Optimised MPI for HPEC Applications
Abstract
We propose an implementation of the MPI standard, suitable for HPEC applications. The HPEC requirements addressed by the proposed implementation include: * support of zero copy transport mechanisms * memory management * handling heterogeneous communication topologies. Zero copy communications are key for HPEC, in order to allocate memory bandwidth to actual communications rather than to data transfers between buffers. The semantics and implementation issues associated with the mapping of MPI primitives on zero copy mechanisms such as VIA or RDMA have been discussed and the feasibility and performance benefits have been demonstrated on the basis of popular MPI implementations such as LAM or MPICH. Optimised, industrial MPI implementations based on zero copy transport should be provided on the high-performance, low latency media suitable for HPEC systems. The implementation described in this paper uses a serial RapidI0 network across PowerPC computing nodes. The applicability to Infiniband or Gigabit ethernet is also discussed. Zero copy communications implies constraints on memory allocation and buffer management; memory buffer management is neither covered nor precluded by the MPI standard. Defining an API allowing the needed level of memory buffer management, while preserving compatibility with the MPI standard, is one of the issues addressed by this implementation. The paper finally proposes a mechanism, compatible with the MPI standard, to describe the communication topology of a HPEC software, such as a dataflow, signal processing application. Such an application is described as a set of tasks interconnected by virtual links. The application graph, and its mapping on a possibly heterogeneous computing and communication infrastructure, is defined through an independent configuration file, allowing to modify the application deployment without recompilation.
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 01, 2005
- Accession Number
- ADA433785
Entities
People
- Benoit Guillon
- Gerard Cristau
- Vincent Chuffart