EUROMPI

We explore in this paper the advantages that accrue from avoiding the use of wildcards in MPI. We show that, with this change, one can efficiently support millions of concurrently communicating light-weight threads using send-receive communication.

Emerging paradigms like High Performance Data Analytics (HPDA) and Deep Learning (DL) pose at least two new design challenges for existing MPI runtimes. First, these paradigms require an efficient support for communicating unusually large messages ...

The performance of AllReduce is crucial at scale. The recursive doubling with pairwise exchange algorithm theoretically achieves O(log2 N) scaling for short messages with N peers, but is limited by improvements in network latency. A multi-way exchange ...

MPI is a popular programming paradigm on parallel machines today. MPI libraries sometimes use O(N) data structures to implement MPI functionality. The IBM Blue Gene/Q machine has 16 GB memory per node. If each node runs 32 MPI processes, only 512 MB is ...

The "postal" model of communication [3, 8] T = α + βn, for sending n bytes of data between two processes with latency α and bandwidth 1/β, is perhaps the most commonly used communication performance model in parallel computing. This performance model is ...

The advent of many-core architectures poses new challenges to the MPI programming model which has been designed for distributed memory message passing. It is now clear that MPI will have to evolve in order to exploit shared-memory parallelism, either by ...

This paper introduces the mig framework: an Open MPI extension to transparently support the migration of application processes, over different nodes of a distributed High-Performance Computing (HPC) system. The framework provides mechanism on top of ...

Future supercomputers will need to support both traditional HPC applications and Big Data/High Performance Analysis applications seamlessly in a common environment. This motivates traditional job scheduling systems to support malleable jobs along with ...

Dynamic Processes support was added to MPI in version 2.0 of the standard. This feature of MPI has not been widely used by application developers in part due to the performance cost and limitations of the spawn operation. In this paper, we propose an ...

We present a library providing functionality beyond the MPI standard for manipulating application data layouts described by MPI derived datatypes. The main contributions are: a) Constructors for several, new datatypes for describing application relevant ...

We examine natural expectations on communication performance using MPI derived datatypes in comparison to the baseline, "raw" performance of communicating simple, noncontiguous data layouts. We show that common MPI libraries sometimes violate these ...

MPI includes all processes in MPI_COMM_WORLD; this is untenable for reasons of scale, resiliency, and overhead. This paper offers a new approach, extending MPI with a new concept called Sessions, which makes two key contributions: a tighter integration ...

This paper presents strategies to parallelize a previously implemented kinetic Monte Carlo (kMC) algorithm. The process under simulation is the precipitation in an aluminum scandium alloy. The selected parallel algorithm is called synchronous parallel ...

Scientific workloads running on current extreme-scale systems routinely generate tremendous volumes of data for postprocessing. This data movement has become a serious issue due to its energy cost and the fact that I/O bandwidths have not kept pace with ...

Dynamic load balancing with diffusive methods is known to provide minimal load transfer and requires communication between neighbor nodes only. These are very attractive properties for highly parallel systems. We compare diffusive methods with state-of-...

We present scalability and performance enhancements to MPI libraries on POWER8 InfiniBand clusters. We explore optimizations in the Parallel Active Messaging Interface (PAMI) libraries. We bypass IB VERBS via low level inline calls resulting in low ...

The MPI all-to-all algorithm is a data intensive, high-cost collective algorithm used by many scientific High Performance Computing applications. Optimizations for small data exchange use aggregation techniques, such as the Bruck algorithm, to minimize ...

Lightweight multi-kernel architectures, where HPC specialized lightweight kernels (LWKs) run side-by-side with Linux on compute nodes, have received a great deal of attention recently due to their potential for addressing many of the challenges system ...

Open MPI provides an implementation of the MPI-3.1 standard supporting native communication over a wide range of high-performance network interconnects. As of version 2.0.0 Open MPI provides two implementations of the MPI-3.1 Remote Memory Access (RMA) ...

The Message Passing Interface (MPI) includes nonblocking collective operations that support additional overlap between computation and communication. These new operations enable complex data movement between large numbers of processes. However, their ...

MPI-3.1 is currently the most recent version of the MPI standard. It adds important extensions to MPI-2, including a simplified semantic for the one-sided communication routines and a new tool interface, capable of exposing performance data of the MPI ...

C tool writers are forced to deal with a number of Fortran and C interoperability issues when intercepting MPI routines and completing them with PMPI. The C based tool has to intercept the Fortran MPI routines and marshal arguments between C and Fortran,...

Density Functional Theory calculations with plane waves and pseudopotentials represent one of the most important simulation techniques in high performance computing. Together with parallel linear algebra (ZGEMM and matrix diagonalization), the most ...

PARSEC is a massively parallel Density-Functional-Theory (DFT) code. Within the modernization effort towards the new Intel Knights Landing platform, we adapted the main computational kernel, represented as high-order finite-difference stencils, to use ...

The issue of halo communication is the decrease of parallel scalability. To overcome the issues, we have introduced "Halo thread" to our simulation code. However, we have not solved the issue basically in the strong scaling. In this study, we have ...

In this poster, we describe how MPI is used at the National Energy Research Scientific Computing Center (NERSC) NERSC is the production high-performance computing center for the US Department of Energy, with more than 5000 users and 800 distinct ...

The present study deals with the Vlasov simulation code, which solves the first-principle kinetic equations called the Vlasov equation for space plasma. In the present study, a five-dimensional Vlasov code with two spatial dimension and three velocity ...