Department of Computer Science at UH

University of Houston

Department of Computer Science

In Partial Fulfillment of the Requirements for the Degree of
Master of Science

Chintu Kshitij V. Mehta

Will defend his thesis

Exploring Parallel I/O for Multi-Threaded Applications using Posix Threads


Parallel architectures aim to increase the overall computing power of a system by providing more nodes per system and/or increasing the number of cores in a single node. But as we succeed in increasing computing power, I/O still remains the slowest operation in a system, thus creating the need to perform I/O in parallel. Distributed memory programming technologies like MPI provide an extensive implementation for parallel I/O, but most shared memory technologies do not have the notion of parallel I/O. This thesis explores parallel I/O techniques on shared memory platforms. A library providing collective I/O interfaces for Posix threads has been developed. Various optimizations on the input data from merging of buffers to distributing I/O tasks amongst threads in an effective manner have been evaluated. Furthermore, an in-depth study of the relationship between the stripe size of a parallel file system such as PVFS2 and the size of a data block in each I/O call has been perf ormed. Results show that the library performs well when minimizing the total number of I/O requests, thereby maximizing the amount of data written in each call. Reducing the amount of data written in each I/O call degrades I/O performance. Tests were performed for 1, 2, 4 and 8 threads. Most cases show a speedup while using a larger number of threads.

Date: Thursday, April 16, 2009
Time: 9:30 AM
Place: 550-PGH
Faculty, students, and the general public are invited.
Advisor: Prof. Edgar Gabriel