FreeBSD and Intel Hyperthreading technology.

Chad Leigh -- Shire.Net LLC chad at
Wed Oct 5 11:38:40 PDT 2005

On Oct 5, 2005, at 11:48 AM, Pranav Peshwe wrote:

> Hello,
>             I have an Intel P4 2.8Ghz processor with Hyperthreading  
> (HT).
> The dmesg displays a message saying HT is present and 2 logical
> CPUs present.I tried toggling the setting in BIOS but no difference.
>     How does the FBSD(v5.4 stable) kernel deal with HT ? Do the  
> internal
> workings( maybe locking, per processor data or other things) change as
> compared to a simple non-HT processor ? or does it use employ SMP
> methods to deal with the 2 logical CPUs presented by a HT processor ?
> I want to do kernel programming on FBSD and my project partners have
> non-HT CPUs.How much difference will HT make ? can it be avoided ?

I would suspect that if you do not run an SMP kernel it won't matter


Chad Leigh -- Shire.Net LLC
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