[nkurz]

Yes, if you don't want all interrupts to handled by CPU0 you'll need a different approach. But doing anything else may be more difficult than it sounds. Do you know if the bug mentioned here is fixed?

http://serverfault.com/questions/380935/how-to-ban-hardware-...

http://code.google.com/p/irqbalance is 403 for me and I haven't been able to check.

[rdtsc]

Setting IRQ affinity for network controllers to either follow or not follow the "high priority" processes seems to do the trick.

I usually do stuff described here:

https://cs.uwaterloo.ca/~brecht/servers/apic/SMP-affinity.tx...

And sometimes following ends up better (same cache), sometimes isolating ends up being better.