enable smp / hyperthreading

jwl at io.dk jwl at io.dk
Mon Nov 7 18:53:23 GMT 2005


I've just installed 6.0-RELASE and am trying to get SMP to work (I have af
Pentium 4 with HT). So I've compiled the kernel with 'options SMP' and
according to dmesg the two CPUs are found:

FreeBSD/SMP: Multiprocessor System Detected: 2 CPUs
 cpu0 (BSP): APIC ID:  0
 cpu1 (AP): APIC ID:  1

But I'm not sure that both are enabled, because at this is at the end of
dmesg and I dont see the other CPU being enabled somewhere:

SMP: AP CPU #1 Launched!

According to 'sysctl -a' there are 2 CPUs, but only 1 active and SMP
doesnt seem to be disabled:

kern.smp.cpus: 2
kern.smp.disabled: 0
kern.smp.active: 1

So I thought that it might help to but 'kern.smp.active=2' in
/boot/loader.conf, but after a reboot it is back to 1 again.

What am I missing here?

regards, Jeppe Larsen

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