PSBLAS

Great addition to any scientific project

Comes with a range of interfaces

Tested on tens of thousands of cores

The PSBLAS library, developed with the aim to facilitate the parallelization of computationally intensive scientific applications, is designed to address parallel implementation of iterative solvers for sparse linear systems through the distributed memory paradigm. It includes routines for multiplying sparse matrices by dense matrices, solving block diagonal systems with triangular diagonal entries, preprocessing sparse matrices, and contains additional routines for dense matrix operations. The current implementation of PSBLAS addresses a distributed memory execution model operating with message passing.

The PSBLAS library version 3 is implemented in the Fortran 2003 programming language, with reuse and/or adaptation of existing Fortran 77 and Fortran 95 software, plus a handful of C routines.

UTILITIES

The test/util directory contains some utilities to convert to/from Harwell-Boeing and MatrixMarket file formats.

DOCUMENTATION

See docs/psblas-3.7.pdf; an HTML version of the same document is available in docs/html, and on this website.

Please consult the sample programs, especially test/pargen/psb_[sd]_pde[23]d.f90

OTHER SOFTWARE CREDITS

We originally included a modified implementation of some of the Sparker (serial sparse BLAS) material; this has been completely rewritten, way beyond the intention(s) and responsibilities of the original developers. The main reference for the serial sparse BLAS is:

Duff, I., Marrone, M., Radicati, G., and Vittoli, C. Level 3 basic linear algebra subprograms for sparse matrices: a user level interface, ACM Trans. Math. Softw., 23(3), 379-401, 1997.

RELEASE

Library releases for PSBLAS.

Release	Date	Sources	Documentation
Version 3.8.1-2	November 13, 2023
Version 3.8.1	September 29, 2023
Version 3.8.0-2	August 5, 2022
Version 3.8.0	May 24, 2022
Version 3.7.0.2	September 24, 2021
Version 3.7.0.1	May 11, 2021
Version 3.7.0-1	April 13, 2021
Version 3.7.0	April 12, 2021

Library releases can be downloaded from: psblas3/releases

INSTALLING

To compile and run our software you will need the following prerequisites (see also SERIAL below):

1. A working version of MPI

2. A version of the BLAS; if you don’t have a specific version for your platform you may try ATLAS available from http://math-atlas.sourceforge.net/

3. We have had good results with the METIS library, from http://www-users.cs.umn.edu/~karypis/metis/metis/main.html. This is optional; it is used in the util and test/fileread directories but only if you specify --with-metis.

4. If you have the AMD package of Davis, Duff and Amestoy, you can specify --with-amd (see ./configure --help for more details).

The configure script will generate a Make.inc file suitable for building the library. The script is capable of recognizing the needed libraries with their default names; if they are in unusual places consider adding the paths with --with-libs, or explicitly specifying the names in --with-blas, etc. Please note that a common way for the configure script to fail is to specify inconsistent MPI vs. plain compilers, either directly or indirectly via environment variables; e.g. specifying the Intel compiler with FC=ifort while at the same time having an MPIFC=mpif90 which points to GNU Fortran. The best way to avoid this situation is (in our opinion) to use the environment modules package (see http://modules.sourceforge.net/), and load the relevant variables with (e.g.)

module load gnu46 openmpi

This will delegate to the modules setup to make sure that the version of openmpi in use is the one compiled with the gnu46 compilers. After the configure script has completed you can always tweak the Make.inc file yourself.

After you have Make.inc fixed, run

make

to compile the library; go to the test directory and its subdirectories to get test programs done. If you specify --prefix=/path you can do make install and the libraries will be installed under /path/lib, while the module files will be installed under /path/modules. The regular and experimental C interface header files are under /path/include.

PACKAGE DISTRIBUTION

The PSBLAS library is also distributed as a package for the following Linux distributions.

SERIAL

Configuring with --enable-serial will provide a fake MPI stub library that enables running in pure serial mode; no MPI installation is needed in this case (but note that the fake MPI stubs are only guaranteed to cover what we use internally, it’s not a complete replacement).

LONG INTEGERS

From version 3.7.0 of PSBLAS, we handle 8-bytes integer data for the global indices of distributed matrices, allowing an index space larger than 2G. The default setting in the configure uses 4 bytes for local indices, and 8 bytes for global indices. This can be tuned using the following configure flags.

Note: If you wish to compile PSBLAS with the Metis interfaces then you need to configure and compile it in a consistent way with the choice made for --with-lpk. This can be achieved by setting the defines in the metis.h library, e.g, to use 8 bytes integers and 4 bytes floats

#define IDXTYPEWIDTH 64
#define REALTYPEWIDTH 32

TODO

Fix all reamining bugs. Bugs? We dont’ have any ! ;-)

The PSBLAS team.

Project lead: Salvatore Filippone

Contributors (roughly reverse cronological order):

• Fabio Durastante
• Soren Rasmussen
• Zaak Beekman
• Ambra Abdullahi Hassan
• Pasqua D’Ambra
• Alfredo Buttari
• Daniela di Serafino
• Michele Martone
• Michele Colajanni
• Fabio Cerioni
• Stefano Maiolatesi
• Dario Pascucci