Re: CONFIG_IRQBALANCE for AMD64?

From: Arjan van de Ven
Date: Fri May 28 2004 - 13:46:15 EST


On Fri, May 28, 2004 at 11:33:32AM -0700, Martin J. Bligh wrote:
> Here's my start at a list ... I'm sure it's woefully incomplete.
>
> 1. Utilize all CPUs roughly evenly for IRQ processing load (anything that's
> not measured by the scheduler at least, because it's unfair to other
> processes).

yep; irqbalance approximates irq processing load by irq count, which seems
to be ok-ish so far.

> Also, we may well have more than 1 CPU's worth of traffic to
> process in a large network server.

One NIC? I've yet to see that ;)

> 2. Provide some sort of cache-affinity for network interrupt processing,
> which also helps us not get into out-of-order packet situations.

yep; irqbalance does that

> 3. Utilize idle CPUs where possible to shoulder the load.

this is in direct conflict with 2; esp since cpus are idle very short times
all the time in busy scenarios (and non-busy scenarios are boring wrt irq
loadf ;)


> 4. Provide such a solution for all architectures.

irqbalanced in principle arch independent since the /proc interface is quite
generic..

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