Disabling System Management Interrupts?

[Brian Kidder]

I'm trying to get a near-realtime system working on a DL380G5 using Red Hat's MRG product. But I'm discovering an unexplained latency that we suspect may be due to SMIs interrupting the kernel and breaking its scheduler. Just doing back-to-back RDTSC instructions occasionally shows latences of several hundred microseconds, when the normal latency is a few dozen nanoseconds.

So, is there a way to verify when SMIs are trigging? How can they be disabled?

I've already disabled iLO2 and USB devices from the BIOS, but that didn't eliminate the latency problem.

-Brian