Hello,

I have a dual 3.3 ghz xeon with dual-core. Its a motherboard from bell micro. Been using it with procnto and all seems 
okay, bios has multi core turned off.

When i turn the multi-core option on and use procnto-smp I see that every few seconds I lose cpu cycles (kernel trace 
shows small, minor operations that normally take 10s of usecs seem to take like 500-750 usecs).

My guess was that perhaps the bios installs some interrupts in this multi-core mode and starts taking interrupts that 
the os is not aware of, and these show up in the kernel trace as being billed to whatever process was running at the 
time.

I physically removed 1 xeon, to make the number of cpus and the kernel traces more manageable, and the problem seems to 
have greatly reduced but still happens every 30-120 seconds with no real pattern to it.

Any tips as to how I should go about debugging this would be appreciated.
Any experience with running 6.3 sp2 on multi core xeons?
how do see which interrupts are handled in the bios?
other tips?

Thanks,
Nitin.