SMP vs. Hyperthreading?

[Alex de Kruijff]

On Sat, Mar 13, 2004 at 02:37:37PM +0100, a at jenisch.at wrote:
> Hi,
> 
> I've got a machine with a P4 that supports HTT (Hyperthreading) so I
> thought about setting up a SMP-kernel.
> 
> Under 4.9 it seems to work (see excerpts from /var/log/messages
> below), whereas on the same exact hardware under 5.2.1 I don't see two
> virtual CPUs working. 
> 
> For a first check I've run "cpuburn" (i.e. burnP6). Under 4.9 with one
> "cpuburn" process active "top" etc. show a cpu-load of about 50% which
> for me means SMP/HTT is active.
> 
> Under 5.2.1 it's a different story though: /var/log/messages shows
> that there are 2 CPUs but the message indicating the second CPU has
> been launched is missing ("/kernel: SMP: AP CPU #1 Launched!"). When I
> run a "cpuburn"-Test under 5.2.1 CPU load indicated by "top" shows
> 100% so I assume SMP/HTT is not active.
> 
> 
> So my primary question is - how do I get SMP running under 5.2.1 with
> a hyperthreading-capable P4??

I installed 5.2 and that came ready to run afther the install. I didn't
have to do anything for it.

-- 
Alex

Articles based on solutions that I use:
http://www.kruijff.org/alex/index.php?dir=docs/FreeBSD/