NCPU\t= %i\n",tid,ncpu); printf("%i : NTHR\t= %i\n",tid,nthr); printf("%i : NPR\t= %i\n",tid,npr); } printf("%i : hello multicore user! I am thread %i out of %i\n",tid,tid,npr); } return(0); } 26
27 Output of Program 1 Output: $gcc -g -O0 -fopenmp hello-openmp.c -o hello-openmp.out $export OMP_NUM_THREADS=`grep 'processor' /proc/cpuinfo wc -l ` $./hello-openmp.out 1 : hello multicore user! I am thread 1 out of 8 0 : NCPU = 2 0 : NTHR = 2 0 : NPR = 2 0 : hello multicore user! I am thread 0 out of 8 Pragma omp parallel: #pragma omp parallel [clauses] Clauses: private(list) shared(list) default(shared none) firstprivate(list) reduction(operator: list) copyin (list) if (scalar_expression) 27
28 Clauses for Parallel Pragma Private #pragrma omp parallel private(i,j) Make a copy of i and j that are local to the thread Must be initialized within the block and used only in block Shared #pragrma omp parallel shared(k,l) Shared between threads Only one area in memory Default #pragrma omp parallel default(none) Every variable must be declared with private,shared,etc #pragrma parallel default(shared) Every variable not listed is a shared variable Firstprivate #pragrma omp parallel firstprivate(m,n) Copy values that existed before parallel block, rest is like private 28
29 Clauses for Parallel Pragma Reduction #pragrma omp parallel reduction(+: sum) Same as private except for Initialization: Based on operator Post parallel block: Reduced using the operator and initial value Copyin #pragrma omp parallel copyin(a) Copy values from master thread If #pragma omp parallel if(a>0) Run in parallel based on a condition Multiple clauses can be used with space in between 29
30 Other Pragmas Critical #pragrma omp critical Following is operation on shared data Allow only one thread at a time Master #pragrma omp master Following must be executed only in the master thread Will be executed only once Single #pragrma omp single Only one thread should execute the following code Waits for all threads to complete till here before continuing (barrier) For #pragrma omp for schedule (dynamic, chunk) Execute following for loop in parallel Divide single loop variable value in chunks Allocate variable chunks to threads on demand Barrier #pragrma omp barrier Wait here till all threads finish execution 30
31 OMP C code Demonstration 31
32 Summary Parllalization cannot be applied on all algorithms There are many ways to parallelize a single algorithm Shared data management is essential to parallelization OpenMP is a library can be used to create parallel programs in C Complexity estimation of parallel algorithms are based on thread count 32
33 References Quinn, M., (2003) Parallel Programming in C with MPI and OpenMP, 1st edn, McGraw- Hill 33
Parallel Processing/Programming
Parallel Processing/Programming with the applications to image processing Lectures: 1. Parallel Processing & Programming from high performance mono cores to multi- and many-cores 2. Programming Interfaces
More informationLecture 4: OpenMP Open Multi-Processing
CS 4230: Parallel Programming Lecture 4: OpenMP Open Multi-Processing January 23, 2017 01/23/2017 CS4230 1 Outline OpenMP another approach for thread parallel programming Fork-Join execution model OpenMP
More informationAdvanced C Programming Winter Term 2008/09. Guest Lecture by Markus Thiele
Advanced C Programming Winter Term 2008/09 Guest Lecture by Markus Thiele Lecture 14: Parallel Programming with OpenMP Motivation: Why parallelize? The free lunch is over. Herb
More informationIntroduction to OpenMP
Introduction to OpenMP Ricardo Fonseca https://sites.google.com/view/rafonseca2017/ Outline Shared Memory Programming OpenMP Fork-Join Model Compiler Directives / Run time library routines Compiling and
More informationOpenMP. António Abreu. Instituto Politécnico de Setúbal. 1 de Março de 2013
OpenMP António Abreu Instituto Politécnico de Setúbal 1 de Março de 2013 António Abreu (Instituto Politécnico de Setúbal) OpenMP 1 de Março de 2013 1 / 37 openmp what? It s an Application Program Interface
More informationECE 574 Cluster Computing Lecture 10
ECE 574 Cluster Computing Lecture 10 Vince Weaver http://www.eece.maine.edu/~vweaver vincent.weaver@maine.edu 1 October 2015 Announcements Homework #4 will be posted eventually 1 HW#4 Notes How granular
More informationModule 10: Open Multi-Processing Lecture 19: What is Parallelization? The Lecture Contains: What is Parallelization? Perfectly Load-Balanced Program
The Lecture Contains: What is Parallelization? Perfectly Load-Balanced Program Amdahl's Law About Data What is Data Race? Overview to OpenMP Components of OpenMP OpenMP Programming Model OpenMP Directives
More informationCS 470 Spring Mike Lam, Professor. OpenMP
CS 470 Spring 2017 Mike Lam, Professor OpenMP OpenMP Programming language extension Compiler support required "Open Multi-Processing" (open standard; latest version is 4.5) Automatic thread-level parallelism
More informationby system default usually a thread per CPU or core using the environment variable OMP_NUM_THREADS from within the program by using function call
OpenMP Syntax The OpenMP Programming Model Number of threads are determined by system default usually a thread per CPU or core using the environment variable OMP_NUM_THREADS from within the program by
More informationCS 470 Spring Mike Lam, Professor. OpenMP
CS 470 Spring 2018 Mike Lam, Professor OpenMP OpenMP Programming language extension Compiler support required "Open Multi-Processing" (open standard; latest version is 4.5) Automatic thread-level parallelism
More informationOpenMPand the PGAS Model. CMSC714 Sept 15, 2015 Guest Lecturer: Ray Chen
OpenMPand the PGAS Model CMSC714 Sept 15, 2015 Guest Lecturer: Ray Chen LastTime: Message Passing Natural model for distributed-memory systems Remote ( far ) memory must be retrieved before use Programmer
More informationTopics. Introduction. Shared Memory Parallelization. Example. Lecture 11. OpenMP Execution Model Fork-Join model 5/15/2012. Introduction OpenMP
Topics Lecture 11 Introduction OpenMP Some Examples Library functions Environment variables 1 2 Introduction Shared Memory Parallelization OpenMP is: a standard for parallel programming in C, C++, and
More informationOpenMP - II. Diego Fabregat-Traver and Prof. Paolo Bientinesi WS15/16. HPAC, RWTH Aachen
OpenMP - II Diego Fabregat-Traver and Prof. Paolo Bientinesi HPAC, RWTH Aachen fabregat@aices.rwth-aachen.de WS15/16 OpenMP References Using OpenMP: Portable Shared Memory Parallel Programming. The MIT
More informationHigh Performance Computing: Tools and Applications
High Performance Computing: Tools and Applications Edmond Chow School of Computational Science and Engineering Georgia Institute of Technology Lecture 2 OpenMP Shared address space programming High-level
More informationDepartment of Informatics V. HPC-Lab. Session 2: OpenMP M. Bader, A. Breuer. Alex Breuer
HPC-Lab Session 2: OpenMP M. Bader, A. Breuer Meetings Date Schedule 10/13/14 Kickoff 10/20/14 Q&A 10/27/14 Presentation 1 11/03/14 H. Bast, Intel 11/10/14 Presentation 2 12/01/14 Presentation 3 12/08/14
More informationOpenMP I. Diego Fabregat-Traver and Prof. Paolo Bientinesi WS16/17. HPAC, RWTH Aachen
OpenMP I Diego Fabregat-Traver and Prof. Paolo Bientinesi HPAC, RWTH Aachen fabregat@aices.rwth-aachen.de WS16/17 OpenMP References Using OpenMP: Portable Shared Memory Parallel Programming. The MIT Press,
More informationOpenMP 2. CSCI 4850/5850 High-Performance Computing Spring 2018
OpenMP 2 CSCI 4850/5850 High-Performance Computing Spring 2018 Tae-Hyuk (Ted) Ahn Department of Computer Science Program of Bioinformatics and Computational Biology Saint Louis University Learning Objectives
More informationParallel quicksort algorithms with isoefficiency analysis. Parallel quicksort algorithmswith isoefficiency analysis p. 1
Parallel quicksort algorithms with isoefficiency analysis Parallel quicksort algorithmswith isoefficiency analysis p. 1 Overview Sequential quicksort algorithm Three parallel quicksort algorithms Isoefficiency
More informationShared Memory Programming with OpenMP. Lecture 3: Parallel Regions
Shared Memory Programming with OpenMP Lecture 3: Parallel Regions Parallel region directive Code within a parallel region is executed by all threads. Syntax: Fortran:!$OMP PARALLEL! block!$omp END PARALLEL
More informationMPI and OpenMP (Lecture 25, cs262a) Ion Stoica, UC Berkeley November 19, 2016
MPI and OpenMP (Lecture 25, cs262a) Ion Stoica, UC Berkeley November 19, 2016 Message passing vs. Shared memory Client Client Client Client send(msg) recv(msg) send(msg) recv(msg) MSG MSG MSG IPC Shared
More informationEPL372 Lab Exercise 5: Introduction to OpenMP
EPL372 Lab Exercise 5: Introduction to OpenMP References: https://computing.llnl.gov/tutorials/openmp/ http://openmp.org/wp/openmp-specifications/ http://openmp.org/mp-documents/openmp-4.0-c.pdf http://openmp.org/mp-documents/openmp4.0.0.examples.pdf
More informationIntroduction to OpenMP. OpenMP basics OpenMP directives, clauses, and library routines
Introduction to OpenMP Introduction OpenMP basics OpenMP directives, clauses, and library routines What is OpenMP? What does OpenMP stands for? What does OpenMP stands for? Open specifications for Multi
More informationCS 470 Spring Mike Lam, Professor. Advanced OpenMP
CS 470 Spring 2018 Mike Lam, Professor Advanced OpenMP Atomics OpenMP provides access to highly-efficient hardware synchronization mechanisms Use the atomic pragma to annotate a single statement Statement
More informationLecture 16: Recapitulations. Lecture 16: Recapitulations p. 1
Lecture 16: Recapitulations Lecture 16: Recapitulations p. 1 Parallel computing and programming in general Parallel computing a form of parallel processing by utilizing multiple computing units concurrently
More informationMango DSP Top manufacturer of multiprocessing video & imaging solutions.
1 of 11 3/3/2005 10:50 AM Linux Magazine February 2004 C++ Parallel Increase application performance without changing your source code. Mango DSP Top manufacturer of multiprocessing video & imaging solutions.
More informationCOMP4510 Introduction to Parallel Computation. Shared Memory and OpenMP. Outline (cont d) Shared Memory and OpenMP
COMP4510 Introduction to Parallel Computation Shared Memory and OpenMP Thanks to Jon Aronsson (UofM HPC consultant) for some of the material in these notes. Outline (cont d) Shared Memory and OpenMP Including
More informationParallel Programming
Parallel Programming OpenMP Nils Moschüring PhD Student (LMU) Nils Moschüring PhD Student (LMU), OpenMP 1 1 Overview What is parallel software development Why do we need parallel computation? Problems
More informationMasterpraktikum - High Performance Computing
Masterpraktikum - High Performance Computing OpenMP Michael Bader Alexander Heinecke Alexander Breuer Technische Universität München, Germany 2 #include ... #pragma omp parallel for for(i = 0; i
More informationThreaded Programming. Lecture 3: Parallel Regions. Parallel region directive. Code within a parallel region is executed by all threads.
Threaded Programming Lecture 3: Parallel Regions Parallel region directive Code within a parallel region is executed by all threads. Syntax: Fortran:!$OMP PARALLEL! block!$omp END PARALLEL C/C++: #pragma
More informationShared Memory Programming with OpenMP
Shared Memory Programming with OpenMP Moreno Marzolla Dip. di Informatica Scienza e Ingegneria (DISI) Università di Bologna moreno.marzolla@unibo.it Copyright 2013, 2014, 2017 2019 Moreno Marzolla, Università
More informationCS 470 Spring Mike Lam, Professor. Advanced OpenMP
CS 470 Spring 2017 Mike Lam, Professor Advanced OpenMP Atomics OpenMP provides access to highly-efficient hardware synchronization mechanisms Use the atomic pragma to annotate a single statement Statement
More informationDistributed Systems + Middleware Concurrent Programming with OpenMP
Distributed Systems + Middleware Concurrent Programming with OpenMP Gianpaolo Cugola Dipartimento di Elettronica e Informazione Politecnico, Italy cugola@elet.polimi.it http://home.dei.polimi.it/cugola
More informationOpenMP Overview. in 30 Minutes. Christian Terboven / Aachen, Germany Stand: Version 2.
OpenMP Overview in 30 Minutes Christian Terboven 06.12.2010 / Aachen, Germany Stand: 03.12.2010 Version 2.3 Rechen- und Kommunikationszentrum (RZ) Agenda OpenMP: Parallel Regions,
More informationChip Multiprocessors COMP Lecture 9 - OpenMP & MPI
Chip Multiprocessors COMP35112 Lecture 9 - OpenMP & MPI Graham Riley 14 February 2018 1 Today s Lecture Dividing work to be done in parallel between threads in Java (as you are doing in the labs) is rather
More informationLab: Scientific Computing Tsunami-Simulation
Lab: Scientific Computing Tsunami-Simulation Session 4: Optimization and OMP Sebastian Rettenberger, Michael Bader 23.11.15 Session 4: Optimization and OMP, 23.11.15 1 Department of Informatics V Linux-Cluster
More informationA Short Introduction to OpenMP. Mark Bull, EPCC, University of Edinburgh
A Short Introduction to OpenMP Mark Bull, EPCC, University of Edinburgh Overview Shared memory systems Basic Concepts in Threaded Programming Basics of OpenMP Parallel regions Parallel loops 2 Shared memory
More informationIntroduction to OpenMP
Introduction to OpenMP Xiaoxu Guan High Performance Computing, LSU April 6, 2016 LSU HPC Training Series, Spring 2016 p. 1/44 Overview Overview of Parallel Computing LSU HPC Training Series, Spring 2016
More informationShared Memory Parallelism - OpenMP
Shared Memory Parallelism - OpenMP Sathish Vadhiyar Credits/Sources: OpenMP C/C++ standard (openmp.org) OpenMP tutorial (http://www.llnl.gov/computing/tutorials/openmp/#introduction) OpenMP sc99 tutorial
More informationShared Memory Programming with OpenMP
Shared Memory Programming with OpenMP (An UHeM Training) Süha Tuna Informatics Institute, Istanbul Technical University February 12th, 2016 2 Outline - I Shared Memory Systems Threaded Programming Model
More informationParallel Numerical Algorithms
Parallel Numerical Algorithms http://sudalab.is.s.u-tokyo.ac.jp/~reiji/pna16/ [ 8 ] OpenMP Parallel Numerical Algorithms / IST / UTokyo 1 PNA16 Lecture Plan General Topics 1. Architecture and Performance
More informationMultithreading in C with OpenMP
Multithreading in C with OpenMP ICS432 - Spring 2017 Concurrent and High-Performance Programming Henri Casanova (henric@hawaii.edu) Pthreads are good and bad! Multi-threaded programming in C with Pthreads
More informationParallel Programming in C with MPI and OpenMP
Parallel Programming in C with MPI and OpenMP Michael J. Quinn Chapter 17 Shared-memory Programming 1 Outline n OpenMP n Shared-memory model n Parallel for loops n Declaring private variables n Critical
More informationOpenMP. A parallel language standard that support both data and functional Parallelism on a shared memory system
OpenMP A parallel language standard that support both data and functional Parallelism on a shared memory system Use by system programmers more than application programmers Considered a low level primitives
More information15-418, Spring 2008 OpenMP: A Short Introduction
15-418, Spring 2008 OpenMP: A Short Introduction This is a short introduction to OpenMP, an API (Application Program Interface) that supports multithreaded, shared address space (aka shared memory) parallelism.
More informationParallel Processing Top manufacturer of multiprocessing video & imaging solutions.
1 of 10 3/3/2005 10:51 AM Linux Magazine March 2004 C++ Parallel Increase application performance without changing your source code. Parallel Processing Top manufacturer of multiprocessing video & imaging
More informationITCS 4/5145 Parallel Computing Test 1 5:00 pm - 6:15 pm, Wednesday February 17, 2016 Solutions Name:...
ITCS 4/5145 Parallel Computing Test 1 5:00 pm - 6:15 pm, Wednesday February 17, 016 Solutions Name:... Answer questions in space provided below questions. Use additional paper if necessary but make sure
More informationOpenMP C and C++ Application Program Interface Version 1.0 October Document Number
OpenMP C and C++ Application Program Interface Version 1.0 October 1998 Document Number 004 2229 001 Contents Page v Introduction [1] 1 Scope............................. 1 Definition of Terms.........................
More informationUvA-SARA High Performance Computing Course June Clemens Grelck, University of Amsterdam. Parallel Programming with Compiler Directives: OpenMP
Parallel Programming with Compiler Directives OpenMP Clemens Grelck University of Amsterdam UvA-SARA High Performance Computing Course June 2013 OpenMP at a Glance Loop Parallelization Scheduling Parallel
More informationShared Memory programming paradigm: openmp
IPM School of Physics Workshop on High Performance Computing - HPC08 Shared Memory programming paradigm: openmp Luca Heltai Stefano Cozzini SISSA - Democritos/INFM
More informationParallel Programming: OpenMP
Parallel Programming: OpenMP Xianyi Zeng xzeng@utep.edu Department of Mathematical Sciences The University of Texas at El Paso. November 10, 2016. An Overview of OpenMP OpenMP: Open Multi-Processing An
More informationParallel Programming in C with MPI and OpenMP
Parallel Programming in C with MPI and OpenMP Michael J. Quinn Chapter 17 Shared-memory Programming 1 Outline n OpenMP n Shared-memory model n Parallel for loops n Declaring private variables n Critical
More informationIntroduction to OpenMP
Introduction to OpenMP Le Yan Objectives of Training Acquaint users with the concept of shared memory parallelism Acquaint users with the basics of programming with OpenMP Memory System: Shared Memory
More informationIntroduction to OpenMP
Introduction to OpenMP Christian Terboven 10.04.2013 / Darmstadt, Germany Stand: 06.03.2013 Version 2.3 Rechen- und Kommunikationszentrum (RZ) History De-facto standard for
More informationOpenMP Introduction. CS 590: High Performance Computing. OpenMP. A standard for shared-memory parallel programming. MP = multiprocessing
CS 590: High Performance Computing OpenMP Introduction Fengguang Song Department of Computer Science IUPUI OpenMP A standard for shared-memory parallel programming. MP = multiprocessing Designed for systems
More informationGCC Developers Summit Ottawa, Canada, June 2006
OpenMP Implementation in GCC Diego Novillo dnovillo@redhat.com Red Hat Canada GCC Developers Summit Ottawa, Canada, June 2006 OpenMP Language extensions for shared memory concurrency (C, C++ and Fortran)
More informationTeaching parallel programming on multi-core and many-core processing architectures
Teaching parallel programming on multi-core and many-core processing architectures P.Bakowski (SMTR) This presentation includes two parts : 1. Teaching parallel programing for multi-core processors (ARM
More informationReview. Tasking. 34a.cpp. Lecture 14. Work Tasking 5/31/2011. Structured block. Parallel construct. Working-Sharing contructs.
Review Lecture 14 Structured block Parallel construct clauses Working-Sharing contructs for, single, section for construct with different scheduling strategies 1 2 Tasking Work Tasking New feature in OpenMP
More informationOpenMP 4. CSCI 4850/5850 High-Performance Computing Spring 2018
OpenMP 4 CSCI 4850/5850 High-Performance Computing Spring 2018 Tae-Hyuk (Ted) Ahn Department of Computer Science Program of Bioinformatics and Computational Biology Saint Louis University Learning Objectives
More informationCS691/SC791: Parallel & Distributed Computing
CS691/SC791: Parallel & Distributed Computing Introduction to OpenMP 1 Contents Introduction OpenMP Programming Model and Examples OpenMP programming examples Task parallelism. Explicit thread synchronization.
More informationComputer Architecture
Jens Teubner Computer Architecture Summer 2016 1 Computer Architecture Jens Teubner, TU Dortmund jens.teubner@cs.tu-dortmund.de Summer 2016 Jens Teubner Computer Architecture Summer 2016 2 Part I Programming
More informationParallel and Distributed Programming. OpenMP
Parallel and Distributed Programming OpenMP OpenMP Portability of software SPMD model Detailed versions (bindings) for different programming languages Components: directives for compiler library functions
More informationOverview: The OpenMP Programming Model
Overview: The OpenMP Programming Model motivation and overview the parallel directive: clauses, equivalent pthread code, examples the for directive and scheduling of loop iterations Pi example in OpenMP
More informationOpenMP, Part 2. EAS 520 High Performance Scientific Computing. University of Massachusetts Dartmouth. Spring 2015
OpenMP, Part 2 EAS 520 High Performance Scientific Computing University of Massachusetts Dartmouth Spring 2015 References This presentation is almost an exact copy of Dartmouth College's openmp tutorial.
More informationLecture 14: Mixed MPI-OpenMP programming. Lecture 14: Mixed MPI-OpenMP programming p. 1
Lecture 14: Mixed MPI-OpenMP programming Lecture 14: Mixed MPI-OpenMP programming p. 1 Overview Motivations for mixed MPI-OpenMP programming Advantages and disadvantages The example of the Jacobi method
More informationShared Memory Parallelism using OpenMP
Indian Institute of Science Bangalore, India भ रत य व ज ञ न स स थ न ब गल र, भ रत SE 292: High Performance Computing [3:0][Aug:2014] Shared Memory Parallelism using OpenMP Yogesh Simmhan Adapted from: o
More informationOpenMP Algoritmi e Calcolo Parallelo. Daniele Loiacono
OpenMP Algoritmi e Calcolo Parallelo References Useful references Using OpenMP: Portable Shared Memory Parallel Programming, Barbara Chapman, Gabriele Jost and Ruud van der Pas OpenMP.org http://openmp.org/
More informationPOSIX Threads and OpenMP tasks
POSIX Threads and OpenMP tasks Jimmy Aguilar Mena February 16, 2018 Introduction Pthreads Tasks Two simple schemas Independent functions # include # include void f u n c t i
More informationIntroduction to OpenMP
Christian Terboven, Dirk Schmidl IT Center, RWTH Aachen University Member of the HPC Group terboven,schmidl@itc.rwth-aachen.de IT Center der RWTH Aachen University History De-facto standard for Shared-Memory
More informationWorkshop Agenda Feb 25 th 2015
Workshop Agenda Feb 25 th 2015 Time Presenter Title 09:30 T. König Talk bwhpc Concept & bwhpc-c5 - Federated User Support Activities 09:45 R. Walter Talk bwhpc architecture (bwunicluster, bwforcluster
More informationShared Memory Programming : OpenMP
Multicore & GPU Programming : An Integrated Approach Shared Memory Programming : OpenMP By G. Barlas Objectives Learn how to use OpenMP compiler directives to introduce concurrency in a sequential program.
More informationOpenMP programming. Thomas Hauser Director Research Computing Research CU-Boulder
OpenMP programming Thomas Hauser Director Research Computing thomas.hauser@colorado.edu CU meetup 1 Outline OpenMP Shared-memory model Parallel for loops Declaring private variables Critical sections Reductions
More informationDepartment of Informatics V. Tsunami-Lab. Session 4: Optimization and OMP Michael Bader, Alex Breuer. Alex Breuer
Tsunami-Lab Session 4: Optimization and OMP Michael Bader, MAC-Cluster: Overview Intel Sandy Bridge (snb) AMD Bulldozer (bdz) Product Name (base frequency) Xeon E5-2670 (2.6 GHz) AMD Opteron 6274 (2.2
More informationParallel Programming using OpenMP
1 Parallel Programming using OpenMP Mike Bailey mjb@cs.oregonstate.edu openmp.pptx OpenMP Multithreaded Programming 2 OpenMP stands for Open Multi-Processing OpenMP is a multi-vendor (see next page) standard
More informationCS420: Operating Systems
Threads James Moscola Department of Physical Sciences York College of Pennsylvania Based on Operating System Concepts, 9th Edition by Silberschatz, Galvin, Gagne Threads A thread is a basic unit of processing
More informationOpenMP loops. Paolo Burgio.
OpenMP loops Paolo Burgio paolo.burgio@unimore.it Outline Expressing parallelism Understanding parallel threads Memory Data management Data clauses Synchronization Barriers, locks, critical sections Work
More informationParallel Programming using OpenMP
1 OpenMP Multithreaded Programming 2 Parallel Programming using OpenMP OpenMP stands for Open Multi-Processing OpenMP is a multi-vendor (see next page) standard to perform shared-memory multithreading
More informationIntroduc)on to OpenMP
Introduc)on to OpenMP Chapter 5.1-5. Bryan Mills, PhD Spring 2017 OpenMP An API for shared-memory parallel programming. MP = multiprocessing Designed for systems in which each thread or process can potentially
More informationOpenMP examples. Sergeev Efim. Singularis Lab, Ltd. Senior software engineer
OpenMP examples Sergeev Efim Senior software engineer Singularis Lab, Ltd. OpenMP Is: An Application Program Interface (API) that may be used to explicitly direct multi-threaded, shared memory parallelism.
More informationCOSC 6374 Parallel Computation. Introduction to OpenMP(I) Some slides based on material by Barbara Chapman (UH) and Tim Mattson (Intel)
COSC 6374 Parallel Computation Introduction to OpenMP(I) Some slides based on material by Barbara Chapman (UH) and Tim Mattson (Intel) Edgar Gabriel Fall 2014 Introduction Threads vs. processes Recap of
More informationParallel Programming in C with MPI and OpenMP
Parallel Programming in C with MPI and OpenMP Michael J. Quinn Chapter 17 Shared-memory Programming Outline OpenMP Shared-memory model Parallel for loops Declaring private variables Critical sections Reductions
More informationArray Packing Implementation A Parallel approach. By, Abhishek Cumbakonam Desikan Rajesh Balasubramanian Ramalingam Sankaran Aswin Gokulachandran
Array Packing Implementation A Parallel approach By, Abhishek Cumbakonam Desikan Rajesh Balasubramanian Ramalingam Sankaran Aswin Gokulachandran The Problem Given an array X, having some labelled items.
More informationOpenMP: Open Multiprocessing
OpenMP: Open Multiprocessing Erik Schnetter June 7, 2012, IHPC 2012, Iowa City Outline 1. Basic concepts, hardware architectures 2. OpenMP Programming 3. How to parallelise an existing code 4. Advanced
More informationOpenMP - Introduction
OpenMP - Introduction Süha TUNA Bilişim Enstitüsü UHeM Yaz Çalıştayı - 21.06.2012 Outline What is OpenMP? Introduction (Code Structure, Directives, Threads etc.) Limitations Data Scope Clauses Shared,
More informationDPHPC: Introduction to OpenMP Recitation session
SALVATORE DI GIROLAMO DPHPC: Introduction to OpenMP Recitation session Based on http://openmp.org/mp-documents/intro_to_openmp_mattson.pdf OpenMP An Introduction What is it? A set of compiler directives
More informationData Environment: Default storage attributes
COSC 6374 Parallel Computation Introduction to OpenMP(II) Some slides based on material by Barbara Chapman (UH) and Tim Mattson (Intel) Edgar Gabriel Fall 2014 Data Environment: Default storage attributes
More informationIntroduction to OpenMP
Introduction to OpenMP Le Yan Scientific computing consultant User services group High Performance Computing @ LSU Goals Acquaint users with the concept of shared memory parallelism Acquaint users with
More informationOpenMP Fundamentals Fork-join model and data environment
www.bsc.es OpenMP Fundamentals Fork-join model and data environment Xavier Teruel and Xavier Martorell Agenda: OpenMP Fundamentals OpenMP brief introduction The fork-join model Data environment OpenMP
More informationOpenMP and MPI. Parallel and Distributed Computing. Department of Computer Science and Engineering (DEI) Instituto Superior Técnico.
OpenMP and MPI Parallel and Distributed Computing Department of Computer Science and Engineering (DEI) Instituto Superior Técnico November 15, 2010 José Monteiro (DEI / IST) Parallel and Distributed Computing
More informationHPCSE - II. «OpenMP Programming Model - Tasks» Panos Hadjidoukas
HPCSE - II «OpenMP Programming Model - Tasks» Panos Hadjidoukas 1 Recap of OpenMP nested loop parallelism functional parallelism OpenMP tasking model how to use how it works examples Outline Nested Loop
More informationAnnouncements. Scott B. Baden / CSE 160 / Wi '16 2
Lecture 8 Announcements Scott B. Baden / CSE 160 / Wi '16 2 Recapping from last time: Minimal barrier synchronization in odd/even sort Global bool AllDone; for (s = 0; s < MaxIter; s++) { barr.sync();
More informationIntroduction to OpenMP.
Introduction to OpenMP www.openmp.org Motivation Parallelize the following code using threads: for (i=0; i
More informationEE/CSCI 451: Parallel and Distributed Computation
EE/CSCI 451: Parallel and Distributed Computation Lecture #7 2/5/2017 Xuehai Qian Xuehai.qian@usc.edu http://alchem.usc.edu/portal/xuehaiq.html University of Southern California 1 Outline From last class
More informationIntroduction to OpenMP
Presentation Introduction to OpenMP Martin Cuma Center for High Performance Computing University of Utah mcuma@chpc.utah.edu September 9, 2004 http://www.chpc.utah.edu 4/13/2006 http://www.chpc.utah.edu
More informationOpenMP and MPI. Parallel and Distributed Computing. Department of Computer Science and Engineering (DEI) Instituto Superior Técnico.
OpenMP and MPI Parallel and Distributed Computing Department of Computer Science and Engineering (DEI) Instituto Superior Técnico November 16, 2011 CPD (DEI / IST) Parallel and Distributed Computing 18
More informationAlfio Lazzaro: Introduction to OpenMP
First INFN International School on Architectures, tools and methodologies for developing efficient large scale scientific computing applications Ce.U.B. Bertinoro Italy, 12 17 October 2009 Alfio Lazzaro:
More informationWide operands. CP1: hardware can multiply 64-bit floating-point numbers RAM MUL. core
RAM MUL core Wide operands RAM MUL core CP1: hardware can multiply 64-bit floating-point numbers Pipelining: can start the next independent operation before the previous result is available RAM MUL core
More informationParallel Programming. OpenMP Parallel programming for multiprocessors for loops
Parallel Programming OpenMP Parallel programming for multiprocessors for loops OpenMP OpenMP An application programming interface (API) for parallel programming on multiprocessors Assumes shared memory
More informationParallel Computing. Lecture 13: OpenMP - I
CSCI-UA.0480-003 Parallel Computing Lecture 13: OpenMP - I Mohamed Zahran (aka Z) mzahran@cs.nyu.edu http://www.mzahran.com Small and Easy Motivation #include #include int main() {
More informationEE/CSCI 451 Introduction to Parallel and Distributed Computation. Discussion #4 2/3/2017 University of Southern California
EE/CSCI 451 Introduction to Parallel and Distributed Computation Discussion #4 2/3/2017 University of Southern California 1 USC HPCC Access Compile Submit job OpenMP Today s topic What is OpenMP OpenMP
More informationIntroduction to OpenMP. Martin Čuma Center for High Performance Computing University of Utah
Introduction to OpenMP Martin Čuma Center for High Performance Computing University of Utah mcuma@chpc.utah.edu Overview Quick introduction. Parallel loops. Parallel loop directives. Parallel sections.
More information