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
WATS: Workload-Aware Task Scheduling in Asymmetric Multi-core Architectures
TL;DR: This paper proposes a Workload-Aware Task Scheduling (WATS) scheme that adopts history-based task allocation and preference-basedtask stealing, which can dynamically adjust the workloads in AMC if the task allocation is less optimal due to approximation in the history- based task allocation.
Proceedings ArticleDOI
Verifying message-passing programs with dependent behavioural types
TL;DR: A concurrent functional language λ≤π is formalised, with a new blend of behavioural types (from π-calculus theory), and dependent function types ( from the Dotty programming language), to specify and verify the intended behaviour of message-passing applications using types, and ensure that, if a program type-checks and compiles, then it will run and communicate as desired.
Proceedings ArticleDOI
Developing, simulating, and deploying peer-to-peer systems using the Kompics component model
TL;DR: This paper describes how the message-passing component model, called Kompics, is used to build overlay network systems using a P2P component framework, where the same implementation can be simulated or deployed in a production environment.
Proceedings ArticleDOI
Theoretically-Efficient and Practical Parallel DBSCAN
Yiqiu Wang,Yan Gu,Julian Shun +2 more
TL;DR: This paper presents new parallel algorithms for Euclidean exact DBSCAN and approximate DBS CAN that match the work bounds of their sequential counterparts, and are highly parallel (polylogarithmic depth).
Proceedings ArticleDOI
A multi-DAG model for real-time parallel applications with conditional execution
TL;DR: This paper proposes a two-step solution that computes a single synchronous DAG of servers for a task modeled by a multi-DAG and shows that these servers are able to supply every execution flow of that task with the required cpu-budget so that the task can execute entirely.
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.