Interrupt prioritization on linux for ppc440

Eugene Surovegin ebs at ebshome.net
Tue Apr 19 08:06:05 EST 2005


On Mon, Apr 18, 2005 at 02:14:23PM -0700, Shawn Jin wrote:
> 
> > What could be interesting, though, is to to make all 4xx IRQs
> > critical, in this case we could use VR to quickly determine which IRQ
> > was asserted, instead of current implementation when we use bit
> > operations. Not sure, if performance gain is really worth the
> > effort :)
> 
> If we use VR to determine which IRQ was asserted, it's kind of
> reverse. We usually fetch a handler by its IRQ number. It could
> require to change irq_desc[] and request_irq().

You seems don't undestand what I'm talking about. VR can help us with 
determining what IRQ was asserted. It has nothing to do with irq_desc.

Curently, we use some bit searching functions like ffs to get IRQ 
number, VR can be used instead.

-- 
Eugene



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