### Provably efficient scheduling for languages with fine-grained parallelismProvably efficient scheduling for languages with fine-grained parallelism

Access Restriction
Subscribed

 Author Blelloch, Guy E. ♦ Gibbons, Phillip B. ♦ Matias, Yossi Source ACM Digital Library Content type Text Publisher Association for Computing Machinery (ACM) File Format PDF Copyright Year ©1999 Language English
 Subject Domain (in DDC) Computer science, information & general works ♦ Data processing & computer science Abstract Many high-level parallel programming languages allow for fine-grained parallelism. As in the popular work-time framework for parallel algorithm design, programs written in such languages can express the full parallelism in the program without specifying the mapping of program tasks to processors. A common concern in executing such programs is to schedule tasks to processors dynamically so as to minimize not only the execution time, but also the amount of space (memory) needed. Without careful scheduling, the parallel execution on $\textit{p}$ processors can use a factor of $\textit{p}$ or larger more space than a sequential implementation of the same program.This paper first identifies a class of parallel schedules that are provably efficient in both time and space. For any computation with w units of work and critical path length d, and for any sequential schedule that takes space s1, we provide a parallel schedule that takes fewer than w/p + d steps on p processors and requires less than s1 + p˙d spaces for the common case where $\textit{d}<<\textit{s}1.The$ paper then describes a scheduler for implementing high-level languages with $\textit{nested}$ parallelism, that generates schedules in this class. During program execution, as the structure of the computation is revealed, the scheduler keeps track of the active tasks, allocates the tasks to the processors, and performs the necessary task synchronization. The scheduler is itself a parallel algorithm, and incurs at most a constant factor overhead in time and space, even when the scheduling granularity is individual units of work. The algorithm is the first efficient solution to the scheduling problem discussed here, even if space considerations are ignored. ISSN 00045411 Age Range 18 to 22 years ♦ above 22 year Educational Use Research Education Level UG and PG Learning Resource Type Article Publisher Date 1999-03-01 Publisher Place New York e-ISSN 1557735X Journal Journal of the ACM (JACM) Volume Number 46 Issue Number 2 Page Count 41 Starting Page 281 Ending Page 321

#### Open content in new tab

Source: ACM Digital Library