Journal ArticleDOI
Scheduling multithreaded computations by work stealing
TLDR
This paper gives the first provably good work-stealing scheduler for multithreaded computations with dependencies, and shows that the expected time to execute a fully strict computation on P processors using this scheduler is 1:1.Abstract:
This paper studies the problem of efficiently schedulling fully strict (i.e., well-structured) multithreaded computations on parallel computers. A popular and practical method of scheduling this kind of dynamic MIMD-style computation is “work stealing,” in which processors needing work steal computational threads from other processors. In this paper, we give the first provably good work-stealing scheduler for multithreaded computations with dependencies.Specifically, our analysis shows that the expected time to execute a fully strict computation on P processors using our work-stealing scheduler is T1/P + O(T ∞ , where T1 is the minimum serial execution time of the multithreaded computation and (T ∞ is the minimum execution time with an infinite number of processors. Moreover, the space required by the execution is at most S1P, where S1 is the minimum serial space requirement. We also show that the expected total communication of the algorithm is at most O(PT ∞( 1 + nd)Smax), where Smax is the size of the largest activation record of any thread and nd is the maximum number of times that any thread synchronizes with its parent. This communication bound justifies the folk wisdom that work-stealing schedulers are more communication efficient than their work-sharing counterparts. All three of these bounds are existentially optimal to within a constant factor.read more
Citations
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Proceedings ArticleDOI
Parallel Batch-Dynamic Graph Connectivity
TL;DR: In this article, a parallel batch-dynamic connectivity algorithm was proposed that is work-efficient with respect to the HDT algorithm for small batch sizes, and is asymptotically faster when the average batch size is sufficiently large.
Proceedings ArticleDOI
Optimal Parallel Algorithms in the Binary-Forking Model
TL;DR: In the binary-forking model, tasks can only fork into two child tasks, but can do so recursively and asynchronously as mentioned in this paper, and the costs are measured in terms of work (total number of instructions), and span (longest dependence chain).
Journal ArticleDOI
MultiMLton: A multicore-aware runtime for standard ML
TL;DR: The rationale, design, and implementation of MultiMLton are described, and experimental results over a range of parallel benchmarks and different multicore architectures including an 864 core Azul Vega 3, and a 48 core non-coherent Intel SCC (Single-Cloud Computer), that justify the design decisions are provided.
A Survey of High-Level Parallel Programming Models
TL;DR: The properties, advantages, and disadvantages of highlevel approaches to parallel programming that are deemed more exible for eciently utilising modern and future heterogeneous architectures are surveyed.
Proceedings ArticleDOI
Scalable distributed depth-first search with greedy work stealing
TL;DR: This work presents a framework for the parallelization of depth-first combinatorial search algorithms on a network of computers using a work stealing strategy coupled with a small number of primitives for the processors to obtain new work and to communicate to other workers.
References
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Journal ArticleDOI
Cilk: An Efficient Multithreaded Runtime System
Robert D. Blumofe,Christopher F. Joerg,Bradley C. Kuszmaul,Charles E. Leiserson,Keith H. Randall,Yuli Zhou +5 more
TL;DR: It is shown that on real and synthetic applications, the “work” and “critical-path length” of a Cilk computation can be used to model performance accurately, and it is proved that for the class of “fully strict” (well-structured) programs, the Cilk scheduler achieves space, time, and communication bounds all within a constant factor of optimal.
Journal ArticleDOI
Bounds for certain multiprocessing anomalies
TL;DR: In this paper, precise bounds are derived for several anomalies of this type in a multiprocessing system composed of many identical processing units operating in parallel, and they show that an increase in the number of processing units can cause an increased total length of time needed to process a fixed set of tasks.
Proceedings ArticleDOI
The implementation of the Cilk-5 multithreaded language
TL;DR: Cilk-5's novel "two-clone" compilation strategy and its Dijkstra-like mutual-exclusion protocol for implementing the ready deque in the work-stealing scheduler are presented.
Journal ArticleDOI
The Parallel Evaluation of General Arithmetic Expressions
TL;DR: It is shown that arithmetic expressions with n ≥ 1 variables and constants; operations of addition, multiplication, and division; and any depth of parenthesis nesting can be evaluated in time 4 log 2 + 10(n - 1) using processors which can independently perform arithmetic operations in unit time.