'stray irq7's cause hang?

[Kris Kennaway]

Steve Franks wrote:
> I've got a new system that hangs after about 2 hours - no
> ctrl-alt-esc, not ctrl-alt-Fn, no ctrl-alt-delete.
> 
> I tried hints.0.apic.disabled="YES" (that's apic, not acpi) (or
> whatever the correct syntax from the handbook is), but I still get the
> hang, and the stray irq 7's.  As far as I can see, there's no other
> dmesg output related.

The stray interrupts may be a red herring.  "Stray" means that no driver 
is handling them, and so there is no driver to screw up :)

I see straq irq 7's on a HP proliant blade system, and also the hard 
hangs (it doesn't even reply to a NMI; this means it is almost certainly 
a hardware error).  However I am now fairly certain the hangs are 
associated to disk failure.  Several of the blades that were hanging 
went on to develop DMA errors from ATA, and after I validated the 
remaining systems with smartctl and took offline yet more blades that 
failed the self-tests, I have not had the problem recur.

Kris