Re: APIC: what is it good for? Can I switch it off?
Stefan Gößling-Reisemann (<email@example.com>) wrote:
> I am trying to find the reason for our fileserver to shutdown
> unexpectedly (and without any warning entries in the logs). I have
> come across a warning during bootup:
> "Spurious 8259A interrupt: IRQ7"
> As a consequence (??) the ERR field in /proc/interrupts increases
> steadily (by an amount of about 60 per hour).
> What does that mean? Is there a hardware glitch??
> After some Google'ing I found that "Spurious ..." seems to be a
> warning which might be related to APIC and IO-APIC being activated in
> the kernel-config. As one source mentioned, the APIC is for
> communication of CPU in SMP-machines. We only have one CPU, so can I
> safely switch it off in the config?
IO-APIC can be used on single processor machines to get more than 16
0: 32809327 IO-APIC-edge timer
1: 14220 IO-APIC-edge i8042
4: 631691 IO-APIC-edge serial
5: 0 IO-APIC-level uhci_hcd, uhci_hcd, uhci_hcd
7: 2 IO-APIC-edge parport0
8: 1 IO-APIC-edge rtc
9: 0 IO-APIC-level acpi
12: 171457 IO-APIC-edge i8042
14: 66254 IO-APIC-edge ide0
15: 92 IO-APIC-edge ide1
16: 2863271 IO-APIC-level nvidia
17: 0 IO-APIC-level eth0
18: 27558 IO-APIC-level EMU10K1
19: 4 IO-APIC-level bttv0, Bt87x audio
This will however only work if the mainboards it.
> On another note: what would be the difference to disabling it via
> "noapic" appended to the boot command? Does that do the same trick?
It should do the same. By the way, you tan switch off the local IO apic
only using the "nolapic" parameter.
Andreas Janssen <firstname.lastname@example.org>
PGP-Key-ID: 0xDC801674 ICQ #17079270
Registered Linux User #267976