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Lundvall, Håkan
Publications (10 of 14) Show all publications
Lundvall, H. & Fritzson, P. (2009). Automatic Parallelization using Pipelining for Equation-Based Simulation Languages. In: : . Paper presented at Proceedings of the 14th Workshop on Compilers for Parallel Computing (CPC'2009).
Open this publication in new window or tab >>Automatic Parallelization using Pipelining for Equation-Based Simulation Languages
2009 (English)Conference paper, Published paper (Refereed)
National Category
Software Engineering
Identifiers
urn:nbn:se:liu:diva-50749 (URN)
Conference
Proceedings of the 14th Workshop on Compilers for Parallel Computing (CPC'2009)
Available from: 2009-10-14 Created: 2009-10-14 Last updated: 2018-01-12
Lundvall, H., Stavåker, K., Fritzson, P. & Kessler, C. (2008). Automatic Parallelization of Simulation Code for Equation-based Models with Software Pipelining and Measurements on Three Platforms. In: Håkan Grahn (Ed.), Proceedings from the First Swedish Workshop on Multi-Core Computing, MCC-08, November 27-28, 2008, Ronneby, Sweden: . Paper presented at First Swedish Workshop on Multi-Core Computing, MCC-08, November 27-28, 2008, Ronneby, Sweden (pp. 60-69). Ronneby, Sweden: Blekinge Institute of Technology
Open this publication in new window or tab >>Automatic Parallelization of Simulation Code for Equation-based Models with Software Pipelining and Measurements on Three Platforms
2008 (English)In: Proceedings from the First Swedish Workshop on Multi-Core Computing, MCC-08, November 27-28, 2008, Ronneby, Sweden / [ed] Håkan Grahn, Ronneby, Sweden: Blekinge Institute of Technology , 2008, p. 60-69Conference paper, Published paper (Refereed)
Abstract [en]

In this work we report results from a new integrated method of automatically generating parallel code from Modelica models by combining parallelization at two levels of abstraction. Performing inline expansion of a Runge-Kutta solver combined with fine-grained automatic parallelization of the right-hand side of the resulting equation system opens up new possibilities for generating high performance code, which is becoming increasingly relevant when multi-core computers are becoming commonplace. An implementation, in the form of a backend module for the OpenModelica compiler, has been developed and used for measurements on two architectures: Intel Xeon and SGI Altix 3700 Bx2. This paper also contains some very recent results of a prototype implementation of this parallelization approach on the Cell BE processor architecture.

Place, publisher, year, edition, pages
Ronneby, Sweden: Blekinge Institute of Technology, 2008
Keywords
Modelica, parallel computing, automatic parallelization, pipelining, multicore processor, scheduling, code optimization, equation-based modeling and simulation
National Category
Computer Sciences
Identifiers
urn:nbn:se:liu:diva-43713 (URN)74600 (Local ID)74600 (Archive number)74600 (OAI)
Conference
First Swedish Workshop on Multi-Core Computing, MCC-08, November 27-28, 2008, Ronneby, Sweden
Available from: 2009-10-10 Created: 2009-10-10 Last updated: 2018-01-12Bibliographically approved
Lundvall, H., Stavåker, K., Fritzson, P. & Kessler, C. (2008). Automatic Parallelization of Simulation Code for Equation-based Models with Software Pipelining and Measurements on Three Platforms.. SIGARCH Computer Architecture News, 36(5)
Open this publication in new window or tab >>Automatic Parallelization of Simulation Code for Equation-based Models with Software Pipelining and Measurements on Three Platforms.
2008 (English)In: SIGARCH Computer Architecture News, ISSN 0163-5964, E-ISSN 1943-5851, Vol. 36, no 5Article in journal (Refereed) Published
Abstract [en]

In this work we report results from a new integrated method of automatically generating parallel code from Modelica models by combining parallelization at two levels of abstraction. Performing inline expansion of a Runge-Kutta solver combined with fine-grained automatic parallelization of the right-hand side of the resulting equation system opens up new possibilities for generating high performance code, which is becoming increasingly relevant when multi-core computers are becoming commonplace. An implementation, in the form of a backend module for the OpenModelica compiler, has been developed and used for measurements on two architectures: Intel Xeon and SGI Altix 3700 Bx2. This paper also contains some very recent results of a prototype implementation of this parallelization approach on the Cell BE processor architecture.

National Category
Software Engineering
Identifiers
urn:nbn:se:liu:diva-50675 (URN)
Available from: 2009-10-13 Created: 2009-10-13 Last updated: 2018-01-12
Lundvall, H. (2008). Automatic Parallelization using Pipelining for Equation-Based Simulation Languages. (Licentiate dissertation). Linköping: Linköping University Electronic Press
Open this publication in new window or tab >>Automatic Parallelization using Pipelining for Equation-Based Simulation Languages
2008 (English)Licentiate thesis, comprehensive summary (Other academic)
Abstract [en]

During the most recent decades modern equation-based object-oriented modeling and simulation languages, such as Modelica, have become available. This has made it easier to build complex and more detailed models for use in simulation. To be able to simulate such large and complex systems it is sometimes not enough to rely on the ability of a compiler to optimize the simulation code and reduce the size of the underlying set of equations to speed up the simulation on a single processor. Instead we must look for ways to utilize the increasing number of processing units available in modern computers. However to gain any increased performance from a parallel computer the simulation program must be expressed in a way that exposes the potential parallelism to the computer. Doing this manually is not a simple task and most modelers are not experts in parallel computing. Therefore it is very appealing to let the compiler parallelize the simulation code automatically. This thesis investigates techniques of using automatic translation of models in typical equation based languages, such as Modelica, into parallel simulation code that enable high utilization of available processors in a parallel computer. The two main ideas investigated here are the following: first, to apply parallelization simultaneously to both the system equations and the numerical solver, and secondly. to use software pipelining to further reduce the time processors are kept waiting for the results of other processors. Prototype implementations of the investigated techniques have been developed as a part of the OpenModelica open source compiler for Modelica. The prototype has been used to evaluate the parallelization techniques by measuring the execution time of test models on a few parallel archtectures and to compare the results to sequential code as well as to the results achieved in earlier work. A measured speedup of 6.1 on eight processors on a shared memory machine has been reached. It still remains to evaluate the methods for a wider range of test models and parallel architectures.

Place, publisher, year, edition, pages
Linköping: Linköping University Electronic Press, 2008. p. 25
Series
Linköping Studies in Science and Technology. Thesis, ISSN 0280-7971 ; 1381
Keywords
Equation-Based languages, automatic parallelization, Modelica, simulation, Ekvationsbaserade språk, automatisk parallellisering, Modelica, simulering
National Category
Computer Sciences
Identifiers
urn:nbn:se:liu:diva-12504 (URN)LIU-TEK-LIC-2008:39 (Local ID)978-91-7393-799-3 (ISBN)LIU-TEK-LIC-2008:39 (Archive number)LIU-TEK-LIC-2008:39 (OAI)
Presentation
2008-09-26, Alan Turing, Hus E, Campus Valla, Linköpings universitet, Linköping, 10:15 (English)
Opponent
Supervisors
Available from: 2008-09-09 Created: 2008-09-09 Last updated: 2018-01-12Bibliographically approved
Lundvall, H., Fritzson, P. & Bachmann, B. (2008). Event Handling in the OpenModelica Compiler and Runtime System. Linköping: Linköping University Electronic Press
Open this publication in new window or tab >>Event Handling in the OpenModelica Compiler and Runtime System
2008 (English)Report (Other academic)
Abstract [en]

This paper gives an introduction and overview of problems and solutions regarding simulating hybrid DAEs (systems of Differential Algebraic Equations) with event-handling, in the context of producing such equations from models in the Modelica language. Iimplementation and measurements are done in the OpenModelica environment. The basic hybrid DAE solution algorithm is presented, followed by a discussion of handling possibly varying structure of the active part of the hybrid DAE, and how to find consistent initial values at start or restart of simulation. The problem of detecting events during continuous-time simulation is dealt with using crossing functions and an algorithm for proper integration with a numerical solver, here DASRT. Event-related aspects of code generation from models are presented, followed by an example showing how the event mechanism works. Finally, preliminary results from translating and simulating two examples models, the bouncing ball and the full wave rectifier, are presented and compared with those from a commercial simulation tool (Dymola), giving identical results.

Place, publisher, year, edition, pages
Linköping: Linköping University Electronic Press, 2008. p. 21
Series
Technical reports in Computer and Information Science, ISSN 1654-7233 ; 2
National Category
Engineering and Technology
Identifiers
urn:nbn:se:liu:diva-12431 (URN)
Available from: 2008-09-04 Created: 2008-09-04 Last updated: 2014-10-08Bibliographically approved
Lundvall, H. & Fritzson, P. (2007). Automatic Parallelization of Mathematical Models Solved with Inlined Runge-Kutta Solvers. In: : . Paper presented at Scandinavian Conference on Simulation and Modeling..
Open this publication in new window or tab >>Automatic Parallelization of Mathematical Models Solved with Inlined Runge-Kutta Solvers
2007 (English)Conference paper, Published paper (Other academic)
Keywords
simulaering, parallellisering, Modelica
National Category
Computer Sciences
Identifiers
urn:nbn:se:liu:diva-41277 (URN)55432 (Local ID)55432 (Archive number)55432 (OAI)
Conference
Scandinavian Conference on Simulation and Modeling.
Available from: 2009-10-10 Created: 2009-10-10 Last updated: 2018-01-13
Lundvall, H. & Fritzson, P. (2007). Automatic Parallelization of Object Oriented  Models Across Method and System. In: : . Paper presented at Proceedings of 6th Eurosim Congress, Ljubjana, Slovenia.
Open this publication in new window or tab >>Automatic Parallelization of Object Oriented  Models Across Method and System
2007 (English)Conference paper, Published paper (Refereed)
Abstract [en]

In this work we report preliminary results of automatically generating parallel code from equation-based models together at two levels: Performing inline expansion of a Runge-Kutta solver combined with fine-grained automatic parallelization of the resulting RHS opens up new possibilities for generating high performance code, which is becoming increasingly relevant when multi-core computers are becoming common-place.We have introduced a new way of scheduling the task graph generated from the simulation problem which utilizes knowledge about locality of the simulation problem. The scheduling is also done in a way that limits communication, to the greatest extent possible, to neighboring processors thus avoiding expensive global synchronization. Preliminary tests on a PC-cluster show speedup that is better than what was achieved in previous work where parallelization was done only at the equation system level.

National Category
Computer Sciences
Identifiers
urn:nbn:se:liu:diva-12429 (URN)
Conference
Proceedings of 6th Eurosim Congress, Ljubjana, Slovenia
Available from: 2008-09-04 Created: 2008-09-04 Last updated: 2018-01-11
Lundvall, H. & Fritzson, P. (2007). Automatic Parallelization of Object Oriented Models Executed with Inline Solvers. In: : . Paper presented at EuroPVM/MPI User Group Meeting..
Open this publication in new window or tab >>Automatic Parallelization of Object Oriented Models Executed with Inline Solvers
2007 (English)Conference paper, Published paper (Other academic)
Keywords
simulering, parallellisering, Modelica
National Category
Computer Sciences
Identifiers
urn:nbn:se:liu:diva-41279 (URN)55434 (Local ID)55434 (Archive number)55434 (OAI)
Conference
EuroPVM/MPI User Group Meeting.
Available from: 2009-10-10 Created: 2009-10-10 Last updated: 2018-01-13
Fritzson, P., Pop, A. D., Lundvall, H., Aronsson, P., Nyström, K., Saldamli, L., . . . Sandholm, A. (2006). OpenModelica - A Free Open-Source Environment for System Modeling, Simulation, and Teaching. In: Proceedings of the2006 IEEE International Conference on Control Applications (CCA)2006 IEEE Conference on Computer-Aided Control Systems Design (CACSD)2006 IEEE International Symposium on Intelligent Control (ISIC): . Paper presented at IEEE International Conference on Control Applications, IEEE International Symposium on Computer-Aided, Control Systems Design, IEEE International Symposium on Intelligent Control, October 4-6, 2006, Munich, Germany (pp. 1588-1595). Munich, Germany: IEEE
Open this publication in new window or tab >>OpenModelica - A Free Open-Source Environment for System Modeling, Simulation, and Teaching
Show others...
2006 (English)In: Proceedings of the2006 IEEE International Conference on Control Applications (CCA)2006 IEEE Conference on Computer-Aided Control Systems Design (CACSD)2006 IEEE International Symposium on Intelligent Control (ISIC), Munich, Germany: IEEE , 2006, p. 1588-1595Conference paper, Published paper (Refereed)
Abstract [en]

Modelica is a modern, strongly typed, declarative, and object-oriented language for modeling and simulation of complex systems. This paper gives a quick overview of some aspects of the OpenModelica environment - an open-source environment for modeling, simulation, and development of Modelica applications. An introduction of the objectives of the environment is given, an overview of the architecture is outlined and a number of examples are illustrated.   

Place, publisher, year, edition, pages
Munich, Germany: IEEE, 2006
National Category
Computer Sciences
Identifiers
urn:nbn:se:liu:diva-35788 (URN)10.1109/CACSD-CCA-ISIC.2006.4776878 (DOI)28586 (Local ID)0-7803-9797-5 (ISBN)0-7803-9797-5 (ISBN)28586 (Archive number)28586 (OAI)
Conference
IEEE International Conference on Control Applications, IEEE International Symposium on Computer-Aided, Control Systems Design, IEEE International Symposium on Intelligent Control, October 4-6, 2006, Munich, Germany
Available from: 2009-10-10 Created: 2009-10-10 Last updated: 2018-01-13
Lundvall, H. & Fritzson, P. (2005). Event Handling in the OpenModelica Compiler and Run-time System. In: : . Paper presented at 46th Conference on Simulation and Modelling of the Scandinavian Simulation Society (SIMS2005), Trondheim, Norway, October 13-14, 2005.
Open this publication in new window or tab >>Event Handling in the OpenModelica Compiler and Run-time System
2005 (English)Conference paper, Published paper (Refereed)
Abstract [en]

The paper gives an introduction to the problem simulating hybrid DAEs with event-handling using the Modelica language. An implementation in the OpenModelica compiler is presented, and some preliminary results are reported.

National Category
Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:liu:diva-110215 (URN)
Conference
46th Conference on Simulation and Modelling of the Scandinavian Simulation Society (SIMS2005), Trondheim, Norway, October 13-14, 2005
Available from: 2014-09-04 Created: 2014-09-04 Last updated: 2014-10-20Bibliographically approved
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