Re: Interrupt forwarding

[Jon Smirl <jonsmirl@gmail.com>]

On Sat, 12 Mar 2005 18:21:19 +0000, Keir Fraser
<Keir.Fraser@cl.cam.ac.uk> wrote:
> 
> On 12 Mar 2005, at 18:11, Ian Pratt wrote:
> 
> > Shared interrupts aren't good news for performance, but they work OK.
> >
> > If a driver domain locks up we can kill and restart it -- for safety we
> > don't rely on it to ack the interrupt.
> 
> Shared interrupts are slightly worse because the irq won't get unmasked
> until all receivers say their work is done. If one lock sup it starves
> the rest -- until this is detected and that domain gets blown away.

After you blow away the domain how do you acknowledge the interrupt?
Is all hardware required to have a tiny driver in the supervisor to
handling acking in this case? If you don't ack it, it is going to keep
interrupting.

> 
> Fortunately the days of shared interrupts are numbered with MSI and
> PCI-Express.
> 
>   -- Keir
> 
> 


-- 
Jon Smirl
jonsmirl@gmail.com


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