Re: [kvm-devel] [RFC] Deferred interrupt handling.

From: Pavel Machek
Date: Wed Jul 25 2007 - 14:30:41 EST


Hi!

I guess this will also allow UIO to work without _any_ kernel parts,
with only slight performance penalty in 'almost-never-happens'
deadlock case?

(Greg, details are below, and better description is in the lkml
thread).
Pavel

> > - Our dummy handler will always return IRQ_HANDLED in case any other
> > previous
> > irqaction did not return such. It will also issue the timer and mask
> > the irq in this case.
>
> Ok
>
> > btw, if I'm not mistaken only after bad 99900/100000 the irq is
> > disabled.
>
> (and with GIT providing that they occurred in a short time period)
>
> > - If the timer pops before the guest acks the irq, the timer handler
> > will
> > ack the irq and unmask it. The timer's job is only to prevent
> > deadlocks.
>
> Ok I see what you are doing. It's either inspired or insane and I am not
> quite sure which of the two. I agree it should work although may cause
> performance crunches now and then and will also need care getting the
> locking right.

--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
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