Title
A proposal for supporting speculation in the openMP taskloop construct
Date Issued
01 January 2019
Access level
metadata only access
Resource Type
conference paper
Author(s)
Baldassin A.
São Paulo State University
Publisher(s)
Springer Verlag
Abstract
Parallelization constructs in OpenMP, such as parallel for or taskloop, are typically restricted to loops that have no loop-carried dependencies (DOALL) or that contain well-known structured dependence patterns (e.g. reduction). These restrictions prevent the parallelization of many computational intensive may DOACROSS loops. In such loops, the compiler cannot prove that the loop is free of loop-carried dependencies, although they may not exist at runtime. This paper proposes a new clause for taskloop that enables speculative parallelization of may DOACROSS loops: the tls clause. We also present an initial evaluation that reveals that: (a) for certain loops, slowdowns using DOACROSS techniques can be transformed in speed-ups of up to 2.14× by applying speculative parallelization of tasks; and (b) the scheduling of tasks implemented in the Intel OpenMP runtime exacerbates the ratio of order inversion aborts after applying the taskloop-tls parallelization to a loop.
Start page
246
End page
261
Volume
11718 LNCS
Language
English
OCDE Knowledge area
Ciencias de la información
Ciencias de la computación
Subjects
Scopus EID
2-s2.0-85072865530
Source
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)
Resource of which it is part
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)
ISSN of the container
03029743
ISBN of the container
978-303028595-1
Conference
15th International Workshop on OpenMP, IWOMP 2019
Sponsor(s)
The authors would like to thank the anonymous reviewers for the insightful comments. This work is supported by FAPESP (grants 18/07446-8 and 18/15519-5).
Sources of information:
Directorio de Producción Científica
Scopus