[CentOS] Does irqbalance actually do anything?

I've got several SMP machines, some running CentOS 4.3 and some running 
Fedora Core 4.  All machine are kept fully updated.  A few are 
Pentium3-based and a few are Pentium4-based.  They are all running the 
irqbalance daemon.

The distribution of interrupts across CPUs is indeed kept balanced, yet 
even after months of uptime ps shows no CPU use whatsoever by irqbalance.   
This from a program that is supposed to wake up every 10 (?) seconds and 
examine the interrupt counts.  Given that there is an IRQ balancing 
scheme in the kernel, I have to wonder if irqbalance is actually being 
used.

The man page for this program consists of a single-sentence description of 
what the program does.  Nice.

Does irqbalance really do anything on contemporary Red Hat-based systems?

Thanks.