Topic: "False Sharing and Contention in Parallel Codes"

Speaker: Paul Preney, SHARCNET

Video link

Recording

 

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Sequential programs can repeatedly read from and write to memory locations seemingly without issues. On the other hand, parallel programs can easily fall prey to weird behaviours resulting in small to very significant issues and/or performance loss that are not always easily attributable to specific pieces of code one has written. Such behaviours can be seen in multithreaded C, C++, Fortran, OpenMP, etc. parallel codes running on shared memory systems. This presentation will discuss false sharing and contention, the issues resulting from them, and how one can address such so as to minimize if not eliminate their negative effects.

The Compute Ontario Colloquia are weekly Zoom presentations on Advanced Research Computing, High Performance Computing, Research Data Management, and Research Software topics, delivered by staff from three Compute Ontario consortia (CAC, SciNet, SHARCNET) and guest speakers. The series began January 2023 and superseded similar series previously delivered by individual consortia (e.g. General Interest Seminars by SHARCNET or User Group Meeting TechTalks by SciNet). The colloquia are one hour long and include time for questions. No registration is required. Presentations are usually recorded and uploaded to the hosting consortium video channel (colloquia hosted by SHARCNET go to our youtube channel).