Solving Linear Algebra (LA) problems is a core task in four out of five EoCoE II Scientific Challenges (SC) and thus the availability of exascale-enabled LA solvers is fundamental in preparing the SC applications for the new exascale ecosystem. The goal of WP3 is to design and implement exascale-enabled LA solvers for the selected applications and to integrate them into the application codes. A co-design approach between LA and SC experts will be used; nevertheless, the solvers will be also developed in a more general perspective, to obtain LA tools useful for a wider range of applications. The LA experts involved in WP3 have a long-standing experience in developing solvers for HPC platforms, and the planned activities will build upon software and methodologies developed by them and tested during EoCoE I. New algorithms and disruptive technologies will be also considered, to tackle the new challenges posed by the envisioned exascale systems.
In order to achieve the previous goal, the following steps will be performed:
- analysis of the LA kernels of the applications, to clearly identify the needs of the applications in terms of LA solvers, and to select the best LA methodologies and software to work with. Actually, this work has been triggered during EoCoE I, providing a sound basis for EoCoE II
- extension, modification, and re-factoring of the selected LA solvers, based on a co-design approach between LA experts and application experts, to ensure that solvers and applications evolve accordingly in their route toward exascale
- design and implementation of novel solvers, for applications where modifying and re-factoring the available LA solvers does not appear satisfactory
- Integration of the LA solvers into the applications, in strict collaboration between LA and application experts, and testing and tuning on problems of interest
The work will address the Material, Water, Fusion and Wind Scientific Challenges, where strong needs for exascale-enabled LA solvers have emerged during EoCoE I. A different task for each SC has been planned, plus a task concerning transversal activities. The HPC packages developed by the LA experts participating in EoCoE II will provide a sound basis.
- Task 3.1 Scalable Solvers for Materials: Luc Giraud (INRIA)
- Task 3.2 Scalable Solvers for Water: Pasqua D’Ambra (CNR)
- Task 3.3 Scalable Solvers for Fusion: Ulrich Rüde (Cerfacs)
- Task 3.4 Scalable Solvers for Wind: Luc Giraud (INRIA)
- Task 3.5 Transversal activities: Alfredo Buttari (CNRS)