Re: [PATCH] Prevent nested interrupts when the IRQ stack is near overflowing v2

Andi Kleen
2010-03-26T06:10:34Z

> Now, I think (and sincerely) that the SCSI situation is likely long since
> fixed, but we have thousands and thousands of drivers, and these kinds of
> things are very hard to notice automatically. Are there any cases around
> that still have busy-loop delays based on real-time in their irq handlers?
> I simply don't know.

This case was already broken back when the x86-64 port used to run
with NMI watchdog on by default, because any IO exception handling
with interrupts off would trigger the NMI watchdog eventually.

I remember having to add bandaids to Fusion for this a long time ago.

Of course ISA drivers might still do it.

-Andi
--
ak@linux.intel.com -- Speaking for myself only.