Subject: Re: [PATCH] irq: Add node_affinity CPU masks for smarter
 irqbalance hints
From: Peter Zijlstra <peterz@infradead.org>
To: Peter P Waskiewicz Jr <peter.p.waskiewicz.jr@intel.com>
Cc: Yong Zhang <yong.zhang0@gmail.com>,
       "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
       "arjan@linux.jf.intel.com" <arjan@linux.jf.intel.com>,
       "davem@davemloft.net" <davem@davemloft.net>,
       "netdev@vger.kernel.org" <netdev@vger.kernel.org>,
       Thomas Gleixner <tglx@linutronix.de>
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Date: Tue, 24 Nov 2009 10:08:56 +0100
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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. Are you talking about some daft userspace thing that
writes into the irq smp_affinity to effect irq balancing?

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