Re: RFC: IRQ affinity (aka interrupt routing)

[Martin Husemann <martin%duskware.de@localhost>]

On Thu, Aug 21, 2014 at 10:50:53AM +0900, Kengo NAKAHARA wrote:
> I think it is easy to set affinity by IRQ number with above output.

Yes, and would be even better if the device/interrupt name would be
allowed as well (intrctl could internally translate it)

> >I am not sure we have a globally unique number available on all 
> >architectures
> >to describe any interrupt.
> 
> I am not sure too. If the architecture does not have a unique number to
> describe interrupts, it may be difficult for the architecture to  support
> thisfeature. I do not think about the architectures other than x86 yet.

I suppose everyone has numbers at some level, but it may be a tree, or at
least multiple PICs at the root. If we need numbers, we can assign them
uniquely via a dfs traversal or similar (or by assigning an incremental
one whenever the relevant *_intr_establish() function is called).

However, I am not sure this is the best aproach. We have made everything
else properly machine independend, see for example pci_intr_establish, the
MD definition of pci_intr_handle_t and pci_intr_string. I think we should
use similar techniques here.

Martin