Subject: Re: [PATCH] irq: Add node_affinity CPU masks for smarter irqbalance hints

From: Arjan van de Ven <[email-masked]>
Date: Tue, 24 Nov 2009 06:43:24 -0800

Peter Zijlstra wrote:
> On Tue, 2009-11-24 at 00:59 -0800, Peter P Waskiewicz Jr wrote:
>>> This all sounds backwards.. we've got a perfectly functional interface
>>> for affinity -- which people object to being used for some reason. So
>>> you add another interface on top, and that is ok?
>>>
>> But it's not functional.  If I set the affinity in smp_affinity, then
>> irqbalance will override it 10 seconds later. 
> 
> And here I was thinking the kernel round-robins IRQ delivery on the mask
> specified there. 

the kernel does no such thing, nor has code to do so.

 > Are you talking about some daft userspace thing that
> writes into the irq smp_affinity to effect irq balancing?

thanks ;)