Messages in this thread | | | From | "Martin Eriksson" <> | Subject | Re: "APIC error on CPUx" - what does this mean? | Date | Mon, 7 Jan 2002 15:40:55 +0100 |
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----- Original Message ----- From: "Petr Vandrovec" <VANDROVE@vc.cvut.cz> To: "Chris Wedgwood" <cw@f00f.org> Cc: <swsnyder@home.com>; "Linux Kernel Mailing List" <linux-kernel@vger.kernel.org>; <alan@lxorguk.ukuu.org.uk> Sent: Monday, January 07, 2002 2:16 PM Subject: Re: "APIC error on CPUx" - what does this mean?
> On 8 Jan 02 at 2:08, Chris Wedgwood wrote: > > On Mon, Jan 07, 2002 at 01:29:42PM +0100, Petr Vandrovec wrote: > > > > They are spurious IRQ 7, just message is printed only once during > > kernel lifetime... I have about three spurious IRQ 7 per each 1000 > > interrupts delivered to CPU. It is on A7V (Via KT133). > > > > Any idea _why_ these occur though? It seems some mainboards produce a > > plethora of these whilst others never produce these... > > Nope. Probably when CPU is in local APIC mode, it acknowledges interrupts > to chipset with different timming, and from time to time CPU still > sees IRQ pending, so it asks for vector, but as chipset has no > interrupt pending, it answers with IRQ7. I did no analysis to find > whether IRQ7 happens directly when we send confirmation to 8259, > or whether it happens due to some noise on IRQ line. > > AFAIK it happens only on VIA based boards, and only if (AMD) CPU is using > APIC.
This (APIC errors) happened very often with my BP6 board too, but with recent kernels I don't get many of these messages.
As for spurious interrupts, I had these coming every five minutes on my Cyrix 6x86/SiS 5597 box. But this "settled" when I moved the box to another corner in the room, and also did some interior adjustments of cables and such (it is a server running in a very crammed slimline desktop box, with a HUB taped to the floppy mount =)
_____________________________________________________ | Martin Eriksson <nitrax@giron.wox.org> | MSc CSE student, department of Computing Science | Umeå University, Sweden
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