1,184 papers · page 31 of 60
This talk has two parts. The first part will discuss possible directions for computer architecture research, including architecture as infrastructure, energy first, impact of new technologies, and cross-layer opportunities. This part is based on a 2012 Computing Community Consort…
We introduce a new approach to automatically extract an idealized logical structure from a parallel execution trace. We use this structure to define intuitive metrics such as the lateness of a process involved in a parallel execution. By analyzing and illustrating traces in terms…
We develop a logging and replay technique for real concurrent execution on multiple cores. Our technique directly works on binaries and does not require any hardware or complex software infrastructure support. We focus on minimizing logging overhead as it only logs a subset of sy…
We examine task mapping algorithms for systems that allocate jobs non-contiguously. Several studies have shown that task placement affects job running time. We focus on jobs with a stencil communication pattern and use experiments on a Cray XE to evaluate novel task mapping algor…
Almost all of today's microprocessors contain memory controllers and directly attach to memory. Modern multiprocessor systems support non-uniform memory access (NUMA): it is faster for a microprocessor to access memory that is directly attached than it is to access memory attache…
False sharing is a notorious problem for multithreaded applications that can drastically degrade both performance and scalability. Existing approaches can precisely identify the sources of false sharing, but only report false sharing actually observed during execution; they do no…
Multithreaded programs execute nondeterministically on conventional architectures and operating systems. This complicates many tasks, including debugging and testing. Deterministic multithreading (DMT) makes the output of a multithreaded program depend on its inputs only, which c…
State-of-the-art MPI libraries rely on locks to guarantee thread-safety. This discourages application developers from using multiple threads to perform MPI operations. In this paper, we propose a high performance, lock-free multi-endpoint MPI runtime, which can achieve up to 40\%…
The Threaded many-core memory (TMM) model provides a framework to analyze the performance of algorithms on GPUs. Here, we investigate the effectiveness of the TMM model by analyzing algorithms for 3 classic problems -- suffix tree/array for string matching, fast Fourier transform…
This paper proposes an efficient parallel algorithm for an important class of dynamic programming problems that includes Viterbi, Needleman-Wunsch, Smith-Waterman, and Longest Common Subsequence. In dynamic programming, the subproblems that do not depend on each other, and thus c…
Loop fusion is an important compiler optimization for improving memory hierarchy performance through enabling data reuse. Traditional compilers have approached loop fusion in a manner decoupled from other high-level loop optimizations, missing several interesting solutions. Recen…
We present a new lock-free algorithm for concurrent manipulation of a binary search tree in an asynchronous shared memory system that supports search, insert and delete operations. In addition to read and write instructions, our algorithm uses (single-word) compare-and-swap (CAS)…
Many scripting languages use a Global Interpreter Lock (GIL) to simplify the internal designs of their interpreters, but this kind of lock severely lowers the multi-thread per-formance on multi-core machines. This paper presents our first results eliminating the GIL in Ruby using…
Today, almost all computer architectures are parallel and heterogeneous; a combination of multiple CPUs, GPUs and specialized processors. This creates a challenging problem for application developers who want to develop high performance programs without the effort required to use…
As the level of parallelism in manycore processors keeps increasing, providing efficient mechanisms for thread synchronization in concurrent programs is becoming a major concern. On cache-coherent shared-memory processors, synchronization efficiency is ultimately limited by the p…
On a cache-coherent multicore multiprocessor system, the performance of a multithreaded application with high lock contention is very sensitive to the distribution of application threads across multiple processors. This is because the distribution of threads impacts the frequency…
As multicore processors become prevalent in modern computer systems, there is a growing need for increasing hardware utilization and exploiting the parallelism of such platforms. With virtualization technology, hardware utilization is improved by encapsulating independent workloa…
Functional algorithmic skeletons promise a high-level programming interface for distributed-memory clusters that free developers from concerns of task decomposition, scheduling, and communication. Unfortunately, prior distributed functional skeleton frameworks do not deliver perf…
The current trend in computer architecture is to increase the number of cores, to create specialized types of cores within a single machine, and to network such machines together in very fluid web/cloud computing arrangements. Compilers have traditionally focused on optimizations…
Dynamic analysis techniques have been proposed to detect potential deadlocks. Analyzing and comprehending each potential deadlock to determine whether the deadlock is feasible in a real execution requires significant programmer effort. Moreover, empirical evidence shows that exis…