NPAC Technical Report SCCS-636
PASSION: Parallel And Scalable Software for Input-Output
Alok Choudhary, Rajesh Bordawekar, Michael Harry, Rakesh Krishnaiyer, Ravi Ponnusamy, Tarvinder Singh, Rajeev Thakur
Submitted September 20 1994
Abstract
We are developing a software system called PASSION: Parallel And
Scalable Software for Input-Output which provides software support
for high performance parallel I/O. PASSION provides support at the
language, compiler, runtime as well as file system level.
PASSION provides runtime procedures for parallel access to files
(read/write), as well as for out-of-core computations. These routines
can either be used together with a compiler to translate out-of-core
data parallel programs written in a language like HPF, or used
directly by application programmers. A number of optimizations such as
Two-Phase Access, Data Sieving, Data Prefetching and
Data Reuse have been incorporated in the PASSION Runtime Library for
improved performance. PASSION also provides an initial framework for
runtime support for out-of-core irregular problems. The goal of the
PASSION compiler is to automatically translate out-of-core data
parallel programs to node programs for distributed memory machines,
with calls to the PASSION Runtime Library. At the language level,
PASSION suggests extensions to HPF for out-of-core programs.
At the file system level, PASSION provides support for buffering and
prefetching data from disks. A portable parallel file system is also
being developed as part of this project, which can be used across
homogeneous or heterogeneous networks of workstations. PASSION also
provides support for integrating data and task parallelism using
parallel I/O techniques.
We have used PASSION to implement a number of out-of-core
applications such as a Laplace's equation solver, 2D FFT, Matrix
Multiplication, LU Decomposition, image processing applications as well as
unstructured mesh kernels in molecular dynamics and computational
fluid dynamics. We are currently in the process of using PASSION in
applications in CFD (3D turbulent flows), molecular structure
calculations, seismic computations, and earth and space science
applications such as Four-Dimensional Data Assimilation.
PASSION is currently available on the Intel
Paragon, Touchstone Delta and iPSC/860. Efforts are underway to port
it to the IBM SP-1 and SP-2 using the Vesta Parallel File System.