Abstract

This report presents optimisations mechanisms within MPICH-Madeleine, the implementation of MPICH over Madeleine. These mechanisms aim to decrease the communication time of derived datatypes for which data is stored in noncontiguous memory areas. The report presents the mechanisms as well as some performance evaluation.

Keywords: MPI, Madeleine, Derived datatypes, Communication times.

1 Introduction

1.1 Context of our Work

1.2 Our Optimisation Mechanisms

2 Optimisation Mechanisms

2.1 The Index Datatype

2.2 The Vector Datatype

2.3 The Struct Datatype

2.4 General Comments

3 Implementation Details

4 Performance Evaluation

4.1 Benchmark for the Index and Vector Datatypes

4.1.1 Benchmark with Fixed Number of Blocks

4.1.2 Varying the Number of Blocks

4.2 Benchmark for the Struct Datatype

5 Discussion

References

A Detailed Performance Results

B Source Code for the Performance Evaluation Programs

B.1 The Index Datatype

B.2 The Vector Datatype

B.3 The Struct Datatype

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Copyright © November 2006 Team Runtime