Proceedings of the 32nd ACM Symposium on Parallelism in Algorithms and Architectures最新文献_第7页

A Computational Model for Tensor Core Units 张量核心单元的计算模型

Proceedings of the 32nd ACM Symposium on Parallelism in Algorithms and Architectures Pub Date : 2019-08-19 DOI: 10.1145/3350755.3400252

Francesco Silvestri, Flavio Vella

引用次数: 8

Optimal Parallel Algorithms in the Binary-Forking Model 二进制分叉模型中的最优并行算法

Proceedings of the 32nd ACM Symposium on Parallelism in Algorithms and Architectures Pub Date : 2019-03-11 DOI: 10.1145/3350755.3400227

G. Blelloch, Jeremy T. Fineman, Yan Gu, Yihan Sun

{"title":"Optimal Parallel Algorithms in the Binary-Forking Model","authors":"G. Blelloch, Jeremy T. Fineman, Yan Gu, Yihan Sun","doi":"10.1145/3350755.3400227","DOIUrl":"https://doi.org/10.1145/3350755.3400227","url":null,"abstract":"In this paper we develop optimal algorithms in the binary-forking model for a variety of fundamental problems, including sorting, semisorting, list ranking, tree contraction, range minima, and ordered set union, intersection and difference. In the binary-forking model, tasks can only fork into two child tasks, but can do so recursively and asynchronously. The tasks share memory, supporting reads, writes and test-and-sets. Costs are measured in terms of work (total number of instructions), and span (longest dependence chain). The binary-forking model is meant to capture both algorithm performance and algorithm-design considerations on many existing multithreaded languages, which are also asynchronous and rely on binary forks either explicitly or under the covers. In contrast to the widely studied PRAM model, it does not assume arbitrary-way forks nor synchronous operations, both of which are hard to implement in modern hardware. While optimal PRAM algorithms are known for the problems studied herein, it turns out that arbitrary-way forking and strict synchronization are powerful, if unrealistic, capabilities. Natural simulations of these PRAM algorithms in the binary-forking model (i.e., implementations in existing parallel languages) incur an Ω(log n) overhead in span. This paper explores techniques for designing optimal algorithms when limited to binary forking and assuming asynchrony. All algorithms described in this paper are the first algorithms with optimal work and span in the binary-forking model. Most of the algorithms are simple. Many are randomized.","PeriodicalId":218208,"journal":{"name":"Proceedings of the 32nd ACM Symposium on Parallelism in Algorithms and Architectures","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120956270","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 49

Simple Local Computation Algorithms for the General Lovász Local Lemma 一般Lovász局部引理的简单局部计算算法

Proceedings of the 32nd ACM Symposium on Parallelism in Algorithms and Architectures Pub Date : 2018-09-21 DOI: 10.1145/3350755.3400250

D. Achlioptas, Themis Gouleakis, Fotis Iliopoulos

引用次数: 2

Self-Stabilizing Task Allocation In Spite of Noise 噪声环境下的自稳定任务分配

Proceedings of the 32nd ACM Symposium on Parallelism in Algorithms and Architectures Pub Date : 2018-05-09 DOI: 10.1145/3350755.3400226

A. Dornhaus, N. Lynch, Frederik Mallmann-Trenn, Dominik Pajak, Tsvetomira Radeva

{"title":"Self-Stabilizing Task Allocation In Spite of Noise","authors":"A. Dornhaus, N. Lynch, Frederik Mallmann-Trenn, Dominik Pajak, Tsvetomira Radeva","doi":"10.1145/3350755.3400226","DOIUrl":"https://doi.org/10.1145/3350755.3400226","url":null,"abstract":"We study the problem of distributed task allocation by workers in an ant colony in a setting of limited capabilities and noisy environment feedback. We assume that each task has a demand that should be satisfied but not exceeded, i.e., there is an optimal number of ants that should be working on this task at a given time. The goal is to assign a near-optimal number of workers to each task in a distributed manner without explicit access to the value of the demand nor to the number of ants working on the task. We seek to answer the question of how the quality of task allocation depends on the accuracy of assessing by the ants whether too many (overload) or not enough (lack) ants are currently working on a given task. In our model, each ant receives a binary feedback that depends on the deficit, defined as the difference between the demand and the current number of workers in the task. The feedback is modeled as a random variable that takes values lack or overload with probability given by a sigmoid function of the deficit. The higher the overload or lack of workers for a task, the more likely it is that an ant receives the correct feedback from this task; the closer the deficit is to zero, the less reliable the feedback becomes. Each ant receives the feedback independently about one chosen task. We measure the performance of task allocation algorithms using the notion of inaccuracy, defined as the number of steps in which the deficit of some task is beyond certain threshold. We propose a simple, constant-memory, self-stabilizing, distributed algorithm that converges from any initial assignment to a near-optimal assignment under noisy feedback and keeps the deficit small for all tasks in almost every step. We also prove a lower bound for any constant-memory algorithm, which matches, up to a constant factor, the accuracy achieved by our algorithm.","PeriodicalId":218208,"journal":{"name":"Proceedings of the 32nd ACM Symposium on Parallelism in Algorithms and Architectures","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130492377","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 5