173 research outputs found
Model-Based Performance Prediction for Concurrent Software on Multicore Architectures
Model-based performance prediction is a well-known concept to ensure the quality of software.Current approaches are based on a single-metric model, which leads to inaccurate predictions for modern architectures.
This thesis presents a multi-strategies approach to extend performance prediction models to support multicore architectures.We implemented the strategies into Palladio and significantly increased the performance prediction power
Project Final Report: HPC-Colony II
This report recounts the HPC Colony II Project which was a computer science effort funded by DOE's Advanced Scientific Computing Research office. The project included researchers from ORNL, IBM, and the University of Illinois at Urbana-Champaign. The topic of the effort was adaptive system software for extreme scale parallel machines. A description of findings is included
Multi-core devices for safety-critical systems: a survey
Multi-core devices are envisioned to support the development of next-generation safety-critical systems, enabling the on-chip integration of functions of different criticality. This integration provides multiple system-level potential benefits such as cost, size, power, and weight reduction. However, safety certification becomes a challenge and several fundamental safety technical requirements must be addressed, such as temporal and spatial independence, reliability, and diagnostic coverage. This survey provides a categorization and overview at different device abstraction levels (nanoscale, component, and device) of selected key research contributions that support the compliance with these fundamental safety requirements.This work has been partially supported by the Spanish Ministry of Economy and Competitiveness under grant TIN2015-65316-P, Basque Government under grant KK-2019-00035 and the HiPEAC Network of Excellence. The Spanish Ministry of Economy and Competitiveness has also partially supported Jaume Abella under Ramon y Cajal postdoctoral fellowship (RYC-2013-14717).Peer ReviewedPostprint (author's final draft
System Level LET with Application to Automotive Design
The logical execution time (LET) programming model has been applied in the automotive industry to master multicore programming of large task systems with complex dependencies. Recent developments in electric powertrains and autonomous vehicle functions raise parallel programming from the multicore level to the vehicle level where the requirements for LET application do not hold any more. This paper introduces System Level LET (SL LET), an extension of LET with relaxed synchronization requirements. While related extensions have been proposed for specific scheduling and communication models before, SL LET can be used with a variety of scheduling algorithms and communication semantics. Furthermore, it can be applied to systems with combinations of LET and other programming models. Yet, SL LET allows end-to-end timing guarantees and preserves essential LET properties required for automotive systems. For illustration, we apply the model to an electric vehicle use case
An Efficient Sliding Mesh Interface Method for High-Order Discontinuous Galerkin Schemes
Sliding meshes are a powerful method to treat deformed domains in
computational fluid dynamics, where different parts of the domain are in
relative motion. In this paper, we present an efficient implementation of a
sliding mesh method into a discontinuous Galerkin compressible Navier-Stokes
solver and its application to a large eddy simulation of a 1-1/2 stage turbine.
The method is based on the mortar method and is high-order accurate. It can
handle three-dimensional sliding mesh interfaces with various interface shapes.
For plane interfaces, which are the most common case, conservativity and
free-stream preservation are ensured. We put an emphasis on efficient parallel
implementation. Our implementation generates little computational and storage
overhead. Inter-node communication via MPI in a dynamically changing mesh
topology is reduced to a bare minimum by ensuring a priori information about
communication partners and data sorting. We provide performance and scaling
results showing the capability of the implementation strategy. Apart from
analytical validation computations and convergence results, we present a
wall-resolved implicit LES of the 1-1/2 stage Aachen turbine test case as a
large scale practical application example
HydroShare – A Case Study of the Application of Modern Software Engineering to a Large Distributed Federally-Funded Scientific Software Development Project
HydroShare is an online collaborative system under development to support the open sharing of hydrologic data, analytical tools, and computer models. With HydroShare, scientists can easily discover, access, and analyze hydrologic data and thereby enhance the production and reproducibility of hydrologic scientific results. HydroShare also takes advantage of emerging social media functionality to enable users to enhance information about and collaboration around hydrologic data and models. HydroShare is being developed by an interdisciplinary collaborative team of domain scientists, university software developers, and professional software engineers from ten institutions located across the United States. While the combination of non–co-located, diverse stakeholders presents communication and management challenges, the interdisciplinary nature of the team is integral to the project’s goal of improving scientific software development and capabilities in academia. This chapter describes the challenges faced and lessons learned with the development of HydroShare, as well as the approach to software development that the HydroShare team adopted on the basis of the lessons learned. The chapter closes with recommendations for the application of modern software engineering techniques to large, collaborative, scientific software development projects, similar to the National Science Foundation (NSF)–funded HydroShare, in order to promote the successful application of the approach described herein by other teams for other projects
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