Arjan van de Ven wrote:
: Jan Kasprzak <kas@xxxxxxxxxx> wrote:
: > The result is
: > that the CPU which receives IRQs for the uplink interface
: > is 100 % busy (softirq mostly), while the other one is 90% idle.
: : one of the hard cases for irqbalance is that irqbalance doesn't have a
: way to find out the actual cpu time spend in the handlers. For
: networking it makes an estimate just based on the number of packets
: (which is better than nothing)... but that breaks down if you have an
: non-symmetry in CPU costs per packet like you have.
: : The good news is that irqthreads at least have the potential to solve
: this "lack of information"; if not, we could consider doing a form of
: microaccounting for irq handlers....
I am not sure whether this would help. In my case, the most of the
in-kernel CPU time is not spend in the irq handler per se, but in softirq
(i.e. checking the packet against iptables rules).