1,184 papers · page 20 of 60
Programs that use hardware transactional memory (HTM) demand sophisticated performance analysis tools when they suffer from performance losses. We have developed TxSampler---a lightweight profiler for programs that use HTM. TxSampler measures performance via sampling and provides…
The 3D reconstruction of cryo-electron microscopy (cryo-EM) structural determination process is highly compute-intensive. It inherently requires accesses of a large 3D model in different and variable orientations, brings tough challenges to GPU architecture and has no effective s…
In the ongoing efforts targeting the vectorization of linear algebra primitives, sparse matrix-matrix multiplication (SpGEMM) has received considerably less attention than sparse Matrix-Vector multiplication (SpMV). While both are equally important, this disparity can be attribut…
Ensemble Kalman filter (EnKF) is one of the most important methods for data assimilation, which is widely applied to the reconstruction of observed historical data for providing initial conditions of numerical atmospheric and oceanic models. With the improvement of data resolutio…
GPUs have benefited many ML algorithms. However, we observe that the performance of existing Latent Dirichlet Allocation(LDA) solutions on GPUs are not satisfying. We present CuLDA_CGS, an efficient approach to accelerate large-scale LDA problems. We delicately design workload pa…
Many computationally expensive problems are solved by a divide-and-conquer algorithm: a problem over a big dataset can be recursively divided into independent tasks over smaller subsets of the dataset. We present a distributed general-purpose framework called T-thinker which effe…
B+tree is one of the most important data structures and has been widely used in different fields. With the increase of concurrent queries and data-scale in storage, designing an efficient B+tree structure has become critical. Due to abundant computation resources, GPUs provide po…
Transactional memory (TM) is heavily used for synchronization in the Haskell programming language, but its performance has historically been poor. We set out to improve this performance using hardware TM (HTM) on Intel processors. This task is complicated by Haskell's retry mecha…
A common task for all deterministic multithreading (DMT) systems is to enforce synchronization determinism. However, synchronization determinism has not been the focus of existing DMT research. Instead, most DMT systems focused on how to order data races remained after synchroniz…
Interactive information retrieval services, such as enterprise search and document search, must provide relevant results with consistent, low response times in the face of rapidly growing data sets and query loads. These growing demands have led researchers to consider a wide ran…
Over the past decade, many programming languages and systems for parallel-computing have been developed, including Cilk, Fork/Join Java, Habanero Java, Parallel Haskell, Parallel ML, and X10. Although these systems raise the level of abstraction at which parallel code are written…
Concurrent sets with range query operations are highly desirable in applications such as in-memory databases. However, few set implementations offer range queries. Known techniques for augmenting data structures with range queries (or operations that can be used to build range qu…
This work proposes a low-overhead half-barrier pattern to schedule fine-grain parallel loops and considers its integration in the Intel OpenMP and Cilkplus schedulers. Experimental evaluation demonstrates that the scheduling overhead of our techniques is 43% lower than Intel Open…
The complexity of shared memory systems is becoming more relevant as the number of memory domains increases, with different access latencies and bandwidth rates depending on the proximity between the cores and the devices containing the data. In this context, techniques to manage…
Scientific applications with single instruction, multiple data (SIMD) computations show considerable performance improvements when run on today's graphics processing units (GPUs). However, the existence of data dependences across thread blocks may significantly impact the speedup…
Shared-memory parallel programs routinely suffer from false sharing---a performance degradation caused by different threads accessing different variables that reside on the same CPU cacheline and at least one variable is modified. State-of-the-art tools detect false sharing via a…
Transactions are widely used in database engines and they becoming increasingly useful as a general synchronization technique for multicore machines [1]. Transactional systems allow a programmer to encapsulate multiple operations inside a transaction. All these operations appear …
A reader-writer lock provides basic methods for shared and exclusive lock acquisition. A thread calling one of these methods may have to wait indefinitely to enter its critical section, with no guarantee of completion.
In cloud computing customers upload data and computation to cloud providers. As they cede their data to the cloud provider, they may cede data confidentiality. We develop SecureMR, a system that analyzes and transforms MapReduce programs to operate over encrypted data. SecureMR m…
Operations of concurrent objects often employ optimistic concurrency-control schemes that consist of a traversal followed by a validation step. The validation checks if concurrent mutations interfered with the traversal to determine if the operation should proceed or restart. A f…