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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Journal ArticleDOI
Locality-aware parallel block-sparse matrix-matrix multiplication using the Chunks and Tasks programming model
TL;DR: In this paper, a distributed quadtree matrix representation is proposed for block-sparse matrix-matrix multiplication on distributed memory clusters, where data locality is exploited without prior information about matrix sparsity pattern.
Proceedings ArticleDOI
Hierarchical memory management for mutable state
TL;DR: This paper couple the memory manager with the thread scheduler to make reading and updating data allocated by nested threads efficient, and proposes techniques for efficient mutation in parallel functional languages.
QuickCSG: Arbitrary and Faster Boolean Combinations of N Solids
TL;DR: A new vertex-centric view of the problem is proposed, which both simplifies the algorithm computing resulting geometric contributions, and vastly facilitates its spatial decomposition, and achieves breakthrough performance, one to two orders of magnitude speedups with respect to state-of-the-art CPU algorithms, on boolean operations over two to several dozen polyhedra.
Proceedings ArticleDOI
Victim Selection and Distributed Work Stealing Performance: A Case Study
Swann Perarnau,Mitsuhisa Sato +1 more
TL;DR: A new performance evaluation of the popular UTS benchmark is presented, in its work stealing implementation, on the scale of ten thousands of compute nodes, and a new performance metric is introduced to assess the time needed by the work stealing scheduler to distribute work among all processes.
Book ChapterDOI
Amortization Results for Chromatic Search Trees, with an Application to Priority Queues
TL;DR: The intention in designing data structures with relaxed balance, such as chromatic search trees, is to facilitate fast updating on shared-memory asynchronous parallel architectures to obtain this, the updating and rebalancing have been uncoupled, so extensive locking in connection with updates is avoided.
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.