MPI is the de facto message passing standard for multicomputers and networks of workstations, established by the MPI Forum, a group of universities, research centers, and national laboratories (from both the United States and Europe), as well as multinational vendors in the area of high performance computing. MPI has been implemented already by several groups. Worldwide acceptance of MPI has been quite rapid. This paper overviews several areas in which MPI can be extended, discusses the merits of making such extensions, and begins to demonstrate how some of these extensions can be made. In some areas, such as intercommunicator extensions, significant progress has been made by us already. In other areas (such as remote memory access), we are merely proposing extensions to MPI that we have not yet reduced to practice. Furthermore, we point out that other researchers are evidently working in parallel with us on their own extension concepts for MPI. 1 Introduction The MPI Forum introduced...

This paper describes the design and implementation in MPI of the parallel vector library CVL, which is used as the basis for implementing nested data-parallel languages such as NESL and Proteus. We outline the features of CVL, and compare the ease of writing and debugging the portable MPI implementation with our experiences writing previous versions in CM-2 Paris, CM-5 CMMD, and PVM 3.0. We give initial performance results for MPI CVL running on the SP-1, Paragon, and CM-5, and compare them with previous versions of CVL running on the CM-2, CM-5, and Cray C90. We discuss the features of MPI that helped and hindered the effort, and make a plea for better support for certain primitives. Finally, we discuss the design limitationsof CVL when implemented on current RISC-based MPP architectures, and outline our plans to overcome this by using MPI as a compiler target. CVL and associated languages are available via FTP.

MPI is the new standard for multicomputer and cluster message passing introduced by the Message-Passing Interface Forum (MPIF) in April 1994. This paper describes the current inter-communicator interface found in MPI and the reasons for its current design. We also motivate the need for additional inter-communicator operations and introduce the extensions we have included in MPIX (MPI eXtension Library), a library of extensions to MPI that we are currently developing. Inter-communicators may be used for a variety of purposes such as in client/server applications (i.e., I/O and graphics servers) and for process management in dynamic process environments and multi-protocol implementations; MPI's definitions are unnecessarily restrictive, so we extend them here. We discuss the inter-communicator collective operations defined in MPIX and illustrate their use. We also discuss additional inter-communicator construction routines not in the original MPI interface, but that are provided in MPIX....

1 1 Introduction 2 1.1 Comments on Timings : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : 6 2 Programming Packages and Tools 6 2.1 Graphical Display of System Use : : : : : : : : : : : : : : : : : : : : : : : : 6 2.2 Parallel Unix Tools : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : 7 2.3 BlockSolve : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : 8 2.4 Fortran M : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : 8 2.5 Chameleon : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : 9 2.6 Parallel Research on Invariant Subspace Methods : : : : : : : : : : : : : : : 10 2.7 MPI : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : 12 2.8 PCN : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : 12 2.9 Portable, Extensible Tools for Scientific Computing (PETSc) : : : : : : : : 13 2.10 p4 : : : : : : : : : : : : : : : : : : : : : : : : : : : ...

This paper presents a new kind of portability system, Unify, which modifies the PVM message passing system to provide (currrently a subset of) the Message Passing Interface (MPI) standard notation for message passing. Unify is designed to reduce the effort of learning MPI while providing a sensible means to make use of MPI libraries and MPI calls while applications continue to run in the PVM environment. We are convinced that this strategy will reduce the costs of porting completely to MPI, while providing a gradual environment within which to evolve. Furthermore, it will permit immediate use of MPI-based parallel libraries in applications, even those that use PVM for user code. We describe several paradigms for supporting MPI and PVM message passing notations in a single environment, and note related work on MPI and PVM implementations. We show the design options that existed within our chosen paradigm (which is an MPI interface added to the base PVM system), and why we chose that par...

On account of the growing number of workstations networks, many communication libraries are now also used outside the parallel computers area. Among those communication libraries, Message Passing Interface (MPI) appears to be an attempt of standardisation for distributedmemory computing systems. However, most people still prefer the other libraries, arguing about MPI's efficiency. The aim of our study is to evaluate the overhead introduced by these different communication libraries and to point out the cost of heterogeneous workstations' use. We tested the well-known de facto standards like PVM or P4, and some MPI implementations available in the public domain, on homogeneous and heterogeneous environments. Our results show that MPI implementations, can also achieve efficient results as good as PVM, but that a stronger heterogeneous support will be needed in the future, because of the increasing speed of networks. 1 Introduction Numerous Message Passing Libraries are available in the ...

In September of 1994 a workshop was held at Argonne National Laboratory on implementation issues for MPI. MPI is a standard message-passing library interface developed during 1993 and 1994 by the MPI Forum, a broadly based group of parallel computing vendors, parallel library writers, and application scientists. The purpose of the Workshop was to gather together those vendors and others actively engaged in implementing the Standard in order to discuss issues raised by the implementation process. A secondary aim was to explore the possibility of pooling some efforts in order to speed and ease the adoption of MPI. Here we briefly describe the implementation efforts that were presented at the Workshop, summarize the discussions that took place on the Standard itself and implementation issues, and offer some general conclusions about the state of the MPI implementation effort worldwide. 1 Introduction During 1993 and 1994, the MPI Forum, a group of parallel computer vendors, library write...

In this paper, we discuss the performance achieved by several implementations of the recently defined Message Passing Interface (MPI) standard. In particular, performance results for different implementations of the broadcast operation are analyzed and compared on the Delta, Paragon, SP1 and CM5. 1 Introduction For the past several years, members of the Parallel Research on Invariant Subspace Methods (PRISM) project have been investigating scalable parallel eigensolvers for distributed memory systems [1, 3]. The ultimate objective of this research is the development of portable and efficient libraries for this fundamental numerical linear algebra kernel. In the course of our work, we, like many other library developers, have been faced with many issues relating to portable programming. Previously, a notable obstacle to library development was the lack of standardization in message passing, from both a programming and a functional point of view. This lack of standardization made it dif...

this report. 2 Project Lifetime

1 1 Introduction 2 1.1 Comments on Timings : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : 6 2 Programming Packages and Tools 6 2.1 Graphical Display of System Use : : : : : : : : : : : : : : : : : : : : : : : : 6 2.2 Parallel Unix Tools : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : 7 2.3 BlockSolve : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : 8 2.4 Fortran M : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : 8 2.5 Chameleon : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : 9 2.6 Parallel Research on Invariant Subspace Methods : : : : : : : : : : : : : : : 10 2.7 MPI : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : 12 2.8 PCN : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : 12 2.9 Portable, Extensible Tools for Scientific Computing (PETSc) : : : : : : : : 13 2.10 p4 : : : : : : : : : : : : : : : : : : : : : : : : : : : ...