Re: [regression] 3.7 ends in APIC panic

[Borislav Petkov]

On Sun, Dec 16, 2012 at 08:46:06PM +0100, Bernd Schubert wrote:
> Hmm, I read it the other way around - x2apic depends on interrupt
> remapping, but interrupt remapping can be used without x2apic.

Ok, you're right. X2APIC should depend on IRQ_REMAP:
https://lwn.net/Articles/289881/

> The help text of CONFIG_IRQ_REMAP also says "x2APIC enhancements or to
> support platforms with CPU's having > 8 bit APIC ID, say Y." I guess
> may CPU has the latter?

I think it is what Yinghai said - you obviously need x2apic kernel
support if you have IRQ_REMAP on.

> Can the kernel panic a bit improved to help user to understand what
> needs to be enabled?

Well, your kernel enables IRQ_REMAP properly:

[    0.031115] Enabled IRQ remapping in x2apic mode

I guess at that stage we could probably check for x2apic support and
scream loudly if it is not present... IMHO.

Thanks.

-- 
Regards/Gruss,
    Boris.

Sent from a fat crate under my desk. Formatting is fine.
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