2001-11-08 21:29:52

by aputhiya

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Subject: APIC Cluster Model

Hi,

Linux uses FLAT MODEL for setting up the IO APIC for SMP machines (Intel IA-32
arch). I was wondering if the CLUSTER MODEL has been implemented in any of
later SMP kernels?

Thanks
Aravindh


2001-11-08 22:02:39

by Andreas Dilger

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Subject: Re: APIC Cluster Model

On Nov 08, 2001 16:28 -0500, aputhiya wrote:
> Linux uses FLAT MODEL for setting up the IO APIC for SMP machines (Intel
> IA-32 arch). I was wondering if the CLUSTER MODEL has been implemented
> in any of later SMP kernels?

Yes, the IBM folks implemented this for CONFIG_MULITQUAD. I don't know
the details, but it is in stock 2.4.13+ kernels at least.

Cheers, Andreas
--
Andreas Dilger
http://sourceforge.net/projects/ext2resize/
http://www-mddsp.enel.ucalgary.ca/People/adilger/

2001-11-09 00:52:43

by Martin J. Bligh

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Subject: Re: APIC Cluster Model


>> Linux uses FLAT MODEL for setting up the IO APIC for SMP machines (Intel
>> IA-32 arch). I was wondering if the CLUSTER MODEL has been implemented
>> in any of later SMP kernels?
>
> Yes, the IBM folks implemented this for CONFIG_MULITQUAD. I don't know
> the details, but it is in stock 2.4.13+ kernels at least.

Look for things switched on clustered_apic_mode - some of it is
specific to IBM NUMA-Q (and should probably be switched on
something else that's also triggered by CONFIG_MULTIQUAD),
but most of it is switching to clustered APIC mode.

If you have another machine that uses this mode, feel free to
mail me any questions you have about what I did.

Martin.