Re: performance impact of using noapic

Mark Hounschell (markh@compro.net)
Wed, 03 Jul 2002 08:31:44 -0400


Stephane Charette wrote:

>
> My questions are:
>
> 1) am I right in thinking that "noapic" will force all interrupts to be handled by 1 CPU?

Yes.

>
> 2) how would you force all interrupts from only 1 hardware device (and not all devices) to be handled by 1 processor, as hinted in the paragraph quoted above?

echo "00000001" > /proc/irq/19/smp_affinity

Will cause irq 19 to be serviced by processor 1

echo "00000003" > /proc/irq/19/smp_affinity

Will allow irq 19 to be serviced by processor 1 and 2

You could also do this in the driver if you wanted.

Note that this will not work when noapic is used..

Mark
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