FreeBSD 6-STABLE and HyperThreading

[Niek Bouman]

Hi,

I have a pc with a pentium4 cpu with HT support running FreeBSD 6-STABLE.

In the GENERIC kernel, SMP is turned off by default. I am wondering 
whether it is useful to enable HT-support.

In the usenet discussions, I have seen a lot about the HT security flaw 
that was detected a while ago. Also I read about some rumours saying 
that the system performance decreases with HT enabled in freebsd, 
because freebsd thinks that there are 2 physical cpu's and adapts the 
workload over them in a way that is not suitable for just one physical 
HT processor.

Could someone give advice on whether it's wise to enable HT-support in 
6-STABLE?

And, is the following correct: enabling SMP (=HT in this case?) is 
nothing more than adding "options SMP" to the kernel config file and 
then do a kernel rebuild & reinstall ?

And what about the scheduler? Is the usage of ULE recommended, or should 
i stick the old one?

(I can't find that much in the handbook about HT/SMP)


thanks in advance for your time and help,
Niek