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DTSTAMP:20260422T000604Z
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DTSTART;TZID=America/Denver:20231115T100000
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UID:submissions.supercomputing.org_SC23_sess303_rpost127@linklings.com
SUMMARY:MPI Performance Analysis in Vlasiator:  Unraveling Communication B
 ottlenecks
DESCRIPTION:Jennifer Faj, Jeremy J. Williams, and Ivy B. Peng (KTH Royal I
 nstitute of Technology, Sweden); Urs Ganse, Markus Battarbee, Yann Pfau-Ke
 mpf, Leo Kotipalo, and Minna Palmroth (University of Helsinki); and Stefan
 o Markidis (KTH Royal Institute of Technology, Sweden)\n\nVlasiator is a p
 opular and powerful massively parallel code for accurate magnetospheric an
 d solar wind plasma simulations. This work provides an in-depth analysis o
 f Vlasiator, focusing on MPI performance using the Integrated Performance 
 Monitoring (IPM) tool. We show that MPI non-blocking point-to-point commun
 ication accounts for most of the communication time. The communication top
 ology shows a large number of MPI messages exchanging data in a six-dimens
 ional grid. We also show that relatively large messages are used in MPI co
 mmunication, reaching up to 256MB. As a communication-bound application, w
 e found that using OpenMP in Vlasiator is critical for eliminating intra-n
 ode communication. Our results provide important insights for optimizing V
 lasiator for the upcoming Exascale machines.\n\nTag: Artificial Intelligen
 ce/Machine Learning, Architecture and Networks, Heterogeneous Computing, I
 /O and File Systems, Performance Measurement, Modeling, and Tools, Post-Mo
 ore Computing, Programming Frameworks and System Software, Quantum Computi
 ng\n\nRegistration Category: Tech Program Reg Pass, Exhibits Reg Pass\n\n
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