Freebsd 6.0 doesnt detect local APIC on a Pentium 3 machine

[Vaibhave Agarwal]

On Mon, 7 Nov 2005, John Baldwin wrote:

> And even then it can't be used for any device interrupts since there aren't 
> any I/O APICs.  On a UP machine without I/O APICs, it's actually probably 
> more optimal to just use irq0 and irq8 for clocks rather than the lapic timer 
> anyway.  The only real possible gain is the ability to use the profiling 
> interrupt from the local APIC.

I got access to the BIOS of the Pentium 3 machine I am using, but it has 
no option to enable/disable the local APIC.

Joseph Koshy is right, Linux enables the local APIC timer while booting 
up. I got the following in the bootup log of Linux 2.4 kernel on the same 
machine.

-------------------------
Local APIC disabled by BIOS -- reenabling.
Found and enabled local APIC!

Using local APIC timer interrupts. 
calibrating APIC timer ...
-------------------------

Though there is no I/O apic in the UP machines, but I only wanted to use 
local APIC timer in the lapic_timer_oneshot() mode to schedule few timers 
accurately.

thanks
vaibhave