[poll] hyperthreading_allowed, hlt_logical_cpus, mp_watchdog

[Andriy Gapon]

I am planning on some changes in head and would like to see if people use the
following features:
- machdep.hyperthreading_allowed tunable and sysctl
- machdep.hlt_logical_cpus tunable and sysctl
- mp_watchdog kernel option

If you are using any of the above, please let me know - better via a private reply:
- which exactly of the mentioned above features you use
- please make distinction between use of tunables and sysctls
- tell for what you use the feature
- provide overview of your hardware, which scheduler you use and intended purpose
of the system

Thank you!
-- 
Andriy Gapon