Thor Lancelot Simon wrote:
> Hm.  Maybe 3000 of those IRQs are timer update IPIs (though I don't
> _think_ that's how it's supposed to work).
> 
> Are you sure you really want hyperthreading switched on?  With two
> physical CPUs, our scheduler may not give you the best performance
> with them set up that way.  You should test and see (with a single
> physical CPU, hyperthreading is in fact usually a win, but a very
> slight one).
> 
> Also, do you really need such a high value of HZ?  You might find that
> decreasing HZ to 256 or 512 gave you a useful reduction in interrupt
> load with little downside.

Hello Thor,

No idea what those IRQs are exactly. `systat vmstat` is reporting me 
cpuX timer (x=0:3).

Yes, I beleive I need hyperthreading on this machine as concurency is 
high about all the time (load average between 6 and 20).

I think HZ=512 is what I need too.