Cheers for the OpenBSD shoutout
Although the security situation in OpenBSD is evolving. The current situation, unless they've changed it again in a snapshot recently, is that by default hyperthreading is disabled by not scheduling tasks against a hyperthreaded instance.
Therefore, if you run top and kick off a multi process compile on a pair of 8 core CPUs with hyperthreading, top will display all 32 'cores' but only show activity on 16 of them.
The real danger is that the number of potential exploits is rapidly multiplying. Whilst some of the issues found are difficult to leverage, I wouldn't put money on this being the case for all future design choices that can be taken advantage of.
Biting the hand that feeds IT
