Re: Activating APIC on single processor

From: John Levon (moz@compsoc.man.ac.uk)
Date: Thu Dec 28 2000 - 12:44:54 EST


On 28 Dec 2000, David Huggins-Daines wrote:

> <fpieraut@casi.polymtl.ca> writes:
>
> > I activate APIC interruption with the configuration of linux kernel
> > 2.4.0test-11. In the linux kernel configuration under processor type and
> > features I activate "APIC and IO-APIC support on uniprocessor", and I
> > desactivate "Symmetric multi-processing support". The only way I found to
> > check APIC activation is looking into /proc/interrupts, no "IO-APIC" can
> > be found there. So I read IO-APIC.txt and I suppose there sould be
> > conflicts with IRQ of my PCI cards. So I remove all my PCI cards and still
> > have no APIC interrupt.
> > Is there another way to check APIC activation?
> > Am-I doing to right things to activate IO-APIC?
>
> You might not actually have an IO-APIC or even a local APIC. This is
> the case with the Mobile PIII for instance (I puzzled over this myself
> for a long time).
>
> To find out for sure, run:
>
> grep 'flags.*apic' /proc/cpuinfo

This isn't for sure. I bet you *do* have a local APIC.

This flag is missing on a Pentium II here - I think the BIOS disables
it. However, it can be enabled in the normal way just fine.

The presence of an IO-APIC is a different matter.

thanks
john

--
"The majority of the stupid is invincible and guaranteed for all time. The
 terror of their tyranny, however, is alleviated by their lack of consistency."
	- Albert Einstein

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