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oai:uvadoc.uva.es:10324/704392024-10-04T19:01:38Zcom_10324_1165com_10324_931com_10324_894col_10324_1335

Llanos Ferraris, Diego Rafael 0eb6c72a1ecd19fb 600 0000-0001-6240-9109 Orden, David c58aca4a-0415-41eb-889b-9ca57eb8e21e Palop del Río, Belén 1906753c553ded35 600 0000-0002-1345-017X 2024-10-04T15:14:34Z 2024-10-04T15:14:34Z 2007 IEEE Transactions on Computers, vol. 56, no. 6, pp. 839-852, June 2007, ISSN 0018-9340. 0018-9340 https://uvadoc.uva.es/handle/10324/70439 10.1109/TC.2007.1030 839 6 852 IEEE Transactions on Computers 56 Producción Científica In this work, we address the problem of scheduling loops with dependences in the context of speculative parallelization. We show that the scheduling alternatives are highly influenced by the dependence violation pattern the code presents. We center our analysis in those algorithms where dependences are less likely to appear as the execution proceeds. Particularly, we focus on randomized incremental algorithms, widely used as a much more efficient solution to many problems than their deterministic counterparts. These important algorithms are, in general, hard to parallelize by hand and represent a challenge for any automatic parallelization scheme. Our analysis led us to the development of MESETA, a new scheduling strategy that takes into account the probability of a dependence violation to determine the number of iterations being scheduled. MESETA is compared with existing techniques, including fixed-size chunking (FSC), the only scheduling alternative used so far in the context of speculative parallelization. Our experimental results show a 5.5 percent to 36.25 percent speedup improvement over FSC, leading to a better extraction of the parallelism inherent to randomized incremental algorithms. Moreover, when the cost of dependence violations is too high to obtain speedups, MESETA curves the performance degradation. This work was supported in part by Junta de Castilla y León under Grant VA031B06 and by Comunidad Autónoma de Madrid under Grant CAM S-0505/DPI/000235. Diego R. Llanos is partially supported by the European Commission under Contract RII3-CT-2003-506079. David Orden is partially supported by Grant MEC MTM2005-08618-C02-02. Belén Palop is partially supported by MCYT TIC2003-08933-C02-01. Part of this work was carried out while David Orden was visiting the Departamento de Informática, Universidad de Valladolid, with the support of the Universidad de Alcalá. application/pdf eng IEEE info:eu-repo/semantics/openAccess Informática Parallelism and concurrency Load balancing and task assignment Scheduling and task partitioning Geometrical problems and computations 1203 Ciencia de Los Ordenadores 3304 New Scheduling Strategies for Randomized Incremental Algorithms in the Context of Speculative Parallelization info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion https://ieeexplore.ieee.org/document/4167793/ SI THUMBNAIL New_Scheduling_Strategies_for_Randomized_Incremental_Algorithms_in_the_Context_of_Speculative_Parallelization.pdf.jpg New_Scheduling_Strategies_for_Randomized_Incremental_Algorithms_in_the_Context_of_Speculative_Parallelization.pdf.jpg IM Thumbnail image/jpeg 1894 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