26,968 research outputs found
Stretching the capacity of Hardware Transactional Memory in IBM POWER architectures
The hardware transactional memory (HTM) implementations in commercially
available processors are significantly hindered by their tight capacity
constraints. In practice, this renders current HTMs unsuitable to many
real-world workloads of in-memory databases. This paper proposes SI-HTM, which
stretches the capacity bounds of the underlying HTM, thus opening HTM to a much
broader class of applications. SI-HTM leverages the HTM implementation of the
IBM POWER architecture with a software layer to offer a single-version
implementation of Snapshot Isolation. When compared to HTM- and software-based
concurrency control alternatives, SI-HTM exhibits improved scalability,
achieving speedups of up to 300% relatively to HTM on in-memory database
benchmarks
Gunrock: A High-Performance Graph Processing Library on the GPU
For large-scale graph analytics on the GPU, the irregularity of data access
and control flow, and the complexity of programming GPUs have been two
significant challenges for developing a programmable high-performance graph
library. "Gunrock", our graph-processing system designed specifically for the
GPU, uses a high-level, bulk-synchronous, data-centric abstraction focused on
operations on a vertex or edge frontier. Gunrock achieves a balance between
performance and expressiveness by coupling high performance GPU computing
primitives and optimization strategies with a high-level programming model that
allows programmers to quickly develop new graph primitives with small code size
and minimal GPU programming knowledge. We evaluate Gunrock on five key graph
primitives and show that Gunrock has on average at least an order of magnitude
speedup over Boost and PowerGraph, comparable performance to the fastest GPU
hardwired primitives, and better performance than any other GPU high-level
graph library.Comment: 14 pages, accepted by PPoPP'16 (removed the text repetition in the
previous version v5
Evaluation of pressure boundary conditions for permeability calculations using the lattice-Boltzmann method
Lattice-Boltzmann (LB) simulations are a common tool to numerically estimate
the permeability of porous media. For valuable results, the porous structure
has to be well resolved resulting in a large computational effort as well as
high memory demands. In order to estimate the permeability of realistic
samples, it is of importance to not only implement very efficient codes, but
also to choose the most appropriate simulation setup to achieve accurate
results. With the focus on accuracy and computational effort, we present a
comparison between different methods to apply an effective pressure gradient,
efficient boundary conditions, as well as two LB implementations based on
pore-matrix and pore-list data structures.Comment: 16 pages, 6 figure
- …