My experience is that when switching CPUs for the IRQ Interrupts, it introduces a delay. In other words, each time it switches CPUs, I would lose interrupts. I am using CentOS for Telephony purposes, so eached dropped interrupts is a potential problem. The first thing that I do on any CentOS box, is disable irqbalance and set them CPUs manually. -- -- Steven http://www.glimasoutheast.org "Steve Snyder" <swsnyder at insightbb.com> wrote in message news:200608250848.57118.swsnyder at insightbb.com... > 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.