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Affichage des articles du janvier, 2018

My GIS performance impact of Meltdown and Spectre patches

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When I saw performance regression few days ago of Meltdown and Spectre patch from cpu conception problem, I would like to perform some basic test to understand if it could slow down my process.

For those who don't know, here : a postgres article about performance regression : https://www.postgresql.org/message-id/20180102222354.qikjmf7dvnjgbkxe@alap3.anarazel.de 
Since some users finished to make benchmark with Meltdown and Spectre patch, I will not test it on my computer.

How to test  ?
First, I tested it on Archlinux based distribution named Manjaro Linux.


To know if patch is applied to my kernel, I just run this command :

$ cat /proc/cpuinfo | grep cpu_insecure Which reports this :

bugs        : cpu_insecure
bugs        : cpu_insecure
bugs        : cpu_insecure
bugs        : cpu_insecure
bugs        : cpu_insecure
bugs        : cpu_insecure
bugs        : cpu_insecure
bugs        : cpu_insecure When showing cpu_insecure, you know that KPTI patch is enable.

Then there is a specific C code…