1,184 papers · page 35 of 60
Modern parallel architectures are emerging with sophisticated hardware consisting of hierarchically placed parallel processors and memories. The properties of memories in a system vary wildly, not only quantitatively (size, latency, bandwidth, number of banks) but also qualitativ…
The virtues of deterministic parallelism have been argued for decades and many forms of deterministic parallelism have been described and analyzed. Here we are concerned with one of the strongest forms, requiring that for any input there is a unique dependence graph representing …
There is an urgent need for novel programming abstractions to leverage the parallelism in modern multicore machines. We introduce S, a new domain-specific language targeting the server-side scripting of high-performance RESTful Web services. S promotes an innovative programming m…
Parallel streaming computations have been studied extensively, and many languages, libraries, and systems have been designed to support this model of computation. In particular, we consider acyclic streaming computations in which individual nodes can choose to filter, or discard,…
Nondeterministic Sequential (NDSeq) specifications have been proposed as a means for separating the testing, debugging, and verifying of a program's parallelism correctness and its sequential functional correctness. In this work, we present a technique that, given a few represent…
We present a parallel implementation of a constraint-based local search algorithm and investigate its performance results for hard combinatorial optimization problems on two different platforms up to several hundreds of cores. On a variety of classical CSPs benchmarks, speedups a…
This paper introduces a programming interface called PARRAY (or Parallelizing ARRAYs) that supports system-level succinct programming for heterogeneous parallel systems like GPU clusters. The current practice of software development requires combining several low-level libraries …
We introduce the first binary search tree algorithm designed for speculative executions. Prior to this work, tree structures were mainly designed for their pessimistic (non-speculative) accesses to have a bounded complexity. Researchers tried to evaluate transactional memory usin…
Multicore machines are quickly shifting to NUMA and CC-NUMA architectures, making scalable NUMA-aware locking algorithms, ones that take into account the machines' non-uniform memory and caching hierarchy, ever more important. This paper presents lock cohorting, a general new tec…
Traditional debuggers are of limited value for modern scientific codes that manipulate large complex data structures. This paper discusses a novel debug-time assertion, called a "Statistical Assertion", that allows a user to reason about large data structures, and the primitives …
Dense matrix factorizations, such as LU, Cholesky and QR, are widely used for scientific applications that require solving systems of linear equations, eigenvalues and linear least squares problems. Such computations are normally carried out on supercomputers, whose ever-growing …
We present Dynamic Out-of-Order Java (DOJ), a dynamic parallelization approach. In DOJ, a developer annotates code blocks as tasks to decouple these blocks from the parent execution thread. The DOJ compiler then analyzes the code to generate heap examiners that ensure the paralle…
Fine-grain thread synchronization has been proved, in several cases, to be outperformed by efficient implementations of the combining technique where a single thread, called the combiner, holding a coarse-grain lock, serves, in addition to its own synchronization request, active …
This paper overviews the first speculative parallelization technique for GPUs that can exploit parallelism in loops even in the presence of dynamic irregularities that may give rise to cross-iteration dependences. The execution of a speculatively parallelized loop consists of fiv…
Cloud computing enables users to perform distributed computing tasks on many virtual machines, without owning a physical cluster. Recently, various distributed computing tasks such as scientific applications are being moved from supercomputers and private clusters to public cloud…
The steady increase of parallelism in high-performance computing platforms implies that communication will be most important in large-scale applications. In this work, we tackle the problem of transparent optimization of large-scale communication patterns using online compilation…
Graphics processing units leverage on a large array of parallel processing cores to boost the performance of a specific streaming computation pattern frequently found in graphics applications. Unfortunately, while many other general purpose applications do exhibit the required st…
R1 is a domain specific language widely used for data analysis by the statistics community as well as by researchers in finance, biology, social sciences, and many other disciplines. As R programs are linked to input data, the exponential growth of available data makes high-perfo…
In this paper, we present a Thread-Level Speculation (TLS) framework whose main feature is to be able to speculatively parallelize a sequential loop nest in various ways, by re-scheduling its iterations. The transformation to be applied is selected at runtime with the goal of min…
Domain-expert productivity programmers desire scalable application performance, but usually must rely on efficiency programmers who are experts in explicit parallel programming to achieve it. Since such programmers are rare, to maximize reuse of their work we propose encapsulatin…