During summer 2022, a second Inria internship (under the supervision of Francieli Boito, Antônio Tadeu Gomes and Luan Teylo) was dedicated to studying and improving the performance of the MHM library for HPC multiscale finite element simulations, developed at the LNCC. Louis Peyrondet, then a student from the University of Bordeaux, developed MSLIO, an I/O kernel of the library, i.e. a software that mimics the I/O behavior of the real application, without compute and communication phases. The motivations for creating an I/O kernel were many-fold: it allows for faster and greener experiments as we can focus only on the behavior that interest us (the I/O part), it allows for faster prototyping of improvements, and it can be used as a benchmark for other research efforts.
A paper describing MSLIO, the I/O behavior of MHM and results with two optimizations – buffering of small requests and a single shared file layout – was published in the WAMCA workshop, held during SBAC-PAD 2022 in Bordeaux, France. The paper, titled I/O performance of multiscale finite element simulations on HPC environments, is available at https://hal.inria.fr/hal-03808833/, and MSLIO is open source and freely available at https://gitlab.inria.fr/lpeyrond/mslio
Louis Peyrondet also presented this work in a hybrid virtual+in-person seminar, held at Inria Bordeaux in October and through a video-conference system to LNCC members.
