Re: Activating APIC on single processor

Re: Activating APIC on single processor

[David Huggins-Daines]

<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

-- 
David Huggins-Daines		-		dhd@eradicator.org
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Re: Activating APIC on single processor

[John Levon]

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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Activating APIC on single processor

[fpieraut]

Hi

I try to activate APIC interrruption on a single processor(PIII) with
kernel2.4.0-test11.

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?

Any help will be very  appreciate
    
Francis Pieraut

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Re: Activating APIC on single processor

[fpieraut]

Hi

I have try to activate APIC in my BIOS, but I didn't have this option.
Have you ever try it?

Tanks
Francis Pieraut


Francis Pieraut

On Thu, 28 Dec 2000, John Levon wrote:

> 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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Re: Activating APIC on single processor

[Mikael Pettersson]

Francis Pieraut wrote:

>I try to activate APIC interrruption on a single processor(PIII) with
>kernel2.4.0-test11.
>
>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?

CONFIG_X86_UP_IOAPIC only works if you actually have an IO-APIC
(the "and" in the description is strict), but most UP boards don't
have one. You should apply the UP-APIC patch, available at:

       http://www.csd.uu.se/~mikpe/linux/upapic/

/Mikael
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