Re: How could smp_error_interrupt get activated on x86?

From: Zwane Mwaikambo
Date: Thu Nov 11 2004 - 20:15:14 EST


On Fri, 12 Nov 2004, Nigel Cunningham wrote:

> I can't for the life of me figure out how one of my suspend2 users could
> get this on a 2.6.9 kernel:
>
> > Software Suspend 2.1.4: Initiating a software suspend cycle.
> > ACPI: PCI Interrupt Link [ALKA] BIOS reported IRQ 0, using IRQ 20
> > ACPI: PCI Interrupt Link [ALKB] BIOS reported IRQ 0, using IRQ 21
> > ACPI: PCI Interrupt Link [ALKC] BIOS reported IRQ 0, using IRQ 22
> > ACPI: PCI Interrupt Link [ALKD] BIOS reported IRQ 0, using IRQ 23
> > APIC error on CPU0: 00(00)
> > ACPI: PCI interrupt 0000:00:0f.0[A] -> GSI 20 (level, low) -> IRQ 177
> > ACPI: PCI interrupt 0000:00:11.5[C] -> GSI 22 (level, low) -> IRQ 193
> > Please include the following information in bug reports:
> > - SUSPEND core : 2.1.4
> > [...]
> >
> > All work fine.
> > Processor and motherboard Athlon Barton 2500+@3200+, EPoX 8KRAI
> (KT600).
> >
> > What is APIC error CPU0: 00(00)?
>
> I know it's really no error (according to the code), but I can't even
> see how the function gets called in the first place:
>
> find -type f | xargs grep smp_error_interrupt
> ./arch/i386/kernel/apic.c:asmlinkage void smp_error_interrupt(void)
> ./arch/x86_64/kernel/apic.c:asmlinkage void smp_error_interrupt(void)
> ./arch/x86_64/kernel/entry.S: apicinterrupt ERROR_APIC_VECTOR,smp_error_interrupt

Ahhh y'see it's by BUILD_INTERRUPT magik;

arch/i386/kernel/entry.S defines BUILD_INTERRUPT, then includes;
include/asm-i386/mach-default/entry_arch.h which does;

BUILD_INTERRUPT(error_interrupt,ERROR_APIC_VECTOR)

Which results in the IDT stub being created for ERROR_APIC_VECTOR

Neat huh? ;)

Regarding your error, has the IOAPIC resumed when you get there?

Zwane

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