The advice in the RT wiki
https://rt.wiki.kernel.org/index.php/HOWTO:_Build_an_RT-application#Hyper_threading
about configuring the kernel and building RT applications was written
in 2014, when we were on the 3.x series. That makes one wonder how
relevant some of it is for the 5.x series, especially since processors
in common use have changed some since then. Some of the advice,
notably about power management, obviously is timeless.
In particular, Daniel Wagner added:
https://rt.wiki.kernel.org/index.php/HOWTO:_Build_an_RT-application#Hyper_threading
"Hyper threading and also out of order execution of CPUs introduces
'random' latencies. As mentioned in power management, it is
recommended to disable these feature (if possible) or carefully
benchmark the performance."
Is the advice still current? Should we RT-users all still turn
hyperthreading off? Given the security vulnerabilities associated
with hyperthreading, there are clearly some use cases where doing so
is indicated anyway.
Thanks,
Alison Chaiken
Aurora Technology
