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Linux vs HPC : life (and death) of strange features

Intervenant(s) : Brice Goglin
Langue : English Niveau : Confirmé
Date : Vendredi 9 juillet 2010 Horaire : 17h00 Durée : 40 minutes
Lieu : ENSEIRB - Amphi B
PDF - 323.1 ko
Slides

The talk

High performance computing (HPC) is one of the areas where Linux is used a lot. However, it is also one area where Linux gets deeply modified, especially because of performance requirements. Indeed, HPC hardware and software technologies involve many optimizations that may or may not look clean, because hardware vendors always want to beat the latest performance record even if the code is not portable and clean anymore. Some people want to put random stuff in the kernel for performance reason. Some developers reject it without reasons that may or may not be valid, including trolls, changes of opinion, and even sometimes mistakes when reviewing patches. Sometimes integrating a HPC feature is easy, sometimes is never happens, sometimes it happens for strange reasons or unplanned help from unrelated developers. Going across numerous examples from the last 10 years (I/O, zero-copy, TOE, OS-bypass, write-combining/PAT, …), I will present how HPC innovations were merged into Linux (or not). I will end the talk with some current HPC problems due to the widespread use of multicore processoes : some kernel developers think they can predict everything and have the kernel handle all applications efficiently automatically, while HPC developers want the kernel to do less and let HPC applications deal with the actual hardware complexity.

The speaker

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Brice Goglin

Brice Goglin is a permanent researcher at INRIA (French institute for research in computer science and robotics, http://www.inria.fr/bordeaux). He works at the LaBRI (computer science research lab in Bordeaux, http://www.labri.fr) where he develops software towards the efficient exploiting of hardware for scientific parallel computing. He has been using free software for 10 years and started contributing about 5 years ago, especially within the Linux kernel and X.org window system through the Debian project.