4,249 research outputs found
SL: a "quick and dirty" but working intermediate language for SVP systems
The CSA group at the University of Amsterdam has developed SVP, a framework
to manage and program many-core and hardware multithreaded processors. In this
article, we introduce the intermediate language SL, a common vehicle to program
SVP platforms. SL is designed as an extension to the standard C language (ISO
C99/C11). It includes primitive constructs to bulk create threads, bulk
synchronize on termination of threads, and communicate using word-sized
dataflow channels between threads. It is intended for use as target language
for higher-level parallelizing compilers. SL is a research vehicle; as of this
writing, it is the only interface language to program a main SVP platform, the
new Microgrid chip architecture. This article provides an overview of the
language, to complement a detailed specification available separately.Comment: 22 pages, 3 figures, 18 listings, 1 tabl
A REST Model for High Throughput Scheduling in Computational Grids
Current grid computing architectures have been based on cluster management and batch queuing systems, extended to a distributed, federated domain. These have shown shortcomings in terms of scalability, stability, and modularity. To address these problems, this dissertation applies architectural styles from the Internet and Web to the domain of generic computational grids. Using the REST style, a flexible model for grid resource interaction is developed which removes the need for any centralised services or specific protocols, thereby allowing a range of implementations and layering of further functionality. The context for resource interaction is a generalisation and formalisation of the Condor ClassAd match-making mechanism. This set theoretic model is described in depth, including the advantages and features which it realises. This RESTful style is also motivated by operational experience with existing grid infrastructures, and the design, operation, and performance of a proto-RESTful grid middleware package named DIRAC. This package was designed to provide for the LHCb particle physics experiment's âワoff-lineâ computational infrastructure, and was first exercised during a 6 month data challenge which utilised over 670 years of CPU time and produced 98 TB of data through 300,000 tasks executed at computing centres around the world. The design of DIRAC and performance measures from the data challenge are reported. The main contribution of this work is the development of a REST model for grid resource interaction. In particular, it allows resource templating for scheduling queues which provide a novel distributed and scalable approach to resource scheduling on the grid
A Functional Safety OpenMP∗ for Critical Real-Time Embedded Systems
OpenMP* has recently gained attention in the embedded domain by virtue of the augmentations implemented in the last specification. Yet, the language has a minimal impact in the embedded real-time domain mostly due to the lack of reliability and resiliency mechanisms. As a result, functional safety properties cannot be guaranteed. This paper analyses in detail the latest specification to determine whether and how the compliant OpenMP implementations can guarantee functional safety. Given the conclusions drawn from the analysis, the paper describes a set of modifications to the specification, and a set of requirements for compiler and runtime systems to qualify for safety critical environments. Through the proposed solution, OpenMP can be used in critical real-time embedded systems without compromising functional safety.This work was funded by the EU project P-SOCRATES (FP7-ICT-2013- 10)
and the Spanish Ministry of Science and Innovation under contract TIN2015-
65316-P.Peer ReviewedPostprint (author's final draft
Computation of Buffer Capacities for Throughput Constrained and Data Dependent Inter-Task Communication
Streaming applications are often implemented as task graphs. Currently, techniques exist to derive buffer capacities that guarantee satisfaction of a throughput constraint for task graphs in which the inter-task communication is data-independent, i.e. the amount of data produced and consumed is independent of the data values in the processed stream. This paper presents a technique to compute buffer capacities that satisfy a throughput constraint for task graphs with data dependent inter-task communication, given that the task graph is a chain. We demonstrate the applicability of the approach by computing buffer capacities for an MP3 playback application, of which the MP3 decoder has a variable consumption rate. We are not aware of alternative approaches to compute buffer capacities that guarantee satisfaction of the throughput constraint for this application
Distributed Preemptive Process Management With Checkpointing And Migration For A Linux-Based Grid Operating System
Kemunculan perkomputeran grid telah membolehkan perkongsian sumber perkomputeran
teragih antara peserta-peserta organisasi maya. Walau bagaimanapun, sistem pengoperasian
kini tidak memberi sokongan paras rendah secukupnya untuk perlaksanaan perisian
grid. Kemunculan suatu kelas sistem pengoperasian yang dipanggil sistem pengoperasian
grid memberikan pengabstrakan peringkat sistem untuk sumber-sumber grid
The advent of grid computing has enabled distributed computing resources to be shared
amongst participants of virtual organisations. However, current operating systems do not
adequately provide enough low-level facilities to accommodate grid software. There is an
emerging class of operating systems called grid operating systems which provide systemslevel
abstractions for grid resources
Towards Formal Interaction-Based Models of Grid Computing Infrastructures
Grid computing (GC) systems are large-scale virtual machines, built upon a
massive pool of resources (processing time, storage, software) that often span
multiple distributed domains. Concurrent users interact with the grid by adding
new tasks; the grid is expected to assign resources to tasks in a fair,
trustworthy way. These distinctive features of GC systems make their
specification and verification a challenging issue. Although prior works have
proposed formal approaches to the specification of GC systems, a precise
account of the interaction model which underlies resource sharing has not been
yet proposed. In this paper, we describe ongoing work aimed at filling in this
gap. Our approach relies on (higher-order) process calculi: these core
languages for concurrency offer a compositional framework in which GC systems
can be precisely described and potentially reasoned about.Comment: In Proceedings DCM 2013, arXiv:1403.768
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