Re: Question on CONFIG_IRQBALANCE / 2.6.x

[Martin J. Bligh]

>> > there's something I don't understand:  With IRQBALANCE *enabled* almost
>> > all interrupts are processed on CPU0.  This changed in an unexpected way
>> > after disabling IRQBALANCE: now all interrupts are distributed uniformly
>> > to both CPUs.  Maybe it's intentional, but it's not what I expect when a
>> > config option named IRQBALANCE is *disabled*.
>> > 
>> > Can anybody comment on this?
>> 
>> If you have a Pentium 3 based system, by default they'll round robin.
>> If you turn on IRQbalance, they won't move until the traffic gets high
>> enough load to matter. That's presumably what you're seeing.
> 
> It's an Athlon box that propably has the same behaviour.  Just another
> question on this topic:  with IRQBALANCE enabled, almost all interupts
> are routet to CPU0.  Lately irq 0 runs on CPU1 and never returns to CPU0
> - is there any obvious reason for that?

If it's not getting interrupts at 1010 per second or so, it won't rotate
them, on the grounds it's not worthwhile.

M.

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