In scientific applications, netCDF [1] was developed to support a view of data as a collection of self-describing, portable, and array-oriented objects that can be accessed through a simple interface. Its parallel I/O interface named parallel netCDF (hereafter PnetCDF) was developed with the help of an MPI-I/O library [2] such as ROMIO [3], and the PnetCDF succeeded in scientific computation [4...

As parallel systems are commonly being built out of increasingly large multicore chips, application programmers are exploring the use of hybrid programming models combining MPI across nodes and multithreading within a node. Many MPI implementations, however, are just starting to support multithreaded MPI communication, often focussing on correctness first and performance later. As a result, bot...

The Message Passing Interface (MPI) is the prevalent programming model used on today’s supercomputers. Therefore, MPI library developers are looking for the best possible performance (shortest run-time) of individual MPI functions across many different supercomputer architectures. Several MPI benchmark suites have been developed to assess the performance of MPI implementations. Unfortunately, t...

The Message Passing Interface (MPI) 3.0 standard includes a significant revision to MPI’s remote memory access (RMA) interface, which provides support for one-sided communication. MPI-3 RMA is expected to greatly enhance the usability and performance of MPI RMA. We present the first complete implementation of MPI-3 RMA and document implementation techniques and performance optimization opportun...

The number of multithreaded Message Passing Interface (MPI) implementations and applications is increasing rapidly. We discuss how multithreaded applications can receive messages of unknown size. As is well known, combining MPI Probe/MPI Recv is not threadsafe, but many assume that trivial workarounds exist. We discuss those workarounds and show how they fail in practice by either limiting the ...

The Message Passing Interface (MPI) standard for programming parallel computers is widely used for building both programs and libraries. Two of the strengths of MPI are its support for libraries and the existence of multiple implementations on many platforms. These two strengths are in conflict, however, when an application wants to use libraries built with different MPI implementations. This p...

Dynamic verification methods are the natural choice for debugging real world programs when model extraction and maintenance are expensive. Message passing programs written using the MPI library fall under this category. Partial order reduction can be very effective for MPI programs because for each process, all its local computational steps, as well as many of its MPI calls, commute with the co...

In this paper we discuss the design and use of a fault tolerant MPI (FT-MPI) that handles process failures in a way beyond that of the original MPI static process model. FT-MPI allows the semantics and associated modes of failures to be explicitly controlled by an application via a modified functionality within the standard MPI 1.2 API. Given is an overview of the FT-MPI semantics, architecture...