Re: [PATCH] x86: check_timer cleanup

From: Maciej W. Rozycki
Date: Mon Feb 09 2009 - 07:34:39 EST


On Mon, 9 Feb 2009, Ingo Molnar wrote:

> > What problems are you referring to, Ingo? Perhaps they should be looked
> > into specifically?
>
> I got a spurious boot failure on a 64-bi testbox:
>
> [ 0.280000] ..TIMER: vector=0x30 apic1=0 pin1=2 apic2=-1 pin2=-1
> [ 0.296000] ..MP-BIOS bug: 8254 timer not connected to IO-APIC
> [ 0.296000] ...trying to set up timer (IRQ0) through the 8259A ...
> [ 0.296000] ..... (found apic 0 pin 2) ...
> [ 0.308000] ....... failed.
> [ 0.308000] ...trying to set up timer as Virtual Wire IRQ...
> [ 0.324000] ..... failed.
> [ 0.324000] ...trying to set up timer as ExtINT IRQ...
> [ 0.340000] ..... failed :(.
> [ 0.340000] Kernel panic - not syncing: IO-APIC + timer doesn't work! Boot with apic=debug and send a report. Then try booting with the 'noapic' option.
>
> Not reproducible. Full bootlog below.

If so, it could have been anything. Even a casual hardware failure. The
timer retriggers by itself producing both edges automatically, so even if
an edge is missed because of the mask, another one follows shortly. I
don't think the change proposed by Yinghai would make any difference here.

Pity you can't use an in-circuit debugger with the x86... :(

Maciej
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